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Phloretin has different glycosylation modes in plants. Phlorizin (phloretin 2′‐O‐glucoside) is one of the glycosylation products of phloretin, and accumulates abundantly in apple plants. However, it is still unclear whether phlorizin is more beneficial for apple plants compared with other glycosylation products of phloretin. We created transgenic apple plants with different glycosylation modes of phloretin. In transgenic plants, the accumulation of phlorizin was partly replaced by that of trilobatin (phloretin 4′‐O‐glucoside) or phloretin 3′,5′‐di‐C‐glycoside. Compared with wild type, transgenic plants with less phlorizin showed dwarf phenotype, larger stomatal size, higher stomatal density and less tolerance to drought stress. Transcriptome and phytohormones assay indicate that phlorizin might regulate stomatal development and behaviour via controlling auxin and abscisic acid signalling pathways as well as carbonic anhydrase expressions. Transgenic apple plants with less phlorizin also showed less resistance to spider mites. Apple plants may hydrolyse phlorizin to produce phloretin, but cannot hydrolyse trilobatin or phloretin 3′,5′‐di‐C‐glycoside. Compared with its glycosylation products, phloretin is more toxic to spider mites. These results suggest that the glycosylation of phloretin to produce phlorizin is the optimal glycosylation mode in apple plants, and plays an important role in apple resistance to stresses. Summary Statement: Compared with other glycosylation modes, the glycosylation of phloretin to produce phlorizin is the optimal mode in apple plants. Phlorizin plays an important role in apple resistance to stresses, via controlling auxin and abscisic acid signalling pathways and carbonic anhydrase expressions. [ABSTRACT FROM AUTHOR]

Abstract Ring rot, caused by Botryosphaeria dothidea, is an important fungal disease of pear fruit during postharvest storage. Melatonin, as a plant growth regulator, plays an important role in enhancing the stress resistance of pear fruits. It enhances the resistance of pear fruits to ring rot by enhancing their antioxidant capacity. However, the underlying mechanism remains unclear. In this study, we examined the effect of melatonin on the growth of B. dothidea. Results showed that melatonin did not limit the growth of B. dothidea during in vitro culture. However, metabolomics and transcriptomics analyses of ‘Whangkeumbae’ pear (Pyrus pyrifolia) revealed that melatonin increased the activity of antioxidant enzymes, including peroxidase (POD), superoxide dismutase (SOD), and polyphenol oxidase (PPO), in the fruit and activated the phenylpropanoid metabolic pathway to improve fruit resistance. Furthermore, melatonin treatment significantly increased the contents of jasmonic acid and phlorizin in pear fruit, both of which could improve disease resistance. Jasmonic acid regulates melatonin synthesis and can also promote phlorizin synthesis, ultimately improving the resistance of pear fruit to ring rot. In summary, the interaction between melatonin and jasmonic acid and phlorizin enhances the antioxidant defense response and phenylpropanoid metabolism pathway of pear fruit, thereby enhancing the resistance of pear fruit to ring rot disease. Our results provide new insights into the application of melatonin in the resistance to pear fruit ring rot.

Abstract Background Nitrogen (N) is essential for plant growth and development. In Lithocarpus polystachyus Rehd., a species known for its medicinal and food value, phlorizin is the major bioactive compound with pharmacological activity. Research has revealed a positive correlation between plant nitrogen (N) content and phlorizin synthesis in this species. However, no study has analyzed the effect of N fertilization on phlorizin content and elucidated the molecular mechanisms underlying phlorizin synthesis in L. polystachyus. Results A comparison of the L. polystachyus plants grown without (0 mg/plant) and with N fertilization (25, 75, 125, 175, 225, and 275 mg/plant) revealed that 75 mg N/plant fertilization resulted in the greatest seedling height, ground diameter, crown width, and total phlorizin content. Subsequent analysis of the leaves using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detected 150 metabolites, including 42 flavonoids, that were differentially accumulated between the plants grown without and with 75 mg/plant N fertilization. Transcriptomic analysis of the L. polystachyus plants via RNA sequencing revealed 162 genes involved in flavonoid biosynthesis, among which 53 significantly differed between the N-treated and untreated plants. Fertilization (75 mg N/plant) specifically upregulated the expression of the genes phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), and phlorizin synthase (PGT1) but downregulated the expression of trans-cinnamate 4-monooxygenase (C4H), shikimate O-hydroxycinnamoyltransferase (HCT), and chalcone isomerase (CHI), which are related to phlorizin synthesis. Finally, an integrated analysis of the transcriptome and metabolome revealed that the increase in phlorizin after N fertilization was consistent with the upregulation of phlorizin biosynthetic genes. Quantitative real-time PCR (qRT‒PCR) was used to validate the RNA sequencing data. Thus, our results indicated that N fertilization increased phlorizin metabolism in L. polystachyus by regulating the expression levels of the PAL, PGT1, 5-O-(4-coumaroyl)-D-quinate 3’-monooxygenase (C3’H), C4H, and HCT genes. Conclusions Our results demonstrated that the addition of 75 mg/plant N to L. polystachyus significantly promoted the accumulation of flavonoids, including phlorizin, and the expression of flavonoid synthesis-related genes. Under these conditions, the genes PAL, 4CL, and PGT1 were positively correlated with phlorizin accumulation, while C4H, CHI, and HCT were negatively correlated with phlorizin accumulation. Therefore, we speculate that PAL, 4CL, and PGT1 participate in the phlorizin pathway under an optimal N environment, regulating phlorizin biosynthesis. These findings provide a basis for improving plant bioactive constituents and serve as a reference for further pharmacological studies.

Objective: Orchitis is a common reproductive disease of male animals, which has serious implications to human and animal reproduction. Additionally, phlorizin (PHN), a common polyphenol in apples and strawberries, has a variety of biological activities, including antioxidant, anti-inflammatory, anti-diabetic, and anti-aging activities. We aimed to determine the protective effects and potential mechanisms of PHN in lipopolysaccharide (LPS)-induced acute orchitis in mice. Method: After 21 days of PHN pretreatment, mice were injected with LPS to induce testicular inflammation, and then the changes of testicular tissue structure, expression of inflammatory factors, testosterone level, expression of testosterone-related genes, adhesion gene and protein expression were detected, and the structural changes in the intestinal flora after PHN treatment were further detected by 16SRNA. Result: Our results demonstrated that PHN treatment reduced LPS-induced testicular injury and body and testicular weight losses. The mRNA expression levels of pro-inflammatory cytokines-related genes and antioxidant enzyme activity were also decreased and elevated, respectively, by PHN administration; however, PHN treatment also reduced the LPS-induced decrease in testosterone levels in the testes. Additionally, further studies found that PHN increased the expression of marker proteins zonula occludens-1 (ZO-1) and occludin associated with the blood testosterone barrier compared with that in LPS treatment groups. To further examine the potential mechanisms of the protective effect of PHN on LPS-induced testicular injury, we compared the differences of gut microbiota compositions between the 100mg/kg PHN treatment group and the control group using 16SRNA. Metagenomic analyses indicated that the abundances of Bacteroidetes, Muribaculaceae, Lactobacillaceae, uncultured bacterium f Muribaculaceae, and Lactobacillus in the PHN treatment group improved, while potential microbes that can induce intestinal diseases, including Verrucomicrobia, Epsilonbacteraeota, Akkermansiaceae, and Akkermansia decreased in the PHN treatment group. Conclusion: Our results indicate that PHN pretreatment might alleviate orchitis by altering the composition of gut microflora, which may provide a reference for reducing the occurrence of acute orchitis in male animals. [ABSTRACT FROM AUTHOR]

Ring rot, caused by Botryosphaeria dothidea, is an important fungal disease of pear fruit during postharvest storage. Melatonin, as a plant growth regulator, plays an important role in enhancing the stress resistance of pear fruits. It enhances the resistance of pear fruits to ring rot by enhancing their antioxidant capacity. However, the underlying mechanism remains unclear. In this study, we examined the effect of melatonin on the growth of B. dothidea. Results showed that melatonin did not limit the growth of B. dothidea during in vitro culture. However, metabolomics and transcriptomics analyses of 'Whangkeumbae' pear (Pyrus pyrifolia) revealed that melatonin increased the activity of antioxidant enzymes, including peroxidase (POD), superoxide dismutase (SOD), and polyphenol oxidase (PPO), in the fruit and activated the phenylpropanoid metabolic pathway to improve fruit resistance. Furthermore, melatonin treatment significantly increased the contents of jasmonic acid and phlorizin in pear fruit, both of which could improve disease resistance. Jasmonic acid regulates melatonin synthesis and can also promote phlorizin synthesis, ultimately improving the resistance of pear fruit to ring rot. In summary, the interaction between melatonin and jasmonic acid and phlorizin enhances the antioxidant defense response and phenylpropanoid metabolism pathway of pear fruit, thereby enhancing the resistance of pear fruit to ring rot disease. Our results provide new insights into the application of melatonin in the resistance to pear fruit ring rot. [ABSTRACT FROM AUTHOR]

