In vitro study on glucose uptake and insulin stimulating properties of Pluchea Indica (L.) less.

Abstract

Insulin resistance and pancreatic β-cells defect are central features of diabetes disorder that may progress to several serious complications. Some of medicinal plants are potential sources for antidiabetic agents. Pluchea indica (beluntas) is widely distributed in Malaysia and it is believed to have antidiabetic properties. A hypoglycemic effect of P. indica in normal rats was reported in the previous study. This research was aimed to study the effects of P. indica in glucose and insulin regulation through cell-based in vitro model by using 3T3-L1 adipocytes and RIN-5F pancreatic β-cells. P indica was extracted using soxhlet apparatus with n-hexane, dichloromethane, ethyl acetate and methanol consequtively. The plant also was macerated using water to yield water extract. In cell viability test, the concentration of 0.2 mg/mL was found to be the maximum concentration of P. indica extracts in the absence of cytotoxicity. The preadipocytes were induced to differentiate into mature adipocytes prior to assay. The methanol extract at concentration of 0.05 mg/mL increased glucose uptake in adipocytes (p<0.05), as indicated by up regulation of adipogenesis-regulator Pparγ and insulin-sensitive glucose transporter 4 (Glut4) mRNAs. The n-hexane and water extracts at concentration of 0.05 mg/mL and 0.1 mg/mL respectively stimulated insulin release in β-cells (p<0.05). Moreover, these extracts elevated the transcription level of insulin receptor substrate 2 (Irs2) and glucose-transporter Glut2 in β-cells. Taken together, this in vitro study was useful for a screening model of P. indica extracts to demonstrate the glucose uptake in adipocytes and insulin secretion activity in β-cells. These findings also suggest that P. indica extract deserves further investigation as a potential agent for diabetes management.