The phytochemical composition and antibacterial activity of the ethanol extract of the leaves capparis spinosa L. Naeema I. Elorofi

Abstract

Capparis spinosa L. (caper), a medicinal plant native to the Mediterranean region, has attracted considerable scientific interest due to its rich phytochemical composition and broad spectrum of biological activities. The present study was designed to comprehensively evaluate the in vitro antibacterial efficacy of ethanolic leaf extracts of C. spinosa against a panel of clinically significant bacterial pathogens, including Micrococcus spp., Acinetobacter spp., Pseudomonas aeruginosa, Klebsiella pneumoniae (UTI isolate), and Staphylococcus aureus. In parallel, the phytochemical profile of the extract was investigated, with quantitative assessment of total phenolic and flavonoid contents to elucidate their potential contribution to antimicrobial activity. Ethanolic extracts were prepared using the maceration extraction method, whereas antibacterial activity was determined by the agar well diffusion assay. Chemical characterization of the extracts was performed using high-performance liquid chromatography (HPLC). In addition, total phenolic content (TPC) and total flavonoid content (TFC) were quantified using the Folin–Ciocalteu and aluminum chloride colorimetric methods, respectively. The results revealed that the ethanolic leaf extract of C. spinosa is a rich source of bioactive phenolic constituents and possesses pronounced antibacterial activity against all tested bacterial strains. These findings underscore the therapeutic potential of C. spinosa as a promising natural antimicrobial agent and support its prospective application in the development of alternative strategies to combat bacterial infections and antimicrobial resistance.

Keywords: Capparis spinosa, ethanolic extract, antibacterial activity, total polyphenols, total flavonoids.