P4HB and type 2 diabetes mellitus: Rats treated with FSE (217.11 ± 2.36 mg/dL), trigonelline (275.13 ± 24.88 mg/dL), and diosgenin (218.32 ± 37.9 mg/dL) showed significant reduction in glucose levels as compared to T2DM group (506.94 ± 7.06 mg/dL). T2DM rats showed two- to threefold increase in ER chaperones Bip, protein disulfide isomerase (PDI), as well as ER stress-related proapoptotic markers CHOP, Caspase12, and Caspase3 in the liver, and increased lipid peroxidation (LPO) and decreased antioxidant levels.