Evaluation of the In Vivo Antioxidant Capacity of Sheep Hemoglobin Hydrolysate in a Rat Model

Sheep hemoglobin hydrolysate (SHH) has important biological antioxidant functions. However, the specific mechanism is not well understood. The aim of this study was to investigate the antioxidant activity of SHH in vivo and its potential mechanism. Eighteen Sprague Dawley rats were randomly divided into DG (gavaged with 0.9% saline), VC (gavaged with vitamin C 100 mg/kg BW) and SHH (gavaged with SHH 800 mg/kg BW) groups. The rats were given intragastric administration for 21 days. On the 22nd day, all rats were intraperitoneally injected with diquat as a challenge. The results showed that SHH treatment had no obvious effect on the growth performance and main organ index of rats after the diquat challenge. Compared to the DG group, the SHH group maintained higher serum T-AOC and GSH-Px levels after the diquat challenge. SHH significantly increased GSH-Px activity in the liver and kidney, and decreased MDA content in the kidney after the diquat challenge. SHH significantly up-regulated the gene expression of TrxR in the liver and Nrf2 in the kidney but had no significant effect on the expression of NF-κB in the kidney. Histopathological observations showed that SHH could improve the morphology of liver cells, and no obvious pathological damage was found in all organs. In conclusion, the relative decrease in oxidative stress markers observed with prophylactic SHH supplementation after diquat challenge may be mediated by the regulation of transcriptional expression of Nrf2-related redox genes. These findings demonstrate SHH's potential as a natural antioxidant and provide promising strategies for converting low-value meat industry byproducts into functional supplements.