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The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p < 0.05) than those of CON group. Compared with CON group, the carcass weight and intramuscular fat content of lambs in TA1 group were increased (p < 0.05) and the meat shear force was decreased (p < 0.05). The trypsin activity in the jejunum and ileum of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Also, tannin supplementation significantly increased (p < 0.05) the level of jejunal and ileal total antioxidant capacity and reduced (p < 0.05) the jejunal malondialdehyde concentration in lambs. The jejunum and ileum of TA1 lambs showed reduced (p < 0.05) tumor necrosis factor-alpha and increased (p < 0.05) interleukin-10 mRNA levels compared with CON lambs. In the jejunum, the secretory immunoglobulin A content of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Lambs supplemented with tannin at the level of 3 g/d increased (p < 0.05) the gene expressions of claudin-1 , claudin-4 and zonula occludens-1 in the jejunum when compared to those of CON and TA2 groups. In summary, tannin supplementation at the level of 3 g/d per animal can improve the production performance and intestinal function of fattening lambs fed a high-concentrate diet. [ABSTRACT FROM AUTHOR]

Chestnut tannin, extracted from the bark or wood of chestnut trees, possesses unique properties that make it valuable in various industries. It serves as a natural source of tannins, which are widely used in the production of leather, textiles, and wood preservation. As research continues to explore its potential applications, chestnut tannin remains a promising resource with diverse industrial uses. Highlighting new use, research and bioeconomy aspects, this study provides a unified perspective on chestnut tannin. New advanced applications will likely emerge shortly.

Chestnut tannin, extracted from the bark or wood of chestnut trees, possesses unique properties that make it valuable in various industries. It serves as a natural source of tannins, which are widely used in the production of leather, textiles, and wood preservation. As research continues to explore its potential applications, chestnut tannin remains a promising resource with diverse industrial uses. Highlighting new use, research and bioeconomy aspects, this study provides a unified perspective on chestnut tannin. New advanced applications will likely emerge shortly. [ABSTRACT FROM AUTHOR]

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p

We showed previously that gallic acid is produced in walnut from 3-dehydroshikimate by a shikimate dehydrogenase (JrSkDH). This study focuses on the next step in the hydrolysable tannin pathway, the formation of 1-O-galloyl-β-D-glucose from the phenolic gallic acid and UDP glucose by a glycosyltransferase. JrGGT1 (UGT84A73) and JrGGT2 (UGT84A74) are predicted to be two such glycosyltransferases, which we expressed in tobacco plants. GC-MS analysis of the transgenic tobacco revealed moderate, yet significant alterations in plant secondary metabolism, such as depleted phenolic acids, including gallic acid. We postulate that these effects are due to JrGGT1 and JrGGT2 activity, as JrGGT orthologs glycosylate these phenolic compounds in vitro. Moreover, JrGGT expression in tobacco caused upregulation of shikimic acid pathway metabolites and differing responses in phenylpropanoids, such as phenolic acids and flavonoids. In transcriptome analysis of walnut pellicle tissues, both JrGGTs showed substantial and significant expression correlations with the gallic acid-producing JrSkDHs and were highly coexpressed with the genetic circuits constituting the shikimic acid and phenylpropanoid biosynthetic pathways. Verification of JrGGT gene expression by transcriptome analysis of 20 walnut tissues revealed striking similarities with that of the pellicle data, with the greatest expression in roots, wood, buds, and leaves of Juglans regia cv. Chandler: tissues that typically accumulate hydrolysable tannins. Like the transgenic tobacco, pellicle metabolomic analyses revealed that many phenylpropanoids correlated negatively with JrGGT expression, while shikimic acid pathway metabolites correlated positively with JrGGT expression. This research supports the hypothesis that JrGGT1 and JrGGT2 play non-trivial roles in metabolism of phenolic acids, flavonoids, and ostensibly, tannins.

Food, feed and beverage processing brings tannins into contact with macromolecules, such as proteins and polysaccharides, leading to different chemical and physical interactions. The interactions of tannins with proteins are well known but less is known about the affinity of tannins to polysaccharides. We used bacterial cellulose from nata de coco as a model compound to investigate how tannins and cellulose interact by adsorption measurements using UPLC-DAD. We also explored how the structure of tannins influences these interactions. The model tannins included nine individual structurally different hydrolysable tannins (HTs) and eight well-defined proanthocyanidin (PA) fractions with different monomeric units, mean degree of polymerization and both A- and B-type linkages. Tannins were found to have both strong and weak interactions with bacterial cellulose, depending on the exact structure of the tannin. For HTs, the main structural features affecting the interactions were the structural flexibility of the HT molecule and the number of free galloyl groups. For PAs, prodelphinidins were found to have a higher affinity to cellulose than procyanidins. Similarly to HTs, the presence of free galloyl groups in galloylated PAs and the flexibility of the PA molecule led to a stronger interaction. Adsorption measurements by UPLC-DAD proved to be a sensitive and rapid tool to evaluate the affinity of tannins to cellulose. [ABSTRACT FROM AUTHOR]

