In vitro antimicrobial activity of Cannabis sativa extracts against Methicillin-resistant Staphylococcus aureus (MRSA)

Abstract

Cannabis sativa is a medicinal plant with promising antimicrobial properties, and humans have been utilising it for thousands of years as a source of food (seeds) and medicine. Antimicrobial resistance remains a significant challenge worldwide, making it difficult to manage microbial infections caused by multidrug-resistant strains. This study assessed the antimicrobial activity of two Cannabis sativa strains from Limpopo Province, South Africa, against multidrug-resistant microorganisms. Methanol and distilled water extracts of the two Cannabis sativa strains were prepared using maceration extraction, and the antimicrobial activity was assessed using standardised assays. Phytochemical constituents of the extracts were analysed using standard qualitative screening methods. Methanol extracts consistently showed the highest yields (>10%), while distilled water had lower yields. The Cannabis sativa extracts exhibited antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) only, and no inhibition of growth was observed on Enterococcus faecium, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. Minimum Inhibitory Concentrations (MICs) of the extracts ranged from 3.13 mg/ml to 12.5 mg/ml, while the Minimum Bactericidal Concentrations (MBCs) values indicated bactericidal activity from 6.25 mg/ml. Preliminary phytochemical screening revealed the presence of various bioactive compounds. These findings demonstrate that Cannabis sativa crude extracts possess localised, low-potency inhibitory effects against MRSA, serving as a baseline for future compound isolation. Consequently, further studies involving compound isolation, quantitative phytochemical analysis, and mechanistic investigations are required to fully evaluate their antimicrobial potential.