STM Article Repository

Antimicrobial susceptibility test of Gongronema latifolium extracts in combination with potash alum
(Alum) were assessed against some clinical bacterial pathogens using disc diffusion (DD) and Agar
well diffusion (AWD) protocols respectively. Ethanolic and methanolic leaf extracts at concentrations
of 0.1-0.3 g were reconstituted in sterile distilled water as well as 1.0-3.0 g of potash alum prior to
application. In-vitro bioactivity of various concentrations of the extracts and in combination with alum
were evaluated by measuring diameter of inhibition zones (DIZs) respectively. The largest inhibition
zones were obtained with Methanolic leaf extract (MLE) on Escherichia coli (14.5±0.5) and
Salmonella typhi (11.5±0.0 mm) with enhanced bioactivity of 19.5±0.7 and 17.5±0.7 mm with potash
alum against Bacillus subtilis, Sal. typhi and Pseudomonas aeruginosa by DD and AWD methods
respectively. However, aqueous leaf extract (ALE) and ethanolic leaf extract (ELE) and their
combinations depicted appreciable antibacterial activity on the pathogens but incomparable to MLE.
Enhancement of bioactivity was achieved with the incorporation of Alum to the leaf extracts
irrespective of solvent of extraction on a dose response fashion particularly by AWD method.
Furthermore, the low MIC values of <0.05 to 0.2mg/ml on the bacteria with MLE and ALE, validates
their potency and broad spectrum activity. In contrast, the very large DIZs of Ciprofloxacin (CP)
reflects the beneficial impact of purified chemotherapeutics against pathogens. Thus, the improved
efficacy of these extracts with natural material such as potash alum would justify future application in
ethnomedicine, nutraceuticals, pharmaceuticals as well as in food systems.