Exploring the Antidiabetic Mechanism of Brachylaena Ilicifolia Using Target Directed in Vitro Screening

ABSTRACT The potential antidiabetic mechanism of Brachylaena ilicifolia aqueous leaf extract was explored using target-directed in vitro screening. The potential of the extract for cytotoxicity and cell proliferation was evaluated using MTT assay in HepG2 cells and Crystal Violet assay in INS-1 cells. The effects of the extract on glucose uptake in liver cells (HepG2) and muscle cells (L6 myotubes) and the lipid accumulation in 3T3-L1 adipocyte were investigated. The inhibitory effects of the extract on α-amylase, α-glucosidase, pancreatic lipase and dipeptidyl peptidase IV (DPP-IV) were also evaluated. The extract demonstrated a low level of toxicity in HepG2 cells with an IC50 value of 105.3 µg mL−1 while also inducing INS-1 cell proliferation at 25 µg mL−1. The treatment of HepG2 and L6 cells with the extract revealed glucose uptake up to 123% in HepG2 cells and 111% in L6 cells without toxicity to these cells. The plant extract had no effect against triglyceride accumulation in 3T3-L1 adipocytes. The extract had no effect on α-amylase, lipase and DPP-IV; however, it demonstrated weak effect against α-glucosidase activity. The findings observed support the traditional usage of B. ilicifolia in the treatment of diabetes, with possible mechanisms of action linked to the enhancement of glucose uptake and stimulation of pancreatic β cell proliferation.