Malva neglecta: A natural inhibitor of bacterial growth and biofilm formation

Malva neglecta, a wild plant that grows in different parts of Lebanon, was noted by residents to have soothing effects if taken during episodes of respiratory tract infections. This study was designed to test for the ability of this plant to inhibit bacterial growth and biofilm formation of clinical bacterial isolates. The results showed that while the aqueous extract of the leaves of the plant did not show any antibacterial effect on the tested bacterial isolates, the methanol extract clearly demonstrated an ability to inhibit the growth of the isolates tested. The agar dilution method revealed that the lower concentrations of the methanol extract of M. neglecta inhibited some isolates, but the inhibition was noted to increase with an increase in the concentration of the extract until at a ratio of 0.3 (volume of extract to volume of the agar medium), the growth of all the tested organisms was completely inhibited. The methanol extract of the plant was also capable of inhibiting the formation of biofilms by many of the clinical isolates tested. The active component in the M. neglecta if identified, purified and proved safe for human consumption, may prove to be a new effective antibacterial agent.