Phytochemical Screening and Antidiabetic Potential of Paeonia emodi in Alloxan-Induced Diabetic Rats: Investigative...

Paeonia emodi has long been used in folk medicine to treat a variety of ailments, including diabetes, skin disorders, dropsy, cuts, wounds, ulcers, fever, and blood disorders, etc., which are generally categorized under the complications of diabetes mellitus. Various species of this genus have also been verified to possess strong anti-diabetic activity. In this context, the current study was designed to investigate the antidiabetic potential to confirm the purported traditional use of P. emodi . Different solvent fractions of P. emodi, i.e., crude methanolic extract (Pe.Cr), n-hexane (Pe.Hex), chloroform (Pe.Chf), ethyl acetate (Pe.EtAc), butanol (Pe.Bt) and aqueous (Pe.Aq) were used for in vitro studies against α-glucosidase, α- amylase, dipeptidyl peptidase-4 (DPP-4), and protein tyrosine phosphatase 1B (PTP-1B) using a spectrophotometer and microplate reader. Among all fractions, Pe.Bt had the most prominent activity and was subjected to GC-MS analysis, in vivo anti-diabetic, pancreas protective, and hepatoprotective studies in alloxan-induced diabetes rats. The animals administered with alloxan (except group1) having FBGL higher than 220 mg/dL were selected and placed in different groups. The first group, which served as a normal control, received normal saline. The second group received a 5% tween-80 suspension, which served as diabetic control. The 3rd, 4th and 5th groups were administered Pe.Bt at the doses of 150, 300, and 500 mg/kg body weight, respectively, through oral gavage. Group six received metformin 50 mg/kg and served as the standard group. Fasting Blood glucose level (FBGL) was checked for 21 days. Liver function tests, insulin level, hepatoprotection, and pancreas protection study were investigated. The α-glucosidase was inhibited effectively by Pe.Bt with an IC₅₀ value of 626 μg/mL. The antioxidant activities also substantiated the excellent inhibitory potential of Pe.Bt. The IC₅₀ value of Pe.Bt against DPPH and ABTS was figured out to be 77 and 139 μg/mL, respectively, which was relatively comparable with ascorbic acid. Similarly, Pe.Bt was found active against PTP-1B and showed a moderate effect against DPP4 with IC₅₀ of 45.13 and 92.45, respectively. In the time frame of 21 days, the metformin and Pe.Bt significantly decreased FBGL on the 21st day to 108 and 96 mg/dL, respectively. Similarly, rats treated with Pe.Bt (500 mg/kg) significantly lowered the level of alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and increased total protein level (TP) in comparison with the diabetic control group. The histopathological study revealed that rats treated with Pe.Bt (500 mg/kg) have a remarkable ameliorative effect on liver and pancreas histological architecture as compared to the diabetic control group. The findings of the current investigations indicated that Pe.Bt possesses strong anti-diabetic, hepatoprotective, anti-oxidant properties and alleviates alloxan-induced pancreatic damage in diabetic rats.