Clove plant (Syzygium aromaticum) is one of the Myrtaceae family. It's a common flavor in food and the traditional medicine. The study's objective was to ascertain whether the clove bud aqueous extract (CAE) and CAE + nanosilver have any biological effects on immune cells and HT-29 colon cancer cell line. Nanosilver was produced through green synthesis approach using CAE. Produced nanosilver was characterized via electron microscope (scanning, SEM) and ultraviolet-visible spectroscopy. CAE and CAE + nanosilver were examined for their active biomolecules using FTIR analysis, p53 contents using real-time PCR, apoptosis and cell cycle arrest power on HT-29 cancer cell line via flow cytometerty and immunomodulatory potential utilizing MTT assay. Results cleared that a spherical nanosilver with a diameter range of 53 nm was formed by CAE. There were several active biomolecules in CAE and CAE + nanosilver. CAE and CAE + nanosilver increased the p53 protein expression and apoptotic cell number in HT-29 colon cancer cells. CAE and CAE + nanosilver could arrest HT-29 cells at the phase G2/M. CAE and CAE + nanosilver stimulated quiescent and PHA-pre-treated splenic cells at higher concentrations, and CAE suppressed quiescent splenic cell when diluted. In conclusion, the safe edible Syzygium aromaticum plant can be utilized to make anti-tumor agent, essentially for colon tumor. As Syzygium aromaticum plant could stimulate immune cells, it can be used as immune-stimulatory agent that can help fight tumor and tumor development.