Phytochemical analysis and evaluation of the antimicrobial and anti-inflammatory activities of Oroxylum indicum (L.) Kurz flowers

Abstract

Introduction: In traditional medicine, various parts of Oroxylum indicum, including roots, stem barks, leaves, and seeds, are used to treat coughs, arthritis, stomach pain, and skin disorders. Although the flowers are edible, their chemical and pharmacological properties remain limited. This study aims to analyze the phytoconstituents, to evaluate the antimicrobial and anti-inflammatory activities, and to provide preliminary screening for the anticancer potential of O. indicum flowers. Methods: The flowers were extracted with 96% ethanol to obtain the crude extract, followed by liquid-liquid partitioning to yield five fractions (OroF.A-E). The chemical constituents of the flower extract were analyzed by LC-HRMS. Antimicrobial activity was assessed by the agar disk diffusion method and Minimum Inhibitory Concentration (MIC) determination. Anti-inflammatory activity was evaluated by quantifying nitric oxide production in LPS-induced RAW264.7. Cytotoxic activity against HepG2 cancer cells was determined using the MTT assay. Results: The chemical profiling of O. indicum flowers via LC-HRMS identified flavonoids (specifically baicalein and chrysin) as the major components, occurring together with several non-flavonoid derivatives. The chloroform fraction exhibited the most potent bioactivity across all assays. It showed the MIC of 1.25 mg/mL against a range of pathogens, including E. coli, P. aeruginosa, E. faecalis, S. aureus, MRSA, C. albicans, and A. niger. Furthermore, the chloroform fraction showed remarkable anti-inflammatory activity with an IC50 of 3.37 ± 0.22 µg/mL, mild activity against HepG2 cells with IC50 of 99.11 ± 1.43 µg/mL. Conclusions: The flowers of O. indicum exhibit several potential bioactivities, particularly anti-inflammatory properties.