Grape Seed Extract Supplementation Attenuates The Heat Stress-induced Responses Function And Mechanism Research Of Jejunum Epithelial Cells In Simmental×Qinchuan Steers

Grape seed extract (GSE), a rich source of polyphenols, is reported to posses antioxidant, anti-inflammatory and immunomodulatory properties. The objective of the present study was to determine whether GSE could attenuate the heat stress-induced responses of jejunum epithelial cells (JEC) in cattle. The JEC of a steer (Simmental × Qinchuan) were exposed to heat stress for 2 h in the absence (0 mg/mL) or presence (10,20,40 and 80 mg/mL) of GSE in the culture medium. When cultured at 40℃, JEC supplemented with GSE exhibited increased glutathione peroxidase activity (P < 0.04), viability (P< 0.004), and mRNA expression of epidermal growth factor (EGF; P< 0.03) and EGF receptor (EGFR; P< 0.01). Under the same conditions, the cells exhibited decreased mRNA expression of IL-8 (P< 0.01) and TNF-a (P< 0.03) and decreased protein concentrations of IL-1β (P< 0.02), Toll-like receptor 4 (TLR4; P< 0.04) and heat shock protein70 (HSP70; P< 0.001). When cultured at 43 ℃, JEC supplemented with GSE exhibited increased catalase activity(P < 0.04), viability (P< 0.001), and mRNA expression of EGF (P< 0.001) and EGFR (P< 0.001) and decreased protein concentrations of IL-1β (P< 0.001), TLR4 (P< 0.03) and HSP70 (P< 0.001), as well as mRNA expression of IL-8 (P< 0.001), TLR4(P< 0.002) and TNF-a (P< 0.001). Temperature×GSE concentration interactions were also observed for the concentrations of IL-1 β (P < 0.001), IL-8(P< 0.001), TNF-a (P< 0.01) and HSP70 (P< 0.04) and viability (P< 0.001) of JEC. The results of the present study indicate that GSE can attenuate the responses of JEC induced by heat stress with in a certain range of temperatures.