Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious clinical urgent problem worldwide. Few new drugs are available against methicillin-resistant S. aureus (MRSA), because MRSA has the ability to acquire resistance to most antibiotics, which consequently increases the cost of medication. In the present study, the antibacterial activity of Euphorbia supina has been investigated. The antibacterial activities of EtOH extract of E. supina and its n-hexane, EtOAc, n-butanol and water fractions were evaluated against 6 strains of methicillin-resistant S. aureus and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MICs) and colorimetric assay using 3- 4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test under dark and light intensity from 2,000 to 18,000 lux. Under dark, the n-hexane fraction of E. supina had a MIC of 31.25 μg/ml. Antimicrobial activity of all the fractions was remarkable especially under illumination from 14,000 to 16,000 lux. E. supine can be considered an alternative MRSA treatment.

Key words: Euphorbia supina, milk purslane, antibacterial, methicillin-resistantStaphylococcus aureus (MRSA), light intensity.