Aloe-Emodin Protects RIN-5F (Pancreatic beta-cell) Cell from Glucotoxicity via Regulation of Pro-Inflammatory Cytokine and Downregulation of Bax and Caspase 3

To determine the protective effect of aloe-emodin (AE) from high glucose induced toxicity in RIN-5F (pancreatic beta-cell) cell and restoration of its function was analyzed. RIN-5F cells have been cultured in high glucose (25 mM glucose) condition, with and without AE treatment. RIN-5F cells cultured in high glucose decreased cell viability and increased ROS levels after 48 hr compared with standard medium (5.5 mM glucose). Glucotoxicity was confirmed by significantly increased ROS production, increased pro-inflammatory (IFN-gamma, IL-1beta,) & decreased anti-inflammatory (IL-6&IL-10) cytokine levels, increased DNA fragmentation. In addition, we found increased Bax, caspase 3, Fadd, and Fas and significantly reduced Bcl-2 expression after 48 hr. RIN-5F treated with both high glucose and AE (20 muM) decreased ROS generation and prevent RIN-5F cell from glucotoxicity. In addition, AE treated cells cultured in high glucose were transferred to standard medium, normal responsiveness to glucose was restored within 8hr and normal basal insulin release within 24 hr was achieved when compared to high glucose.

Study on antidiabetic effect of aqueous extract from Pulsatilla chinensis / 中草药

Objective: To study the blood glucose lowering activity of aqueous extract from Pulsatilla chinensis (AEPC) on Streptozocin (STZ)-induced type-2 diabetic rats. Methods: AEPC was obtained through traditional aqueous extraction procedure; Oral glucose tolerance test was employed for the preliminary study of AEPC's blood glucose lowering activity; For further study, STZ-induced neonatal diabetic rat model was used, and the serum SGPT, SGOT, ALP, serum urea, triglycerides, total cholesterol, HDLC, total protein, and serum insulin were tested; The Kunming rats were used for acute toxicity experiments, with the highest dose of 1 000 mg/kg body weight; Insulin release from RIN 5F cells was performed to study the mechanism of AEPC on antidiabetes effect. Results: Oral glucose tolerance test showed AEPC could lower the blood sugar, and the optimal activity was observed at a dose of 20 mg/kg body weight; In neonatal STZ-induced type-2 diabetic rats, treatement with 20 mg/kg AEPC for 20 d resulted in significant blood glucose lowering activity, liver glycogen and serum biological parameters back to normal; The acute toxicity results showed that no obvious toxicity was observed even at 1 000 mg/kg dose; At last, AEPC could promote the secretion of insulin from RIN 5F cells. Conclusion: AEPC shows the anti-diabetes activity on STZ-induced type-2 diabetic rats, which may be the result of its effect on promoting insulin release from pancreatic α-cells.