In vitro effects of Geranium graveolens, Sarcopoterium spinosum and Varthemia iphionoides extracts on pancreatic MIN6 proliferation and insulin secretion and on extrapancreatic glucose diffusion

Geranium graveolens, Sarcopoterium spinosum and Varthemia iphionoides are utilized traditionally for diabetes ethnomedicine in Jordan. Their aqueous extracts (AE) for antidiabetic activity and mechanism of action were investigated in vitro. Insulin secretion and pancreatic proliferation as well as glucose diffusion in vitro bioassays were recruited. Similar to L-alanine, S. spinosum AE (0.01 and 0.5 mg/ml) potentiated acute glucose-stimulated Ca2+ regulated insulin secretion in the clonal pancreatic beta-cell line MIN6 (19.3 and 20.6 folds, P < 0.001). G. graveolens and V. iphionoides AEs were inactive. Comparable to GLP-1-enhanced beta-cell proliferation, G. graveolens AE (0.01 and 0.05 mg/ml), S. spinosum (0.1 mg/ml) and V. iphionoides AEs (0.5 and 1 mg/ml) induced augmentations in pancreatic BrdU incorporation (P < 0.05-0.001). Performing effectively as guar gum diffusional hindrance, all three plants' AE concentrations retarded 24 h glucose efflux into external solution across dialysis membrane (P < 0.05-0.001). Conclusively beta-cell mass expansion was augmented and carbohydrate absorption was reduced by all selected plants. Exceptionally, S. spinosum stimulated pancreatic insulin secretion.