Antioxidant and Anti-inflammatory Activities of Bauhinia ungulata L. (Fabaceae) on LPS-Stimulated RAW 264.7 Cells

Objective: The present study aimed to investigate the antioxidant, immunomodulatory and antimicrobial activities of Bauhinia ungulata L. Method: A flavonoid-rich fraction was obtained from the Bauhinia ungulata L stem, called the ethyl acetate fraction of Bauhinia ungulata (FABU). The total antioxidant capacity of the FABU was determined through the phosphomolibdenium reduction method. For the evaluation of its antioxidant activity on a cell culture model, LPS-stimulated RAW 264.7 cells were treated with different concentrations of FABU and the reactive oxygen species (ROS), nitric oxide (NO), hydrogen peroxide (H₂O₂) and thiobarbituric acid reactive substances (TBARS) production levels were measured. For the analysis of its immunomodulatory capacity, TNF-α, TGF-β and IL-10 levels were determined in the culture supernatant. In order to determinate the antimicrobial activity of FABU, antifungal and antibacterial susceptibility testing was performed against Candida albicans, methicillinsensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa strains. Result: The FABU demonstrated neither significant antimicrobial activity nor immunodulatory capacity; on the other hand, its potential antioxidant activity was demonstrated by the phosphomolibdenium reduction assay. Also, FABU treatment inhibited the ROS, NO, H₂O₂ and TBARS levels in the supernatant of LPS-stimulated cells. Conclusion: A significant reduction in the amount of reactive oxygen and nitrogen species (RONS) was observed, in addition to lipid peroxidation inhibition. Our data suggest that the FABU is a natural antioxidant complex that may interfere in the cascade of cell damage caused by free radicals and a promising potential drug in chronic disease models in which immunopathogenicity involves high levels of RONS.