The Potential Clinical Value of Curcumin and its Derivatives in Colorectal Cancer.

BACKGROUND: Curcumin, a naturally occurring polyphenol, possesses pleiotropic pharmacologic properties, including anti-inflammatory and anti-oxidant activities. Epidemiological evidence suggests that curcumin intake is associated with a reduced risk of Colorectal Cancer (CRC), highlighting the enormous potential of this botanical agent in the prevention and treatment of CRC. OBJECTIVE: We summarize the anticancer activity of curcumin and its derivatives in CRC. METHODS: We conducted a literature review on the therapeutic effects of curcumin and its derivatives in CRC. RESULTS: In this review, a summary of the activities of curcumin in the treatment of CRC regarding its bioavailability, anticancer activity, modes of action, curcumin delivery systems have been provided based on the researches from preclinical experiments. Also, we discuss the therapeutic effects of curcumin derivatives in CRC. The human clinical trials that used curcumin or curcumin derivatives for the treatment of CRC are also highlighted here. CONCLUSION: Curcumin possesses great potential as a chemopreventive agent in CRC. Moreover, emerging evidence reveals that it can be an effective adjuvant to CRC therapy. To date, few studies have explored the anticolon cancer activity of curcumin formulation and curcumin derivatives in vivo; therefore, more works are needed to confirm their effectiveness. In clinical trials, curcumin treatment protocols (formulation, dose, and duration) vary among studies. However, these trials consistently point out that the compound is well-tolerated and safe, albeit with little consensus on its therapeutic efficacy.

Genistein protects against DSS-induced colitis by inhibiting NLRP3 inflammasome via TGR5-cAMP signaling.

NLRP3 inflammasome has been reported to be associated with inflammatory bowel disease including colitis due to its potential ability to induce IL-1ß secretion. Emerging studies have demonstrated that Genistein, a major isoflavone, has potential anti-inflammatory effects in murine model colitis. However, its anti-inflammatory mechanism remains unclear. The effects of Genistein in dextran sulfate sodium (DSS)-induced murine colitis via targeting NLRP3 inflammasome was investigated in this study. Also, the mechanisms of protective action of Genistein in DSS-induced colitis may relate to TGR5 signaling. Genistein treatment not only remarkably attenuated loss of body weight and shortening of colon length but also significantly reduced inflammatory cells infiltration and pro-inflammatory mediator production in serum and colon. Moreover, Genistein treatment down-regulated production of caspase-1 and IL-1ß and increased intracellular cAMP level, which were similar to the treatment for INT-777, a semi-synthetic TGR5 agonist, in phorbol myristate acetate (PMA)-differentiated monocytic THP-1 cells and U937 cells. These protective effects of Genistein might be attributed by ubiquination of NLRP3 which was induced due to interaction of cAMP with NLRP3. Furthermore, the effects of Genistein on NLRP3 inflammasome disappeared in TGR5-silenced U937 cells. In conclusion, our study unveils that Genistein was able to inhibit NLRP3 inflammasome via TGR5-cAMP signaling in macrophages. It therefore might be a potential effective drug for inflammatory bowel diseases.

Ginsenoside Rd ameliorates colitis by inducing p62-driven mitophagy-mediated NLRP3 inflammasome inactivation in mice.

Previous studies reported that Ginsenoside Rd (Rd) had anti-inflammatory and anti-cancer effects. However, the molecular mechanism underlying the inhibition effect of Rd on colitis in mice hasn't been clarified clearly. Here, in our study, we detected the effects of Rd on dextran sulfate sodium (DSS)-induced murine colitis, and found that oral administration of Rd dose-dependently alleviated DSS-induced body weight loss, colon length shortening and colonic pathological damage with lower myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities and higher glutathione level. In addition, the production of pro-inflammatory cytokines (IL-1ß, TNF-a and IL-6) in both serum and colonic tissues were significantly down-regulated by Rd administration. The activation of NLRP3 inflammasome was also suppressed in Rd-treated group, resulting in reduced caspase-1 production and IL-1ß secretion. In vitro, Rd remarkably inhibited NLRP3 inflammasome activation which was mostly dependent on the mitochondrial translocation of p62 and mitophagy. Importantly, Rd-driven inhibition of the NLRP3 inflammasome was significantly blocked by various autophagy inhibitors. Furthermore, upregulation of AMPK/ULK1 signaling pathway accounted for Rd-induced autophagy, which was also seen in vivo. In conclusion, our results demonstrated the function of Rd on the inhibition NLRP3 inflammasome and its potential application for the treatment of NLRP3-associated diseases.