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BACKGROUND: Microplastics (MPs) are small particles of plastic (≤5 mm in diameter). In recent years, oral exposure to MPs in living organisms has been a cause of concern. Leaky gut syndrome (LGS), associated with a high-fat diet (HFD) in mice, can increase the entry of foreign substances into the body through the intestinal mucosa. OBJECTIVES: We aimed to evaluate the pathophysiology of intestinal outcomes associated with consuming a high-fat diet and simultaneous intake of MPs, focusing on endocrine and metabolic systems. METHODS: C57BL6/J mice were fed a normal diet (ND) or HFD with or without polystyrene MP for 4 wk to investigate differences in glucose tolerance, intestinal permeability, gut microbiota, as well as metabolites in serum, feces, and liver. RESULTS: In comparison with HFD mice, mice fed the HFD with MPs had higher blood glucose, serum lipid concentrations, and nonalcoholic fatty liver disease (NAFLD) activity scores. Permeability and goblet cell count of the small intestine (SI) in HFD-fed mice were higher and lower, respectively, than in ND-fed mice. There was no obvious difference in the number of inflammatory cells in the SI lamina propria between mice fed the ND and mice fed the ND with MP, but there were more inflammatory cells and fewer anti-inflammatory cells in mice fed the HFD with MPs in comparison with mice fed the HFD without MPs. The expression of genes related to inflammation, long-chain fatty acid transporter, and Na+/glucose cotransporter was significantly higher in mice fed the HFD with MPs than in mice fed the HFD without MPs. Furthermore, the genus Desulfovibrio was significantly more abundant in the intestines of mice fed the HFD with MPs in comparison with mice fed the HFD without MPs. Muc2 gene expression was decreased when palmitic acid and microplastics were added to the murine intestinal epithelial cell line MODE-K cells, and Muc2 gene expression was increased when IL-22 was added. DISCUSSION: Our findings suggest that in this study, MP induced metabolic disturbances, such as diabetes and NAFLD, only in mice fed a high-fat diet. These findings suggest that LGS might have been triggered by HFD, causing MPs to be deposited in the intestinal mucosa, resulting in inflammation of the intestinal mucosal intrinsic layer and thereby altering nutrient absorption. These results highlight the need for reducing oral exposure to MPs through remedial environmental measures to improve metabolic disturbance under high-fat diet conditions. [ABSTRACT FROM AUTHOR]

Malignant melanoma is a fatal cancer. Signal transducer and activator of transcription 3 (STAT3) has been proposed as a therapeutic target of melanoma. An herbal formula Huai-Hua-San (HHS) comprising Sophorae Flos (SF) and Gardeniae Fructus (GF) is traditionally used for treating cancers including melanoma, but the pharmacological basis is unknown. This study aimed to investigate the anti-melanoma effects of an ethanolic extract of HHS (HHSE), and explore the involvement of STAT3 signaling in the effects. An UPLC-TOF/MS method was developed to control the quality of HHSE. A B16F10 allograft mouse model and three melanoma cell lines (B16F10, A375 and A2058) were used to determine the anti-melanoma effects of HHSE. Dacarbazine (DTIC) and Stattic were used as positive controls. Cell viability was detected using MTT and crystal violet staining assays. Cell apoptosis was analyzed by flow cytometry after the cells were stained with Annexin-V/PI. Cell invasive ability was examined using the transwell assay. Protein levels were determined by Western blotting. The contents of crocin I, crocin II, quercetin and kaempferol in HHSE were 0.59%, 0.98%, 4.66% and 1.15%, respectively. A clinically relevant dose of HHSE (0.1 g/kg/day, i.g. for 15 consecutive days) significantly suppressed B16F10 tumor growth in mice. HHSE dose-dependently reduced cell viability and dampened invasion of, and induced apoptosis in, melanoma cells. Mechanistic studies revealed that HHSE inhibited the phosphorylation/activation of STAT3 in B16F10 allografts and in cultured melanoma cells. In cell models, HHSE also inhibited the phosphorylation of STAT3 upstream kinases, JAK2 (Tyr1007/1008) and Src (Tyr416), lowered STAT3 nuclear levels, and down-regulated the protein levels of STAT3-targeted molecules. Over-activation of STAT3 in A375 cells significantly attenuated the cytotoxic effects of HHSE. HHSE exhibits anti-melanoma effects in cell and mouse models. Inhibition of STAT3 signaling contributes to the anti-melanoma mechanisms of HHSE. Our findings lay a groundwork for developing HHSE as a modern agent for melanoma management, and provide pharmacological justifications for the traditional use of HHS in treating melanoma. Image 1 [ABSTRACT FROM AUTHOR]