Background: Nitrogen (N) is essential for plant growth and development. In Lithocarpus polystachyus Rehd., a species known for its medicinal and food value, phlorizin is the major bioactive compound with pharmacological activity. Research has revealed a positive correlation between plant nitrogen (N) content and phlorizin synthesis in this species. However, no study has analyzed the effect of N fertilization on phlorizin content and elucidated the molecular mechanisms underlying phlorizin synthesis in L. polystachyus. Results: A comparison of the L. polystachyus plants grown without (0 mg/plant) and with N fertilization (25, 75, 125, 175, 225, and 275 mg/plant) revealed that 75 mg N/plant fertilization resulted in the greatest seedling height, ground diameter, crown width, and total phlorizin content. Subsequent analysis of the leaves using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detected 150 metabolites, including 42 flavonoids, that were differentially accumulated between the plants grown without and with 75 mg/plant N fertilization. Transcriptomic analysis of the L. polystachyus plants via RNA sequencing revealed 162 genes involved in flavonoid biosynthesis, among which 53 significantly differed between the N-treated and untreated plants. Fertilization (75 mg N/plant) specifically upregulated the expression of the genes phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), and phlorizin synthase (PGT1) but downregulated the expression of trans-cinnamate 4-monooxygenase (C4H), shikimate O-hydroxycinnamoyltransferase (HCT), and chalcone isomerase (CHI), which are related to phlorizin synthesis. Finally, an integrated analysis of the transcriptome and metabolome revealed that the increase in phlorizin after N fertilization was consistent with the upregulation of phlorizin biosynthetic genes. Quantitative real-time PCR (qRT‒PCR) was used to validate the RNA sequencing data. Thus, our results indicated that N fertilization increased phlorizin metabolism in L. polystachyus by regulating the expression levels of the PAL, PGT1, 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase (C3'H), C4H, and HCT genes. Conclusions: Our results demonstrated that the addition of 75 mg/plant N to L. polystachyus significantly promoted the accumulation of flavonoids, including phlorizin, and the expression of flavonoid synthesis-related genes. Under these conditions, the genes PAL, 4CL, and PGT1 were positively correlated with phlorizin accumulation, while C4H, CHI, and HCT were negatively correlated with phlorizin accumulation. Therefore, we speculate that PAL, 4CL, and PGT1 participate in the phlorizin pathway under an optimal N environment, regulating phlorizin biosynthesis. These findings provide a basis for improving plant bioactive constituents and serve as a reference for further pharmacological studies. [ABSTRACT FROM AUTHOR]

Dihydrochalcones (DHCs) constitute a specific class of flavonoids widely known for their various health-related advantages. Melatonin (MLT) has received attention worldwide as a master regulator in plants, but its roles in DHC accumulation remain unclear. Herein, the elicitation impacts of MLT on DHC biosynthesis were examined in Lithocarpus litseifolius, a valuable medicinal plant famous for its sweet flavor and anti-diabetes effect. Compared to the control, the foliar application of MLT significantly increased total flavonoid and DHC (phlorizin, trilobatin, and phloretin) levels in L. litseifolius leaves, especially when 100 μM MLT was utilized for 14 days. Moreover, antioxidant enzyme activities were boosted after MLT treatments, resulting in a decrease in the levels of intracellular reactive oxygen species. Remarkably, MLT triggered the biosynthesis of numerous phytohormones linked to secondary metabolism (salicylic acid, methyl jasmonic acid (MeJA), and ethylene), while reducing free JA contents in L. litseifolius. Additionally, the flavonoid biosynthetic enzyme activities were enhanced by the MLT in leaves. Multiple differentially expressed genes (DEGs) in RNA-seq might play a crucial role in MLT-elicited pathways, particularly those associated with the antioxidant system (SOD, CAT, and POD), transcription factor regulation (MYBs and bHLHs), and DHC metabolism (4CL, C4H, UGT71K1, and UGT88A1). As a result, MLT enhanced DHC accumulation in L. litseifolius leaves, primarily by modulating the antioxidant activity and co-regulating the physiological, hormonal, and transcriptional pathways of DHC metabolism. [ABSTRACT FROM AUTHOR]

Background/Aim: Rheumatoid arthritis (RA) is an inflammatory autoimmune disease, and management of it is still a challenge. The present investigation assessed the potential preventive effect of phlorizin on rats with RA. Materials and Methods: A total of 40 healthy Wistar rats were used for this study. Bovine type II collagen and Freund's incomplete adjuvant (1:1 and 1 mg/ml) were administered on days 1 and 8 of the protocol to induce RA in rats; treatment with phlorizin at 60 or 120 mg/kg was started after the 4th week of the protocol, and its effect on inflammation, level of inflammatory cytokines, and expression of proteins were estimated in RA rats. Moreover, an in vitro study was performed on fibroblast-like synoviocytes (FLSs), and the effects of phlorizin on proliferation, apoptosis, and expression of the mechanistic target of rapamycin kinase pathway protein after stimulating these cells with tumor necrosis factor α (TNF-α) were estimated. Results: The data obtained from the study indicate that phlorizin has the potential to mitigate inflammation and enhance weight management in rats with RA induced by bovine type II collagen (CII). The level of inflammatory cytokines in the serum and the expression of protein kinase B (AKT), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), and mechanistic target of rapamycin kinase (mTOR) proteins in the joint tissue were reduced in phlorizin-treated rats with RA. In this investigation, phlorizin was shown to reverse the histological abnormalities in the joint tissue of rats with RA. The in-vitro study showed that phlorizin reduced proliferation and had no apoptotic effect on TNF- α-stimulated FLSs. Expression of AKT, PI3K, and mTOR proteins was also down-regulated in phlorizin-treated TNF- α-stimulated FLSs. Conclusion: Phlorizin protects against inflammation and reduces injury to synovial tissues in RA by modulating the AKT/PI3K/mTOR pathway. [ABSTRACT FROM AUTHOR]

Burns usually result in damage and loss of skin forming irregular wound wounds. The lack of skin tissue protection makes the wound site highly vulnerable to bacterial infections, hindering the healing process. However, commonly used wound dressings do not readily provide complete coverage of irregular wounds compared to regular wounds. Therefore, there is an urgent need to prepare a wound dressing with high antimicrobial efficacy for the administration of drugs to irregular wounds. In this study, a chitosan (CS)/polyvinylpyrrolidone (PVP) composite nanofiber membrane (CS/PVP/Phlorizin) loaded with root bark glycosides (Phlorizin) was developed using an electrostatic spinning technique. The incorporation of phlorizin, a natural antioxidant, into the fiber membranes notably boosted their antimicrobial and antioxidant capabilities, along with demonstrating excellent hydrophilic characteristics. In vitro cellular experiments showed that CS/PVP/Phlorizin increased Hacat cell viability with the presence of better cytocompatibility. In scald wound healing experiments, Phlorizin-loaded nanofibrous membranes significantly promoted re-epithelialization and angiogenesis at the wound site, and reduced the inflammatory response at the wound site. Therefore, the above results indicate that this nanofiber membrane is expected to be an ideal dressing for burn wounds.

Phlorizin, as a flavonoid from a wide range of sources, is gradually becoming known for its biological activity. Phlorizin can exert antioxidant effects by regulating the IL-1β/IKB-α/NF-KB signaling pathway. At the same time, it exerts its antibacterial activity by reducing intracellular DNA agglutination, reducing intracellular protein and energy synthesis, and destroying intracellular metabolism. In addition, phlorizin also has various pharmacological effects such as antiviral, antidiabetic, antitumor, and hepatoprotective effects. Based on domestic and foreign research reports, this article reviews the plant sources, extraction, and biological activities of phlorizin, providing a reference for improving the clinical application of phlorizin. [ABSTRACT FROM AUTHOR]

Phlorizin (PHL) is a natural compound with strong antioxidant properties mainly found in apples. In this paper, the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation, fluorescence spectra, circular dichroism (CD), and fourier transform infrared (FT-IR) spectra at a molecular level. Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching. Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces, and that of trypsin was electrostatic forces. The ground state complexes PHL and protease have a moderate affinity of 105 L/mol PHL binds more strongly to trypsin than to pepsin. CD and FT-IR spectra results showed that pepsin/trypsin decreased the β-sheet content and slightly changed its secondary structure upon PHL. These experimental results are mutually verified with the predicted computer-aid simulation results. Upon PHL and trypsin binding, the antioxidant capacity of PHL was elevated. Nevertheless, the antioxidant capacity of PHL was decreased after binding to pepsin. This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.

