Potential of cranberry-based herbal synergies for diabetes and hypertension management.Asia Pac J Clin Nutr. 2006; 15(3):433-41.AP
Water soluble cranberry-based phytochemical combinations with oregano, rosemary, and Rhodiola rosea were evaluated for total phenolic content, related antioxidant activity and inhibition of diabetes management-related alpha -glucosidase, pancreatic alpha-amylase inhibition, and hypertension-related ACE-I inhibitory activities. Water extracts of oregano had 114.9 mg/g DW of phenolics which was highest among all the extracts tested, whereas the 75% cranberry with 25% oregano combinations had the highest phenolics (38.9 mg/g DW) among all the combinations tested. The water extracts of oregano had the highest DPPH radical inhibition activity (73.6 %), whereas among combinations the 75% cranberry and 25% oregano had the highest DPPH radical inhibition activity (50.8 %). These results indicated a correlation between total phenolic content and antioxidant activity. The water extracts of pure Rhodiola rosea had the highest alpha -glucosidase inhibition, whereas the 75% cranberry and 25% Rhodiola rosea combination had the highest inhibition among the combinations. In the case of alpha -amylase inhibition the water extracts of Rhodiola rosea had the highest inhibition, whereas the 75% cranberry with 25% Rhodiola rosea combination had the highest inhibition among the combinations. All the water extracts tested indicated that they had anti-ACE-I inhibitory activity. More specifically, among the water extracts 100% cranberry had the highest ACE-I inhibitory activity and among the combination the 75% cranberry with 25% rosemary had the highest ACE-I inhibitory activity. The analysis of alpha -glucosidase,alpha -amylase, and ACE-I inhibitory activities suggested that inhibition depend on the phenolic profile of each unique extract and by bringing together synergistic combinations to cranberry, health beneficial functionality was enhanced. This enhanced functionality in terms of high alpha -glucosidase and alpha -amylase inhibitory activities indicate the potential for diabetes management, and high ACE-I inhibitory activity indicates the potential for hypertension management.