Antibacterial activity of aqueous and methanol extracts of Althaea officinalis and Althaea cannabina from Turkey

The crude methanol and aqueous extracts of aerial parts of Althaea officinalis L. and Althaea cannabina L. ( Malvaceae) have been investigated for their antibacterial activity by using disk diffusion assays against 137 strains belonging to 52 bacteria species. The minimum inhibitory concentrations ( MIC) of single compounds were determined by the microbroth dilution method. The results showed that the aqueous extracts from aerial parts of both species had no antibacterial effects against the test microorganisms, whereas the methanol extracts of both species tested exhibited significant antibacterial activity, especially against Acidovorax facilis, Bacillus sp., Enterobacter hormachei, and Kocuria rosea. In comparison with each other, Althaea officinalis was the most effective against the bacteria used in this study. This is the first report of the antibacterial potency of Althaea officinalis and Althaea cannabina on a range of food-borne bacteria. The results provide evidence that Althaea officinalis and Althaea cannabina might indeed be potential sources of new antibacterial agents.