Synergies of herbal teas on improved plasma antioxidant capacity and postprandial hypoglycemic response in healthy adults
Herbal teas play a major role in the global traditional food cultures. There are a variety of herbal teas used for general wellness and prevention and management of chronic diseases including diabetes mellitus. The present study aimed to determine the phenolic content and antioxidant activities of herbal teas prepared with matured jackfruit (Artocarpus heterophyllus) leaves after senescence and abscission, and dried Cassia (Cassia auriculata) flowers and buds. The sensory evaluation was performed using 50 untrained panelists to determine the amount of herbal ingredient to be used in the preparation of herbal tea. Furthermore, the potential single dose efficacy of three herbal teas, namely, Jackfruit leaves tea (JLT), Cassia flower tea (CFT) and mixed jackfruit leaves and Cassia flower tea (JCT) on postprandial glycemic response and plasma antioxidant capacity (PAC) of healthy adults were investigated. Phenolics were identified using high performance liquid chromatography–tandem mass spectrometry. A randomized crossover study was led with 16 healthy adults who consumed 250 mL of freshly prepared herbal beverage with 50 g glucose and 50 g glucose in 250 mL water as the control randomly within three visits with a washout period of four days between two visits. Blood samples were collected using microcapillary tubes at the baseline and postprandial at 30, 45, 60, 90, and 120 min. The plasma was analyzed for glucose concentration (PGC) and PAC. JLT and JCT showed a significant reduction of PGC compared to the control at 30, 45, and 60 min time points. JLT and JCT showed higher efficacy in plasma glucose reduction than CFT. All herbal teas significantly increased PAC at the end of 120 min post ingestion. Further research is warranted to examine the synergistic effect of two mixed ingredients for herbal tea and the long-term efficacy of multiple dose ingestion of respective herbal teas in the prevention and management of hyperglycemia and type 2 diabetes.