Methanolic leaf extract of Gymnema sylvestre augments glucose uptake and ameliorates insulin resistance by upregulating glucose transporter-4, peroxisome proliferator-activated receptor-gamma, adiponectin, and leptin levels in vitro.
OBJECTIVE
The present study was undertaken to evaluate the effect of methanolic leaf extract of Gymnema sylvestre (MLGS) on glucose transport (GLUT) and insulin resistance in vitro.


METHODS
Peroxisome proliferator-activated receptor-gamma (PPAR-γ) and GLUT-4 expression were assessed in L6 myotubes for concluding the GLUT activity, and adiponectin and leptin expression was studied in 3T3 L1 murine adipocyte cell line to determine the effect of MLGS (250-750 μg/ml) on insulin resistance.


RESULTS
The findings of the experiments have demonstrated a significant and dose-dependent increase in glucose uptake in all the tested concentrations of MLGS, further the glucose uptake activity of MLGS (750 μg/ml) was at par with rosiglitazone (50 μg/ml). Concomitantly, MLGS has shown enhanced GLUT-4 and PPAR-γ gene expressions in L6 myotubes. Furthermore, cycloheximide (CHX) had completely abolished the glucose uptake activity of MLGS when co-incubated, which further confirmed that glucose uptake activity of MLGS was linked to enhanced expression of GLUT-4 and PPAR-γ. In addition, in another experimental set, MLGS showed enhanced expression of adiponectin and leptin, thus confirms the ameliorative effect of MLGS on insulin resistance.


CONCLUSIONS
These findings suggest that MLGS has an enhanced glucose uptake activity in L6 myotubes, and ameliorate the insulin resistance in 3T3 L1 murine adipocyte cell line in vitro.
Department of Biotechnology, Padmashree Institute of Information Sciences, Bengaluru, Karnataka, India.
Puttanarasaiah Mahesh
PM
Kumar
Connexios Life Sciences Pvt. Ltd., Bengaluru, Karnataka, India.
Marikunte V
MV
Venkataranganna
Department of Microbiology and Biotechnology, Bangalore University, Bengaluru, Karnataka, India.
Kirangadur
K
Manjunath
Department of Pharmacology, PES College of Pharmacy, Bengaluru, Karnataka, India.
Gollapalle L
GL
Viswanatha
Radiant Research Services Pvt. Ltd., Bengaluru, Karnataka, India.
Godavarthi
G
Ashok
3T3 L1 murine adipocyte cell line; Adiponectin; Gymnema sylvestre; L6 myotubes; antidiabetic activity; diabetes; glucose transport; leptin; peroxisome proliferator-activated receptor-gamma