In vivo antidiabetic and antioxidant potential of Psychotria dalzellii in streptozotocin-induced diabetic rats

Abstract

Psychotria species have been known forwide array of health benefits as per traditional knowledge and only a few \nscientific evidences are available. In the current study in vivo antidiabetic property of methanol extract of \nPsychotria dalzellii (MEPD) was elucidated in alloxan-induced type 1 diabetes in Wistar rats. MEPD, acetone \nand ethylacetate extractswere examined for potential anti-diabetic properties (α-amylase and α-glucosidase inhibition) \nin in vitro and the significantly potent extract – MEPD was analyzed for in vivo antioxidant activity. \nBlood glucose levels, TBARS, antioxidant, creatinine, alkaline phosphatase etc., were measured. Results of the \nstudy revealed that, oral intubation of 400 mg kg−1b.w. of MEPD for a period of 20 days prior inducing diabetes \nresulted in the normalization of blood glucose level (259.83±10.11 mg/dL as opposed to induced 389.5±8.97; \nhealthy animals had 129.16 ± 4.12 mg/dL glucose) suggesting the antidiabetic potency of MEPD. Biochemical \nanalysis substantiated the antidiabetic property of MEPD as revealed by normalization of altered TBARS/oxidant \nand antioxidant levels. Results were further substantiated by in vitro studies, where MEPD exhibited good antioxidant \nactivity – reducing power activity (IC50–8.81 U/mg vs Ascorbic acid – 6.21 U/mg;MEPD); hydrogen peroxide \nactivity (IC50−26.57 μg/mL vs Ascorbic acid 19.12 μg/mL); MEPD inhibited α-amylase and α-glucosidase \nactivity with (IC50 47.11±2.8 μg/mL vs Acarbose – IC50 40.86±1.7 μg/mL); (IC50 40.34±1.2 μg/mL vs Acarbose \n– IC50 40.99±2.3 μg/mL); providing evidence for the first time for the antidiabetic property of P. dalzellii. The potent \nanti-type I diabetic property could be due to antioxidant and inhibition of α-glucosidase/amylase which results \nin control of release of glucose levels into the circulation. Phytochemical analysis of revealed that MEPD is \nenriched in phenolics and flavonoids compound. In order to understand its probable mechanism of action, antioxidant \nstatus during healthy, diabetic and sample treated groups of animals were also investigated.