Plant tannins are known for their anthelmintic and antiparasitic activities and have been increasingly studied to battle the ever-growing problem of anthelmintic resistance. While tannins have been shown to exhibit these activities on their own, one approach would be to use them as complementary nutrients alongside commercial anthelmintics. So far, research on the interactions between tannins and anthelmintics is limited, and few studies have reported both synergistic and antagonistic effects depending on the type of tannin and the method used. These interactions could either strengthen or weaken the efficacy of commercial anthelmintics, especially if tannin-rich diets are combined with anthelmintics used as oral drenches. To study these interactions, a series of hydrolysable tannins (HTs) was selected, and their direct interactions with thiabendazole (TBZ) were evaluated by isothermal titration calorimetry (ITC), which allowed the detection of the exothermic interaction but also the roles and significances of different structural features of HTs in these interactions. Our results show that HTs can have a direct interaction with the benzimidazole anthelmintic TBZ and that the interaction is strengthened by increasing the number of free galloyl groups and the overall molecular flexibility of HTs. [ABSTRACT FROM AUTHOR]

Non-isocyanate polyurethane (NIPU) foams from a commercial hydrolysable tannin extract, chestnut wood tannin extract, have been prepared to determine what chemical species and products are taking part in the reactions involved. This method is based on two main steps: the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine. The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions. The carbohydrate skeleton of the hydrolysable tannin is also able to participate through its hydroxyl groups to the same two reactions rendering the whole molecular complex able to react to form NIPUs. The analysis by Matrix-Assisted Laser Desorption Ionization (MALDI-TOF) mass spectrometry and 13C Nuclear Magnetic Resonance (13C NMR) to further investigate the reaction mechanisms involved revealed the unsuspected complexity of chestnut hydrolysable tannin, with different fragments reacting in different manners forming a hardened network of considerable complexity. As the morphology and performance of these types of foams changes slightly with the change in the amount of glutaraldehyde and hexamine hardeners, the best performing foam formulation previously determined was scanned by SEM and analysed chemically for the structures formed. [ABSTRACT FROM AUTHOR]

This study provided evidence that the inclusion of hydrolysable tannin (HT) in high soybean meal (SBM) diets improved growth performance and glycolipid metabolism of largemouth bass (Micropterus salmoides). In vivo , various levels of HT were added to high SBM diets and fed to largemouth bass (initial weight: 6.00 ± 0.03 g) for 56 days. Results showed that a high level of SBM led to the reduction in growth performance, as evidenced by decreased weight gain rate and impaired hepatic function. Dietary supplementation with HT (1.0 g/kg) improved growth performance of largemouth bass, accompanied by the enhancements in hepatic antioxidant capacity and glycolipid metabolism. In vitro , HT facilitated glucose utilization in hepatocytes and positively influenced the modulation of crucial genes within the PI3K/Akt signaling pathway. Conversely, administration of LY294002 (a PI3K inhibitor) reversed the detrimental effects observed in hepatocytes exposed to high glucose levels. Overall, incorporating HT (1.0 g/kg) into the diet enhanced liver health and improved the absorption and utilization of SBM in largemouth bass, potentially achieved through modulation of the PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

In order to study the metabolomic responses of rapeseed meal on grass carp and the role that tannin plays in those responses, grass carp were fed four diets for an eight week trial. Two were practical diets: FM diet contained 10% fishmeal without rapeseed meal, RM diet contained 50% rapeseed meal without fishmeal; the other two were semi-purified diets without (T0) or with 1.25% (T1) of supplemental hydrolysable tannin. The tannin content in the RM diet was close to that of T1. The rate of weight gain for RM was significantly lower than FM, while the feed conversion ratio in the T1 was significantly higher than T0. The muscle lipid and protein content was significantly lower and glycogen higher in the RM and T1 compared to the other treatments. The percent of muscle-saturated fatty acid (SFA) in the RM and T1 groups was significantly lower than FM and T0 groups, respectively, while the mono-unsaturated fatty acid (MUFA) in the RM group was significantly higher than FM. The hepatic activities of alanine aminotransferase and aspartate aminotransferase were lower and the hepatic glycogen and malonaldehyde were higher in the T1 and RM than the other treatments. The total serum protein, globulin, and triglycerides were significantly higher in T1 and RM; the alanine aminotransferase in the T1 was significantly higher than T0; and the aspartate aminotransferase in the RM and T0 groups were significantly higher than the other treatments. In a metabolomic assay, 29 differential metabolites were identified between T0 and T1, 23 metabolites were downregulated, and 6 metabolites were upregulated in T1 compared to T0. Ninety-two differential metabolites were identified between FM and RM, 31 metabolites were downregulated, and 61 metabolites were upregulated in RM compared to FM. These indicated that lipid utilization and carbohydrate metabolism might be improved, while the protein metabolism was suppressed by rapeseed meal. The abnormal protein and lipid metabolism may be partly caused by tannin in the rapeseed meal, as the tannin contained within the rapeseed meal seemed to bring different effects that the tannin additive.

