Curcumin: Structure, Biology and Clinical Applications

Abstract

Curcumin, the principal polyphenolic curcuminoid derived from the rhizome Curcuma longa, is present in an Indian spice, turmeric. Curcumin possesses antitumor, antioxidant, and anti-inflammatory properties, and has been studied as a cancer chemopreventive agent. Curcumin is extensively studied, evaluated and accepted for its wide range of medicinal properties. The therapeutic activities of curcumin for a wide variety of diseases such as diabetes, allergies, arthritis and other chronic and inflammatory diseases have been known for a long time. The mechanisms of therapeutic action of curcumin include inhibition of several cell signaling pathways at multiple levels, immune-modulation, effects on cellular enzymes such as cyclooxygenase and glutathione S-transferases and effects on angiogenesis and metastasis. It has ability to affect gene transcription and induce cell cycle arrest and apoptosis. Although curcumin is a highly pleiotropic molecule with an excellent safety profile targeting multiple diseases, it could not achieve its optimum therapeutic outcome in clinical trials, largely due to its low solubility and poor bioavailability. Based on the results of the clinical trials, curcumin can be developed as a therapeutic drug through improvement in formulations or delivery systems, enabling its enhanced absorption and cellular uptake. In this review article, we provide a comprehensive outlook for the therapeutic potential of curcumin, and discuss future strategies and potential challenges involved in the use of curcumin.