Inhibition of Dehydrogenase Activity in Sputum Bacterial Isolates by hot aqueous extracts of selected Nigeria anti-cough plants

The exploration of plant-based medications as primary therapeutic agents for the treatment of various ailments is currently ongoing. The present study evaluates the antimicrobial properties of hot aqueous leaf extracts of Piper guineense, Gongronema latifolium, and Vernonia amygdalina against clinical sputum isolates. The isolates were characterised based on morphology and biochemical properties. The dehydrogenase enzyme assay and the Agar-well diffusion techniques were used in evaluating the antimicrobial activity of plants, singly and in combination at ratios of 1:1:1. Streptococcus species (46.16%), Klebsiella species (23.08%), Escherichia coli (15.38%), and Proteus species (15.38%) were all present in the bacteria isolates at high prevalence rates. The aqueous extract of V. amygdalina produced the highest level of antimicrobial activity, followed by the combined extract, which inhibited the growth of Klebsiella spp and Escherichia coli at 200 mg/mL. At 200 mg/mL, G. latifolium and P. guineense inhibited Streptococcus species with a 14 mm-diameter zone. When compared to the standard drug, Gentamicin, results of the dehydrogenase activity assay indicate that V. amygdalina and the combined extract exhibited the most favourable IC50 values of 8.69 g/mL, and 9.04 g/mL, 6.37 g/mL, and 9.87 g/mL against E. coli and Proteus spp, respectively. The high IC50 values indicated that Klebsiella spp resisted the plant extracts considerably. Plant aqueous extracts have shown that they are potential natural drug agents for treating and managing cough-causing organisms.