Phytochemical Screening And Antimicrobial Activity Of Agarista Salicifolia And Phyllanthus Reticulatus Against Some Human Pathogens

Abstract

This study aimed to evaluate in vitro antimicrobial activities of Agarista salicifolia and Phyllanthus reticulatus plants extracted by different solvents against five human pathogens. Antimicrobial activity of plant extracts was carried out by agar disk diffusion, minimum inhibitory concentration (MIC), ant-biofilm activity, anti-quorum sensing assay, and bioautography for purified compound. Phytochemical screening tests were carried out following standard protocols and the result revealed that steroids, tannins, saponins and flavonoids were present in the ethanol extract of leaves of Agarista salicifolia. The leaves and roots of Agarista salicifolia and Phyllanthus reticulatus, respectively, were extracted with ethanol and afforded 7.5% and 6.3 % yield, respectively. Antimicrobial activities of ethanol leave extracts of Agarista salicifolia showed maximum activity against Staphylococcus aureus (25.3±1.2 mm) and minimum activity against Candida albicans (11±1.52 mm). The ethanol root extract of Phyllanthus reticulatus showed maximum activity against Staphylococcus aureus (17.7±1.20 mm) and minimum activity against Pseudomonas aeruginosa (10.7±2.92 mm). A relatively low MIC value was recorded for the leave extract of Agarista salicifolia (25mg/ml) against the tested pathogens. The highest anti-biofilm activity was shown by Agarista salicifolia ethanol leaves extract on Salmonella typhimurim through test tube method. Highest anti-swarming activities were shown by Agarista salicifolia leave extract at 50mg/ml on Salmonella typhimurim, Pseudomonas aeruginosa and Candida albicans. Antiquorum sensing activity by Agarista salicifolia leaves extract against Staphylococcus aureus, Streptococcus pyogen and Salmonella typhimurium at 5mg/ml. Bioautography test displayed that compound 1 inhibited the growth of Pseudomonas aeruginosa better than the Staphylococcus aureus. Silica gel column chromatography to leaves extract of Agarista salicifolia afforded one acylaminosugars derivative characterized as N-acetyl chitobiose derivative. The overall results of the present study revealed that Agarista salicifolia leave extract has high antimicrobial, anti-biofilm and anti-quorum sensing activity against the test microoriganisms thus; Agarista salicifolia is a better source of antimicrobial agent hence can be of interest in the development of new chemotherapeutic drug.