Bile-processed coptidis rhizoma water extract alleviates insulin resistance induced by glucosamine in HepG2 cells by activating the PI3K/AKT/FoxO1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Coptis chinensis, a traditional Chinese herb, has demonstrated potential therapeutic effects against IR and T2DM. Pig bile is the gallbladder bile extracted from the domestic pig, Sus scrofa domestica Brisson. The "Compendium of Materia Medica" documents that it is primarily used to treat conditions such as typhoid fever, heat-induced thirst, bone heat, extreme fatigue, and diabetes. The traditional way of making Bile-processed Coptidis Rhizoma (BRC), which is a processed form of Coptis chinensis(RC) using pig bile. Processing Coptis chinensis with bile aligns with the traditional Chinese medicine processing principles of "mutual reinforcement through combination" and "enhancing cold properties with cold ingredients." Furthermore, this method represents a unique technique within traditional Chinese medicine. Nevertheless, the pharmacological mechanisms behind bile-processed Coptis chinensis in treating type 2 diabetes mellitus (T2DM)necessitate further investigation.

AIM OF THE STUDY: In traditional Chinese medicine, diabetes is known as "Xiao Ke," considered a heat syndrome. Both Coptis and bile have records of treating "Xiao Ke" in ancient texts, and we believe that bile-processed Coptis can combine the hypoglycemic properties of both, enhancing the treatment of diabetes. The point of this study was to look into how BRC water extract affects glucosamine-induced insulin resistance in HepG2 cells.

MATERIALS AND METHODS: UPLC-QQQ-MS quantified the alkaloids and bile acids in BRC and RC. Cell viability was assessed using the CCK-8 assay. Insulin-resistant HepG2 (IR-HepG2) cells were established via 24-h incubation with 9 mM glucosamine. Glucose consumption and glycogen content were measured after BRC treatment (25-100 μg/mL). Periodic Acid-Schiff (PAS) staining was used to look for glycogen, and Oil Red O staining was used to look for lipid buildup. Quantitative real-time PCR (qRT-PCR) and Western blotting were used to look at the levels of gene and protein expression.

RESULTS: After processing, the content of some alkaloids was significantly increased. BRC treatment increased the amount of glucose used by IR-HepG2 cells (p < 0.01), raised the amount of glycogen in cells (p < 0.01), and decreased the production of lipids. Mechanistically, BRC increased the phosphorylation and total protein levels of PI3K/AKT/FOXO1 in IR-HepG2 cells (p < 0.01), leading to a decrease in the expression of glucose-6-phosphatase (G6Pase) in IR-HepG2 cells (p < 0.01).

CONCLUSION: By starting up the PI3K/AKT/FOXO1 signaling pathway, BRC helps HepG2 cells that are insulin-resistant because of glucosamine. This returns glycolipid metabolic homeostasis. These results back up the traditional use of processing bile to make Coptis chinensis work better as an anti-diabetic.