Increased Glucose Uptake and Insulin Binding Activity of Nerium Oleander in Hepatocytes and Adipocytes

Abstract

Type 2 diabetes mellitus (DM) affects a large population worldwide. DM is often considered as a syndrome of disordered glucose metabolism. Current conventional drug therapies for DM are usually insufficient and medicinal herbs with antihyperglycemic activities are increasingly sought by diabetic patients and health care professionals. Nerium Oleander (N.O.) is known to be effective in lowering of postprandial blood glucose in DM patients as a folk remedy. In this study we aimed to evaluate effect of N.O. distillate in glucose uptake activity of hepatocytes and adipocytes. The human hepatoma cells Hep3B and mouse adipocyte 3T3-L1 cells were cultured. Depending on the groups, different concentrations insulin (1, 10, 20 IU/ml) and N.O. (0.1, 1, 10, 50 µg/ml) were added to medium for 48 h. Cellular toxicity and proliferation were evaluated by LDH secretion levels and MTT test. A metabolizable fluorescent derivative of glucose, 2-NBDG and FITC-insulin were used for glucose uptake and insulin binding activity. Insulin increased cellular proliferation and decreased LDH leakage and apoptosis in both cell types. Lower dosages of N.O. has no significant effect on apoptosis and cell number while at the highest dosages minimal cytotoxicity was seen mainly in adipocytes. Main effect of N.O. treatment was increased glucose uptake in Hep3B and 3T3-L1 cells (P<0.001). Our results showed that N.O. may be offered as new approaches to treatment of type 2 diabetes by modulating cellular glucose uptake.

Exploring a natural MDR reversal agent: potential of medicinal food supplement Nerium oleander leaf distillate

“…Hydrodistillation (an original method) was used to obtain leaf distillate from N. oleander in this study. The distillate was not toxic to mammary carcinoma MCF-7 cells according to the results which are very similar to the findings for liver cells HEP3B by Yazihan et al [11] . We found also that the distillate has antagonistic interaction with paclitaxel and vincristine which also show that it does not have toxic effect on cell proliferation.…”

“…We found also that the distillate has antagonistic interaction with paclitaxel and vincristine which also show that it does not have toxic effect on cell proliferation. According to the previous studies, N. oleander distillate is not toxic to animal models, so N. oleander may be used in treatment of some diseases [11] . The effects of N. oleander distillate as food supplement on rats taking high fat diet were investigated also by the same group.…”

“…Bas et al reported that N. oleander distillate may be used as dietary supplement to treat high blood cholesterol level in diabetic rats [10] . Yazihan et al also suggested that N. oleander distillate is not toxic to non carcinoma cells [11] .…”

Implications from a pharmacogenomic analysis:Nerium oleanderleaf distillate supplemented diet regulates cholesterol metabolism in rats

“…Regulation of lipid metabolism which is controlled by very complex metabolic pathways and by diet type is enlightened to some extent at the gene expression level. It is also revealed that non-toxic N. oleander leaf distillate (Kars et al, 2013;Yazihan et al, 2013) may be used as a supplement to regulate cholesterol metabolism in animal models. Further functional and pharmacological assessments will be conducted by our group to suggest the unique N. oleander leaf distillate as a medicinal food supplement.…”

“…Some types of N. oleander leaf extracts prepared in different solvents were found to be anti-proliferative in cancer cells (Fu et al, 2005). Nerium oleander leaf distillate, however, was declared by our group as non-toxic to normal and cancer cells (Kars et al, 2013;Yazihan et al, 2013).…”