Evaluation Of Antmicrobial Properties, Acute Toxicity and Immunostimulatory Potential of Phyllanthus amarus

Abstract

The proposed incorporation of medicinal plants into mainstream primary healthcare programmes in Nigeria will require rigorous scientific scrutiny of both their therapeutic potentials and safety. Phyllanthus amarus is one of the medicinal plants widely used traditionally for the remedy of upper respiratory tract infections in Nigeria. The methanolic extract of the plant was fractionated and assessed for antimicrobial activity against Bacillus subtilis, E. coli, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and Candida albicans by agar diffusion method. All the fractions were active against the test organisms with the exception of the chloroform fraction. Ethyl acetate fraction exhibited the highest activity with zones of inhibition of 23, 20, 20, 18.5, 23 and 18mm against the test organisms respectively. The minimum inhibitory concentration of the extract against the test organisms were 3.125, 6.25, 25, 25, 3.125, and 1.56 mg/ml respectively while the minimum bactericidal concentrations were 6.25, 100, 50, 100, 6.25 6. 25 mg/ml. The extract was found to be practically non toxic with LD50 = 774.6mg/kg body weight. The plant extract also showed a good immunostimulatory activity by increasing white blood cell proliferation when administered into Wister rats at doses of 100 and 1000mg/ml. The result of this investigation supports the popular use of this plant for the traditional remedy of infectious diseases possibly caused by these test organisms.