Phytochemical analysis and antibacterial activity towards methicillin-resistant Staphylococcus aureus of leaf extracts from Argania spinosa (L.) Skeels

• Published in: Plant biosystems Vol. 151; no. 4; pp. 649 - 656
• Main Authors: Bonvicini, F., Antognoni, F., Mandrone, M., Protti, M., Mercolini, L., Lianza, M., Gentilomi, G. A., Poli, F.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 04-07-2017; Taylor & Francis Ltd
• Subjects: (L.) Skeels; Antibacterial activity; Antibacterial materials; antibiotic-resistant clinical isolates; antimicrobial activity; Argania spinosa; Bacteria; Chemotherapy; Clinical isolates; Drug resistance; Flavonols; Gram-negative bacteria; In vitro methods and tests; Leaves; Lipophilic; Methicillin; methicillin-resistant; pentacyclic terpenoids; Phenolic compounds; Phenols; Quercetin; Staphylococcus aureus; Staphylococcus infections; Strains (organisms); Terpenes
• ISSN: 1126-3504; 1724-5575
• DOI: 10.1080/11263504.2016.1190418

Argania spinosa (L.) Skeels is an endemic Moroccan species belonging to Sapotaceae family. In this work, lipophilic and aqueous extracts were obtained from leaves and subjected to a chemical profiling by MS and LC-MS/MS. Pentacyclic terpenoids were identified and quantified in the lipophilic fraction, while phenolic compounds (mainly belonging to flavonols and flavan-3-ols) were identified in the aqueous fraction. The antibacterial activities of fractions were evaluated in vitro against both reference Gram-positive and -negative bacterial strains and clinical isolates of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA); in addition, the compounds quantified as main components in each extract were assayed against reference strains. A relevant antibacterial activity was observed against reference MSSA and MRSA strains of S. aureus: for the lipophilic fraction, MIC
50
values obtained were 177.8 and 170.6 μg/mL for the former and the latter, respectively, while for the aqueous fraction were 215.5 and 233.3 μg/mL. These inhibitory activities could be mainly ascribed to ursolic and oleanolic acids, among pentacyclic terpenoids, and to quercetin concerning phenolic compounds. A remarkable antibacterial activity was also observed against clinical isolates, thus argan leaves can be considered of interest in the chemotherapy of human infections.