ANTIMICROBIAL AND PHYTOCHEMICAL PROPERTIES OF PHYLLANTHUS NIRURI LINN

Abstract

Phyllanthus niruri Linn is used in traditional medicine to treat various illnesses. The purpose of this study is to evaluate its antimicrobial activity, phytochemical constituents and its toxicity. Aqueous and ethanol extract of the plant were investigated for their antimicrobial activity using agar well diffusion method against clinical isolates from human samples. The plant was harvested at Osun state University Osogbo, Nigeria. The crude extract of the plant were tested against eight bacterial pathogens and three species of fungi. The bacterial species are Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhyimurium, Shigella flexneri, Staphylococcus aureus, Streptococus viridian, while the fungi species are Candida albicans, Aspergillus flavus and Aspergillus niger. The standard antibiotic (0.5μg Ciprofloxacin) used against the bacteria showed the highest sensitivity (41mm) against Proteus mirabilis and the least sensitivity (20mm) against Shigella flexneri, Escherichia coli,, Klebsiella pneumoniae and Staphylococcus aureus. The standard antifungal used against the fungi was 100mg/ml ketoconazole and it showed the highest sensitivity (15mm) against Candida albicans and the least sensitivity (2mm) against Aspergillus niger. The extract of Phyllanthus niruri showed sensitivity (ranged from 2 - 24mm) against the bacteria species and the fungi (ranged from 2 – 12mm). The MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) of the ethanolic extract ranged from 25mg/ml to 160mg/ml with the lowest value demonstrated against Escherichia coli and the highest value demonstrated against Candida albicans. Phytochemical analysis revealed that the plant extracts contained some phyto constituents which are tanins, flavonoids, balsam, cardiac glycosides, terpenes and sterols which might be responsible for its antimicrobial activity. Acute toxicity in rats gave an LD50 of >5162mg/kg body weight. In this study the toxicity of ethanolic extract was evaluated on Wistar albino rats of weight range 83 - 105g at doses 300, 600, 1,200 and 1,500mg/kg body weight. Oral administration of these doses produced no obvious toxicity. The packed cell volume and red blood cell count of the tested rat was within a minimal variation (PCV - 31.5 to 37.5% and RBC – 3.85 to 4.6 x 1012/L) while the total leucocyte count7.9 ± 1.38 to 12.43 ± 3.21 x 109/L of the test rat was within the control range (11.7 ± 3.26 x 109/L). This study demonstrated reduced level of Aspartate aminotansaminase (AST), Alanine aminotransaminase (ALT), Alkaline phosphatase (ALP) and creatinine which showed there was neither hepatocellular damage nor kidney damage. Statistically there was no significant difference at P ≤ 0.05. However the hyperchromasia of the liver tissue and vacuolations of the podocytes is suggestive of potential toxic properties of P. niruri L. if administered at a high concentration.