High Fischer ratio oligopeptides from hard-shelled mussel:Preparation and hepatoprotective effect against acetaminophen-induced liver injury in mice

High Fischer ratio oligopeptides(HFOPs)have a variety of physiological activities,but there are few literatures reporting the hepatoprotective effects of HFOPs against acetaminophen(APAP)-induced liver injury.The ob-jectives of this study were to establish the preparation process of HFOPs from hard-shelled mussel(Mytilus coruscus)(HFOPs-HM)and investigate the hepatoprotective effects and potential mechanisms of HFOPs-HM against APAP-induced liver injury in mice.Therefore,trypsin and papain were selected as the endo and exog-enous proteases for preparing HFOPs-HM according to the degree of hydrolysis(DH)of hard-shelled mussel hydrolysates,and activated carbon of XHJ-200 displayed the best effect to remove aromatic amino acids ac-cording to the Fischer ratio(OD220/OD280)and its parameters were optimized as adsorption time of 3.0 h and solid-liquid ratio of 1:10.The HFOPs-HM’s Fischer ratio and average molecular weight were 26.03(>20)and 878.54 Da,respectively.Furthermore,a mice model of liver injury induced by APAP was established.HFOPs-HM could significantly improve liver index and histopathological features,decrease the serum alanine aminotrans-ferase(ALT)and aspartate transaminase(AST)activities,increase the glutathione content and superoxide dis-mutase(SOD)and catalase(CAT)activities.Further research demonstrated that HFOPs-HM could alleviate liver oxidative stress in liver tissue via activating the Nrf2 pathway to initiate the intracellular antioxidant enzyme system.In addition,HFOPs-HM also suppressed liver inflammation by downregulating the secretion of TNF-α,IL-1β,and IL-6.Thus,HFOPs-HM could serve as an auxiliary functional dietary molecule applied in function products to alleviate drug-induced liver injury.