Abstract
Public health is seriously threatened by the rise of antibiotic-resistant strains of bacteria, especially methicillin resistant Staphylococcus aureus (MRSA). This study investigated the phytochemical compounds, and possible antibacterial effects of a methanolic extract of the cactus species Opuntia monacantha Haw. against MRSA. The powdered substance was extracted with methanol and filtered, and the filtrate was partitioned with n-hexane, chloroform and ethyl acetate. The fractions with higher percentage yields such as the n-hexane and chloroform fractions went through GC-MS analysis. They consist of various compounds that are known to have strong antioxidant and antimicrobial activities. The antimicrobial activity of the plant was measured via a diffusion assay. On the basis of these results, the Opuntia monacantha crude methanolic extract, and the n-hexane and chloroform fractions significantly inhibited all the MRSA strains used in the test at 100, 75 and 50 mg/mL. Furthermore, the minimum inhibitory concentrations of various fractions of the methanolic extract of Opuntia monacantha were also examined. Therefore, Opuntia could be a promising candidate for strengthening the existing formulations in pharmaceutical science for the treatment of MRSA. However, additional research is necessary before its therapeutic use is recommended. The results are intended to provide important new information for the creation of sustainable and alternative antimicrobial agents.