Antibacterial activity of Orobanche cernua extract.

The effect of the parasitic plant Orobanche cernua extract was evaluated on 5 different Gram-positive and Gram-negative bacteria. Dilution experiments show that the minimum inhibitory concentration (MIC; microgram/ml) of the extract was as follows: Staphylococcus aureus-1526.5; Streptococcus sp.-3125; Streptococcus pyogenes-25,000 and both for Bacillus cereus and Escherichia coli-50,000 micrograms/ml. Data indicated that the MIC of 3125 micrograms/ml is equal to cefotaxime (30 micrograms) and tobromycin (10 micrograms) activity against Streptococcus sp. and S. aureus, respectively; 25,000 and 50,000 micrograms/ml is equal to cefotaxime (30 micrograms) activity against S. pyogenes and B. cereus, respectively, and 50,000 micrograms/ml is equal to nalidixic acid (30 micrograms) activity against E. coli. It can be concluded that the O. cernua extract displays remarkable activity against some Gram-positive bacteria such as Streptococcus and Staphylococcus.