Wound healing: a new perspective on glucosylated tetrahydrocurcumin.

Wound healing represents a dynamic set of coordinated physiological processes observed in response to tissue injury. Several natural products are known to accelerate the process of wound healing. Tetrahydrocurcumin (THC), an in vivo biotransformed product/metabolite of curcumin, is known to exhibit a wide spectrum of biological activities similar to those of native curcuminoids. The poor bioavailability of these curcuminoids limits their clinical applications. The present study highlights the percutaneous absorption and wound healing activity of glucosyl-conjugated THC (glucosyl-THC) in male Wistar rats. A high plasma concentration of glucosyl-THC (4.35 µg/mL) was found in rats 3 hours after application. A significant enhanced wound healing activity and reduced epithelialization time were observed in rats that received glucosyl-THC. This may have been due to the improved bioavailability of the glucosyl compound. The nonstaining and lack of skin-sensitive side effects render the bioconjugated glucosyl-THC a promising therapeutic compound in the management of excision wounds and in cosmetic applications, in the near future.

Synthesis and biological evaluation of glucosyl curcuminoids.

Medicinal plants proved to be a rich source in exploring a variety of lead structures in the development of new drugs. The natural curcuminoids have gained considerable attention in recent years for their multiple beneficial pharmacological and biological activities. Clinical application of these curcuminoids is often impaired due to their poor water solubility, resulting in low in vivo bioavailability of the active compound in humans. The objective of the present study is to synthesize glucosyl conjugates of curcumin 1 and tetrahydrocurcumin 4 and to evaluate their biological activities. The study highlights the synthesis of curcumin-ß-di-glucoside 3 (yield 71%) and tetrahydrocurcumin-ß-di-glucoside 6 (yield 64%) in good yields in a biphasic reaction medium using a phase transfer catalyst under simple and ecofriendly conditions. Both the glucosyl curcuminoids showed enhanced antioxidant, tyrosinase enzyme inhibitory, antimicrobial and potent cytotoxic activity. The improved biological activity may be due to the increased solubility of the glucosyl conjugated compounds compared to the native curcuminoids; this was further confirmed by partition coefficient studies. Thus, the synthesized glucosyl curcumin may serve as promising future therapeutic molecule in the management of cancer, whereas glucosyl tetrahydrocurcumin can be a useful ingredient in achromatic food and in cosmetic applications.