Antibacterial activity and cytotoxicity of flavonoids compounds isolated from Pseudarthria hookeri Wight & Arn. (Fabaceae)

Pseudarthria hookeri is used in Africa for the treatment of pneumonia, cough, abdominal pains and diarrhea. However the bioactive constituents underlying the health benefits associated with P. hookeri remain unknown. In this study, the antibacterial activity and the cytotoxicity of compounds isolated from Pseudarthria hookeri were investigated. The antibacterial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the broth microdilution method and the antiproliferative effect against cancer cells was determined by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. Compounds 1 and 4 showed the highest antibacterial effect with minimum inhibitory concentration (MIC) values ranging from 16 to 32 and 8 to 64 μg/mL, against Gram-positive and Gram negative bacteria, respectively. The same compounds induced a remarkable cytotoxic activity toward human T-Cell leukemia Jurkat cells with respective IC50 values of 3.59 and 5.59 μg/mL. Our results suggest that flavonoids from P. hookeri exhibit significant antibacterial activity and antiproliferative effect on human cancer cell lines. These compounds might underlie the health benefits associated with the plant. Compounds 1 and 4 emerged as promising drug candidates, highlighting their potential as lead compounds.