Deltamethrin (DEL), a commonly used pyrethroid pesticide, results in higher reactive oxygen species (ROS) levels in aquatic animals, which consequently unbalance the redox state. Phlorizin (PHL) is a flavonoid and a natural product promising to prevent or reduce pesticide-induced oxidative stress. Artemia is a micro-crustacean widely used in marine hatcheries and an experimental aquatic organism for environmental toxicology research. This research aimed to evaluate the toxicity of DEL on Artemia and the antioxidative effect of PHL against the toxicity. Results show that 0.08-mg/mL PHL exerted its antioxidative effects on hatching percentage of the cysts in 24-h incubation and on body length and survival rate of Artemia in 12-d culture. After 12-d culture, 12-, 24-, and 36-h DEL exposure showed significant drops in SOD, CAT, and GSH-Px enzyme activities, and significant increases in ROS and malondialdehyde (MDA) levels in Artemia (P<0.05). On the contrary, 0.08-mg/mL PHL application improved the enzyme activities and decreased the ROS and MDA levels (P<0.05). Moreover, 0.08-mg/mL PHL significantly increased mRNA expression levels of Cu/Zn SOD, CAT, GST, HO-1, NQO1, and Nrf2, and decreased mRNA expression level of Keap1 in the DEL-exposed Artemia (P<0.05). Therefore, DEL is toxic to Artemia, while PHL alleviates DEL-induced oxidative damage by possibly regulating the Nrf2 signaling pathway. This study provided a theoretical basis for PHL to reduce pesticide-induced toxicity in aquatic animals. [ABSTRACT FROM AUTHOR]

Both phloretin and phlorizin (phloretin 2′-O-glucoside) extracted from the peel of apples are attributed to particular flavonoid dihydrochalcones with multiple pharmacological activities. However, metabolite structural characterization of these two components, which may accumulate to exert their pharmacological effects, remains insufficient. The present study aimed to comparatively clarify the metabolic pathways of phloretin and phlorizin after oral administration individually to Sprague-Dawley (SD) rats. Therefore, a rapid, integrate and systematic analytical strategy based on characteristic fragment ion fishing was proposed for the screening and identification of metabolites coming from phloretin and phlorizin using UHPLC-Q-Exactive Orbitrap mass spectrometry in parallel reaction monitoring mode. As a result, a total of 50 phloretin metabolites and 52 phlorizin metabolites were individually identified from different biological samples including rat plasma, urine, and faeces. Moreover, glucuronidation, sulfation, carbonylation and hydrolyzation were revealed to be the main metabolic pathways of phlorizin, while decarbonylation, glucuronidation and sulfation were regarded as the predominant biotransformation pathways as for phloretin. This is the first systematic study on comparison of metabolic profiles of phlorizin and phloretin in disease states, which was helpful to declare the complicated structure activity relationships between phlorizin and phloretin and shed light to their action mechanism.

The specific role of phlorizin (PHL), which has antioxidant, anti-inflammatory, hypoglycemic, antiarrhythmic and antiaging effects, on myocardial fibrosis (MF) and the related pharmacological mechanisms remain unknown. The objective of this study was to determine the protective actions of PHL on isoprenaline (ISO)-induced MF and its molecular mechanisms in mice. PHL was administered at 100 and 200 mg/kg for 15 consecutive days with a subcutaneous injection of ISO (10 mg/kg). MF was induced by ISO and alleviated by treatment with PHL, as shown by reduced fibrin accumulation in the myocardial interstitium and decreased levels of myocardial enzymes, such as creatinine kinase-MB, lactate dehydrogenase, and aspartate transaminase. In addition, PHL significantly decreased the expression of the fibrosis-related factors alpha smooth muscle actin, collagen I, and collagen III induced by ISO. The generation of intracellular reactive oxygen species induced by ISO was attenuated after PHL treatment. The malondialdehyde level was reduced, whereas the levels of superoxide dismutase, catalase, and glutathione were elevated with PHL administration. Moreover, compared to ISO, the level of Bcl-2 was increased and the level of Bax protein was decreased in the PHL groups. PHL relieved elevated TNF-α, IL-1β, and IL-18 levels as well as cardiac mitochondrial damage resulting from ISO. Further studies showed that PHL downregulated the high expression of hexokinase 1 (HK1), NLRP3, ASC, Caspase-1, and GSDMD-N caused by ISO. In conclusion, our findings suggest that PHL protects against ISO-induced MF due to its antioxidant, anti-apoptotic, and anti-inflammatory activities and via inhibition of pyroptosis mediated by the HK1/NLRP3 signaling pathway in vivo.

Literature data suggest that apple-derived products, including phenol-enriched extracts, may reduce food intake in rodent models of diet-induced obesity. With the intent of further expanding this research issue, the present study investigated the effect of an apple branch extract (ABE)--standardized for the polyphenol, phlorizin (22.93%)--on regular food intake in healthy, nonobese Wistar rats. Rats were given unlimited access to standard food pellets and water in the homecage. Acute, intragastric treatment with ABE (0, 300, and 900 mg/kg) effectively and selectively reduced food intake. The effect of 900 mg/kg ABE was closely replicated by acute treatment with 200 mg/kg pure phlorizin, suggesting that this was the likely active ingredient underlying the effect of ABE on food intake. These results further strengthen the hypothesis that apple-derived products may represent a promising option for novel pharmacotherapies for eating disorders and overweight. [ABSTRACT FROM AUTHOR]

Phlorizin (PRZ) is a natural product that belongs to a class of dihydrochalcones. The unique pharmacological property of PRZ is to block glucose absorption or reabsorption through specific and competitive inhibitors of the sodium/glucose cotransporters (SGLTs) in the intestine (SGLT1) and kidney (SGLT2). This results in glycosuria by inhibiting renal reabsorption of glucose and can be used as an adjuvant treatment for type 2 diabetes. The pharmacokinetic profile, metabolites of the PRZ, and efficacy of metabolites towards SGLTs are unknown. Therefore, the present study on the characterization of hitherto unknown in vivo metabolites of PRZ and pharmacokinetic profiling using liquid chromatography‐electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS) and accurate mass measurements is undertaken. Plasma, urine, and feces samples were collected after oral administration of PRZ to Sprague–Dawley rats to identify in vivo metabolites. Furthermore, in silico efficacy of the identified metabolites was evaluated by docking study. PRZ at an intraperitoneal dose of 400 mg/kg showed maximum concentration in the blood to 439.32 ± 8.84 ng/mL at 1 h, while phloretin showed 14.38 ± 0.33 ng/mL at 6 h. The pharmacokinetic profile of PRZ showed that the maximum concentration lies between 1 and 2 h after dosing. Decreased blood glucose levels and maximum excretion of glucose in the urine were observed when the PRZ and metabolites were observed in plasma. The identification and characterization of PRZ metabolites by LC/ESI/MS/MS further revealed that the phase I metabolites of PRZ are hydroxy (mono‐, di‐, and tri‐) and reduction. Phase II metabolites are O‐methylated, O‐acetylated, O‐sulfated, and glucuronide metabolites of PRZ. Further docking study revealed that the metabolites diglucuronide metabolite of mono‐hydroxylated PRZ and mono‐glucuronidation of PRZ could be considered novel inhibitors of SGLT1 and SGLT2, respectively, which show better binding affinities than their parent compound PRZ and the known inhibitors. [ABSTRACT FROM AUTHOR]

Dihydrochalcones (DHCs) constitute a specific class of flavonoids widely known for their various health-related advantages. Melatonin (MLT) has received attention worldwide as a master regulator in plants, but its roles in DHC accumulation remain unclear. Herein, the elicitation impacts of MLT on DHC biosynthesis were examined in Lithocarpus litseifolius, a valuable medicinal plant famous for its sweet flavor and anti-diabetes effect. Compared to the control, the foliar application of MLT significantly increased total flavonoid and DHC (phlorizin, trilobatin, and phloretin) levels in L. litseifolius leaves, especially when 100 μM MLT was utilized for 14 days. Moreover, antioxidant enzyme activities were boosted after MLT treatments, resulting in a decrease in the levels of intracellular reactive oxygen species. Remarkably, MLT triggered the biosynthesis of numerous phytohormones linked to secondary metabolism (salicylic acid, methyl jasmonic acid (MeJA), and ethylene), while reducing free JA contents in L. litseifolius. Additionally, the flavonoid biosynthetic enzyme activities were enhanced by the MLT in leaves. Multiple differentially expressed genes (DEGs) in RNA-seq might play a crucial role in MLT-elicited pathways, particularly those associated with the antioxidant system (SOD, CAT, and POD), transcription factor regulation (MYBs and bHLHs), and DHC metabolism (4CL, C4H, UGT71K1, and UGT88A1). As a result, MLT enhanced DHC accumulation in L. litseifolius leaves, primarily by modulating the antioxidant activity and co-regulating the physiological, hormonal, and transcriptional pathways of DHC metabolism.

