Invitro free radical scavenging capacity of dimethylglycine sodium salt and its protective ability against oleic acid hydroperoxide-induced oxidative damage in IPEC-J2 cells.

Abstract

The aim of the present study was to evaluate the invitro free radical scavenging capacity of dimethylglycine sodium (DMG‑Na) and its protective ability against oleic acid hydroperoxide (OAHPx)‑induced oxidative damage in IPEC‑J2 cells. Initially, the free radical scavenging activities of water‑soluble pigments (DMG‑Na, betalain, capsanthin and cyanidin‑3‑rutinoside) were measured and compared with those of Trolox. Subsequently, freshly collected swine blood was mixed with heparin and centrifuged to obtain erythrocytes. In order to induce the free radical chain oxidation in erythrocytes, the aqueous peroxyl radicals were generated by thermal decomposition of 2,2'‑azobis(2‑amidinopropane) dihydrochloride (AAPH) in oxygen. A 2% suspension of porcine erythrocytes in PBS buffer were pre‑incubated for 30min at 37˚C with DMG‑Na (32µM), followed by incubation with or without AAPH (75mM) for 5h with gentle shaking. Additionally, IPEC‑J2 cells were randomly assigned to four groups (n=6per group): Cells treated with phosphate buffered saline (PBS); cells treated with DMG‑Na (32µM); cells treated with oleic acid hydroperoxides (OAHPx, 20µM; TO group); cells treated with DMG‑Na (32µM) followed by OAHPx (20µM; DTO group). The cells were cultured in Dulbecco's modified Eagle's medium, Ham's F‑12mixture, 1.5mM HEPES, 5% (v/v) fetal bovine serum, 1% (v/v) insulin‑transferrin‑selenium mixture, 1% (v/v) penicillin‑streptomycin mixture and 2.5µg/ml fungizone (37˚C, 5% CO2). The results showed that DMG‑Na exerted the strongest free radical scavenging capacity at 0.32M from 0.08‑0.64M, and that it could prevent AAPH‑induced porcine erythrocyte hemolysis by increasing its antioxidant capacity (P<0.05). The results also demonstrated that antioxidant capacity and antioxidant‑associated gene expression increased in the DTO group relative to the TO group (P<0.05), indicating that DMG‑Na prevented the OAHPx‑induced oxidative damage in IPEC‑J2 cells by improving the antioxidant capacity and antioxidant‑associated gene expression.