Phytochemical screening of ethanol and methanol extract of pimpinella anisum and comparison of antibacterial assays of prevalent organisms in Bangladesh

Abstract

There simply aren't enough new drugs in the pharmaceutical pipeline to keep pace with the evolution of drug-resistant bacteria, the so-called superbugs”. Medicinal plants synthesize a vast array of secondary metabolites that are important for human life. For medicinal purpose, antimicrobial activity of substances derived from plant extracts has been recognized for many years. The antimicrobial activity of the ethanol, methanol and aqueous extracts of the seeds of Pimpinella anisum L. (Apiaceae) was tested for their potential antimicrobial activities against Salmonella typhii, Staphylococcus aureus, Shigella flexineri, Streptococcus pneumonae, Klebsiella sp., Bacillus cereus, Pseudomonas aeruginosa, Bacillus subtilis, Proteus vulgaris, Enterotoxicogenic E.coli (ETEC), Klebsiella pneumonae and Streptococcus pyogenes. Extracts of different days had variable effects on the common pathogenic organisms chosen in context of Bangladesh. Positive antibacterial effect of aniseed was shownagainstfour types of bacteria, Shigella flexineri, Bacillus Subtilis, Streptococcus Pneumoniae and ETEC. Day 5 methanol extract showed the greatest activity against Bacillus subtilis and Streptococcus pneumoniae. Also the Day 5 methanol extract showed maximum activity against Shigella flexineri, Bacillus subtilis and Enterotoxicogenic E.coli (ETEC) indicating high sensitivity to the extract. However the ethanol extract had no effect on ETEC. Phytochemicals such as tannin, saponin, phlobatanin, terpenoid, flavonoid and phenolic compounds were detected in both ethanol and methanol extracts as the extracts showed corresponding test result positive. Both the extracts yielded a negative result for the phytochemicals cardiac glycoside, phlobatannin and steroids. Variation in the solubility of these phytochemicals in different solvents may have an effect leading to the difference in antibacterial action. It is expected that the findings of this study will stimulate researchers to design clinical trials that may lead to the development of less expensive antimicrobial agents.