Antibacterial activity of ethyl acetate extract from Parkia speciosa pericarp against selected bacteria / Norfarah Izzaty Razaly

Parkia speciosa which is also known as petai is commonly found in tropical countries such as Thailand, Indonesia and Malaysia. This plant is usually eaten raw, as flavor to cuisine and pickled in salt. Besides, folks also believed that Parkia speciosa have the ability to treat kidney inflammation and toothache. Previous study has also proved that, Parkia speciosa have medicinal properties such as hypoglycemic agent, antitumor and antimutagenicity. Usually, only the green seed of Parkia speciosa are consumed while its pericarp is left as waste. Thus, in this study we focused on this discarded part of Parkia speciosa, its pericarp, to evaluate its potential to be utilized as an antimicrobial agent. The pericarp was extracted using ethyl acetate as solvent. The antibacterial activity of extract was determined by disk diffusion and broth dilution methods against four types of bacteria; Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhimurium. It was found that the Parkia speciosa pericarp extract exhibited good antibacterial activity toward Staphylococcus aureus and Bacillus cereus while Escherichia coli and Salmonella typhimurium were resistant toward the extract. The lowest concentration of extract that has effect on Staphylococcus aureus and Bacillus cereus were 7.813 mg/mL and 1.953 mg/mL. Thus, the extract may have the potential to be used as antimicrobial agent.