Protective Effect of Water Extract of Citrus Pomace against AAPH-Induced Oxidative Stress In Vitro in Vero Cells and In Vivo in Zebrafish

Citrus pomace (CP) is a by-product occurred during juice or other products processing. The enormous amount of CP caused serious environmental issues. However, CP is rich in a variety of bioactive compounds. In the present study, a water extract of CP (CPW) was prepared from the by-product and the in vitro and in vivo antioxidant activities of CPW were investigated. The in vitro antioxidant activities of CPW were evaluated by measuring the free radical scavenging activity and protective effects against 2,2-azobis(2-amidinopropane) hydrochloride (AAPH)-induced oxidative stress in Vero cells. CPW scavenges 1,1-diphenyl-2-picrylhydrazyl, alkyl, and hydroxyl radicals at IC(50) of 0.16±0.00, 0.31±0.01, and 0.86±0.02 mg/mL, respectively. In addition, CPW improved cell viability and scavenged intracellular reactive oxygen species (ROS) in AAPH-stimulated Vero cells in a dose-dependent manner. The in vivo antioxidant activities of CPW were investigated in a model of AAPH-induced zebrafish embryos. CPW significantly improved the survival rates and reduced heartbeat rates in AAPH-stimulated zebrafish. Furthermore, the intracellular ROS and cell death levels were remarkably decreased in CPW-treated zebrafish. Therefore, the present results indicated that CPW possesses potent in vitro and in vivo antioxidant properties and could be a potential ingredient used in food, pharmaceutical, and cosmetic industries.