Vitamin C combined with oregano essential oil, Origanum vulgare, reduced oxidative damage in Astyanax aff. bimaculatus exposed to air

Abstract

Abstract The dietary impacts of water-soluble (vitamin C) and fat-soluble (oregano essential oil, OEO) antioxidants on the stress responses and redox status of Astyanax aff. bimaculatus exposed to the air were assessed. Five diets with vitamin C (VC 0, VC 40, VC 80, VC 120, and VC 160 mg kg− 1) with or without OEO inclusion (0 or 1,000 mg kg− 1) were evaluated. After 55 days of feeding, fish were exposed to air for 5 min. VC 120 and VC 160 reduced glycemia. In the gills, VC 120 and VC 160 reduced oxidative damage (malondialdehyde, MDA, and carbonylated proteins, PC) and superoxide dismutase (SOD) activity only in the presence of OEO. By contrast, in the absence of VC, OEO increased PC levels and SOD activity. In the liver, all VC concentrations, without OEO, reduced MDA, whereas, in the presence of OEO, vitamin C reduced MDA only at VC 40 e VC 160. All vitamin C concentrations, independently of OEO, reduced PC levels and SOD and catalase (CAT) activity. By contrast, OEO increased CAT and glutathione S-transferase (GST) activity regardless of VC level. Although VC 40 with 1,000 mg kg− 1 OEO was sufficient to reduce oxidative damage to lipids in the gills and liver, reduction in protein and lipid damage in the gills was only obtained with at least VC 120 + OEO. Therefore, we recommend simultaneous supplementation of these antioxidants, as their combined use is more efficient in reducing oxidative damage in A. aff. bimaculatus subjected to air.