Biological activity and flavonoid profile of five species of the Bursera genus

Background: The genus Bursera Jacq. ex. L. concentrates its diversity in Mexico. Among the secondary metabolites that can be isolated from organic its extracts are flavonoids and lignans. Research question: Do the biological activity of the hydroalcoholic extracts from five Bursera species studied depend on their flavonoid content? Study site: Oaxaca, Mexico. Methods: The extracts of B. aptera Ramírez, B. fagaroides (Kunth) Engl., B. schlechtendalii Engl., B. galeottiana Engl., B. morelensis Ramírez were analyzed by High Resolution Liquid Chromatography (HPLC) to determine their flavonoid composition. The antiradical DPPH, anti-inflammatory, antibacterial and antifungal activities of the extracts were determined. Results: Phlorizin and quercetin were conserved in both stems and leaves of the five species studied. The phloretin was present only in the leaves of B. aptera . The highest antibacterial activity was observed against Staphylococcus epidermidis and Salmonella typhimurium by the extracts of leaves of B. aptera (MIC 0.002 mg/mL) and the stems of B. fagaroides (MIC 0.015 mg/mL). The extract of stems of B. morelensis against Fusarium boothii presented the highest antifungal effect (lower than 50 ?g/mL). The anti-inflammatory activity of B. fagaroides was 51.24 % edema inhibition (1 mg/ear) compare to 78.76 % of indomethacin (0.358 mg/ear). Conclusion: The presence of flavonoids in five species studied suggests the richness of these compounds in Bursera genus. The biological activities studied indicated the potential medicinal use of these species and the role that the flavonoids play in plant physiology.