KT-NB inhibits cell proliferation and reduces cell viability. (A) HeLa cells were treated with different concentration of KT-NB (1.35 μg/ml, 6.75 μg/ml, 13.5 μg/ml). DMSO was used as control. Cell numbers were determined using a haemocytometer at different time points. (B) Human lung carcinoma (A-549), human bladder papillary transitional cell carcinoma (BFTC905), human breast carcinoma (MCF-7), human larynx Epidermoid carcinoma (HEp-2), human uterus sarcoma (MED-SA) and HeLa cells were treated with 1.5625 μg/ml, 3.125 μg/ml, 6.25 μg/ml, 12.5 μg/ml, 25 μg/ml of KT-NB for 72 h and harvested for MTT assay. Results were based on three independent experiments.