Curr Pharm Biotechnol. 2020 Aug 6. Epub 2020 Aug 6. PMID: 32767918
Comparative Inhibitory Efficacy on the iNOS/NO System of Curcumin- and Tetrahydrocurcumin-Self-Microemulsifying Liquid Formulation in Chronic Gastric Ulcer Model.
BACKGROUND: Curcumin was found to accelerate gastric ulcer healing by a main mechanism through suppression of iNOS mediated inflammation. Although tetrahydrocurcumin (THC) is claimed as an active antioxidant principle of curcumin, its antiulcer activity has not been systematically examined. The utility of self- microemulsifying drug delivery systems (SMEDDS) for curcumin and THC formulations in liquid form was also found to increase the rate and extent of release of curcumin- and THC-SMEDDS. Nevertheless, the beneficial antiulcer efficacy of these nanoproducts has not yet been evaluated.OBJECTIVE: This study aimed to evaluate and compare antiulcer efficacy of curcumin- and THC-SMEDDS through inhibition of the iNOS/NO system in rat model.METHODS: Antiulcer efficacy was compared in terms of an ability to accelerate the healing of gastric ulcerincluding the inhibitory efficacy on inflammatory NO production in activated macrophages and iNOS mRNA expression at the ulcerated area.RESULTS: THC was found to have less ulcer healing capacity than curcumin with a lack of significant inhibitory effect on the iNOS/NO system. SMEDDS used in the study significantly increased the inhibitory efficacy of THC on iNOS/NO production and iNOS mRNA expression into a comparable inhibitory potency to that of curcumin. An oral administration of curcumin- or THC-SMEDDS once a day was capable of exerting a comparable curative efficacy to a twice-daily oral administration of curcumin or THC.CONCLUSION: The SMEDDS used in the study could bring an enhancement of inhibitory efficacy on the iNOS/NO system of antiulcer drug, leading to a reduction of daily dosing and dosing frequency.