Antibacterial activity of methanol root extract of Indigofera lupatana Baker F.

Indigofera lupatana Baker F. (locally known as Mugiti) has been used by Mbeere community of Kenya to treat cough, diarrhea, pleurisy and gonorrhea. These infectious diseases are caused by pathogenic micro-organisms such as, Klebsiella pneumoniae, Salmonella typhi, Escherichia coli, and Neisseria gonorrhea, among others. Infectious diseases are a cause of morbidity and mortality in humans and animals. Their effects are further aggravated by drug resistance, making it difficult to contain these infections. This calls for search of new drugs that will mitigate these problems. Indigenous plants are promising as a cheap alternative source of new therapeutic agents. Powdered sample of I. lupatana Baker F. roots were extracted using methanol solvent. The resultant extract was subjected to anti-microbial assay. The extract showed the highest activity against Bacillus subtilis (28.0 mm), Bacillus cereus (22.0 mm), Escherichia coli (21.7mm), Staphylococcus aureus (16.7 mm), Klebsiella pneumonia (15.3 mm) and Proteus mirabilis (12.3 mm), Pseudomonas aeruginosa (11.7 mm), Salmonella typhimurium (11.3 mm). The phytochemical studies of extract fractions showed presence of phenolics, flavonoids, tannins, saponins, terpenoids, cardiac glycosides, steroids and phlobatannins. These compounds are responsible for the bioactivity of the sample fractions. The activity was greater among the Gram positive bacteria than Gram negative bacteria. The MIC ranged from between 25 to 400mg/ml.