Modulating effects of steviol and steviol glycosides on adipogenesis, lipogenesis, glucose uptake and insulin resistance in 3T3-L1 adipocyte model

Stevia rebaudiana Bertoni is famous for sweetness due to the content of steviol glycosides (SG). This study aimed \nto determine the effect of SG (stevioside, rebaudioside A) and steviol on adipogenesis and lipogenesis in the 3T3- \nL1 model. Test compounds were also analysed for their ability to affect glucose uptake in hypertrophied insulin- \nresistant 3T3-L1 adipocytes. The most active compound in modulating adipogenesis, lipogenesis and insulin \nresistance was steviol, SG metabolism product. Steviol (10 μM, 100 μM) significantly down-regulated the \nexpression of adipogenic transcription factors (PPARγ, C/EBPα, SREBP1) and lipogenic genes (FAS, aP2, LPL), \nwhich caused decreased lipid accumulation and triglyceride content in adipocytes. Treatment of insulin-resistant \nadipocytes with steviol (1 μM) and stevioside (1 μM, 10 μM) increased GLUT-4 transcript level and improved \nglucose uptake. Steviol also lowered resistin gene expression, which may mitigate insulin resistance in hyper- \ntrophied adipocytes. This study promotes SG as potential health-promoting ingredients in low-calorie functional \nfoods.