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

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 ß 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.

Enrichment of flavonoid-rich extract from Bidens bipinnata L. by macroporous resin using response surface methodology, UHPLC-Q-TOF MS/MS-assisted characterization and comprehensive evaluation of its bioactivities by analytical hierarchy process.

The extract of Bidens bipinnata L. exhibited wide spectrum of bioactivities owing to the presence of flavonoids. In this study, a purification process was developed to enrich the flavonoid-rich extract from B. bipinnata L. (BBTF). AB-8 resin was selected for the purification of total flavonoids. Response surface methodology coupled with Box-Behnken design was employed to optimize the purification condition; it was optimized as pH 5.1, volume of ethanol 80 ml, flow rate of ethanol 1.8 bed volume per hour (BV/h) and concentration of ethanol 76.0%. The total flavonoid content of BBTF was 56.48% under the optimal conditions. The identification of flavonoids in BBTF was conducted using UHPLC-ESI-Q-TOF MS. A total of 14 compounds, including 12 flavonoids, were identified in BBTF. Finally, the in vitro antioxidant activities, α-glucosidase and α-amylase inhibitory activities of BBTF were comprehensively analyzed by an analytical hierarchy process. The results indicated that it exhibited higher bioactivities than the crude extract. These findings suggested that the optimized process could significantly enhance the purity of flavonoids and their bioactivities. This study showed a comprehensive analysis of a total flavonoid extract of B. bipinnata L. for the first time, which could provide a useful approach for its purification process and quality control as well as bioactivities.