Nelumbo Nucifera leaf extract attenuated pancreatic β-cells toxicity induced by interleukin-1β and interferon-γ, and increased insulin secrection of pancreatic β-cells in streptozotocin-induced diabetic rats.

OBJECTIVE

To evaluate the effect of Nelumbo Nucifera leaf water extract (NNLE) on insulinoma (RIN) cells induced by interleukin-1β (IL-1β) and interferon-g (IFN-γ), and injured pancreatic β-cells induced by Streptozotocin (STZ) in rats.

METHODS

The anti-oxidative effects of NNLE were assessed using 1,1-diphenyl-2-picryl hydrazyl (DPPH) and nitric oxide (NO) scavenging assays. The inhibitory effect of NNLE on α-glucosidase and DPP (dipeptidyl peptidase)-IV was measured in vitro. Pancreatic β-cell protective and insulin secretory effects were assessed, using IL-1β and IFN-γ-induced rat RIN cells. STZ-induced diabetic rats were treated with 50, 100, and 400 mg/kg NNLE for 4 weeks. The effects of NNLE on blood glucose (BG), body weight (BW), and lipid profiles were measured.

RESULTS

NNLE inhibited DPPH, NO, α-glucosidase, and DPP-IV which were directly linked to the function of β-cells. Furthermore, NNLE protected RIN cells from toxicity induced by IL-1β and IFN-γ, decreased NO production, and increased insulin secretion. NNLE caused a significant reduction in blood glucose, triglyceride (TG), total cholesterol (TC), blood urea nitrogen (BUN), and creatinine in STZ-induced diabetic rats. Furthermore, it significantly decreased BW loss in STZ-induced diabetic rats.

CONCLUSIONS

Our results suggest that NNLE reduced the toxicity in insulinoma cells and increased insulin secretion in pancreatic β-cells in STZ-induced diabetic rats.