PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITIES OF AQUEOUS AND ETHANOLIC LEAF AND STEM EXTRACTS OF EUPHORBIA HIRTA ON SOME CLINICAL ISOLATES

Abstract

Medicinal plants have been widely used for centuries as sources of therapeutic agents, with Euphorbia hirta traditionally used to treat respiratory, gastrointestinal, and skin infections. The increasing prevalence of multidrug-resistant bacterial strains has intensified the need for alternative antimicrobial agents derived from natural sources. This study aims to evaluate the phytochemical constituents and antibacterial activities of ethanolic and aqueous leaf and stem extracts of E. hirta against clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumoniae. The plant materials were collected, identified, and extracted by maceration in ethanol and distilled water. Phytochemical screening was performed to detect the presence of polyphenols, tannins, flavonoids, saponins, and alkaloids. Antimicrobial activity was assessed using the agar well diffusion method, while the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Results revealed that the ethanol extracts contained higher concentrations of polyphenols, flavonoids, and alkaloids compared to the aqueous extracts, whereas tannins were more abundant in the aqueous extracts. The ethanol leaf extract exhibited the highest antimicrobial activity, particularly against P. aeruginosa and S. aureus, with inhibition zones of 23.5 mm and 19.5 mm, respectively, at 500 mg/ml. The aqueous stem extract showed notable activity against S. pneumoniae (16.5 mm at 500 mg/ml). The MIC values indicated that the ethanol stem extract was the most effective against P. aeruginosa (62.5 mg/mL), whereas aqueous extracts required higher concentrations (500 mg/mL. MBC results suggested that all extracts were more bacteriostatic than bactericidal. These findings support the traditional medicinal use of E. hirta and highlight its potential as a natural antimicrobial agent. The ethanol extracts, particularly from the leaves, demonstrated the strongest antibacterial effects, suggesting that ethanol is an optimal solvent for extracting bioactive antimicrobial compounds. Further research is recommended to isolate and characterize specific compounds and explore their mechanisms of action for potential pharmaceutical applications.