ANONGNUCH THAKAM, NISAKORN SAEWAN*
*Corresponding author nisakorn saewan
School of Cosmetic Science, Mae Fah Luang University, 333 Thasud, 57100, Muang, Chiangrai, Thailand

Abstract

Curcumin, a natural compound, is known to have many pharmacological properties. A major problem in its application in cosmetic products is that it rapidly decomposes under high temperature and exposure to light. To overcome issue, curcumin compelxes with transition metals were prepared. In this study, the Zn (II) and Mg (II) were complexed with curcumin, and the resulting products were characterized by means of spectroscopic techniques, including MS, UV-vis and IR. The spectra data have revealed that the metal-atom complex with two curcumin molecules at the diketone moiety afford M(Cur)2. The thermal and UV stability of the complexes were analysed in solution and emulsion systems employed as a model for the application of curcumin in pharmaceutical and cosmetic industries. At all storage conditions, the metal complexes showed higher stability when compared with free curcumin. These results suggest that the stability of curcumin in emulsion was increased due to its complexation with Zn (II) and Mg (II).

INTRODUCTION

Curcumin, a polyphenol found in plants belonging to the Curcuma genus, is known to have a wide varierety of therapeutic effects, such as anti-cancer (1), anti-inflammatory (2), inhibition of bacterial and fungal growth (3-4), anti-oxidant and inhibition of tyrosinase enzyme activity (5-7), etc. Due to its therapeutical properties, this natural phytochemical is popularly used in food supplements, cosmetics, pharmaceuticals, and for many other uses. However, curcumin is prone to degradation when it is exposed to oxidation, light, alkalinity, enzymes and heat. Degradation limits its application in pharmaceutical and cosmetic products (8-9). One way to enhance the stability and biological activity of curcumin, consists in complexting it with transition metal ions (10-14). The curcumin-copper (II) complex showed a six fold greater lipid-peroxidation inhibition than curcumin by TBARs (Thiobarbituric acid reactive substances) assay (10). Barik and Vajragupta have demonstrated that the curcumin-copper (II) and manganese (II) complexes showed a ten fold superoxide dismutase (SOD) inhibition than the free curcumin (10,12). Curcumin showed a two fold l ...