Abstract

Tecoma stans of the Bignoniaceae family, is an important medicinal plant. Different extracts of the leaves and branches of T. stans were evaluated as antibacterial potential against the growth of some human bacterial strains using the disc diffusion and minimum inhibitory concentration (MIC) methods as well as the antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolic and total flavonoid contents weredetermined. The different extracts of T. stans were obtained by successive solvent extraction with methanol and its fractions; ethyl acetate (EtOAc), chloroform (CHCl₃), n-butanol and aqueous. The methanol, EtOAc and CHCl₃ extracts of T. stans showed significant effect against the tested bacteria (Bacillus subtilis, Micrococcus luteus,Sarcina lutea, Staphylococcus aureus, Escherichia coli, Serratia marcescens,Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa). The methanol extract of the leaves exhibited the highest amount of total phenolics (50.3±3 mg gallic acid equivalents/g extract) and flavonoids (40.66±5.03 mg catechin equivalents/g extract). The EtOAc fraction of leaves and branches extracts showed the highest total antioxidant activity (%) with  83.4±0.31 and 82.06±0.54%, respectively followed by CHCl₃ fraction of leaves extracts (79.17±0.20%). These findings provide scientific evidence to support traditional medicinal uses of T. stans and indicate a promising potential for the development of an antibacterial and antioxidant agent from T. stans trees.

Key words: Antioxidant activity, antibacterial activity, total phenolics, total flavonoids,Tecoma stans