Antioxidant synergistic effects of Osmanthus fragrans flowers with green tea and their major contributed antioxidant compounds

Shuqin Mao,Kaidi Wang,Shuting Yao,Weisu Huang,Yukun Lei,Baiyi Lu

doi:10.1038/srep46501

Abstract

The antioxidant synergistic effects of Osmanthus fragrans flowers with green tea were evaluated, and their major antioxidant compounds contributed to the total amount of synergy were determined. The antioxidant compounds in O. fragrans flowers with green tea were identified by LC-MS and quantified by UPLC-PDA. The synergistic antioxidant interactions between O. fragrans flowers with green tea and their antioxidant compounds were tested using the Prieto’s model after the simulated digestion. The main antioxidant compounds in O. fragrans flowers were acteoside and salideroside, whereas the main antioxidant compounds in green tea were caffeine, gallic acid, and L-epicatechin. The significant synergistic effect between O. fragrans flowers and green tea was observed and among nearly all of the combinations of their antioxidant compounds. Among the combinations, acteoside and gallic acid contributed most to the antioxidant synergy between O. fragrans flowers and green tea. However, the simulated digestion decreased this antioxidant synergy because it reduced the contents and the antioxidant capacities of their compounds, as well as the antioxidant synergy among the compounds.

Highlights

The type of interactive effects is often determined through extremely simple relationships and through basic procedures instead of classical approaches[14]
In this study, we aimed to measure the antioxidant synergy between O. fragrans flowers and green tea as well as among the antioxidant compounds in O. fragrans flowers with green tea using a simulated digestion model
The results showed that O. fragrans flowers had synergistic antioxidant effects with all the teas (Fig. 1)

Summary

Introduction

The type of interactive effects is often determined through extremely simple relationships and through basic procedures instead of classical approaches[14]. A procedure has been described to identify and quantify the interactive effects between two antioxidants and applied to investigate interactive mechanisms in complex mixtures of antioxidants[15]. The total phenylethanoid glycoside contents and antioxidant activities in O. fragrans flowers were reported to decrease significantly after digestion[16]. Other studies showed that the total antioxidant capacity in tea extracts decreased after digestion in vitro[17]. In this study, we aimed to measure the antioxidant synergy between O. fragrans flowers and green tea as well as among the antioxidant compounds in O. fragrans flowers with green tea using a simulated digestion model. The major compounds which have the most contribution to antioxidant synergy were identified. We aimed to analyse the influence of simulated digestion and examine the factors involved in this influence

Objectives

Methods

Results