Search

As part of our ongoing silybin project, this study aims to introduce a basic nitrogen-containing group to 7-OH of 3,5,20-O-trimethyl-2,3-dehydrosilybin or 3-OH of 5,7,20-O-trimethyl-2,3-dehydrosilybin via an appropriate linker for in vitro evaluation as potential anti-prostate cancer agents. The synthetic approaches to 7-O-substituted-3,5,20-O-trimethyl-2,3-dehydrosilybins through a five-step procedure and to 3-O-substituted-5,7,20-O-trimethyl-2,3- dehydrosilybins via a four-step transformation have been developed. Thirty-two nitrogen-containing derivatives of silybin have been achieved through these synthetic methods for the evaluation of their antiproliferative activities towards both androgen-sensitive (LNCaP) and androgen-insensitive prostate cancer cell lines (PC-3 and DU145) using the WST-1 cell proliferation assay. These derivatives exhibited greater in vitro antiproliferative potency than silibinin. Among them, 11, 29, 31, 37, and 40 were identified as five optimal derivatives with IC50 values in the range of 1.40–3.06 µM, representing a 17- to 52-fold improvement in potency compared to silibinin. All these five optimal derivatives can arrest the PC-3 cell cycle in the G0/G1 phase and promote PC-3 cell apoptosis. Derivatives 11, 37, and 40 are more effective than 29 and 31 in activating PC-3 cell apoptosis. [ABSTRACT FROM AUTHOR]

The term "flavonoids" is created for a large class of polyphenolic compounds featuring two aromatic rings (A and B) and a central heterocyclic ring C. More than 4,000 flavonoids have already been obtained throughout the plant kingdom. An inverse correlation between the intake of dietary flavonoids and the incidence of prostate cancer can be generally well-observed from several epidemiological studies worldwide, which encouraged several research groups to examine both in vitro and in vivo the potential of whole extracts of flavonoidenriched dietary plants and purified flavonoids in preventing and treating prostate cancer. Nine subclasses of naturally occurring dietary flavonoids have so far been explored and identified to possess clinical potential in preventing and treating prostate cancer. We review herein the antiprostate cancer potential (including in vitro potency, in vivo efficacy, and clinical studies), structure-activity relationships, and the mechanism of actions of the nine subclasses of naturally occurring flavonoids.

Background: The generic name "flavonolignan" was created in 1968 for a relatively small class of naturally occurring hybrid molecules biogenetically originated from ubiquitous flavonoids and lignans (phenylpropanoids). The first group of flavonolignans was extracted from Silybum marianum that has long been used for hepatoprotection. Recently, the medicinal merit of flavonolignans has been extended to the prostate cancer management., Methods: Systematic interpretation and summarization of the relevant literature., Results: Over forty naturally occurring flavonolignans have so far been obtained from various plants. Certain flavonolignans have been demonstrated by in vitro cell-based and in vivo animal-based experiments, and human clinical studies i) to possess effective chemopreventive function against various tumor promoters; ii) to show the anti-angiogenic efficacy; iii) to have potential in treating prostate cancer; iv) to sensitize prostate tumors to chemotherapeutic agents through down-regulation of P-glycoprotein and other mechanisms; and v) to be used by prostate cancer patients to protect or treat the hepatotoxicity caused by several chemotherapies. Certain flavonolignans can synergize with well-established chemotherapeutic agents for prostate cancer., Conclusion: This review provides a systematic and in-depth overview of the promise and potential of flavonolignans in prostate cancer management, which covers their chemopreventive effect, chemotherapeutic treatment, mechanisms of actions, synthetic derivatives, structure-activity relationships, and the difference in inhibiting prostate cancer cell proliferation between certain flavonoligans and their respective flavonoid counterpart. This summarization aims to provide valuable insights into further and rational development of flavonolignans for prostate cancer management by interpreting the data reported in the literature.

This review is to describe synergistic effects of various combinations of dietary natural products including curcumin, quercetin, soybean isoflavones, silibinin, and EGCG that have potential for the treatment of prostate cancer. These data can provide valuable insights into the future rational design and development of synergistic and/or hybrid agents for potential treatment of prostate cancer.