Prostate cancer chemoprevention by natural agents: Clinical evidence and potential implications

Abstract

Prostate cancer (PCa) is the most common non-skin cancer and the second leading cause of cancer-related deaths in American men. Due to its long latency period, PCa is considered as an ideal cancer type for chemopreventive interventions. Chemopreventive agents include various natural or synthetic agents that prevent or delay cancer development, progression and/or recurrence. Pre-clinical studies suggest that many natural products and dietary agents have chemopreventive properties. However, a limited number of these agents have been tested in clinical trials, with varying success. In this review, we have discussed the available clinical studies regarding the efficacy of natural chemopreventive agents against PCa, including tea polyphenols, selenium, soy proteins, vitamins and resveratrol. We have also provided a discussion on the clinical challenges and opportunities for the potential use of chemopreventive agents against PCa. Based on available literature, it appears that the variable outcomes of the chemopreventive clinical studies necessitate a need for additional studies with more rigorous designs and methodical interpretations in order to measure the potential of the natural agents against PCa.

Dietary Factors and Supplements Influencing Prostate-Specific Antigen (PSA) Concentrations in Men with Prostate Cancer and Increased Cancer Risk: An Evidence Analysis Review Based on Randomized Controlled Trials

“…In the phytotherapeutic field, it appears that high-quality studies are lacking, with the majority of RCTs being underpowered [ 229 ]. In parallel, as already mentioned by others, PCa chemoprevention by natural agents is not supported by the available evidence [ 230 ]. Therefore, the need for well-designed trials to expand the existing knowledge, replicate the findings, and aggregate the results is necessitated [ 231 ].…”

Allium vegetables for possible future of cancer treatment

“…It has recently been noted that these vegetables, in addition to the conventional antibacterial, antifungal, antiviral, antiprotozoal, and antiworm effects, showed extensive in vitro and in vivo antiproliferative, antimotility, and cytotoxic potentials against cancer cells (Abdelrahman, Mahmoud, El‐Sayed, Tanaka, & Tran, ; Chu et al, ; Kazemi, Zolfaghari, Keivanloo Shahrestanaki, & Sadeghi Dinani, ; Kocić‐Tanackov et al, ; Packia Lekshmi, Viveka, Jeeva, & Raja Brindha, ; Sharifi‐Rad et al, ). These nutritive greens, especially garlic, are associated with a reduced risk of prostate cancer (Chhabra et al, ; Nicastro, Ross, & Milner, ). Assessing the in vitro and in vivo anticancer activities of Allium species showed that high‐volume intake of Allium genus like garlic has prophylaxis effects, which reduces the risk of breast, colon, stomach, and prostate cancers (Miraghajani, Rafie, Hajianfar, Larijani, & Azadbakht, ; Pan, Zheng, & Ho, ).…”

“…-Antioxidant (ROS scavenging) (Lai et al, 2013), (Sak, 2014), (Chae et al, 2012) (Abuharfeil, Salim, & Von Kleist, 2001) (Cheng et al, 2013;Khan, Afaq, Syed, & Mukhtar, 2008;Ying et al, 2012) (Continues) (Marlett, 2000;Upadhyay, 2016b) (Onwuamah et al, 2014;Tang, Huang, Chang, Fu, & Yang, 2009) (Lee, Cha, Selenge, Solongo, & Nho, 2007; 2017; Kazemi, Zolfaghari, Keivanloo Shahrestanaki, & Sadeghi Dinani, 2018;Kocić-Tanackov et al, 2017;Packia Lekshmi, Viveka, Jeeva, & Raja Brindha, 2015;Sharifi-Rad et al, 2016). These nutritive greens, especially garlic, are associated with a reduced risk of prostate cancer (Chhabra et al, 2018;Nicastro, Ross, & Milner, 2015). Assessing the in vitro and in vivo anticancer activities of Allium species showed that high-volume intake of Allium genus like garlic has prophylaxis effects, which reduces the risk of breast, colon, stomach, and prostate cancers (Miraghajani, Rafie, Hajianfar, Larijani, & Azadbakht, 2018;Pan, Zheng, & Ho, 2018).…”

Quercetin–Resveratrol Combination for Prostate Cancer Management in TRAMP Mice

“…PCa incidence increases with age, which makes it more difficult to manage this disease. Recent studies demonstrating the beneficial effect of modifying dietary habits have been suggested to manage multiple diseases, including PCa [ 3 , 62 , 63 ]. Here, we found that dietary supplementation with the grape antioxidants quercetin and resveratrol together had significant antitumor effects against PCa in both prevention and intervention settings.…”

“…Historically, plant-based and dietary agents have been used medicinally in a variety of health conditions, including PCa [ 3 , 4 ]. The grape antioxidant resveratrol (chemically: 3,5,4′-trihydroxystilbene) is one such agent that is being extensively studied for its health-promoting effects.…”