The hydrolysable tannins from pomegranate peel have been known to exert several health benefits, majorly anti-diabetic properties. The study identified polyphenols present in pomegranate peel hydrolysable tannin (PPHT) and examined their physical stability at varying pH (2.0 – 8.0) and temperatures (4, 20 and 40 °C). PPHT showed stability at acidic pH, but conversely, it degraded at neutral and basic pH. Therefore, this work aimed to encapsulate hydrolysable tannins from pomegranate peel in the internal aqueous phase of W/O/W double emulsion. The study revealed that the double emulsion formulated with span 80-to-lecithin ratio of 1:1 (as lipophilic emulsifier) and gum Arabic concentration of > 2% (as hydrophilic emulsifier) increased the storage stability up to 60 days at ambient condition. In-vitro digestibility showed that PPHT was released from the double emulsion in the intestinal phase. Also, more than 3.75 times increase in the bioaccessibility was observed for encapsulated PPHT as compared to crude PPHT. Korsmeyer-Peppas model fitted best with the experimental data, indicating Fickian diffusion as the mechanism of PPHT release from the double emulsion. Furthermore, kinetic stability was observed for the double emulsion throughout the storage at pH 3.0 – 8.0 and at pasteurization temperatures (LTLT and HTST). Thus, these results facilitated the formulation of PPHT encapsulated double emulsion with enhanced bioaccessibility, storage and physical stability.

Food, feed and beverage processing brings tannins into contact with macromolecules, such as proteins and polysaccharides, leading to different chemical and physical interactions. The interactions of tannins with proteins are well known but less is known about the affinity of tannins to polysaccharides. We used bacterial cellulose from nata de coco as a model compound to investigate how tannins and cellulose interact by adsorption measurements using UPLC-DAD. We also explored how the structure of tannins influences these interactions. The model tannins included nine individual structurally different hydrolysable tannins (HTs) and eight well-defined proanthocyanidin (PA) fractions with different monomeric units, mean degree of polymerization and both A- and B-type linkages. Tannins were found to have both strong and weak interactions with bacterial cellulose, depending on the exact structure of the tannin. For HTs, the main structural features affecting the interactions were the structural flexibility of the HT molecule and the number of free galloyl groups. For PAs, prodelphinidins were found to have a higher affinity to cellulose than procyanidins. Similarly to HTs, the presence of free galloyl groups in galloylated PAs and the flexibility of the PA molecule led to a stronger interaction. Adsorption measurements by UPLC-DAD proved to be a sensitive and rapid tool to evaluate the affinity of tannins to cellulose.

Plant tannins are known for their anthelmintic and antiparasitic activities and have been increasingly studied to battle the ever-growing problem of anthelmintic resistance. While tannins have been shown to exhibit these activities on their own, one approach would be to use them as complementary nutrients alongside commercial anthelmintics. So far, research on the interactions between tannins and anthelmintics is limited, and few studies have reported both synergistic and antagonistic effects depending on the type of tannin and the method used. These interactions could either strengthen or weaken the efficacy of commercial anthelmintics, especially if tannin-rich diets are combined with anthelmintics used as oral drenches. To study these interactions, a series of hydrolysable tannins (HTs) was selected, and their direct interactions with thiabendazole (TBZ) were evaluated by isothermal titration calorimetry (ITC), which allowed the detection of the exothermic interaction but also the roles and significances of different structural features of HTs in these interactions. Our results show that HTs can have a direct interaction with the benzimidazole anthelmintic TBZ and that the interaction is strengthened by increasing the number of free galloyl groups and the overall molecular flexibility of HTs.

