Antioxidant Activity Of Bioactive Peptides From Sheep Blood

This study investaged that the antioxidant activity of bioactive peptides from sheep blood.In this study,sheep hemoglobin was treated by enzymolysis,and the optimal protease was selected based on its hydrolysis characteristics and antioxidant activity.The optimal preparation process was determined by single factor test and response surface methodology.The antioxidant capacity in vitro was explored from the perspective of scavenging free radicals and reducing power,then the diquat oxidative stress model of rats was established for antioxidant test in vivo.The experimental results showed that:1.E protease,M protease,F protease and N protease were used to hydrolyze sheep hemoglobin.DPPH scavenging rate and hydroxyl radical scavenging rate were used as evaluation indexes,and M protease was selected as the best hydrolysis enzyme.The optimal conditions for preparation of antioxidant peptides from sheep blood were obtained by single factor and response surface design,as follows: hydrolysis temperature49 ?,substrate concentration 7%,hydrolysis time 3 h,hydrolysis p H 7.0 and enzyme addition 5%.Under these conditions,the DPPH clearance rate of antioxidant peptides was 98.15%.2.The antioxidant peptides from sheep blood were freeze-dried into powder,and prepared into different concentrations of solution with distilled water.The antioxidant activity was evaluated in vitro by measuring its reducing power,OH free radical scavenging rate,DPPH free radical scavenging rate and ABTS free radical scavenging capacity.The results showed that the IC50 clearance rates of antioxidant peptides from sheep blood to DPPH free radical,hydroxyl free radical and ABTS free radical were 2.59 mg / ml,6.42 mg / ml and 0.84 mg / ml,respectively.3.Eighteen Wistar rats were selected to establish oxidative stress model by diquate,and 800 mg / kg BW was determined as the dose to alleviate oxidative stress.They were fed with antioxidant peptides from sheep blood.There was no significant difference in feed intake,body weight and organ weight among the groups(P > 0.05).The MDA in blood of rats decreased significantly after 14 days of feeding(P < 0.05).The levels of SOD and T-AOC were increased but there was no significant difference among the groups(P > 0.05).After treat by diquate,the antioxidant peptides from sheep blood could alleviate the oxidative stress state of rats.The antioxidant peptide had effects on the expressions of Nrf2 and NF-k B in liver,kidney and ileum of rats.