A controlled in vitro study of the effectiveness of Withania somnifera herbal tincture and homoeopathic dilution (1X and 6X) against selected gram-positive and gram-negative bacteria

Abstract

The aim of this study was to establish the efficacy of Withania somnifera in tincture, 1X and 6X homoeopathic dilutions (in 62% v/v ethanol) as an antimicrobial agent against the in vitro growth of Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli and Staphylococcus aureus, as compared to 62% v/v ethanol only. The disc diffusion method was employed. W somnifera is indigenous to southern Africa and its use is well established amongst the traditional healers for many varied complaints. Infusions, decoctions and tinctures of the fresh and dry whole root are used. (Gericke and Van Wyk, 2000:150.) For this study 20 plates of Mueller-Hinton agar were inoculated with each bacteria, resulting in a total of 100 plates. Four dry discs previously impregnated with the test substances and two antibiotic discs were equidistantly placed on each plate and incubated at 3rC. The vancomycin and gentamycin discs were included to account for plate-to-plate variations in the sensitivity of the bacteria to the antimicrobial substances. The plates were observed at 18, 24 and 48-hour intervals. ' Statistical analysis was performed using the Friedman test to compare test and control substances at each observation interval. The Mann-Whitney-U test was used to compare the mean inhibition zones between test and control substances