Abstract Background Food intake and eating behavior are two important risk factors that lead to obesity and other associated metabolic and reproductive disorders like polycystic ovarian syndrome (PCOS). Most of the phytonutrients like hydrolysable tannin (HT) have the ability to reduce the nutrient intake that might be a suitable remedy for weight management of females in their reproductive age. Therefore, the present research is aimed to find out the effect of HT on nutrient intake, weekly body weight, blood glucose, serum lipids, minerals, immunoglobulins and satiety hormones in PCOS rats. Materials and methods A total of forty five adult healthy female rats of 56 days old, weighed 135 ± 5 g with two consecutive estrous cycles were selected. In order to induce PCOS in rats, the intramuscular injection of 4 mg/rat/kg Estradiol- Valerate was used. After induction, a Complete Randomized Design was used to divide the rats into five equal groups (n = 9) named as Pc0, Pc0.5, Pc1, Pc1.5 and Pc2. The groups of rats were offered different doses of HT i.e. 0, 0.5, 1, 1.5 and 2 % respectively per kg body weight in solution form through oral gavage once in a day for 60 days. Results After the intake of different levels of HT, the statistical results had shown a significant decrease (p 0.05) was observed on serum protein and calcium levels. Conclusions The study concluded that HT had a therapeutical potential to decrease the nutrient intake and its anti-nutritional property could be used as remedy for the management of body weight, hyperglycemia, dyslipidemia and cardiovascular risk factors of PCOS rats.

A new hydrolysable tannin, ethyl castavaloninate (1), was isolated from the seeds of Quercus wutaishanica, along with nine known compounds, γ-tocopherol (2), ethyl brevifolincarboxylate (3), brevifolin (4), (–)-7,7′-dioxodihydroguaiaretic acid (5), (–)-pinoresinol (6), (–)-dihydrodehydrodiconiferyl alcohol (7), (+)-isolariciresinol (8), decarboxylated ellagic acid (9), and ellagic acid 4-O-xylopyranoside (10). The structure of 1 was determined by spectroscopic methods, including NMR, HR-ESI-MS, and IR spectra. This is the first report of compounds 2–10 from the genus Quercus. [ABSTRACT FROM AUTHOR]

The hydrolysable Tannin (HT) is one of the phenolic compounds extracted from different vegetables and plants. The study was planned to evaluate the effect of HT on the weekly body weight gain, nutrient intake and ovarian histopathology of the healthy female rats. The 45 female rats (135g±5g) were completely randomized into five groups i.e. HT0.5, HT1, HT1.5 and HT2 while HT0 was considered control group. The rats were offered different levels of HT 0.5,1, 1.5 and 2% in solution form through oral gavage method once in a day for six weeks. A significant decrease was observed (푃 = 0.05) in weekly body weight, nutrient intake and weight gain of healthy female rats. No effect on water intake was observed (푃 > 0.05). The histopathology showed a well defined primary and secondary follicles, corpora lutea and graffian follicles. In conclusion the HT has shown negative effect on the nutrient intake but it has shown positive effect in reducing body weight of animals while no prominent histopathological changes and no signs of inflammation, follicular atresia or no detrimental effects were observed on the structural integrity of the ovaries of healthy female rats. [ABSTRACT FROM AUTHOR]

The effects of dietary supplementation of tannins mix (quebracho and chestnut) in rabbit diet were evaluated for productive performances, health parameters and digestibility in order to quantify their practical utilisation in the rearing system. One-hundred and twenty Martini group hybrid rabbits of 30 days old were fed four different diets for 60 days. The diets were formulated as: basal diet (negative control, C), basal diet supplemented by 0.3% of tannins mix (T0.3), basal diet supplemented by 0.6% of tannins mix (T0.6) and basal diet supplemented with coccidiostat (positive control, CC). Live performances did not show any significant differences, moreover, no significant differences were observed for all carcase traits except for gastrointestinal tract (p = .015, lowest values for T0.3 diet). Also, digestibility of the feed and faecal microbial load was not influenced by tannins addition. Slight differences between the diets were detected in catalase and glutathione peroxidase concentrations in plasma, as a common trend was revealed with higher values of C than the other diets. From an economical point of view, T0.3 diet showed to be more profitable than CC and T0.6. Tannins addition might be taken into account as potential feed additive in rabbit feeds, as it does not affect negatively the productive performances, digestibility and induce a slight increase of antioxidant status.Highlights On an economical point of view tannin diet showed to be more profitable than a diet added with coccidiostat. Addition of tannins in rabbits’ feed did not affect negatively productive performances and digestibility. Tannins represent a valuable feed additive in rabbit farming as a slightly increase of antioxidant status was induced.

