Ulva prolifera Extract Alleviates Intestinal Oxidative Stress via Nrf2 Signaling in Weaned Piglets Challenged With Hydrogen Peroxide.

Yanzhong Feng,Zhimin An,Haifeng Zhang,Di Liu,Heshu Chen,Xiang Li,Wentao Wang,Xinmiao He,Fenglan Li

doi:10.3389/fimmu.2020.599735

Abstract

Background Ulva prolifera extract contains a variety of functional active substances. Whether these substances had any beneficial effects on the small intestine of weaned piglets under oxidative stress remained unknown.MethodWe explored the effects of U. prolifera extract on oxidative stress and related mechanisms in weaned piglets and intestinal porcine epithelial cells (IPEC-J2) challenged with hydrogen peroxide.Results U. prolifera extract was found to mainly consist of polyphenols and unsaturated fatty acids. U. prolifera extract increased total antioxidant capacity and superoxide dismutase (SOD) activity, while it decreased malondialdehyde content, in the serum of weaned piglets challenged with hydrogen peroxide. Moreover, U. prolifera extract increased mRNA expression of SOD and catalase, as well as the intestinal expression of nuclear NF-E2-related factor 2 (Nrf2), both in vitro and in vivo. Furthermore, U. prolifera extract decreased reactive oxygen species and improved mitochondrial respiration in IPEC-J2 cells treated with hydrogen peroxide. However, AMPK inhibition did not affect nuclear Nrf2 expression and only partially affected the effects of U. prolifera extract on oxidative stress.ConclusionWe suggest that U. prolifera extract alleviates oxidative stress via Nrf2 signaling, but independent of AMPK pathway in weaned piglets challenged with hydrogen peroxide. These results shed new insight into the potential applications of U. prolifera extract as a therapeutic agent for the prevention and treatment of oxidative stress-induced intestinal diseases.

Highlights

Ulva prolifera is a common green algae that blooms in the Bohai and the Yellow Seas of China [1]
When the piglets’ diet was supplemented with U. prolifera extract, the growth performance was unchanged compared with control piglets, even if the piglets were challenged with hydrogen peroxide
Piglets challenged with hydrogen peroxide had lower total antioxidant capacity (TAOC) and superoxide dismutase (SOD) activities, but higher MDA content in serum, while no such changes were observed in piglets supplemented with U. prolifera extract (Figures 1D–F)

Summary

Introduction

Ulva prolifera is a common green algae that blooms in the Bohai and the Yellow Seas of China [1]. Many components such as polyphenols, flavonoids, and polysaccharides have been extracted from U. prolifera [3,4,5]. U. prolifera extract has the potential to be used for the prevention and treatment of diseases such as diabetes and non-alcoholic fatty liver diseases [4, 7]. It remains unknown whether U. prolifera extract has any effects on oxidative damage in the intestine. Ulva prolifera extract contains a variety of functional active substances Whether these substances had any beneficial effects on the small intestine of weaned piglets under oxidative stress remained unknown

Methods

Results

Conclusion