Inhibition of Steroidogenesis in Prostate Cancer Cells by Both a Natural and Another Synthetic Steroid

Studies suggest that vegetarians and Asians have lower mortality rates from prostate cancer compared to men who follow a Western diet. β-sitosterol, a key compound of plant-based diets, has been found to induce significant changes in the ultrasonic structure of the prostatic adenomas, making it a promising candidate for further prostate cancer research. Consequently, we investigated the potential of β-sitosterol and the synthetic derivative 2 as potent inhibitors of androgen synthesis, a critical process for the growth and survival of prostate tumor LNCaP cells. Solubilized LNCaP microsomes were used as a source of SRD5A1 and AKR1C3 to monitor androgen synthesis from labeled androstenedione, both in the presence and absence of β-sitosterol or 2. Furthermore, the effect of these steroids on LNCaP viability was determined using the MTT method. Our findings revealed significant insights into the androgen synthesis pathways in LNCaP cells. The most efficient metabolic route for dihydrotestosterone formation was the conversion of androstenedione to 5α-androstanedione rather than from testosterone in LNCaP. This conclusion is supported by the Vmax values for 5α-androstanedione formation (271.05 ± 5.0 ng/mg protein/min) and the Vmax of testosterone formation (80.1 ± 8.0 ng/mg protein/min). Both β-sitosterol and 2 demonstrated substantial inhibitory effects of these enzymes for dihydrotestosterone formation and significantly reduced cell viability, highlighting their therapeutic potential. These findings enhance our understanding of the inhibitory effects of β-sitosterol and 2 on LNCaP cells and suggest their promising application in the treatment of prostate cancer.