We showed previously that gallic acid is produced in walnut from 3-dehydroshikimate by a shikimate dehydrogenase (JrSkDH). This study focuses on the next step in the hydrolysable tannin pathway, the formation of 1-O-galloyl-β-D-glucose from the phenolic gallic acid and UDP glucose by a glycosyltransferase. JrGGT1 (UGT84A73) and JrGGT2 (UGT84A74) are predicted to be two such glycosyltransferases, which we expressed in tobacco plants. GC-MS analysis of the transgenic tobacco revealed moderate, yet significant alterations in plant secondary metabolism, such as depleted phenolic acids, including gallic acid. We postulate that these effects are due to JrGGT1 and JrGGT2 activity, as JrGGT orthologs glycosylate these phenolic compounds in vitro. Moreover, JrGGT expression in tobacco caused upregulation of shikimic acid pathway metabolites and differing responses in phenylpropanoids, such as phenolic acids and flavonoids. In transcriptome analysis of walnut pellicle tissues, both JrGGTs showed substantial and significant expression correlations with the gallic acid-producing JrSkDHs and were highly coexpressed with the genetic circuits constituting the shikimic acid and phenylpropanoid biosynthetic pathways. Verification of JrGGT gene expression by transcriptome analysis of 20 walnut tissues revealed striking similarities with that of the pellicle data, with the greatest expression in roots, wood, buds, and leaves of Juglans regia cv. Chandler: tissues that typically accumulate hydrolysable tannins. Like the transgenic tobacco, pellicle metabolomic analyses revealed that many phenylpropanoids correlated negatively with JrGGT expression, while shikimic acid pathway metabolites correlated positively with JrGGT expression. This research supports the hypothesis that JrGGT1 and JrGGT2 play non-trivial roles in metabolism of phenolic acids, flavonoids, and ostensibly, tannins.

This study evaluated the effects of hydrolysable tannin (HT) and condensed tannin (CT) on the bacterial community, fermentation quality, and proteolysis of alfalfa silage. Alfalfa was wilted to a dry matter (DM) of 35% fresh weight and ensiled with or without 4% HT or 4% CT. The application rates of tannins were based on fresh weight, and each treatment was ensiled in triplicate. After 60 d of fermentation, the CT-treated group had lower concentrations of ammonia nitrogen (NH3-N) and free amino acid nitrogen (AA-N), but greater lactic acid concentration, than those in the control and HT-treated silage (p < 0.05). Compared to the control group, the application of tannins increased the abundance of Pseudomonas (negatively correlated with aminopeptidases activity), and decreased the abundance of Pediococcus—which was positively correlated with aminopeptidases activity—and the concentrations of non-protein nitrogen (NPN), NH3-N, and AA-N. The application of HT decreased the abundance of Lactobacillus and increased the abundances of Enterococcus, while the opposite results were observed in the CT-treated group. The application of HT and CT reduced the proteolysis in treated silages, but the two were different in terms of their mechanism and their effects on the bacterial communities of the alfalfa silage.

We showed previously that gallic acid is produced in walnut from 3-dehydroshikimate by a shikimate dehydrogenase (JrSkDH). This study focuses on the next step in the hydrolysable tannin pathway, the formation of 1- O -galloyl-β-D-glucose from the phenolic gallic acid and UDP glucose by a glycosyltransferase. JrGGT1 (UGT84A73) and JrGGT2 (UGT84A74) are predicted to be two such glycosyltransferases, which we expressed in tobacco plants. GC-MS analysis of the transgenic tobacco revealed moderate, yet significant alterations in plant secondary metabolism, such as depleted phenolic acids, including gallic acid. We postulate that these effects are due to JrGGT1 and JrGGT2 activity, as JrGGT orthologs glycosylate these phenolic compounds in vitro. Moreover, JrGGT expression in tobacco caused upregulation of shikimic acid pathway metabolites and differing responses in phenylpropanoids, such as phenolic acids and flavonoids. In transcriptome analysis of walnut pellicle tissues, both JrGGT s showed substantial and significant expression correlations with the gallic acid-producing JrSkDH s and were highly coexpressed with the genetic circuits constituting the shikimic acid and phenylpropanoid biosynthetic pathways. Verification of JrGGT gene expression by transcriptome analysis of 20 walnut tissues revealed striking similarities with that of the pellicle data, with the greatest expression in roots, wood, buds, and leaves of Juglans regia cv. Chandler: tissues that typically accumulate hydrolysable tannins. Like the transgenic tobacco, pellicle metabolomic analyses revealed that many phenylpropanoids correlated negatively with JrGGT expression, while shikimic acid pathway metabolites correlated positively with JrGGT expression. This research supports the hypothesis that JrGGT1 and JrGGT2 play non-trivial roles in metabolism of phenolic acids, flavonoids, and ostensibly, tannins. [ABSTRACT FROM AUTHOR]

