Mangosteen xanthone γ-mangostin exerts lowering blood glucose effect with potentiating insulin sensitivity through the mediation of AMPK/PPARγ.

Diabetes mellitus (DM) is concomitant with significant morbidity and mortality and its prevalence is accumulative in worldwide. The conventional antidiabetic agents are known to mitigate the symptoms of diabetes; however, they may also cause side and adverse effects. There is an imperative necessity to conduct preclinical and clinical trials for the discovery of alternative therapeutic agents that can overcome the drawbacks of current synthetic antidiabetic drugs. This study aimed to investigate the efficacy of lowering blood glucose and underlined mechanism of γ-mangostin, mangosteen (Garcinia mangostana) xanthones. The results showed γ-Mangostin had a antihyperglycemic ability in short (2 h)- and long-term (28 days) administrations to diet-induced diabetic mice. The long-term administration of γ-mangostin attenuated fasting blood glucose of diabetic mice and exhibited no hepatotoxicity and nephrotoxicity. Moreover, AMPK, PPARγ, α-amylase, and α-glucosidase were found to be the potential targets for simulating binds with γ-mangostin after molecular docking. To validate the docking results, the inhibitory potency of γ-mangostin againstα-amylase/α-glucosidase was higher than Acarbose via enzymatic assay. Interestingly, an allosteric relationship between γ-mangostin and insulin was also found in the glucose uptake of VSMC, FL83B, C2C12, and 3T3-L1 cells. Taken together, the results showed that γ-mangostin exerts anti-hyperglycemic activity through promoting glucose uptake and reducing saccharide digestion by inhibition of α-amylase/α-glucosidase with insulin sensitization, suggesting that γ-mangostin could be a new clue for drug discovery and development to treat diabetes.

Garcinia linii extracts exert the mediation of anti-diabetic molecular targets on anti-hyperglycemia.

Different portions (stem GIS and leaf GIL) of Garcinia linii were extracted by ethanol/water and crude extracts were employed to investigate the contents of total phenol and flavonoids, antioxidation activities, and inhibitory activities of α-amylase and α-glucosidase via enzymatic assay and OGTT and OSTT for lowering glucose levels. The data revealed that GlS and GlL contained different levels of flavonoids and total phenol. Furthermore, the results showed the extracts exhibited remarkable antioxidation activities and inhibitory activities of α-amylase and α-glucosidase. In silico docking studies were done using Gold software and the probable molecules retrieved from PubChem were docked with several anti-diabetic relate targets, the results showed several components of G. linii could potentially inhibit diabetic molecules when compared with clinic drugs. The cell glucose uptake data also confirmed that GlL and GlS could retain the active component in the regulation of insulin, AMPK, PPARγ, and DPP4. In vivo, the evidence showed G. linii extracts including syringaldehyde suppressed effect of hyperglycemia on OSTT and OGTT assays. These results suggest that G. linii extract has a potential therapeutic value for the treatment of diabetes in humans.