A survey on Hibiscus rosa—sinensis, Alcea rosea L. and Malva neglecta Wallr as antibacterial agents.

Abstract: Objective: To guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds. Methods: Ethanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria (Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Bacillus cereus, Bacillus anthracis, Escherichia coli Streptococcus pyogenes). The extracts were obtained from aerial parts of Hibiscus rosa (H. rosa)-sinensis (leaf and flower), Alcea rosea (A. rosea) L. (leaf and flower) and Malva neglecta (M. neglecta) Wallr (flower). Results: These extracts had inhibitory effects at different concentrations (0.05, 0.10, 0.20 and 0.40 g/mL) against above mentioned bacteria. Escherichia coli was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of M. neglecta against Staphylococcus epidermidis (22 mm) and followed by ethanolic extract from flower of H. rosa against Staphylococcus epidermidis and Staphylococcus aureus (20 mm). The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values against Staphylococcus epidermidis were equal (MIC=MBC=5 mg/mL for M. neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL). Conclusions: These findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment. [Copyright &y& Elsevier]