Moringa oleifera plant grows in many countries worldwide and being utilized as a customary medication. The current study aimed to investigate the biological effect of Moringa oleifera leaf extract (MOE) alone or in combination with silver nanoparticles (AgNPs) on colon cancer, microbial cell growth. MOE was utilized in the green synthesis of AgNPs. The characterization of AgNPs was done by UV-Vis-spectrophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM). MOE was tested for their sugars, active biomolecules, ROS, protein contents. Results revealed that created AgNPs are about 61 nm in diameter. There were no detectable sugar and protein in MOE, but it contains ROS and active biomolecules. MOE and MOE+AgNPs exerted mild antibacterial action and increased the number of apoptotic cells and p53 protein expression of HT-29 colon cancer cells. MOE and MOE+AgNPs could arrest HT-29 cells at G2/M phase and stimulate splenic cell growth. Both extract preparations showed antioxidant activities. Because MOE and MOE+AgNP stimulated immune cells and activated apoptosis in cancer cells, these preparations can be utilized as anticancer agents.