A randomized in vitro investigation on the modulation of the TGF-β signaling pathway and induction of apoptosis in colorectal cancer cells by green seaweed Caulerpa racemosa

Colorectal cancer (CRC) poses a significant global health burden, necessitating innovative treatment strategies. This study evaluates the potential of Caulerpa racemosa extract, a natural compound, to modulate the transforming growth factor-beta (TGF-β) signaling pathway and induce apoptosis in CRC cells. HT-29 cells served as an in vitro CRC model. The cells were exposed to an n-hexane extract of C. racemosa, and TGF-β1 expression was assessed using immunofluorescence. Apoptosis was quantified via annexin V and propidium iodide staining through flow cytometry. C. racemosa extract significantly downregulated TGF-β1 expression compared to the control group, suggesting its potential as a CRC tumorigenesis and progression inhibitor. The extract displayed robust pro-apoptotic activity, with the 800 μg/mL dose significantly increasing early apoptotic cells compared to the 1200 μg/mL dose. Other dose comparisons showed no significant differences, indicating an optimal dosage range for early apoptosis induction at 800 μg/mL. The 1200 μg/mL dose also induced a notable increase in necrotic/late apoptotic cells compared to the control, triggering a more potent apoptotic response in advanced stages. Our study highlights the potential of C. racemosa extract to modulate the TGF-β signaling pathway and induce apoptosis in CRC cells. The observed dose-dependent effects on early and late apoptotic cells suggest potential applications as a preventive or therapeutic agent in CRC treatment. Further investigations are warranted to explore the extract's role in combatting CRC's complex pathogenesis.