Phlorizin, as a flavonoid from a wide range of sources, is gradually becoming known for its biological activity. Phlorizin can exert antioxidant effects by regulating the IL-1β/IKB-α/NF-KB signaling pathway. At the same time, it exerts its antibacterial activity by reducing intracellular DNA agglutination, reducing intracellular protein and energy synthesis, and destroying intracellular metabolism. In addition, phlorizin also has various pharmacological effects such as antiviral, antidiabetic, antitumor, and hepatoprotective effects. Based on domestic and foreign research reports, this article reviews the plant sources, extraction, and biological activities of phlorizin, providing a reference for improving the clinical application of phlorizin.

Marine-derived natural products are secondary metabolites widely used for various therapeutic applications. The present study was carried out to isolate the bioactive compound from seagrass Syringodium isoetifolium and explored the in vitro, in silico and in vivo anticancer activity against hepatocellular carcinoma. The bioactive compound was isolated from an aqueous ethanol extract of S. isoetifolium by column chromatography. The in vitro anticancer effect of the isolated compound was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Acridine Orange/Ethidium Bromide (AO/EtBr), DNA fragmentation, flow cytometry and western blotting against HepG2 cell lines. The molecular docking and diethylnitrosamine and carbon tetrachloride-induced hepatocellular carcinoma in BALB/c mice were also done. Liver morphology, hematological and biochemical parameters and histopathological examination were also performed in the present work. The structure of the isolated compound was confirmed by 1H NMR, 13C NMR, FT-IR and mass spectral data. The in vitro anticancer activity confirmed the occurrence of apoptosis in isolated phlorizin-treated HepG2 cells. Docking studies of the isolated compound into the binding site of NAD+-dependent deacetylase showed a better binding cavity against SIRT3 protein. The in vivo anticancer activity of phlorizin significantly reduced the malignant tumor and normalized the hematological and biochemical parameters. The histopathological examination of DEN+CCl 4 -induced HCC mice reveals promising anticancer activity. The present study concluded that the isolated compound of phlorizin from Syringodium isoetifolium had potential anticancer activity against hepatocellular carcinoma. [Display omitted] • Seagrass is one among the unexplored marine resource. • Bioactive compounds from seagrass would be modern-day drugs. • First study on isolation and characterization of phlorizin from seagrass against hepatocellular carcinoma in mice model. • Isolated phlorizin exhibited potential anticancer activity against HepG2 cell lines. • Phlorizin showed a significant binding affinity with SIRT3 protein. [ABSTRACT FROM AUTHOR]

The isolation of phlorizin from the bark of an apple tree in 1835 led to a flurry of research on its inhibitory effect on glucose transporters in the intestine and kidney. Using phlorizin as a prototype drug, antidiabetic agents with more selective inhibitory activity towards glucose transport at the kidney have subsequently been developed. In contrast, its hydrolysis product in the body, phloretin, which is also found in the apple plant, has weak antidiabetic properties. Phloretin, however, displays a range of pharmacological effects including antibacterial, anticancer, and cellular and organ protective properties both in vitro and in vivo. In this communication, the molecular basis of its anti-inflammatory mechanisms that attribute to its pharmacological effects is scrutinised. These include inhibiting the signalling pathways of inflammatory mediators' expression that support its suppressive effect in immune cells overactivation, obesity-induced inflammation, arthritis, endothelial, myocardial, hepatic, renal and lung injury, and inflammation in the gut, skin, and nervous system, among others. [ABSTRACT FROM AUTHOR]

Simple Summary: Cell migration is the main obstacle to the treatment of highly invasive brain cancer glioblastoma multiforme (GBM). We investigated in vitro the potential role of two solute carrier proteins (SLCs), SLC5A1 and SLC5A3, and their respective substrates, glucose and inositol, in GBM cell migration. We found that GBM cell motility was increased by medium supplementation with glucose and inositol and was strongly impaired by inhibition of SLC5A1/3 proteins. Using conventional and super-resolution fluorescence microscopy, we showed that both SLCs were not only highly expressed in migrating GBM cells, but they also localized to the lamellipodia, i.e., the migration-governing cell protrusions. Taken together, our data suggest that SLC5A1 and SLC5A3 are involved in GBM cell migration, presumably by mediating solute transport, osmotic water fluxes and thus local volume regulation in the lamellipodium. (1) Background: The recurrence of glioblastoma multiforme (GBM) is mainly due to invasion of the surrounding brain tissue, where organic solutes, including glucose and inositol, are abundant. Invasive cell migration has been linked to the aberrant expression of transmembrane solute-linked carriers (SLC). Here, we explore the role of glucose (SLC5A1) and inositol transporters (SLC5A3) in GBM cell migration. (2) Methods: Using immunofluorescence microscopy, we visualized the subcellular localization of SLC5A1 and SLC5A3 in two highly motile human GBM cell lines. We also employed wound-healing assays to examine the effect of SLC inhibition on GBM cell migration and examined the chemotactic potential of inositol. (3) Results: While GBM cell migration was significantly increased by extracellular inositol and glucose, it was strongly impaired by SLC transporter inhibition. In the GBM cell monolayers, both SLCs were exclusively detected in the migrating cells at the monolayer edge. In single GBM cells, both transporters were primarily localized at the leading edge of the lamellipodium. Interestingly, in GBM cells migrating via blebbing, SLC5A1 and SLC5A3 were predominantly detected in nascent and mature blebs, respectively. (4) Conclusion: We provide several lines of evidence for the involvement of SLC5A1 and SLC5A3 in GBM cell migration, thereby complementing the migration-associated transportome. Our findings suggest that SLC inhibition is a promising approach to GBM treatment. [ABSTRACT FROM AUTHOR]

The concentration of glucose in plasma is held within narrow limits (4-10 mmol/l), primarily to ensure fuel supply to the brain. Kidneys play a role in glucose homeostasis in the body by ensuring that glucose is not lost in the urine. Three membrane proteins are responsible for glucose reabsorption from the glomerular filtrate in the proximal tubule: sodium-glucose cotransporters SGLT1 and SGLT2, in the apical membrane, and GLUT2, a uniporter in the basolateral membrane. 'Knockout' of these transporters in mice and men results in the excretion of filtered glucose in the urine. In humans, intravenous injection of the plant glucoside phlorizin also results in excretion of the full filtered glucose load. This outcome and the finding that, in an animal model, phlorizin reversed the symptoms of diabetes, has stimulated the development and successful introduction of SGLT2 inhibitors, gliflozins, in the treatment of type 2 diabetes mellitus. Here we summarise the current state of our knowledge about the physiology of renal glucose handling and provide background to the development of SGLT2 inhibitors for type 2 diabetes treatment.

Phlorizin (phloridzin) is a polyphenolic phytochemical primarily found in unripe Malus (apple). It is a glucoside of phloretin and acts as an inhibitor of renal glucose transport, thus lowering blood glucose. The objective of this study was to determine effects of dietary supplementation with phlorizin on stress response, aging, and age-related diseases using Caenorhabditis elegans as a model system. Survival after oxidative stress or ultraviolet irradiation was significantly increased by pre-treatment of phlorizin. Dietary supplementation with phlorizin also significantly extended lifespans without reducing fertility. Age-related decline of muscle function was delayed by supplementation with phlorizin. Phlorizin induced the expression of stress-responsive genes hsp-16.2 and sod-3 and nuclear localization of DAF-16, a FOXO transcription factor modulating stress response and lifespan in C. elegans. Amyloid-beta-induced toxicity was significantly reduced by phlorizin. This effect was dependent on DAF-16 and SKN-1. Increased mortality induced with a high-glucose diet was partially prevented by phlorizin via SKN-1. Inactivation of dopaminergic neurons observed in a Parkinson's disease model was completely recovered by supplementation with phlorizin. Genetic analysis suggests that lifespan extension by phlorizin is mediated through oxidative stress response and autophagy. Taken together, these data suggest that phlorizin has strong anti-oxidant and anti-aging activities with potential to be developed as a novel anti-oxidant nutraceutical against aging and age-related diseases. [ABSTRACT FROM AUTHOR]

