Phytochemical screening and antimicrobial activity of leaves of ‘traveler’s tree’ (Ravenala madagascariensi.)

Abstract

Traveler’s tree (Ravenala madagascariensis Sonn.), of family Strelitziaceae is endemic to the island of Madagascar. In present study investigations were conducted to extract and screen the primary and secondary metabolites from dried leaves of the plant and determine their antimicrobial activity against seven bacteria and four fungi. The pharmacognosy of its leaves indicated the presence of alkaloids, flavonoids, steroids, triterpenoids, tannins, saponins, coumarins, anthraquinones, phlobatannins, anthocyanins, proteins, amino acids and carbohydrates. Antimicrobial activity of the leaves of R. madagascariensis showed maximum activity against Shigella, Bacillus and E.coli where zone of inhibition was 21 mm at 1000 µg/ml while commercially available antibiotic Streptomycin used as positive control showed zone of inhibition as 25-, 15- and 23 mm respectively at same concentration of 1000 µg/ml. The extract activity was higher than commercially available antibiotic against Pseudomonas and Bacillus showing inhibition zone of 16- and 21 mm respectively, while it was 15 mm in Streptomycin. The activity of Streptomycin and dried powdered leaf extract against E.coli showed zone of inhibition as 23- and 21 mm respectively while it was 18 and 20 mm respectively against Klebsiella. However the extract showed less activity against all the four fungi tested as compared to positive control Streptomycin.