Critical need for clinical trials: an example of a pilot human intervention trial of a mixture of natural agents protecting lymphocytes against TNF-alpha induced activation of NF-kappaB.

Humans typically consume "natural agents" that are believed to be chemoprotective and are known to decrease inflammation biomarker NF-kappaB in vitro; however, no intervention studies in humans have been done to date. This commentary documents the in vivo results as a powerful example for supporting the superiority of a complex mixture of natural agents. Human volunteers consumed two 500 mg capsules (BID) containing a mixture of natural agents for a period of 2 weeks, and blood samples were collected pre- and post-intervention. The purified lymphocytes were subjected to ex-vivo exposure to TNF-alpha or kept as untreated control. The mean NF-kappaB DNA binding activity was increased upon TNF-alpha treatment in pre-intervention samples; however, TNF-alpha was unable to induce NF-kappaB in post-intervention samples, suggesting that the mixture of four important natural agents could be useful to protect humans against oxidative stress.

New difluoro Knoevenagel condensates of curcumin, their Schiff bases and copper complexes as proteasome inhibitors and apoptosis inducers in cancer cells.

PURPOSE: Emerging evidence clearly suggests the potential chemopreventive and anti-tumor activity of a well known "natural agent" curcumin. However, studies have shown that curcumin is not readily bioavailable, and thus the tissue bioavailability of curcumin is also poor except for gastrointestinal track. Because of the potential biological activity of curcumin, many studies have attempted for making a better analog of curcumin that is equally effective or better with increased bioavailability, which was the purpose of our current study. METHODS: We have designed and synthesized new difluoro Knoevenagel condensates of curcumin and Schiff bases along with their copper (II) complexes and evaluated their biological activities with respect to the inhibitory effects on purified rabbit 26S proteasome, and growth inhibition and induction of apoptosis in colon and pancreatic cancer cell lines. RESULTS: All copper complexes possess distorted square planar geometries with 1:1 metal to ligand stoichiometry with reversible copper redox couple. The difluoro compound CDF exhibited inhibitory effects on purified rabbit 20S proteasome or cellular 26S proteasome, and caused both growth inhibition of cancer cell lines and induced apoptotic cell death in our preliminary assessment. CONCLUSION: Our results suggest that our newly synthesized classes of curcumin analogs could be useful as chemopreventive and/or therapeutic agents against cancers.