In vitro evaluation ofthe antibacterial activity of Atriplex halimus

Abstract

Atriplex halimus (common names: Guettaf, orache, sea purslane) is a shrub from the Chenopodiaceae family, native to North Africa (Morocco, Algeria, Tunisia, Libya, Egypt). A bushy plant with silvery foliage, it has been acclimatized around the Mediterranean basin, then successfully introduced along the Atlantic coast. This plant is very widespread in Algeria and is distinguished by its remarkable ability to tolerate extreme environmental conditions, notably high soil salinity and drought. The objective of this study is to conduct a phytochemical analysis of the hydroethanolic extract of the aerial part of this plant, and to evaluate its antibacterial potential in vitro. The yield of the hydroethanolic extract was estimated at 28%. Indeed, characterization tests based on physicochemical reactions enabled a phytochemical screening, revealing the presence of flavonoids, saponosides, catechin tannins, terpenes and steroids, and the absence of quinones, alkaloids, and gallic tannins. Atriplex halimus showed antibacterial potential against the growth of Staphylococcus saprophyticus and Streptococcus pneumoniae, and a lower inhibitory capacity on Citrobacter freundii and Klebsiella pneumoniae. Thus, the diameters of the inhibition zones, measured by the solid medium diffusion method (aromatogram), varied between 10.46 mm and 12.95 mm, and the minimum inhibitory concentrations (MICs) ranged between 12.50 and 50 mg/ml. Moreover, the MBC/MIC ratio indicated a bactericidal effect on the tested bacterial strains. The results of this research show that the hydroethanolic extract of Atriplex halimus contains various

chemical compounds and exhibits strong antibacterial activity, particularly against Gram- positive bacteria.