Etude phytochimique et biologique de trois différents extraits aèriens bruts de la plante Peganum harmala L., 1753, récoltée dans la région de Ghardaïa.

Abstract

In order to contribute to the valorization of the spontaneous plants known for their therapeutique virtues;the purpose of our studies is the valorisation of saharan medicinal plantePeganum harmalaL.by characterizing it’s with phytochimical screening and evaluating it’s antimicrobial activity of three leaves extracts. Leaves of the plant were subjected to extraction with reflux in méthanol /water , the extract of éthyl acetate were extracted with Soxhlet ,whereas extrait dichlorométhane /water was obtained by maceration . To identify the mostimportante phytochemical classes in aerial parts of these extracts of the plant, wehave been using phytochemical by several qualitative methods based on precipitation phenomena or staining with specific reagents. The results obtained by the phytochemical show the richness of this extracts with alkaloids and steroids……etc. We have shown that aqueus dichlorométhane is the extractor of coumarins and quinines libre,while éthyl acetate has the ability to extract of cardiac glycosides and reducing compounds . The antimicrobial activity of the extracts towards four bacterial strains (Gram+ and Gram-) and three fungi strains was assessed using to the disc diffusion agar; generally the extract of éthyl acetate has developed hight inhibitory effect to the others . Especially Staphylococcus aureus, Penicillium glabrum and Candida albicanswhich are registered maximum areas (11±1.5mm, 11.75±2.36 mmand 13 ± 1mm),while the strongest activities obtained with theextractdichlorométhane /water , on C. albicans(13±1mm).Antimicrobial properties observed are related to the complexity of the chemical composition and the synergy between them. The richness of the extracts of P.harmalain alkaloids and steroids her antimicrobial powers could justify the validity of certain therapeutic virtues granted to these plant in traditional medicine.