Phlorizin is a plant-derived molecule with relevant anti-diabetic activity, making this compound a potential functional component in nutraceutical formulations for the management of glycemia. It is noteworthy that promising sources for the extraction of phlorizin include apple tree leaves, a by-product of apple fruit production. The main aim of this study was to optimize the extraction process of phlorizin from Annurca apple tree leaves (AALs) using response surface methodology (RSM), and to determine the potential nutraceutical application of the obtained extract. The results of the RSM analysis indicate a maximum phlorizin yield of 126.89 ± 7.579 (mg/g DW) obtained under the following optimized conditions: MeOH/H2O, 80:20 + 1% HCOOH as the extraction solvent; 37.7 °C as the extraction temperature; and 170 min as the time of extraction. The HPLC-DAD-HESI-MS/MS analysis performed on the extract obtained under such conditions, named optimized Annurca apple leaves extract (OAALE), led to the identification of twenty-three phenolic molecules, with fifteen of them quantified. To explore the nutraceutical potential of OAALE, the in vitro antioxidant activity was evaluated by DPPH, ABTS, and FRAP assays, resulting in 21.17 ± 2.30, 38.85 ± 0.69, and 34.14 ± 3.8 μmol Trolox equivalent/g of extract, respectively. Moreover, the IC50 of 0.330 mg/mL obtained from the advanced glycation end-product inhibition assay, further supported the antidiabetic potential of OAALE. [ABSTRACT FROM AUTHOR]

Dihydrochalcones (DHCs) are flavonoids produced as a side branch of the phenylpropanoid pathway. DHCs are found at high concentrations in apples (Malus spp.) but not in pears (Pyrus spp.) or other members of the Rosaceae. Biosynthesis of DHCs in apple has been hypothesized to occur via reduction of p-coumaroyl CoA by a Malus × domestica hydroxycinnamoyl CoA double-bond reductase (MdHCDBR) followed by the action chalcone synthase to produce phloretin or via direct reduction of naringenin chalcone to phloretin via an unknown enzyme. In this study, we report that genetic downregulation of MdHCDBR does not reduce DHC concentrations in apple leaves. We used comparative transcriptome analysis to identify candidate naringenin chalcone reductases (NCRs), designated MdNCR1a-c, expressed in apple leaves but not fruit. These MdNCR1 genes form an expanded gene cluster found exclusively in apple. Transient expression of MdNCR1 genes in Nicotiana benthamiana leaves indicated they produced DHCs at high concentrations in planta. Recombinant MdNCR1 utilized naringenin chalcone to produce phloretin at high efficiency. Downregulation of NCR genes in transgenic apple reduced foliar DHC levels by 85-95%. Reducing DHC production redirected flux to the production of flavonol glycosides. In situ localization indicated that NCR proteins were likely found in the vacuolar membrane. Active site analysis of AlphaFold models indicated that MdNCR1a-c share identical substrate binding pockets, but the pockets differ substantially in related weakly active/inactive NCR proteins. Identifying the missing enzyme required for DHC production provides opportunities to manipulate DHC content in apple and other fruits and has other applications, e.g., in biofermentation and biopharming., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

The long-term high-fat, high-sugar diet exacerbates type 2 diabetes mellitus (T2DM)-related cognitive impairments. Phlorizin, a well-studied natural compound found in apples and other plants, is recognized for its bioactive properties, including modulation of glucose and lipid metabolism. Despite its established role in mitigating metabolic disorders, the neuroprotective effects of phlorizin, particularly against diabetes-related cognitive dysfunction, have not been fully elucidated. Therefore, the present study aimed to investigate the effect of dietary supplementation of phlorizin on high-fat and high-fructose diet (HFFD)-induced cognitive dysfunction and evaluate the crucial role of the microbiota-gut-brain axis. We found that dietary supplementation of phlorizin for 14 weeks effectively prevented glucolipid metabolism disorder, spatial learning impairment, and memory impairment in HFFD mice. In addition, phlorizin improved the HFFD-induced decrease in synaptic plasticity, neuroinflammation, and excessive activation of microglia in the hippocampus. Transcriptomics analysis shows that the protective effect of phlorizin on cognitive impairment was associated with increased expression of neurotransmitters and synapse-related genes in the hippocampus. Phlorizin treatment alleviated colon microbiota disturbance, mainly manifested by an increase in gut microbiota diversity and the abundance of short-chain fatty acid (SCFA)-producing bacteria. The level of microbial metabolites, including SCFA, inosine 5'-monophosphate (IMP), and D (-)-beta-hydroxybutyric acid (BHB) were also significantly increased after phlorizin treatment. Integrating multiomics analysis observed tight connections between phlorizin-regulated genes, microbiota, and metabolites. Furthermore, removal of the gut microbiota via antibiotics treatment diminished the protective effect of phlorizin against HFFD-induced cognitive impairment, underscoring the critical role of the gut microbiota in mediating cognitive behavior. Importantly, supplementation with SCFA and BHB alone mimicked the regulatory effects of phlorizin on cognitive function. Therefore, phlorizin shows promise as a potential nutritional therapy for addressing cognitive impairment associated with metabolic disorders. Further research is needed to explore its effectiveness in preventing and alleviating neurodegenerative diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Burns usually result in damage and loss of skin forming irregular wound wounds. The lack of skin tissue protection makes the wound site highly vulnerable to bacterial infections, hindering the healing process. However, commonly used wound dressings do not readily provide complete coverage of irregular wounds compared to regular wounds. Therefore, there is an urgent need to prepare a wound dressing with high antimicrobial efficacy for the administration of drugs to irregular wounds. In this study, a chitosan (CS)/polyvinylpyrrolidone (PVP) composite nanofiber membrane (CS/PVP/Phlorizin) loaded with root bark glycosides (Phlorizin) was developed using an electrostatic spinning technique. The incorporation of phlorizin, a natural antioxidant, into the fiber membranes notably boosted their antimicrobial and antioxidant capabilities, along with demonstrating excellent hydrophilic characteristics. In vitro cellular experiments showed that CS/PVP/Phlorizin increased Hacat cell viability with the presence of better cytocompatibility. In scald wound healing experiments, Phlorizin-loaded nanofibrous membranes significantly promoted re-epithelialization and angiogenesis at the wound site, and reduced the inflammatory response at the wound site. Therefore, the above results indicate that this nanofiber membrane is expected to be an ideal dressing for burn wounds., Competing Interests: Authors AL, GX, CD, XS, LY, and MY were employed by Jilin Aodong Yanbian Pharmaceutical Co, Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yang, Ma, Li, Xia, Li, Ding, Sun, Yan, Yang and Zhao.)

• Phlorizin ameliorates the rheumatoid arthritis in CIA induced RA rats. • Anti-arthritic effect of phlorizin was performed by in vitro analysis. • Phlorizin ameliorates the arthritic score in CIA induced RA rats. • Phlorizin protects RA by reducing inflammatory cytokines and regulating Akt/PI3K/mTOR pathway. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease and management of it still a challenge. Given report evaluates protective effect of phlorizin on RA and also postulates the molecular mechanism of its action. Bovine type II collagen (CIA) and Freund's incomplete adjuvant (1:1 and 1 mg/ml) was administered on 1st and 8th day of protocol to induce RA in rats and treatment with phlorizin 60 and 120 mg/kg was started after 4th week of protocol. Level of inflammatory cytokines and expression of proteins were estimated in phlorizin treated RA rats. Moreover in-vitro study was performed on Fibroblast-like synoviocytes (FLSs) and effect of phlorizin was estimated on proliferation, apoptosis and expression of mTOR pathway protein after stimulating these cell lines with Tumour Necrosis Factor alpha (TNF-α). Data of study suggest that phlorizin reduces inflammation and improves weight in CIA induced RA rats. Level of inflammatory cytokines in the serum and expression of Akt/PI3K/mTOR proteins in the join tissue was reduced in phlorizin treated RA rats. Phlorizin also reported to reverse the histopathological changes in the joint tissue of RA rats. In-vitro study supports that phlorizin reduces proliferation and no apoptotic effect on TNF-α stimulated FLSs. Expression of Akt/PI3K/mTOR proteins also downregulated in phlorizin treated TNF-α stimulated FLSs. In conclusion, phlorizin protects inflammation and reduces injury to the synovial tissues in RA, as it reduces autophagy by regulating Akt/PI3K/mTOR pathway. [ABSTRACT FROM AUTHOR]

• Metabolic fate of PHZ during in vitro incubation with microbiota was reveled; • Lactobacillus plays an important role in the catabolism of PHZ to PHT; • PHZ-enriched Lactobacillus supports its prebiotic properties. As ubiquitous components among fruits, polyphenols, including flavonoids and phenolic acids, are somewhat embarrassed on their health benefits but low bioavailability, triggering a hotspot on their interaction with microbiota. Due to its structural characteristics similar to flavonoids and phenolic acids, dihydrochalcone phlorizin (PHZ) was selected as a reference, to illustrate its step-by-step metabolic fate associated with microbiota. The results confirmed that the metabolic flux of PHZ starts with its conversion to phloretin (PHT), sequentially followed by the formation of 3-(4-hydroxyphenyl) propionic acid (PHA), and 4-hydroxyphenylacetic acid (4-HPAA). Catabolic characteristics was comparatively elucidated by introducing apparent and potential kinetics. Besides, coupling catabolic processes with microbial changes suggested several potential bacteria involving in PHZ metabolism, as well as those regulated by PHZ and its metabolites. In particular, seven strains from Lactobacillus were selectively isolated and confirmed to be essential for deglycosylation of PHZ, implying a potential synergistic effect between PHZ and Lactobacillus. [ABSTRACT FROM AUTHOR]