Tannin, an antinutritional component of plant proteins was fed to grass carp (Ctenopharyngodon idellus, 8. 18 ± 0.81 g) for 8 weeks to investigate their tolerance levels. Semi-purified diets (T0, T1, T2, and T3) with varying levels of hydrolysable tannin (0, 0.75, 1.25, and 1.75% respectively) were used. No significant difference was obtained in weight gain, while feed conversion ratio of T0 was significantly lower than T2. Muscle protein content of T0 and T3 were significantly higher than T2, while lipid content of T0 was significantly higher than other groups. Muscle and hepatic glycogen in T0 were significantly lower than other groups. Muscle saturated fatty acids in T3 were significantly higher than T0, and lowest in T1 and T2, while the poly-unsaturated fatty acids in T1 and T2 were higher than T0 and lowest in T3. Significant increases were obtained in trypsin and amylase activities as tannin levels increased, the lipase activity of T0 and T1 was significantly higher than T2 and T3. Activities of hepatic alanine aminotransferase and aspartate aminotransferase decreased with increasing tannin level. The total protein in serum of T2 was significantly higher than T0 and T1 and lowest in T3, whereas globulin of T2 was significantly higher than T0 and T3 and lowest in T1, while albumin of T1 was significantly higher than other groups. Urea nitrogen of T0 was significantly higher than other groups, triglyceride and total cholesterol significantly increased with tannin level and decreased in T3, significant decreases were obtained in low-density lipoprotein cholesterol and high-density lipoprotein cholesterol in T3. mRNA expression of intestinal TOR was significantly upregulated as dietary tannin increased. In hepatopancreas, the expression of glucokinase in T1 was significantly higher than T2, and lowest in T0 and T3, pyruvate kinase in T2 was significantly higher than T0 and T1 and lowest T3. The expression of lipoprotein lipase upregulated as tannin level and downregulated in T3, and fatty acid synthase downregulated as tannin level. In conclusion, grass carp could tolerate 1.75% dietary tannin without influencing growth. However, 1.25% tannin impaired digestion and metabolism of protein, decreased the deposition of lipid and promoted utilization of carbohydrate.

An on-farm experiment was conducted in order to evaluate effects of graded supplementation with chestnut tannin extract to cows in situations of excessive dietary protein supply on a low-input organic dairy farm. Respectively 10 Swiss Fleckvieh cows received twice per day 1 kg of experimental pellets containing either 0, 50 or 100 g/kg of chestnut extract (targeted at approximately 0, 5 and 10 g extract/kg of total dietary dry matter). Experimental feeding lasted for 21 days. Measurements and collection of milk, faeces and urine spot samples were performed in weeks 0 (baseline), 1 and 3. All cows were kept in one herd on pasture; fresh grass and grass hay were provided in the barn during night. Milk yield was recorded and cows wore sensor halters for recording chewing activity. In urine, total nitrogen and purine derivatives were measured; faeces were analyzed for protein, fibre and particle fractions; in milk, solid concentrations were determined. The data was analyzed with a general linear model. Cows did not show differences in general eating and rumination behaviour, but needed time to accept the tannin-containing pellets. Milk yield and composition were not affected by treatment, except for lactose content. No relevant differences between treatments were found for urinary and faecal parameters. In conclusion, although technically easy to supplement, pellets containing chestnut tannin extract were not readily accepted by the cows and effects on protein digestion and metabolism were not found. Successful on-farm application of chestnut extract in order to improve nitrogen efficiency therefore seems questionable. [ABSTRACT FROM AUTHOR]

