Anticancer Activity of Roburic Acid: In Vitro and In Silico Investigation

Natural compounds remain a valuable source of anticancer agents due to their structural diversity and multi-targeted mechanisms of action. Roburic acid (RA), a tetracyclic triterpenoid, has been identified as a substance capable of inhibiting key NF-κB and MAPK signaling pathways through direct interaction with TNF-α, as well as preventing the production of inflammatory mediators and cancer progression. In this study, we evaluated the biological activity of RA against a panel of human cancer cell lines-DLD-1, HT-29, and HCT-116 (colorectal), PC-3 (prostate), and BxPC-3 (pancreatic)-as well as two non-malignant lines: WI-38 (fibroblasts) and CCD-841 CoN (colon epithelium). RA exhibited a concentration-dependent inhibitory effect on cancer cell metabolic activity, with colorectal cancer cells showing relatively higher sensitivity, particularly at shorter incubation times. To distinguish between cytotoxic and cytostatic effects, we performed trypan blue exclusion combined with a cell density assessment, clonogenic assay, and BrdU incorporation assay. The results from these complementary assays confirmed that RA acts primarily through an antiproliferative mechanism rather than by inducing cytotoxicity. In addition, NF-κB reporter assays demonstrated that RA attenuates TNF-α-induced transcriptional activation at higher concentrations, supporting its proposed anti-inflammatory properties and potential to modulate pro-tumorigenic signaling. Finally, our in silico studies predicted that RA may interact with proteins such as CAII, CES1, EGFR, and PLA2G2A, implicating it in the modulation of pathways related to proliferation and cell survival. Collectively, these findings suggest that RA may serve as a promising scaffold for the development of future anticancer agents, particularly in the context of colorectal cancer.