Role of the flavonoid-rich fraction in the antioxidant and cytotoxic activities of Bauhinia forficata Link. (Fabaceae) leaves extract

Abstract

Bauhinia forficata Link. is utilised as an antidiabetic in Brazilian folk-medicine; furthermore, its antioxidant properties suggest a potential usefulness in the prevention of diabetes complications associated with oxidative stress. The contribution of a flavonoid-rich fraction (FRF), HPLC-PDA-ESI-MS characterised, to the antioxidant and cytotoxic properties of B. forficata hydro-alcoholic leaves extract was evaluated for the first time. Both extract and FRF showed radical-scavenging activity and reducing power with a strong relationship with the flavonoid content found; hence, flavonoids are mainly responsible for the primary antioxidant activity of B. forficata extract. The extract significantly decreased FO-1 cell viability at the higher concentrations. FRF did not exert any effect; thus, flavonoids do not appear to be responsible for the cytotoxicity of the extract. The extract resulted virtually non-toxic against both Artemia salina and normal human lymphocytes, demonstrating potential selectivity in inhibiting cancer cell growth. Finally, no antimicrobial activity was observed against the bacteria and yeasts tested.

Keywords::

• Bauhinia forficata Link.
• flavonoid-rich fraction
• phenolic profile
• antioxidant activity
• cytotoxic activity

Acknowledgements

The authors are grateful to Prof. Guido Ferlazzo for providing useful guidance and laboratory facilities for the studies of cytotoxicity on FO-1 cells. They also gratefully thank Shimadzu and Sigma-Aldrich/Supelco Corporations for their continuous support.

Disclosure statement

No potential conflict of interest was reported by the authors.