Yong Chen

The aim of this study was to investigate the protective effects and potential mechanisms of Tetrahydrocurcumin (THC) on methionine–choline-deficient diet (MCD)-induced MASH in C57BL/6 mice by using multi-omics techniques. The C57BL/6 mice were fed with the MCD for 8 weeks to establish a MASH model, while THC (100 mg·kg⁻¹·d⁻¹) and obeticholic acid (6.5 mg·kg⁻¹·d⁻¹) were administered via gavage to the THC group and the positive control group, respectively. The biochemical indexes of the serum and liver were detected using kits. Liver tissue sections were taken to observe the pathomorphological changes. Serum lipid and bile acid contents were measured via LC-MS, and the changes in ileal intestinal flora were detected by 16S rDNA high-throughput sequencing technology. The results revealed that THC significantly attenuated oxidative stress and lipid accumulation in NCTC-1469 cells and relieved hepatic injury and oxidative stress, reduced hepatic TG content, and improved hepatic steatosis in mice. THC alleviated 34 lipid abnormalities caused by the MCD; increased the abundance and diversity of intestinal flora, the ratio of Firmicutes to Bacteroidota, and the abundance of the probiotic (Verrucomicrobiota, Christensenellaceae, Akkermansiaceae, Lachnospiraceae, Desulfovibrionaceae); and reduced the abundance of obesity-associated pathogenic flora such as Firmicutes. Bile acid analysis showed that THC administration reduced the levels of serum toxic bile acid 7-KDCA and CA. In addition, RT-qPCR studies showed that THC down-regulated the transcript levels of the hepatic lipogenesis-related genes Srebp1c, Acc1, Scd1, and Fas, and up-regulated the transcript levels of the hepatic bile acid secretion-related genes Mrp2 and Bsep. The above results suggest that THC may alleviate MCD-induced MASH by downregulating liver Srebp1c, Acc1, Scd1, and Fas levels to inhibit lipid synthesis, upregulating Mrp2 and Bsep levels to regulate serum toxic BA levels, up-regulating the abundance of intestinal probiotic flora, and down-regulating the abundance of intestinal harmful bacterial flora. The multi-omics findings from the above study identified potential new mechanisms by which THC alleviates MASH, providing new reference targets for the development of anti-MASH drugs. These results also offer a basis for screening clinical diagnostic biomarkers for MASH and provide new directions for personalized diagnosis and treatment.

With the increasing prevalence of insomnia-related diseases, the effective treatment of insomnia has become an important health research topic. Lavender (Lavandula angustifolia Mill.) essential oil (LEO) is a commonly used medicine for the treatment of insomnia and neurological disorders. However, neither the active components nor its sedative–hypnotic mechanism have been fully discovered. This study aimed to screen the main active terpenes and discover the possible mechanism of LEO through network pharmacology in the treatment of insomnia-related diseases, as well as to verify our hypothesis in insomnia mice. The results showed that, in LEO’s 15 potential active ingredients, beta-myrcene had strong sedative–hypnotic effects through the serotonergic synaptic pathway according to the network pharmacological prediction. Further, PCPA(DL-4-chlorophenylalanine)-induced insomnia mice were treated with beta-myrcene for one day or seven days. The quiet state of insomnia mice was increased effectively, and the hypnotic effect was enhanced by anaobarbital sodium by prolonging sleep duration, decreasing sleep latency, and increasing the rate of falling asleep. Beta-myrcene reduced the damage to hypothalamic neuron cells induced by PCPA and increased neurotransmitter levels of GABA, 5-HT, and Glu in the serum and hypothalamus of insomnia mice. Meanwhile, beta-myrcene exerted an improvement in insomnia by upregulating relevant genes and protein expression in the serotonergic synaptic pathway. These results support the merit of the sedative–hypnotic activity of LEO. Beta-myrcene, a terpene in LEO, may be the main source of its sedative–hypnotic properties. It may serve as a good potential compound in future clinical studies on coping with insomnia.

