Quercetin-3- O-rutinoside from Moringa oleifera Downregulates Adipogenesis and Lipid Accumulation and Improves Glucose Uptake by Activation of AMPK/Glut-4 in 3T3-L1 Cells

Natural product-based therapeutic alternatives have drawn immense interest to deal with growing incidence of metabolic disorders. Rutin (quercetin-3-O-rutinoside) is found in a variety of fruits, vegetables, and plant beverages. In the present study, rutin was isolated from Moringa oleifera Lam., leaves and its anti-lipidemic and anti-adipogenic activity was evaluated through inhibition of key digestive enzymes and in vitro cell culture experiments using 3T3-L1 adipocytes. Rutin treatment substantially reduced α-glucosidase and pancreatic lipase activities with IC₅₀ values of 40 and 35 μg/ml, respectively. MTT assay with 3T3-L1 cells demonstrated the non-toxic effect of rutin up to 160 μg/ml. Oil Red O-stained images of rutin-treated 3T3-L1 cells depicted that rutin considerably reduced lipid content and adipogenesis (79.9%), and enhanced glycerol release in 3T3-L1 cells when compared to untreated cells. Rutin significantly (p < 0.05) enhanced glucose uptake in 3T3-L1 adipocytes and also led to reduced levels of leptin but enhanced levels of adiponectin. Western blot analysis of rutin-treated (40 µg/ml) adipocytes showed phosphorylation of AMPK, upregulated expression of Glut-4 (1.31-fold) and UCP-1 (1.47-fold), but downregulated expression of PPAR-γ by 0.73-fold. At transcriptional level, similar trends were observed in the mRNA expression of the above genes, except AMPK. Our results demonstrate that rutin isolated from M. oleifera significantly alleviates lipid content and adipogenesis, and improves glucose uptake through regulating PPAR-γ and AMPK signaling pathways; thus, rutin can be considered as a potential therapeutic agent against adiposity and glucose intolerance.