Phenolic Profile and Antioxidant Activity of the Edible Tree Peony Flower and Underlying Mechanisms of Preventive Effect on H2O2-Induced Oxidative Damage in Caco-2 Cells.

Xiang Xiang,Yang Yang,Beta Beta,Liu Liu

doi:10.3390/foods8100471

Abstract

The entire phenolic profiles and antioxidant activities of different organs of the edible tree peony flowers (Fengdan Bai (FDB)) were analyzed. HPLC-quadrupole time-of-flight mass spectrometer (Q-TOF-MS/MS) analyses of individual phenolic compounds revealed that the petal and stamen contained higher levels of flavonoid glycosides than other organs (p < 0.05). Kaempferol-3,7-di-O-glucoside was the dominant flavonoid in these two organs, however, the calyx and ovary contained higher contents of gallic acid derivatives than other organs (p < 0.05). Hexa-O-galloyl-glucose was the dominant species in the calyx and ovary. At the same concentration of total phenolic extract (TPE), the stamen had the highest protection effect on Caco-2 cell oxidative damage induced by H2O2. The antioxidant effect was attributed to potent antioxidant capability; restored redox state due to the increased expression of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD); and improved barrier function of Caco-2 cell owing to increased zonula occludens-1 (ZO-1), CLDN3 (Claudin 3), and occludin mRNA expression. As a new resource food, the edible tree peony flower is a potential functional food material and natural antioxidants resource.

Highlights

With increasing evidence that reactive oxygen species (ROS) induce oxidative stress during the development of various chronic and degenerative diseases, such as cancer, cardiovascular disease, diabetes mellitus, and aging, radical-scavenging antioxidants for preventing oxidative stress-related diseases have received great attention [1]
Hank’s balanced salt solution (HBSS), dulbecco’s modified eagle medium /F12 (DMEM/F12), anti-anti and fetal bovine serum (FBS) T-75 culture flasks, Transwell Permeable supports (0.6 cm2, 0.4 μm pore size), and cell culture plate were purchased from Invitrogen, Fisher Scientific (Ottawa, ON, Canada)
Compounds were identified by comparing with the authentic standards, or tentatively identified by comparing their mass and UV spectral characteristics with those reported in the literature (Supplementary File)

Summary

Introduction

With increasing evidence that reactive oxygen species (ROS) induce oxidative stress during the development of various chronic and degenerative diseases, such as cancer, cardiovascular disease, diabetes mellitus, and aging, radical-scavenging antioxidants for preventing oxidative stress-related diseases have received great attention [1]. The increased demand for new, natural antioxidant foods has generated an interest in edible flowers in recent years [2,3,4]. Tree peony (Paeonia suffruticosa Andr.) is native to China with more than 1600 years’ history of cultivation, and is considered as a traditional ornamental and medicinal plant [5]. The flower color of tree peony is diverse with nine categories that include red, white, green, pink, blue, purple, black, yellow, and dual colors [5]. The antioxidant activity is attributed mainly to anthocyanins in the purple, pink, and red categories [6,7], and flavonoids in the yellow and white categories [6,8].

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Results

Conclusion