Anti-staphylococcal and toxic activity of Minthostachys mollis, Argemone subfusiformis and Solanum americanum extracts

Abstract

Introduction: Bacterial evolution and inappropriate use of antibiotics increase the drug resistance of Staphylococcus aureus. Gradually, infection rates by resistant strains increase significantly. Objective: To evaluate the in vitro anti-staphylococcal activity of ethanolic extracts of Minthostachys mollis, Argemone subfusiformis and Solanum americanum and their toxicity against metanauplii of Artemia salina. Methods: Experimental research, ethanolic extracts of Minthostachys mollis, Argemone subfusiformis and Solanum americanum were used at different concentrations against 3 Staphylococcus aureus strains. Bactericidal activity was evaluated with agar disk diffusion and broth macrodilution techniques. The degree of toxicity was determined based on the range of mean lethal concentrations. In addition, Artemia salina larvae that survived after 24 hours of exposure were counted. Results: The ethanolic extracts of Minthostachys mollis and Argemone subfusiformis at 1000mg/mL presented greater bactericidal activity against Staphylococcus aureus. The highest value of the minimum bactericidal concentration was obtained with the extract of Solanum americanum (200mg/mL). Regarding toxicity, the Minthostachys mollis and Solanum americanum extracts showed lower lethality at concentrations of 5 and 10 mg/mL. Values of 3.6 and 13.8 mg/mL were obtained for the lethal doses of muña and American black nightshade, respectively. Conclusion: The ethanolic extracts of Minthostachys mollis and Argemone subfusiformis presented bactericidal activity against S. aureus strains. Furthermore, it was demonstrated that the extracts of Minthostachys mollis and Solanum americanum at the lowest concentrations evaluated did not generate toxicity in Artemia salina.

Keywords

• efectos tóxicos
• extractos de plantas
• staphylococcus aureus.