Antimicrobial, phytochemical and pharmacological 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 toxicity and its therapuetic effect invivo in experimentally infected rat. Aqueous and ethanol extract of the plant were investigated for their antimicrobial activity using agar well diffusion method against clinical isolates from human samples. Antimicrobial evaluation of crude extract was done against eight bacterial pathogens and three fungi. viz Escherichia coli, Pseudomonasaeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhyimurium, Shigella flexneri, Staphylococcus aureus, Streptococus viridian, Candidaalbicans, 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(10mm) against S. flexneri, E. coli. K. pneumoniae and S.aureus. ketoconazole was used as antifungal at 100mg/ml result revealed highest sensitivity (15mm)against C. albicans and the least sensitivity (2mm) against A. niger. The extract of P. 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 ethanol extract ranged from 25mg/ml to 160mg/ml with the lowest value demonstrated against E.coli and the highest value demonstrated against C. albicans. Phytochemical analysis revealed that the ethanol extract contained some phytoconstituents which are tanins, flavonoids, balsam, cardiac glycosides, terpenes and sterols which might be responsible for its antimicrobial activity.In this study the toxicity of ethanol extract was evaluated on albino rats of weight range 83–105g and oral administration of various doses produced no obvious toxicity or sign of weakness as observed at 5000mg/kg body weight. 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 × 1012/L) while the total leucocyte count7.9 ± 1.38 to 12.43 ± 3.21 × 109/L of the test rat was within the control range (11.7 ± 3.26 × 109/L). There was no significant differences p ≤ 0.05 in creatinine, aspartate aminotansferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) compared with control which received no extract administration. Histopathological sectioning examination revealed little morphological variations from the normal tissues. However no hepatocellular nornephrotic damage was observed.The therapeutic effect of the extract were evaluated at different doses in rats infected with E. coli as test organism at doses of300mg/kgbd weight, 600mg/kgbd weight, 1200mg/kgbd weight and 1500mg/kgbdweight. Ciprofloxacin was used as the positive control drug to compare the effect of the extract. The extract showed a dose dependence response with effective response observed in 1200mg/kgbd weight and 1500mg/kgbdweight. There was no significant difference (P≤ 0.5) between the highest dose of the extract 1500mg/kgbd weight and the control drug Ciprofloxacin. Conclusively the crude plant extract was able to show some level of antimicrobial activity both in vitro and in vivo. Therefore further studies is required to isolate the effective biomolecules responsible for this significant observed activities in the extract.