Phytochemical screening and antimicrobial activity of extracts of Cassia alata L. leaves and seeds

The aim of the study is to determine the presence of some bioactive compounds in Cassia alata L. leaves and seeds extracts such as tannins, saponins, anthraquinones and flavonoids. Total polyphenol contents (TPC) of leaves and seeds extracts are 59.211 mg GAE/g DW and 1.816 mg GAE/g DW, respectively, while their antioxidant capacities (AC) are 8.14 μmol Fe/g DW and 2.75 μmol Fe/g DW, respectively. The antimicrobial activity is determined by the paper disc diffusion method combined with the minimum inhibitory concentration (MIC). Leaves extract inhibits S. aureus and E. coli at MIC of 400 mg/mL; S. enteritidis and B. subtilis at MIC of 800 mg/mL. Besides, seeds extract also inhibits S. aureus at MIC of 200 mg/mL; E. coli, S. enteritidis and B. subtilis at MIC of 400 mg/mL. However, leaves and seeds extracts of C. alata do not show any inhibitions on the growth of A. niger. Keywords: Antibacterial activity, Antioxidant, Cassia alata L., Extract, MIC.