The study has been commenced to discover the potential of Phlorizin (dual SGLT inhibitor) in streptozotocin induced dementia of Alzheimer's disease (AD) type. Injection of Streptozotocin (STZ) was given via i.c.v. route (3 mg/kg) to induce dementia of Alzheimer's type. In these animals learning and memory was evaluated using Morris water maze (MWM) test. Glutathione (GSH) and thiobarbituric acid reactive species (TBARS) level was quantified to evaluate the oxidative stress; cholinergic activity of brain was estimated in term of acetylcholinesterase (AChE) activity; and the levels of myeloperoxidase (MPO) were measured as inflammation marker. The mice model had decreased performance in MWM, representing impairment of cognitive functions. Biochemical evaluation showed rise in TBARS level, MPO and AChE activity, and fall in GSH level. The histopathological study revealed severe infiltration of neutrophils. In the study, Phlorizin/Donepezil (serving as positive control) treatment mitigate streptozotocin induced cognitive decline, histopathological changes and biochemical alterations. The results suggest that Phlorizin decreased cognitive function via its anticholinesterase, antioxidative, antiinflammatory effects and probably through SGLT inhibitory action. It can be conferred that SGLTs can be an encouraging target for the treatment of dementia of AD. [ABSTRACT FROM AUTHOR]

Abstract Background This research article aims to study at molecular level by in silico GRIP docking the effectivity of the detected compounds in value added black tea or VABT, prepared in a chemometrically optimized ratio of Black tea:Cinnamon (Cinnamomum zeylanicum):Ginger (Zingiber officinale):Cardamom (Elettaria cardamomum) in combating diabesity. Results The compounds in VABT were identified by liquid chromatography-mass chromatography. Basing on the desirability function, the chemometrically optimized weight ratio of VABT was determined to be 420:50:54:26 (Black tea:cinnamon:ginger:cardamom). Among the identified molecules, phlorizin, 6-gingerol, procyanidin, and epicatechin were docked with insulin receptor kinase, pancreatic lipase-colipase complex, and human FTO. The high negative dock scores of the test molecules in inhibiting the enzymes suggest their potency. Conclusions Thus, the results of in silico studies predicted the potency of VABT in combating diabesity. VABT thus has potency and can serve as a nutrotherapeutic entity against diabesity.

Aline David-Silva,1 João Victor Esteves,1 Mychel Raony PT Morais,2 Helayne Soares Freitas,1 Telma Maria Zorn,2 Maria Lucia Correa-Giannella,3 Ubiratan Fabres Machado1 1Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil; 2Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil; 3Laboratório de Carboidratos e Radioimunoensaio, LIM-18, Hospital das Clinicas HCFMUSP, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, BrazilCorrespondence: Ubiratan Fabres MachadoDepartment of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, SP 05508-900, BrazilTel +55 11 30917494Email ubiratan@icb.usp.brPurpose: NAFLD is a hepatic component of type 2 diabetes mellitus (T2D), in which impaired hepatic glucose production plays an important role. Inhibitors of sodium glucose transporter 2 (SGLT2) reduce glycemia and exert beneficial effects on diabetic complications. Recently, dual SGLT1/2 inhibition has been proposed to be more effective in reducing glycemia. We hypothesized that improving hepatic glucose metabolism induced by SGLT1/2 inhibition could be accompanied by beneficial effects on NAFLD progression.Methods: Glycemic homeostasis, hepatic glucose production and NAFLD features were investigated in obese T2D mice, treated with SGLT1/2 inhibitor phlorizin for 1 week.Results: T2D increased glycemia; insulinemia; hepatic expression of phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase) and glucose transporter 2 (Slc2a2 gene); hepatocyte nuclear factors 1A/4A/3B-binding activity in Slc2a2; endogenous glucose production; liver weight, plasma transaminase concentration as well as hepatic inflammation markers, and induced histological signals of non-alcoholic steatohepatitis (NASH, according to NASH-CRN Pathology Committee System). Phlorizin treatment restored all these parameters (mean NASH score reduced from 5.25 to 2.75 P< 0.001); however, plasma transaminase concentration was partially reverted and some hepatic inflammation markers remained unaltered.Conclusion: NAFLD accompanies altered hepatic glucose metabolism in T2D mice and that greatly ameliorated through short-term treatment with the dual SGLT1/2 inhibitor. This suggests that altered hepatic glucose metabolism participates in T2D-related NAFLD and highlights the pharmacological inhibition of SGLTs as a useful approach not only for controlling glycemia but also for mitigating development and/or progression of NAFLD.Keywords: GLUT2, PEPCK, G6Pase, phlorizin, NASH

The isolation of phlorizin from the bark of an apple tree in 1835 led to a flurry of research on its inhibitory effect on glucose transporters in the intestine and kidney. Using phlorizin as a prototype drug, antidiabetic agents with more selective inhibitory activity towards glucose transport at the kidney have subsequently been developed. In contrast, its hydrolysis product in the body, phloretin, which is also found in the apple plant, has weak antidiabetic properties. Phloretin, however, displays a range of pharmacological effects including antibacterial, anticancer, and cellular and organ protective properties both in vitro and in vivo. In this communication, the molecular basis of its anti-inflammatory mechanisms that attribute to its pharmacological effects is scrutinised. These include inhibiting the signalling pathways of inflammatory mediators’ expression that support its suppressive effect in immune cells overactivation, obesity-induced inflammation, arthritis, endothelial, myocardial, hepatic, renal and lung injury, and inflammation in the gut, skin, and nervous system, among others.

Aim:In this study, we aimed to investigate the effects of phloretin and phlorizin which are potent antioxidants, anti inflammatory and antiapoptotic agents on the prevention of glutamate-induced neurotoxicity which is an excitatory neurotransmitter.Materials and Methods:In our study, the newly born rat cortex was used. Glutamate was applied in concentration 3x10-3 and 6x10-3 M 2 hours after application of phloretin in concentrations 10-5 M and 2x10-5 M and phlorizin in concentrations 10-5 and 2x10-5 M. mRNA isolation was performed from the cells 6 hours after glutamate administration. 24 hours later, metiltiazol difenil tetrazolium (MTT) test, total oxidant and antioxidant capacity measurements were performed.Results:In our study, phloretin and phlorizin showed the best neuroprotective effect in high dose, while glutamate reduced cell viability in increased doses. Increased total oxidant capacity due to toxicity has been significantly improved by phloretin and phlorizin. Decreased antioxidant capacity in the toxicity group showed improvement with the application of phloretin and phlorizin. When phloretin and phlorizin were applied alone, they did not affect cell viability significantly, they increased antioxidant capacity and decreased oxidant capacity. İncreased tumor necrosis factor-alpha (TNF-α) mRNA expression after glutamate administration decreased significantly with the application of phloretin and phlorizin. Increased caspase 9 and caspase 3 mRNA expression due to glutamate showed improvement with the application of phloretin and phlorizin.Conclusion:These findings suggest that phloretin and phlorizin, potent antioxidant, antiinflammatory and antiapoptotic agents, may be protective in glutamate-induced neurotoxicity and can be used as therapeutic agents for preventing glutamate-induced neurological disorders.

Objective: Orchitis is a common reproductive disease of male animals, which has serious implications to human and animal reproduction. Additionally, phlorizin (PHN), a common polyphenol in apples and strawberries, has a variety of biological activities, including antioxidant, anti-inflammatory, anti-diabetic, and anti-aging activities. We aimed to determine the protective effects and potential mechanisms of PHN in lipopolysaccharide (LPS)-induced acute orchitis in mice., Method: After 21 days of PHN pretreatment, mice were injected with LPS to induce testicular inflammation, and then the changes of testicular tissue structure, expression of inflammatory factors, testosterone level, expression of testosterone-related genes, adhesion gene and protein expression were detected, and the structural changes in the intestinal flora after PHN treatment were further detected by 16SRNA., Result: Our results demonstrated that PHN treatment reduced LPS-induced testicular injury and body and testicular weight losses. The mRNA expression levels of pro-inflammatory cytokines-related genes and antioxidant enzyme activity were also decreased and elevated, respectively, by PHN administration; however, PHN treatment also reduced the LPS-induced decrease in testosterone levels in the testes. Additionally, further studies found that PHN increased the expression of marker proteins zonula occludens-1 (ZO-1) and occludin associated with the blood testosterone barrier compared with that in LPS treatment groups. To further examine the potential mechanisms of the protective effect of PHN on LPS-induced testicular injury, we compared the differences of gut microbiota compositions between the 100 mg/kg PHN treatment group and the control group using 16SRNA. Metagenomic analyses indicated that the abundances of Bacteroidetes , Muribaculaceae , Lactobacillaceae , uncultured bacterium f Muribaculaceae , and Lactobacillus in the PHN treatment group improved, while potential microbes that can induce intestinal diseases, including Verrucomicrobia , Epsilonbacteraeota , Akkermansiaceae , and Akkermansia decreased in the PHN treatment group., Conclusion: Our results indicate that PHN pretreatment might alleviate orchitis by altering the composition of gut microflora, which may provide a reference for reducing the occurrence of acute orchitis in male animals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Guo, Li, Huang, Li, Zhang and Qu.)