Non-alcoholic fatty liver disease (NAFLD) has emerged as the leading cause of chronic liver disease worldwide. Caspase 8 and FADD-like apoptosis regulator (CFLAR) has been identified as a potent factor in mitigating non-alcoholic steatohepatitis (NASH) by inhibiting the N-terminal dimerization of apoptosis signal-regulating kinase 1 (ASK1). While arginine methyltransferase 1 (PRMT1) was previously reported to be associated with increased hepatic glucose production, its involvement in hepatic lipid metabolism remains largely unexplored. The interaction between PRMT1 and CFLAR and the methylation of CFLAR were verified by Co-IP and immunoblotting assays. Recombinant adenoviruses were generated for overexpression or knockdown of PRMT1 in hepatocytes. The role of PRMT1 in NAFLD was investigated in normal and high-fat diet-induced obese mice. In this study, we found a significant upregulation of PRMT1 and downregulation of CFLAR after 48h of fasting, while the latter significantly rebounded after 12h of refeeding. The expression of PRMT1 increased in the livers of mice fed a methionine choline-deficient (MCD) diet and in hepatocytes challenged with oleic acid (OA)/palmitic acid (PA). Overexpression of PRMT1 not only inhibited the expression of genes involved in fatty acid oxidation (FAO) and promoted the expression of genes involved in fatty acid synthesis (FAS), resulting in increased triglyceride accumulation in primary hepatocytes, but also enhanced the gluconeogenesis of primary hepatocytes. Conversely, knockdown of hepatic PRMT1 significantly alleviated MCD diet-induced hepatic lipid metabolism abnormalities and liver injury in vivo, possibly through the upregulation of CFLAR protein levels. Knockdown of PRMT1 suppressed the expression of genes related to FAS and enhanced the expression of genes involved in FAO, causing decreased triglyceride accumulation in OA/PA-treated primary hepatocytes in vitro. Although short-term overexpression of PRMT1 had no significant effect on hepatic triglyceride levels under physiological conditions, it resulted in increased serum triglyceride and fasting blood glucose levels in normal C57BL/6J mice. More importantly, PRMT1 was observed to interact with and methylate CFLAR, ultimately leading to its ubiquitination-mediated protein degradation. This process subsequently triggered the activation of c-Jun N-terminal kinase 1 (JNK1) and lipid deposition in primary hepatocytes. Together, these results suggested that PRMT1-mediated methylation of CFLAR plays a critical role in hepatic lipid metabolism. Targeting PRMT1 for drug design may represent a promising strategy for the treatment of NAFLD.

This study was aimed to clarify the effect of honokiol (Hon) on the activity of Cytochrome P450 (CYP450) enzymes, and the level of mRNA expression of liver and kidney transporters in type 2 diabetic rats induced by high-fat diet and strepotozotocin. Rats were randomly divided into normal control (NC) group, diabetic control (DC) group and Hon groups (n = 6). The activities of hepatic CYP1A2, CYP2E1, CYP2C, CYP2B, CYP3A and CYP4A, and the mRNA expression levels of hepatic and renal transporters, were determined. Compared to the NC group, the activities of CYP1A2, CYP2E1, CYP4A and CYP2C in DC group were increased by 2.36-, 2.10-, 2.55- and 1.86-fold, respectively. The mRNA expression levels of hepatic Oat2, Oatp2b1 and Oatp1a5, and renal Oct1, Octn2, Oatp2b1 and Oatp1a5, were significantly down-regulated, while the mRNA expression levels of hepatic Octn2, Oatp3a1, Oatp1a1 and Mdr2, and renal Oat2, Mrp4 and Bcrp, were significantly upregulated. Compared to the DC group, Hon treatment significantly inhibited the activity of hepatic CYP2E1, CYP4A, 3A and CYP1A2 by 45.6%, 29.2%, 22.7% and 20.7% in Hon high dose group, respectively. Moreover, Hon treatment significantly inhibited the mRNA expression levels of renal Bcrp and Mrp4 by 2.63-fold and 1.54-fold, while significantly upregulated the mRNA expression levels of hepatic Oat2 and Oatp2b1 by 1.52-fold and 1.54-fold in Hon high dose group, respectively. The results suggested that under the diabetes condition, the changes of CYP450 activity and transporter expression inevitably interfere the normal transport, metabolism and efficacy of drugs. The present work firstly reported that Hon treatment ameliorated the abnormal change of hepatic CYP activity (including CYP2E1, CYP4A and CYP1A2) and the transporter mRNA expression (including hepatic Oat2 and Oatp2b1, renal Bcrp and Mrp4) in type 2 diabetic rats induced by high-fat diet and strepotozotocin, which are associated with the occurrence and development of diabetes.