In vitro antimicrobial activity of Antibact, an herbal medicinal product against standard and clinical bacterial isolates

In vitro antimicrobial activities of ethanol and aqueous “Antibact”, herbal products consisting of a combination of the leaves and branches of four different plants were evaluated against twenty one pathogenic bacteria. Saponins, reducing sugars, phenolics, polyuronides, and triterpenes were the major phyto-constituents of both the aqueous and ethanol “Antibact”. The LD50 analysis revealed the products were safe (LD50>5000 mg/kg bodyweight) for in vivo use. All the isolates (100%) were resistant to at least five of the 12 antibiotics used in the study. In total, the aqueous “Antibact” inhibited the growth of 5 out of the 21 (23.81%) microbes used with an average zone of inhibition of 9.73 ± 0.35 mm. Thirteen (61.90%) out of the 21 microbes used were susceptible to the ethanol “Antibact”, registering an average inhibition zone of 10.80 ± 0.18 mm. In the case of the minimum inhibitory concentration (MIC), the aqueous “Antibact” exhibited MIC range of 4.00 to 32.00 mg/ml and 0.50 to 8.00 mg/ml, while the ethanol “Antibact” recorded MIC range of 2.00 to 8.00 and 1.00 to 2.00 mg/ml for the wild and standard strains, respectively. The average minimum bactericidal concentration (MBC) for the aqueous “Antibact” was 32.00 mg/ml while the ethanol “Antibact” had MBC range of 4.00 to 16.00 mg/ml and 4.00 to 8.00 mg/ml for the wild and standard strains, respectively. In conclusion, both “Antibact” were safe for human use and effective against some pathogenic bacteria in vitro. However, ethanol “Antibact” showed better antimicrobial activity.   Key words: Antibact, antimicrobial activity, clinical isolate, drug-resistant.