RecruitingDrug trialGreen Tea and Quercetin in Combination With Docetaxel Chemotherapy in Castration-resistant Prostate Cancer PatientsThe goal of this clinical trial is to find out if taking natural products green tea and quercetin along with docetaxel chemotherapy improves the therapy of advanced prostate cancer, i.e., metastatic castration-resistant prostate cancer (mCRPC). It will also learn about the safety of this combination. Researchers will compare green tea plus quercetin to a placebo (a look-alike substance that contains no drug) in combination with docetaxel to see if green tea and quercetin works to improve the therapeutic effect of docetaxel.