Antibacterial activity of Plectranthus amboinicus (Lour.) Spreng extracts against pathogenic bacteria

Abstract

Plectranthus amboinicus (Lour.) Spreng is the most important aromatic medicinal plant and has antimicrobial activity. This study investigated the major bioactive constituents and antibacterial activity of P. amboinicus extracts. The results revealed that the dominant phytochemicals that might be responsible for its bioactivity are alkaloids, terpenoids, tannins, phenolics, luteolin, and verbascoside. The herbal extract showed antibacterial capacity against the Staphylococcus aureus (MRSA) strain PB57, with a maximum zone of inhibition. The MIC and MBC values of the extract were found to be 7.81 mg/ml and 15.63 mg/ml, respectively. However, the cytotoxicity results indicated that the extract at concentrations lower than the MIC had a cytotoxic effect on fibroblasts. These findings suggest that P. amboinicus extract has great potential for use as an antimicrobial agent. Therefore, the toxicity of each compound contained in the herbal crude extract should be examined further in the future.