Citrus wastes can modulate cell cycle to induce cytotoxicity in human colon cancer cells with differing p53 status

Both in vitro and in vivo studies have demonstrated the efficacy of citrus fruits in mitigating chronic conditions, including cancer and cardiovascular diseases. While the chemopreventive properties of whole citrus are widely recognized, the specific anticancer potential of its agricultural byproducts remains largely unexplored. To address this gap, we investigated the effects of citrus waste—comprising peels, immature fruits, and juice processing residues—on HCT116 human colon carcinoma cells with distinct p53 status. Flow cytometry and trypan blue exclusion assays revealed a significant suppression of cellular metabolic activity. Notably, the treatment inhibited the proliferation of both p53-wildtype and p53-null HCT116 cells in a dose-, time-, and p53-dependent manner, triggering profound sub-G1 cell cycle arrest. These findings underscore the chemopreventive potential of citrus waste in restraining tumor growth via apoptosis, warranting further investigation to delineate the precise underlying molecular mechanisms.