Antioxidant and prebiotic gut-microbiota effects of dietary phenolic compounds in Etlingera elatior extracts

Etlingera elatior, commonly found in South East Asia, is known to have high antioxidant activities. The purposes of the present work were to investigate the effects of different solvents on the extraction of total phenolic (TPC) and flavonoid compounds (FC) of E. elatior inflorescences, and to test their antioxidant and prebiotic effects. The highest yield (14.12%) of E. elatior extract was obtained from a 50% ethanol extract with the highest TPC and flavonoids contents being observed in 70 and 95% ethanol extracts. The ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6sulphonic acid (ABTS) and iron chelating activities were also investigated. The results showed that the 70% ethanol extract had high values for DPPH, FRAP, and ABTS, whereas the 95% ethanol extract had higher iron chelating activities. The E. elatior TPC showed a prebiotic-like effect by significantly decreasing the populations of harmful bacteria through the production of short chain fatty acids. The present work demonstrated that E. elatior has the potentials for applications as a natural functional ingredient for the modulation of gut microbiota. (C) All Rights Reserved