Effect of vernonia amygdalina aqueous extract on INS-1 cell line under glucose stimulation

Abstract

Vernonia amygdalina (VA) is one of the most popular herbs in treatment of diabetes. Nevertheless, it is lack of scientific evidence of VA aqueous extract on pancreatic β-cells in vitro in case of high glucose stress. Hence, this study at first examined the cytotoxic of VA extract on INS-1 cell line, that gave an outcome IC50=662.3μg/mL. Thereafter, a concentration of the extract was counted to examine its effect of reactive oxygen species (ROS) signaling on nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway under glucotoxicity. The results showed that there was no significant change in expression of Nrf2 during fluctuating high glucose stress but a remarkably rise in NAD(P)H quinone dehydrogenase 1 (Nqo1) mRNA (P<0.05). On the other hand, no increase in insulin secretion under glucose stimulation was observed. This finding proposed an ability of VA aqueous extract to stimulate expression of cellular scavenging ROS enzyme, rescue pancreatic β-cells from oxidative stress and protect the cells during chronic high glucose condition. KEYWORDS Vernonia amygdalina, Diabetes, INS-1 cell line