Amelioration of altered adipokines expression and serine/threonine phosphorylation of IRS1 in alloxan-induced diabetes by Potentilla fulgens and its phytochemical constituents

Abstract

The present study is aimed at investigating the modulation of serine/threonine phosphorylation of IRS1 and the gene expression oftotal IRS1 and adipokines including TNF-α, IL-6 and adiponectin by the plant Potentilla fulgens and its phytochemical constituents catechin and (-)-epicatechin. Alloxan-induced diabetic mice with a two-to three-fold increase in their blood glucose levels were taken for the study. The level of protein expression of total (tIRS1), tyrosine (pIRS1), and serine phosphorylated IRS1 (pIRS1 ser307) was analysed by western blot, and the gene expression level of tIRS1, IL-6, TNF-α, and adiponectin was analysed by real-time PCR. Since evidences strongly suggest that adiponectin, TNF-α, and IL-6 are implicated in insulin resistance and type 2 diabetes, therefore these three adipokines have been targeted in our study with an aim to investigate the anti-inflammatory and antidiabetic effects of our plant Potentillafulgens(PF) andits phytochemicals. The results strongly demonstrates the capability of PF and its phytochemicals to modulate the ser/thr phosphorylation state of IRS1 by downregulating the serine 307 phosphorylation while simultaneously upregulating the tyrosine phosphorylation of IRS1. The results also indicate the ability of the same to alleviate inflammation in alloxan induced diabetes by modulating the expression of the insulin sensitizing hormone adiponectin and the pro-inflammatory cytokines L-6 and TNF-α.