GLP1R and diabetes mellitus: When studying the mechanism of berberine in the treatment of diabetes, a study has already pointed out that berberine can promote insulin secretion, improve insulin resistance and inhibit pancreatic islet β cell dysfunction (He Q. et al., 2022), Meanwhile, a study has also confirmed that berberine promotes the secretion of GLP-1 by L cell in intestinal tissue, while activating GLP-1R and the phosphorylation of PKA through endocrine pathways (Sun S. et al., 2022).