A 56-d feeding trial was carried out to assess the effects of dietary hydrolysable tannin (HT) and condensed tannin (CT) on growth performance, whole body composition, digestive enzyme activities, serum metabolites, antioxidant and immune response, and intestinal and liver histomorphology of Chinese sea bass (Lateolabrax maculatus). Four diets were formulated to contain 0 (T1), 2 g/kg of CT (T2), 2 g/kg of HT (T3), and 1 g/kg of CT plus 1 g/kg of HT (T4). A total of 640 fish were randomly divided into 16 tanks with 4 tanks per diet. Results showed that the final body weight, weight gain rate and specific growth rate were ranked as T1 > T2 > T4 > T3 (P < 0.05). Feed conversion ratio was ranked as T1 < T4 < T2 < T3 (P < 0.05). Compared to T2, feed intake was higher (P < 0.05) in T1 but lower (P < 0.05) in T3 and T4, intestinal trypsin, lipase and amylase activities were higher (P < 0.05) in T1 but lower (P < 0.05) in T3, the total cholesterol and triacylglycerol were higher (P < 0.05) in T1 but lower (P < 0.05) in T3, the aspartate aminotransferase was lower (P < 0.05) in T1 but higher (P < 0.05) in T3, the serum total antioxidant capacity, superoxide dismutase and lysozyme were lower (P < 0.05) in T1 but higher (P < 0.05) in T3. Intestinal villus and hepatocyte in T2, T3, and T4 had different degrees of injury. The villus length was higher (P < 0.05) but the villus width was lower (P < 0.05) in T1 than those in other groups. In summary, dietary 2 g/kg of CT and HT inhibited digestion, induced intestinal and liver injury and reduced growth of L. maculatus. Compared to HT, CT had stronger growth-inhibiting effect and damage on fish, suggesting CT should be chosen carefully as dietary supplement in L. maculatus. ● This study is the first to compare effects of dietary condensed and hydrolysable tannins on Lateolabrax maculatus. ● Both condensed and hydrolysable tannins inhibited digestion and induced intestinal and liver injury. ● Condensed tannin had stronger growth-inhibiting effect and destructiveness to L. maculatus than hydrolysable tannin. [ABSTRACT FROM AUTHOR]

Valonea tannin is a natural product readily extracted from acorn shells that has been suggested to have potential skin whitening properties. This study investigated the tyrosinase inhibition activity of extracted valonea tannin and the associated structure–function activity. Nuclear magnetic resonance spectroscopy and molecular weight analysis with gel permeation chromatography revealed that valonea tannin could be characterized as a hydrolysable tannin with galloyl, hexahydroxydiphenoyl and open formed-glucose moieties and an average molecular weight of 3042 ± 15 Da. Tyrosinase inhibition assays demonstrated that valonea tannin was 334 times more effective than gallic acid and 3.4 times more effective than tannic acid, which may relate to the larger molecular size. Kinetic studies of the inhibition reactions indicated that valonea tannin provided tyrosinase inhibition through mixed competitive–uncompetitive way. Stern–Volmer fitted fluorescence quenching analysis, isothermal titration calorimetry analysis and in silico molecule docking showed valonea tannin non-selectively bound to the surface of tyrosinase via hydrogen bonds and hydrophobic interactions. Inductively coupled plasma-optical emission spectroscopy and free radical scavenging assays indicated the valonea tannin had copper ion chelating and antioxidant ability, which may also contribute to inhibition activity. These results demonstrated the structure–function activity of valonea tannin as a highly effective natural tyrosinase inhibitor that may have commercial application in dermatological medicines or cosmetic products.

The effects of dietary supplementation of tannins mix (quebracho and chestnut) in rabbit diet were evaluated for productive performances, health parameters and digestibility in order to quantify their practical utilisation in the rearing system. One-hundred and twenty Martini group hybrid rabbits of 30 days old were fed four different diets for 60 days. The diets were formulated as: basal diet (negative control, C), basal diet supplemented by 0.3% of tannins mix (T0.3), basal diet supplemented by 0.6% of tannins mix (T0.6) and basal diet supplemented with coccidiostat (positive control, CC). Live performances did not show any significant differences, moreover, no significant differences were observed for all carcase traits except for gastrointestinal tract (p =.015, lowest values for T0.3 diet). Also, digestibility of the feed and faecal microbial load was not influenced by tannins addition. Slight differences between the diets were detected in catalase and glutathione peroxidase concentrations in plasma, as a common trend was revealed with higher values of C than the other diets. From an economical point of view, T0.3 diet showed to be more profitable than CC and T0.6. Tannins addition might be taken into account as potential feed additive in rabbit feeds, as it does not affect negatively the productive performances, digestibility and induce a slight increase of antioxidant status. On an economical point of view tannin diet showed to be more profitable than a diet added with coccidiostat. Addition of tannins in rabbits' feed did not affect negatively productive performances and digestibility. Tannins represent a valuable feed additive in rabbit farming as a slightly increase of antioxidant status was induced. [ABSTRACT FROM AUTHOR]

