Asparagus racemosus and Geodorum densiflorum lectins induce apoptosis in cancer cells by altering proteins and genes expression.

A lectin (designated as ARL) was purified first time from the Asparagus racemosus root with the molecular weight of 14.0 kDa containing about 4.8% carbohydrate. ARL showed hemagglutination activity in both mice and human erythrocytes that were inhibited by three complex sugars among the 26 sugars tested. ARL was thermostable that mostly preserved activity at its optimum pH 8.0. Around 48% and 52.5% human colorectal cancer (HCT-116) cells growth was inhibited by 160 μg/ml of ARL and 256 μg/ml of previously purified Geodorum densiflorum rhizome lectin (GDL). Induction of apoptosis in HCT-116 cells was confirmed by Hoechst 33342 staining, caspase inhibitors, but ROS generation was only observed for ARL. The expression level of BAX and p53 genes increased with a decrease of PARP gene expression for both lectins. The expression of FAS and FADD were increased with the decrease of WNT after treatment with GDL. ARL inhibited 68% and 26% of Ehrlich ascites carcinoma cell growth in vivo in mice after treating with 3.0 and 1.5 mg/kg/day doses for five consecutive days. ARL increased the expression level of NFκB and arrested S cell cycle phase in EAC cells, in contrast, G2/M phase was arrested by ARL and GDL in HCT-116.