Phytochemical Screening and Antibacterial Analysis of Launaea nudicaulis

摘要

Launaea nudicaulis was investigated for antibacterialactivity against four bacterial strains namely Bacillus cereus(MTCC-10085), Staphyllococcus aureus (MTCC-3160), Salmonellaenterica ser. typhi (MTCC-733) and Serratia marcescens (MTCC-9527). Five different plant extracts (petroleum ether, chloroform,acetone, methanol and water) were prepared from leaves by usingsoxhlet exraction method with % yield of 3.19 %, 35.22 %, 12.87 %,30.96 % and 8.21 % respectively. Preliminary screening of variousextracts for phytochemicals revealed the presence of many secondarymetabolites including tannins, steroids, flavonoids, alkaloids,glycosides, terpenoids etc. Then, antibacterial activity was examinedusing Resazurin based Microbroth Dilution Assay (RMDA) and DiskDiffusion Assay (DDA). According to results of RMDA, acetoneextract showed highest activity against S. aureus, S. enterica ser.typhi and S. marcescens i.e. MIC values 0.19 mg/ml, 0.39 mg/ml and0.19 mg/ml respectively. In DDA, the acetone extract showedmaximum zone of inhibition against S. aureus, S. enterica ser. typhiand S. marcescens i.e. 14.76 mm, 13.54 mm and 14.95 mmrespectively. While petroleum ether, chloroform, methanol and waterextracts showed less activity against tested bacteria. The mechanismsof antibiosis indicated that the acetone extract was highlybactericidal against S. aureus, S. enterica ser. typhi and S.marcescens. The antibacterial activities of L. nudicaulis againsttested organisms provide the platform for its utilization in herbalindustry.