Phlorizin (PHZ) is one of the main pharmacologically active ingredients in Lithocarpus polystachyus . We have previously shown that PHZ inhibits the replication of bovine viral diarrhea virus (BVDV), but the exact antiviral mechanism, especially in vivo , is still unknown. Here, we further confirm that PHZ has good protective effects in BVDV-infected mice. We analyzed BVDV-induced CD3 + , CD4 + , and CD8 + T cells among peripheral blood lymphocytes and found that PHZ significantly restored their percentage. Metagenomic analyses revealed that PHZ markedly improved the richness and diversity of intestinal microbiota and increased the abundance of potentially health-related microbes (families Lachnosipiraceae , Ruminococcaceae , and Oscillospiraceae ). Specifically, the relative abundance of short chain fatty acid (SCFA)-producing bacteria, including Lachnospiraceae&#95;UCG -006, unclassified&#95;f&#95;Ruminococcaceae , Oscillibacter , Intestinimonas , Blautia , and Lachnoclostridium increased significantly after PHZ treatment. Interestingly, BVDV-infected mice that received fecal microbiota from PHZ-treated mice (PHZ-FMT) had a significantly lower viral load in the duodenum and jejunum than untreated mice. Pathological lesions of duodenum and jejunum were also greatly reduced in the PHZ-FMT group, confirming a significant antiviral effect. These findings show that gut microbiota play an important role in PHZ's antiviral activity and suggest that their targeted intervention might be a promising endogenous strategy to prevent and control BVDV.

Background/aim: Rheumatoid arthritis (RA) is an inflammatory autoimmune disease, and management of it is still a challenge. The present investigation assessed the potential preventive effect of phlorizin on rats with RA., Materials and Methods: A total of 40 healthy Wistar rats were used for this study. Bovine type II collagen and Freund's incomplete adjuvant (1:1 and 1 mg/ml) were administered on days 1 and 8 of the protocol to induce RA in rats; treatment with phlorizin at 60 or 120 mg/kg was started after the 4th week of the protocol, and its effect on inflammation, level of inflammatory cytokines, and expression of proteins were estimated in RA rats. Moreover, an in vitro study was performed on fibroblast-like synoviocytes (FLSs), and the effects of phlorizin on proliferation, apoptosis, and expression of the mechanistic target of rapamycin kinase pathway protein after stimulating these cells with tumor necrosis factor α (TNF-α) were estimated., Results: The data obtained from the study indicate that phlorizin has the potential to mitigate inflammation and enhance weight management in rats with RA induced by bovine type II collagen (CII). The level of inflammatory cytokines in the serum and the expression of protein kinase B (AKT), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), and mechanistic target of rapamycin kinase (mTOR) proteins in the joint tissue were reduced in phlorizin-treated rats with RA. In this investigation, phlorizin was shown to reverse the histological abnormalities in the joint tissue of rats with RA. The in-vitro study showed that phlorizin reduced proliferation and had no apoptotic effect on TNF-α-stimulated FLSs. Expression of AKT, PI3K, and mTOR proteins was also down-regulated in phlorizin-treated TNF-α-stimulated FLSs., Conclusion: Phlorizin protects against inflammation and reduces injury to synovial tissues in RA by modulating the AKT/PI3K/mTOR pathway., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Three new phlorizin derivatives, 6"-O-vanilloylphlorizin (1), 6"-O-(4-hydroxybenzoyl)phlorizin (2), 6"-O-feruloylphlorizin (3), along with four known dihydrochalcones, phlorizin (4), 3-hydroxyphlorizin, trilobatin, and 6"-O-acetylphlorizin were isolated from the leaves of Lithocarpus litseifolius. Their structures were established by analysis of extensive spectroscopic data. The new compounds were shown to be non-cytotoxic when tested against A549, HeLa, HepG2, and MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

Phlorizin (phloridzin) is a polyphenolic phytochemical primarily found in unripe Malus (apple). It is a glucoside of phloretin and acts as an inhibitor of renal glucose transport, thus lowering blood glucose. The objective of this study was to determine effects of dietary supplementation with phlorizin on stress response, aging, and age-related diseases using Caenorhabditis elegans as a model system. Survival after oxidative stress or ultraviolet irradiation was significantly increased by pre-treatment of phlorizin. Dietary supplementation with phlorizin also significantly extended lifespans without reducing fertility. Age-related decline of muscle function was delayed by supplementation with phlorizin. Phlorizin induced the expression of stress-responsive genes hsp-16.2 and sod-3 and nuclear localization of DAF-16, a FOXO transcription factor modulating stress response and lifespan in C. elegans. Amyloid-beta-induced toxicity was significantly reduced by phlorizin. This effect was dependent on DAF-16 and SKN-1. Increased mortality induced with a high-glucose diet was partially prevented by phlorizin via SKN-1. Inactivation of dopaminergic neurons observed in a Parkinson’s disease model was completely recovered by supplementation with phlorizin. Genetic analysis suggests that lifespan extension by phlorizin is mediated through oxidative stress response and autophagy. Taken together, these data suggest that phlorizin has strong anti-oxidant and anti-aging activities with potential to be developed as a novel anti-oxidant nutraceutical against aging and age-related diseases.

Phlorizin is a plant-derived molecule with relevant anti-diabetic activity, making this compound a potential functional component in nutraceutical formulations for the management of glycemia. It is noteworthy that promising sources for the extraction of phlorizin include apple tree leaves, a by-product of apple fruit production. The main aim of this study was to optimize the extraction process of phlorizin from Annurca apple tree leaves (AALs) using response surface methodology (RSM), and to determine the potential nutraceutical application of the obtained extract. The results of the RSM analysis indicate a maximum phlorizin yield of 126.89 ± 7.579 (mg/g DW) obtained under the following optimized conditions: MeOH/H2O, 80:20 + 1% HCOOH as the extraction solvent; 37.7 °C as the extraction temperature; and 170 min as the time of extraction. The HPLC-DAD-HESI-MS/MS analysis performed on the extract obtained under such conditions, named optimized Annurca apple leaves extract (OAALE), led to the identification of twenty-three phenolic molecules, with fifteen of them quantified. To explore the nutraceutical potential of OAALE, the in vitro antioxidant activity was evaluated by DPPH, ABTS, and FRAP assays, resulting in 21.17 ± 2.30, 38.85 ± 0.69, and 34.14 ± 3.8 μmol Trolox equivalent/g of extract, respectively. Moreover, the IC50 of 0.330 mg/mL obtained from the advanced glycation end-product inhibition assay, further supported the antidiabetic potential of OAALE.

Both phloretin and phlorizin (phloretin 2′-O-glucoside) extracted from the peel of apples are attributed to particular flavonoid dihydrochalcones with multiple pharmacological activities. However, metabolite structural characterization of these two components, which may accumulate to exert their pharmacological effects, remains insufficient. The present study aimed to comparatively clarify the metabolic pathways of phloretin and phlorizin after oral administration individually to Sprague-Dawley (SD) rats. Therefore, a rapid, integrate and systematic analytical strategy based on characteristic fragment ion fishing was proposed for the screening and identification of metabolites coming from phloretin and phlorizin using UHPLC-Q-Exactive Orbitrap mass spectrometry in parallel reaction monitoring mode. As a result, a total of 50 phloretin metabolites and 52 phlorizin metabolites were individually identified from different biological samples including rat plasma, urine, and faeces. Moreover, glucuronidation, sulfation, carbonylation and hydrolyzation were revealed to be the main metabolic pathways of phlorizin, while decarbonylation, glucuronidation and sulfation were regarded as the predominant biotransformation pathways as for phloretin. This is the first systematic study on comparison of metabolic profiles of phlorizin and phloretin in disease states, which was helpful to declare the complicated structure activity relationships between phlorizin and phloretin and shed light to their action mechanism. [ABSTRACT FROM AUTHOR]

