Considering I generally include turmeric in most food preparations, the following paper makes for depressing reading:
The Essential Medicinal Chemistry of Curcumin
Kathryn M. Nelson, Jayme L. Dahlin, Jonathan Bisson, James Graham, Guido F. Pauli,
and Michael A. Walters
ABSTRACT:
Curcumin is a constituent (up to ?5% ) of the traditional medicine known as turmeric. Interest in the therapeutic use of turmeric and the relative ease of isolation of curcuminoids has led to their extensive investigation. Curcumin has recently been classified as both a PAINS (panassay interference compounds) and an IMPS (invalid metabolic panaceas) candidate. The likely false activity of curcumin in vitro and in vivo has resulted in >120 clinical trials of curcuminoids against several diseases.
No doubleblinded, placebo controlled clinical trial of curcumin has been successful. This manuscript reviews the essential medicinal chemistry of curcumin and provides evidence that curcumin is an unstable, reactive, nonbioavailable compound and, therefore, a highly improbable lead. On the basis of this in-depth evaluation, potential new directions for research on curcuminoids are discussed.
CONCLUSIONS: FUTURE CURCUMIN RESEARCH:
At first, curcumin appeared to offer great potential for the development of a therapeutic from a Natural product (turmeric) that is classified as a “generally recognized as safe” material. Unfortunately, no form of curcumin, or its closely related analogues, appears to possess the properties required for a good drug candidate (chemical stability, high water solubility, potent and selective target activity, high bioavailability, broad tissue distribution, stable metabolism, and low toxicity). The in vitro interference properties of curcumin do, however, offer many traps that can trick unprepared researchers into misinterpreting the results of their investigations.
With respect to curcumin/curcuminoids and in vivo studies and clinical trials, we believe there is rather “much ado about nothing”. Certainly, the low systemic exposure levels reported in clinical trials do not support its further investigation as a therapeutic..
http://pubs.acs.org/doi/pdf/10.1021/acs.jmedchem.6b00975
The Essential Medicinal Chemistry of Curcumin
Kathryn M. Nelson, Jayme L. Dahlin, Jonathan Bisson, James Graham, Guido F. Pauli,
and Michael A. Walters
ABSTRACT:
Curcumin is a constituent (up to ?5% ) of the traditional medicine known as turmeric. Interest in the therapeutic use of turmeric and the relative ease of isolation of curcuminoids has led to their extensive investigation. Curcumin has recently been classified as both a PAINS (panassay interference compounds) and an IMPS (invalid metabolic panaceas) candidate. The likely false activity of curcumin in vitro and in vivo has resulted in >120 clinical trials of curcuminoids against several diseases.
No doubleblinded, placebo controlled clinical trial of curcumin has been successful. This manuscript reviews the essential medicinal chemistry of curcumin and provides evidence that curcumin is an unstable, reactive, nonbioavailable compound and, therefore, a highly improbable lead. On the basis of this in-depth evaluation, potential new directions for research on curcuminoids are discussed.
CONCLUSIONS: FUTURE CURCUMIN RESEARCH:
At first, curcumin appeared to offer great potential for the development of a therapeutic from a Natural product (turmeric) that is classified as a “generally recognized as safe” material. Unfortunately, no form of curcumin, or its closely related analogues, appears to possess the properties required for a good drug candidate (chemical stability, high water solubility, potent and selective target activity, high bioavailability, broad tissue distribution, stable metabolism, and low toxicity). The in vitro interference properties of curcumin do, however, offer many traps that can trick unprepared researchers into misinterpreting the results of their investigations.
With respect to curcumin/curcuminoids and in vivo studies and clinical trials, we believe there is rather “much ado about nothing”. Certainly, the low systemic exposure levels reported in clinical trials do not support its further investigation as a therapeutic..
http://pubs.acs.org/doi/pdf/10.1021/acs.jmedchem.6b00975