A COMPARATIVE STUDY OF EXTRACT OF SUCCULENT LEAVES OF LIVING PLANT WITH METHANOLIC AND AQUEOUS EXTRACT OF BERLERIA LUPULINA LINDL. AGAINST PATHOGENIC MICROBES BY DISC DIFFUSION AND SPECTROPHOTOMETRY

摘要

Berleria lupulina Lindl. was evaluated for its reported antimicrobial activity in a novelway. The extract of succulent leaves collected from living plant was studied along with conventionalmethanolic and watery extracts made from the dry leaves of the plant. The extracts were tested onthree pathogenic bacteria and the antimicrobial activity was tested both by conventional single discdiffusion method and a novel Spectrophotometric method. In disc diffusion study, it was found thatthe methanolic extract (100 mg/ml. and 200 mg/ ml.) diluted in 70% of methanol and extract of succulentleaves can induce 12 mm, 13 mm and 14 mm diameter zone of inhibition comparable with 24 mm ofCeftriaxone against Escherichia coli. The zone of inhibition against Staphylococcus aureus were13 mm, 14 mm, 15 mm and 25 mm and against Salmonella enteritides were 12 mm, 14 mm, 15 mm and28 mm correspondingly. The watery extract made from the dry plant and the methanolic extractdiluted in water failed to induce any inhibition in growth of the organisms. In spectrophotometricstudy, the methanolic extract showed antimicrobial efficacy in the concentration of 10 mg/ml. orabove against Salmonella enteritides and Staphylococcus aureus. But against Escherichia coli, effectivecontrol was found in 20 mg/ml concentration. The fresh extract of the plant showed antimicrobialefficacy in the concentration of 16.5%. The anti microbial efficacy above that concentration cannotbe detected in the available spectrophotometrical method for presence of color material in that freshextract.