Abstract Background Recent large-scale clinical trials have shown that SGLT2-inhibitors reduce cardiovascular events in diabetic patients. However, the regulation and functional role of cardiac sodium–glucose cotransporter (SGLT1 is the dominant isoform) compared with those of other glucose transporters (insulin-dependent GLUT4 is the major isoform) remain incompletely understood. Given that glucose is an important preferential substrate for myocardial energy metabolism under conditions of ischemia–reperfusion injury (IRI), we hypothesized that SGLT1 contributes to cardioprotection during the acute phase of IRI via enhanced glucose transport, particularly in insulin-resistant phenotypes. Methods and results The hearts from mice fed a high-fat diet (HFD) for 12 weeks or a normal-fat diet (NFD) were perfused with either the non-selective SGLT-inhibitor phlorizin or selective SGLT2-inhibitors (tofogliflozin, ipragliflozin, canagliflozin) during IRI using Langendorff model. After ischemia–reperfusion, HFD impaired left ventricular developed pressure (LVDP) recovery compared with the findings in NFD. Although phlorizin-perfusion impaired LVDP recovery in NFD, a further impaired LVDP recovery and a dramatically increased infarct size were observed in HFD with phlorizin-perfusion. Meanwhile, none of the SGLT2-inhibitors significantly affected cardiac function or myocardial injury after ischemia–reperfusion under either diet condition. The plasma membrane expression of GLUT4 was significantly increased after IRI in NFD but was substantially attenuated in HFD, the latter of which was associated with a significant reduction in myocardial glucose uptake. In contrast, SGLT1 expression at the plasma membrane remained constant during IRI, regardless of the diet condition, whereas SGLT2 was not detected in the hearts of any mice. Of note, phlorizin considerably reduced myocardial glucose uptake after IRI, particularly in HFD. Conclusions Cardiac SGLT1 but not SGLT2 plays a compensatory protective role during the acute phase of IRI via enhanced glucose uptake, particularly under insulin-resistant conditions, in which IRI-induced GLUT4 upregulation is compromised.

Purpose: To compare the improving effects of diabetic erectile dysfunction with two anti-glycemic agents; phlorizin and insu-lin. Materials and Methods: Sixty Sprague-Dawley rats were divided into four groups (n=15 in each group): normal control (C), untreated diabetic rats (D), and diabetic rats treated by phlorizin (P) or insulin (I). Ten weeks after the diabetic induction using an injection of streptozotocin (55 mg/kg), four weeks of diabetic control was conducted. Erectile response, Western blot, and immunohistochemistry were assessed. Results: During the experiment, the C-group showed continuous weight gain, while the other groups suffered from weight loss. After start of diabetic control, the body weight of I-group was increased; whereas, there was no meaningful change in the P-group. Meanwhile, comparable blood glucose levels were achieved in the P- and I-groups. The erectile response was markedly decreased in the D-group, whereas the P- and I-groups were similar as good as the C-group. In addition, D-group showed the significant decrease in the cavernosal smooth muscle content and increased apoptosis. Platelet endothelial cell adhesion molecule-1 protein expression, phosphorylation of endothelial nitric oxide synthase and myosin phosphatase target subunit 1 were significantly distorted in the D-group, while the P- and I-groups were comparable with the C-group. Conclusions: Phlorizin treatment resulted in the improvement of erectile function as same as insulin despite the lack of ana-bolic weight gains. These results suggest that control of blood glucose level rather than a type of anti-glycemic agents is more important for the prevention and treatment of diabetic erectile dysfunction

Docynia indica is used as a plant resource for both medicine and food in minority areas of southwestern China and Southeast of Asia, especially Docynia indica leaves, which are often used as a kind of functional tea in daily life. In our previous research, it has found that D. indica is rich in polyphenols (mainly phlorizin (PHZ)). Although PHZ is the first polyphenolic competitive inhibitor of sodium-dependent glucose transporters (SGLTs) to be discovered, the promotion and application of PHZ are limited due to its extremely low bioavailability. As a kind of aglycons, phloretin (PHT) possesses a better bioavailability and bioactivity than PHZ. Therefore, the conversion of PHZ to PHT in D. indica leaves by the method of biotransformation can be applied to solve the above issue. In this study, Aspergillus niger and Eurotium cristatum were used to transform PHZ to PHT in D. indica. Compared with Aspergillus niger, Eurotium cristatum can cause the equimolar conversion of PHZ to PHT. However, Aspergillus niger resulted in the complete degradation of PHZ. In the process of deep fermentation, PHZ in D. indica leaves was gradually biotransformed into PHT, and its content was as high as ~ 12% after fermentation. With the increase of PHT content, the antioxidant and antibacterial activity of Docynia indica leaves increased. By the acute toxicity evaluation, it was confirmed that Docynia indica leaves and Eurotium cristatum fermented leaves were much safer. These results indicate that Eurotium cristatum fermentation has the ability to transform the functional compounds in Docynia indica leaves and increase the antioxidant and antibacterial activity of Docynia indica, thus making it a substitute for PHT and functional tea. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the hypoglycemic and hypolipidemic effects of phlorizin on sweet tea in rats with diabetes. Diabetic rat model was established by feeding with HFD (high‐fat diet) and then treating with intraperitoneal injection of STZ (streptozocin). The experiments were divided into therapeutic and preventive experiments. In both experiments, rats were divided into normal, diabetic control, positive control, and phlorizin groups. Symptoms of diabetes, fasting blood glucose (FBG) levels, serum lipid parameters, and pathological changes in the pancreas and liver were evaluated. It was found that the symptoms of diabetes were improved by phlorizin treatment. In addition, phlorizin could decrease FBG, improve serum lipid levels, protect against damaged pancreas islet, and decrease fat deposition in hepatic cells. These effects of phlorizin can be shown only attain to a certain dosage. It can be concluded that phlorizin has the therapeutic and preventive effects on hyperlipidemia and hyperglycemia in diabetes rats. [ABSTRACT FROM AUTHOR]

Although sodium glucose cotransporter 1 (SGLT1) has been identified as one of the major SGLT isoforms expressed in the heart, its exact role remains elusive. Evidence using phlorizin, the most common inhibitor of SGLTs, has suggested its role in glucose transport. However, phlorizin could also affect classical facilitated diffusion via glucose transporters (GLUTs), bringing into question the relevance of SGLT1 in overall cardiac glucose uptake. Accordingly, we assessed the contribution of SGLT1 in cardiac glucose uptake using the SGLT1 knockout mouse model, which lacks exon 1. Glucose uptake was similar in cardiomyocytes isolated from SGLT1-knockout (Δex1KO) and control littermate (WT) mice either under basal state, insulin, or hyperglycemia. Similarly, in vivo basal and insulin-stimulated cardiac glucose transport measured by micro-PET scan technology did not differ between WT and Δex1KO mice. Micromolar concentrations of phlorizin had no impact on glucose uptake in either isolated WT or Δex1KOderived cardiomyocytes. However, higher concentrations (1 mM) completely inhibited insulin-stimulated glucose transport without affecting insulin signaling nor GLUT4 translocation independently from cardiomyocyte genotype. Interestingly, we discovered that mouse and human hearts expressed a shorter slc5a1 transcript, leading to SGLT1 protein lacking transmembrane domains and residues involved in glucose and sodium bindings. In conclusion, cardiac SGLT1 does not contribute to overall glucose uptake, probably due to the expression of slc5a1 transcript variant. The inhibitory effect of phlorizin on cardiac glucose uptake is SGLT1-independent and can be explained by GLUT transporter inhibition. These data open new perspectives in understanding the role of SGLT1 in the heart. [ABSTRACT FROM AUTHOR]

Maternal obesity increases the risk of obesity and metabolic disorders (MDs) in offspring, which can be mediated by the gut microbiota. Phlorizin (PHZ) can improve gut dysbiosis and positively affect host health; however, its transgenerational metabolic benefits remain largely unclear. This study aimed to investigate the potential of maternal PHZ intake in attenuating the adverse impacts of a maternal high-fat diet on obesity-related MDs in dams and offspring. The results showed that maternal PHZ reduced HFD-induced body weight gain and fat accumulation and improved glucose intolerance and abnormal lipid profiles in both dams and offspring. PHZ improved gut dysbiosis by promoting expansion of SCFA-producing bacteria, Akkermansia and Blautia , while inhibiting LPS-producing and pro-inflammatory bacteria, resulting in significantly increased fecal SCFAs, especially butyric acid, and reduced serum lipopolysaccharide levels and intestinal inflammation. PHZ also promoted intestinal GLP-1/2 secretion and intestinal development and enhanced gut barrier function by activating G protein-coupled receptor 43 (GPR43) in the offspring. Antibiotic-treated mice receiving FMT from PHZ-regulated offspring could attenuate MDs induced by receiving FMT from HFD offspring through the gut microbiota to activate the GPR43 pathway. It can be regarded as a promising functional food ingredient for preventing intergenerational transmission of MDs and breaking the obesity cycle.