Flavonoids-rich extract from Bidens bipinnata L. protects pancreatic β-cells against oxidative stress-induced apoptosis through intrinsic and extrinsic pathways

Abstract

Ethnopharmacological relevance: As a traditional Chinese medicinal, Bidens bipinnata L. has been used to treat many diseases with a long history in China. The anti-diabetic effects of extract from B. bipinnata have been demonstrated in the previous reports.

Aim of the study: The protective effects of flavonoids-rich extract from B. bipinnata (BBTF) on cell damage induced by H₂O₂ in pancreatic β cell and its potential mechanisms were evaluated.

Materials and methods: MTT, ROS production, nuclear staining and flow cytometry assays were adopted to determine the effects of BBTF on cell viability, production of ROS and cell apoptosis in H₂O₂-treated INS-1 cell. Cell apoptosis-related proteins expressions were detected by Western blot assay.

Results: Pre-treatment of BBTF could significantly increase INS-1 cell viability, inhibit the production of intracellular ROS and reduced the characteristic features of cell apoptosis induced by H₂O₂ in INS-1 cells. The studies of the underlying mechanism showed that BBTF could regulate Bax and Bcl-2 proteins expressions, suppress the phosphorylation of JNK, ERK and p38, as well as down-regulate Fas and FasL proteins expressions induced by H₂O₂. The expressions of caspase-8, caspase-9 and caspase-3 were therefore decreased.

Conclusion: The results indicated that flavonoids-rich extract from B. bipinnata could be a natural agent in diabetic prevention and therapy.

Keywords: Bidens bipinnata; Cell apoptosis; Flavonoids-rich extract; Oxidative stress; Pancreatic β cell; Protective effect.