Turmeric: old spice, new spice.

The history of chemical investigations into the yellow components of turmeric can be traced from 1815. Although the major yellow component of turmeric, curcumin, often is represented as a 1,3-diketone in the solid state and in nonaqueous solution, it exists in the enol form. The struggle to identify the chemical structure of curcumin continued for nearly a century and was complicated by the difficult purification of curcumin and by the presence of two additional yellow components. Food remains the main use for turmeric (old spice); its use as a dye has diminished since the 19th century, but it may have pharmaceutical uses (new spice).

Curcumin, an active constiuent of the ancient medicinal herb Curcuma longa L.: some uses and the establishment and biological basis of medical efficacy.

The root extract, curcumin (diferuloylmethane), is a constituent of the ancient herbal medicine Jiawei-Xiaoyaosan that has been used for dyspepsia, stress, and mood disorders. Curcumin engenders a diverse profile of biological actions that result in changes in oxidative stress, inflammation, and cell-death pathways. Combined with its historical use in medical practice and its safety profile, curcumin has been studied for its potential therapeutic applications in cancer, aging, endocrine, immunological, gastrointestinal, and cardiac diseases. In addition, data in animal models and in humans have also begun to be collected in stroke, Alzheimer's disease, and Parkinson's disease. A compelling new body of literature is also mounting to support the efficacy of curcumin in stress and mood disorders. Current understanding of the biological basis for antidepressant-relevant biochemical and behavioral changes shows convergence with some mechanisms known for standard antidepressants. In addition, the mechanisms of the antidepressant-like pharmacology of curcumin also appear to overlap with those of other disease states. Thus, ancient wisdom might be built into this interesting and newly-appreciated natural molecule. Although curcumin is a primary ingredient in anti-aging pills, cosmetic creams, eye treatments, diet products, etc, a key hurdle to the development of curcumin for disease treatment and prevention is overcoming its low oral bioavailability. Although multiple approaches to this problem are being examined, a solution to the bioavailability issue will be needed to ensure appropriate tissue exposures of curcumin in clinical investigation. Progress in this regard is underway.

Bioactive compounds: historical perspectives, opportunities, and challenges.

Mom's conventional wisdom of eating fruits and vegetables to lead a healthy life has evolved with scientific, fact-finding research during the past four decades due to advances in science of "Foods for Health". Epidemiological and prospective studies have demonstrated the vital role of fruits, vegetables, and nuts in reducing the risk of cancer and cardiovascular diseases. In recent years, several meta-analyses strongly suggested that by adding one serving of fruits and vegetables to daily diet, the risk of cardiovascular diseases will be decreased up to 7%. The multidisciplinary and partnership efforts of agriculture and medical scientists across the globe stimulated interest in establishing certain interdisciplinary centers and institutes focusing on "Foods for Health". While the consumption of various healthy foods continues, several questions about toxicity, bioavailability, and food-drug interactions of bioactive compounds are yet to be fully understood on the basis of scientific evidence. Recent research on elucidation of the molecular mechanisms to understand the "proof of the concept" will provide the perfect answer when consumers are ready for a "consumer-to-farm" rather than the current "farm-to-consumer" approach. The multidisciplinary research and educational efforts will address the role of healthy foods to improve eye, brain, and heart health while reducing the risk of cancer. Through this connection, this review is an attempt to provide insight and historical perspectives on some of the bioactive compounds from the day of discovery to their current status. The bioactive compounds discussed in this review are flavonoids, carotenoids, curcumin, ascorbic acid, and citrus limonoids.