Si-Jun-Zi-Tang (SJZT) is a traditional Chinese medicine formula used to treat chronic and debilitating diseases including melanoma. SJZT-based therapies have achieved good clinical outcomes in melanoma management. However, the pharmacological basis of SJZT for its clinical use in melanoma treatment is not fully understood. To investigate the anti-melanoma effects and mechanism of action of an ethanolic extract of SJZT. SJZT was extracted using 50% ethanol. A murine B16 melanoma-bearing mouse model was employed to investigate the anti-melanoma effects of SJZT. microRNA (miRNA) and mRNA levels were examined by RT-qPCR, and protein levels were measured by Western blotting. SJZT significantly inhibited B16 tumor growth in mice. Mechanistic investigations revealed that SJZT elevated miR-34b (a tumor suppressing miRNA), and lowered c-Met (a miR-34b target gene) and β-catenin (a downstream molecule of c-Met signaling) expression levels in the B16 tumors. In this study we found, for the first time, that SJZT exerts anti-melanoma effects and regulates the miR-34b/c-Met/β-catenin pathway in a melanoma mouse model. Our findings provide pharmacological justifications for the clinical use of SJZT in treating melanoma. Image 1 • An ethanolic extract of Si-Jun-Zi-Tang , a traditional Chinese medicine formula, suppresses B16 melanoma growth in mice. • Si-Jun-Zi-Tang regulates the miR-34b/c-Met/β-catenin pathway in B16 tumors. • This study provides pharmacological justifications for the traditional use of Si-Jun-Zi-Tang in treating melanoma. [ABSTRACT FROM AUTHOR]

Gastritis can lead to ulcers and the development of gastric cancer. The rhizome of Atractylodes macrocephala Koidz. (Asteraceae), a traditional Chinese medicinal herb, is prescribed for the treatment of gastric disorders, hepatitis and rheumatism. Its bio-active compounds are considered to be particularly effective in this regard. However, the molecular processes of the herb's anti-inflammatory activity remain obscure. This study elucidates a mechanism upon which an ethanolic extract of this herb (Am-EE) exerts anti-inflammation effects in RAW264.7 macrophage cells (RAW cells) stimulated by lipopolysaccharide (LPS) treatment and HCl Ethanol-stimulated gastritis rats. To investigate the anti-gastritis activities of Am-EE and explore the mode of action. Ethanol (95%) was used to prepare Am-EE. The quality of the extract was monitored by HPLC analysis. The in vivo effects of this extract were examined in an HCl Ethanol-stimulated gastritis rat model, while LPS-stimulated RAW cells were used for in vitro assays. Cell viability and nitric oxide (NO) production were observed by MTT and Griess assays. Real-time PCR was used to examine mRNA expression. The PGE 2 ELISA kit was employed to detect prostaglandin E 2 (PGE 2). Enzyme activities and protein contents were examined by immunoblotting. Luciferase reporter gene assays (LRA) were employed to observe nuclear transcription factor (NF)-κB activity. The SPSS (SPSS Inc., Chicago, Illinois, United States) application was used for statistical examination. HPLC analysis indicates that Am-EE contains atractylenolide-1 (AT-1, 1.33%, w/w) and atractylenolide-2 (AT-2, 1.25%, w/w) (Additional Figure. A1). Gastric tissue damage (induced by HCl Ethanol) was significantly decreased in SD rats following intra-gastric application of 35 mg/kg Am-EE. Indistinguishable to the anti-inflammation effects of 35 mg/kg ranitidine (gastric medication). Am-EE treatment also reduced LPS-mediated nitric oxide (NO) and prostaglandin E 2 (PGE 2) production. The mRNA and protein synthesis of inducible cyclooxygenase (COX)-2 and NO synthase (iNOS) was down-regulated following treatment in RAW cells. Am-EE decreased NF-κB (p50) nuclear protein levels and inhibited NF-κB-stimulated LRA activity in RAW cells. Lastly, Am-EE decreased the up-regulated levels of phosphorylated IκBα and Akt proteins in rat stomach lysates and in LPS challenged RAW cell samples. Our study illustrates that Am-EE suppresses the Akt/IκBα/NF-κB pathway and exerts an anti-inflammatory effect. These novel conclusions provide a pharmacological basis for the clinical use of the A. macrocephala rhizome in the treatment and prevention of gastritis and gastric cancer. [Display omitted] [ABSTRACT FROM AUTHOR]

To better understand the link between fatty acid signaling and the pleiotropic effects of fatty acids in the pancreatic beta-cell, we investigated whether fatty acids regulate immediate-early response genes (IEGs) coding for transcription factors implicated in cell proliferation, differentiation, and apoptosis. Palmitate and oleate, but not long-chain polyunsaturated fatty acids, caused a pronounced accumulation of c-fos and nur-77 mRNAs in beta-cells (INS cells) to an extent similar to that produced by the protein kinase C (PKC) activator phorbol myristate acetate (PMA). The effect was dose dependent and occurred at concentrations between 0.1 and 0.5 mmol/l in the presence of 0.5% albumin. The action of the fatty acid occurred at the transcriptional level, and the mRNA accumulation displayed a bell-shaped kinetics with a maximal effect at 1 h. 2-Bromopalmitate was ineffective, indicating that fatty acids must be metabolized to cause their effect. Neither fatty acid was able to induce c-fos and nur-77 in PKC-downregulated cells or cells incubated in the presence of the Ca2+ channel blocker nifedipine or the Ca2+ chelator EGTA, suggesting involvement of the PKC and Ca2+ signaling pathways. Palmitate and oleate also increased c-fos protein expression and DNA binding activity of the transcription factor AP-1. Oleate, but not palmitate, increased [3H]thymidine incorporation in INS cells. Finally, both palmitate and oleate caused c-fos and nur-77 mRNA accumulation in isolated rat islets. It is suggested that IEG induction by the most abundant circulating fatty acids plays a role in the adaptive process of the beta-cell to hyperlipidemia. These results have implications for our understanding of obesity-associated diabetes and the link between fatty acids and tumorigenesis. [ABSTRACT FROM AUTHOR]

Image 1 [ABSTRACT FROM AUTHOR]