Prostate cancer is the second most common cancer among men, with the Caribbean experiencing the highest mortality rates globally. Conventional treatments rely on chemotherapy, often leading to resistance and adverse effects. This has spurred interest in alternative therapies with targeted mechanisms. Hexadecanoic acid, a naturally occurring saturated fatty acid, has demonstrated anticancer properties, including apoptosis induction and cell cycle modulation. This study examines the effects of hexadecanoic acid-enriched extracts from Dioscorea cayenensis and Dioscorea alata on prostate cancer cells.

Hexadecanoic acid-enriched extracts from D. cayenensis and D. alata yams were tested on DU145 prostate cancer and RWPE-1 normal prostate cells. Cytotoxicity was assessed via MTS assay (IC₅₀ determination). Morphological changes were observed microscopically. Flow cytometry evaluated G1/S arrest, and Western blotting analyzed cyclin D and CDK4 expression.

Treatment of DU145 cells with hexadecanoic acid-enriched extracts resulted in significant antiproliferative effects, with an IC₅₀ of 18 µg/mL, while RWPE-1 cells exhibited minimal cytotoxicity (IC₅₀ >200 µg/mL). Morphological changes were observed in DU145 cells following treatment, suggesting cellular stress or apoptosis. Flow cytometry analysis confirmed that treatment induced G1/S cell cycle arrest, indicating disruption of cell cycle progression. Western blot analysis revealed a marked reduction in cyclin D and CDK4 expression, further supporting the role of hexadecanoic acid in regulating cell cycle progression. These findings suggest that hexadecanoic acid exerts its anticancer effects through dual inhibition of cyclins and CDKs, leading to G1/S arrest in prostate cancer cells.

Hexadecanoic acid-enriched extracts from D. cayenensis and D. alata demonstrate selective cytotoxicity against DU145 prostate cancer cells while sparing normal prostate cells. The observed G1/S cell cycle arrest and downregulation of cyclin D and CDK4 indicate a targeted mechanism of action. Given its selective anticancer properties, hexadecanoic acid may serve as a promising natural therapeutic agent for prostate cancer. Further molecular and in vivo studies are necessary to validate its clinical potential.