Antidiabetic effect of combination of fractionated-extracts of Andrographis paniculata and Centella asiatica: In vitro study

Objective: To examine the effect of combination of Andrographis paniculata herb fraction (AHF) and Centella asiatica herb fraction (CHF) on PPARγ and GLUT4 mRNA expressions in 3T3-L1 adipocyte, and its effect on insulin-stimulated glucose uptake. Methods: 3T3-L1 adipocyte cells were used to investigate gene expression of PPAR γ and GLUT4 proteins by reverse transcription-polymerase chain reaction method. The adipocyte cells were differentiated by using insulin, dexamethasone and 3-isobutyl-1-methylxanthine from 3T3-L1 cells. Pioglitazone, AHF, CHF and the combination of both herbs were evaluated on glucose uptake activity, PPARγ and GLUT4 mRNA expressions in 3T3-L1 adipocyte. Results: The results showed that combination of AHF at 30 μg/mL and CHF at 10 μg/mL could enhance insulin-stimulated glucose uptake. The combination also increased PPARγ and GLUT4 mRNA expressions significantly in comparison to those of negative control (DMSO). These effects were equal in comparison to those of pioglitazone (0.02 μM) and its single extracts. Conclusions: The combination of AHF and CHF can increase glucose uptake and insulin sensitivity through up-regulation of PPARγ and GLUT4 mRNA expressions in 3T3-L1 adipocyte