Tannins are useful for many industrial applications owing to their strong chelating, antibacterial, and antioxidant properties. Hydrolysable tannins (HTs) are suitable for feed additives to replace antibiotics because of their low anti-nutritional effects. However, regulation of HT biosynthesis in plants remains largely unknown. Here, we found that the HTs are predominant phenols in Chinese cork oak (Quercus variabilis) and their contents in cupules were much higher than those in other tissues; simultaneously, the expression of UGT84A13 , a key gene for the first step of HT biosynthesis, was also high. RNA-seq analysis revealed 351 candidate genes whose expressions were correlated with UGT84A13 expressions and HT contents. Comprehensive analysis of the HD-Zip family identified subfamily I members— HB20 and HB26 —as candidate genes responsible for regulation of UGT84A13 expression and HT biosynthesis. Subcellular localization assays showed that both HD-Zip proteins were localized to the nucleus. Interestingly, HB20 and HB26 had distinct trans-activating domains. Y1H and luciferase assays finally confirmed that HB26, instead of HB20, interacted with UGT84A13 promoter and activated its expression. This study provides valuable data for different tissues of Q. variabilis and new insights into the transcriptional regulation of UGT84A13 and HT biosynthesis, thereby laying the foundation for molecular breeding and enhancement of HT biosynthesis. • Q. variabilis cupules are specifically enriched with hydrolysable tannins. • RNA-seq identified two HD-Zip genes potentially involved in HT biosynthesis. • HD-Zip I subfamily members, HB20 and HB26, have distinct trans-activating domains. • HB26 interacted with UGT84A13 promoter and activated its expression. [ABSTRACT FROM AUTHOR]

Three oligomeric hydrolysable tannins, coriariins K, L, and M, which were previously undescribed, together with five known hydrolysable tannins were isolated from dried leaves of Coriaria japonica . Their structures were determined based on 1D and 2D NMR spectroscopy, HR-ESI-MS, and ECD spectroscopy experiments. Among the isolated compounds, coriariin M has a unique trimer structure where both dehydrodigalloyl and valoneoyl group linkages were found between the hydrolysable tannin monomers. Dimeric hydrolysable tannins coriariins K and L, having a dehydrodigalloyl group as the linking unit, were structurally related to coriariin A, the main hydrolysable tannin of this plant species. Additionally, the complexation of the eight hydrolysable tannins isolated in this study with bovine serum albumin (BSA) to form water-soluble macromolecules was analyzed using native polyacrylamide gel electrophoresis (PAGE). A comparison of the behaviors of the oligomeric hydrolysable tannins suggested the participation of the hexahydroxydiphenoyl group and the importance of the molecular sizes of the hydrolysable tannins in the formation of macromolecules. [ABSTRACT FROM AUTHOR]

The fruit and hulls of the water caltrop (Trapa taiwanensis Nakai) are used as hepatoprotective herbal tea ingredients in Taiwan. The stability of hydrolysable tannins in herbal drinks has rarely been reported. In the present study, two hydrolysable tannins, tellimagrandin II (TGII) and 1,2,3,4,6-pentagalloylglucopyranose (PGG), were isolated from water caltrop hulls. The stability of the two compounds was evaluated by treatment with various pH buffer solutions, simulated gastric fluid and intestinal fluid, different temperatures, and photo-irradiation at 352 nm in different solvents. Results showed that TGII and PGG were more stable in a pH 2.0 buffer solution (with 91.88% remaining) and in a water solution with 352 nm irradiation (with 95% remaining). TGII and PGG were more stable in methanol or ethanol solutions (with >93.69% remaining) than in an aqueous solution (with

Phyllanthus debilis Klein ex Willd. is wild medicinal plant used in the traditional system of medicine. This plant has been actively used for hepatoprotection and to cure many diseases including jaundice and so on; which leads to complete extinction of this particular species. Therefore, the chitosan mediated cost effective cell suspension method has been developed for the production of hydrolysable tannin. The hydrolysable tannins are the main therapeutically active constituents with antioxidant, anticancer, and antimicrobial properties. An in vitro cell suspension culture was optimized by adding chitosan for production of hydrolysable tannin. According to the growth kinetics, a maximum biomass of 4.46 ± 0.06 g fresh cell weight and 1.33 ± 0.04 g dry cell weight were obtained from the optimal suspension medium consisted of MS medium + 0.5 mg L −1 BAP + 1.5 mg L −1 NAA. Chitosan was treated at the stationary phase which leads to the highest accumulation of hydrolysable tannin compared to the untreated control. Hydrolysable tannin was observed and compared using HPLC at the Rt of 4.91 in both chitosan treated and untreated cells. This is the first ever report where use of chitosan has been done to enhance the production of the hydrolysable tannin in P. debilis using cell suspension culture technique. [ABSTRACT FROM AUTHOR]