Low-Molecular-Weight Hydrolysate from Black Goat Extract Had Antioxidative and Anti-Inflammatory Effects in Macrophage Cells via Inhibition of MAPKs and NF-B Pathways

This study evaluated the antioxidative and anti-inflammatory effects of a low-molecular-weight hydrolysate derived from black goat extract using alcalase, ProteAX, and trypsin (APT6 < 3 kDa). The APT6 < 3 kDa exhibited high antioxidative activities with estimated contents of 41.24% for antioxidative amino acids and 49.55% for hydrophobic amino acids. APT6 < 3 kDa inhibited nitric oxide and prostaglandin E-2 production in RAW 264.7 cells induced by lipopolysaccharide (p < 0.05), which was accompanied by the inhibition of inducible nitric oxide synthase and cyclooxygenase-2 protein expression. Additionally, APT6 < 3 kDa downregulated the mRNA expression and production of TNF-alpha and IL-1 beta (p<0.05). Mechanistically, these anti-inflammatory effects of APT6 < 3 kDa were shown by downregulating the MAPK and NF-kappa B pathways in a dose-dependent manner. Overall, 43 peptides were isolated from a certain fraction (F5) of APT6 < 3 kDa, demonstrating high antioxidative and anti-inflammatory activities. These results suggest that identified peptides from APT6 < 3 kDa possess natural antioxidants and hold potential as anti-inflammatory agents.