Modulation of inflammatory mediators underlies the antitumor effect of the combination of morusin and docetaxel on prostate cancer cells

Prostate cancer stands as a prominent contributor to male mortality in cancer cases. Docetaxel (Doc) is a commonly used treatment, but some patients do not respond well due to drug toxicity and resistance. Morusin, a prenylated flavonoid found in Morus alba, show strong anticancer properties. The aim of this study was to investigate the combined effect of morusin and docetaxel on prostate cancer cells, while exploring the underlying mechanisms. The IC₅₀ values of morusin, docetaxel, and their combination on PC3 cells were evaluated using the sulforhodamine-B (SRB) assay. In addition, various markers including glutathione (GSH), malondialdehyde (MDA), inflammatory mediators (IL-6, TNF-α, NF-κB, and IL-10), NQO1, NRF2, and apoptotic markers (Bax and Bcl2) were evaluated. Co-administration of morusin and Doc significantly reduced Doc IC₅₀ value, indicating enhanced cytotoxicity. The combination therapy affected inflammatory mediators by increasing IL-6 levels and reducing elevated TNF-α and NF-κB levels. Furthermore, the combination reduced GSH levels and augmented MDA, NQO1 and NRF2 levels, which have a crucial role in the cellular response to oxidative stress. Moreover, morusin enhanced apoptosis induced by Doc through increasing Bax levels and decreasing Bcl-2 expression. Molecular docking analyses confirmed morusins' activity against the target proteins studied. In conclusion, the combination of morusin and docetaxel showed enhanced efficacy at lower drug concentrations in treating prostate cancer. The combination therapy may reduce drug resistance by modulating inflammatory mediators and regulating antioxidant markers. The results of this study indicate the possibility of morusin in being a supplementary treatment option for prostate cancer.