Lemon gum (Citrus x latifolia) enhances IL-1Β expression and suppresses colon tumor growth in vivo with a favorable safety profile.

Natural polysaccharides are increasingly recognized for their immunomodulatory and antitumor properties. This study evaluated the effects of Lemon Gum (LG), a polysaccharide from Citrus × latifolia, on in vitro cytotoxicity and in vivo antitumor activity in BALB/c mice bearing murine colon tumors. Cytotoxicity was assessed using the MTT assay in CT26.WT, B16-F10, and L929 cell lines. In the animal model, tumor inhibition following treatment, relative organ weight, as well as biochemical, hematological, and histopathological parameters were evaluated to determine the systemic effects of the treatment, in addition to the expression of inflammatory cytokines analyzed by qRT-PCR. LG showed no cytotoxicity in vitro but exhibited antitumor effects in vivo, with tumor inhibition rates of 16.46% and 33.16% at 50 and 100 mg/kg/day, respectively. No significant biochemical or hematological toxicity was detected, although a slight increase in relative liver weight occurred at both doses. Histopathology revealed mild, potentially reversible hepatic alterations. qRT-PCR analysis demonstrated upregulation of Il1b, Ifng, Tlr4, and Il12 with no significant changes in Il4, Il6, Il18, Il33 and Tgfb expression across the experimental groups. These findings indicate that LG exerts moderate in vivo antitumor activity, potentially linked to immunostimulatory mechanisms, and displays a favorable safety profile, supporting its potential for further biomedical investigation.