Preparation Of Antioxidant Peptides From Grass Carp And Its Metabolism In Vivo

Grass carps as one of China’s four freshwater fish, is loved by the majority of consumers. They are also a good source of high quality protein, has a high nutritional value. More and more people are now taking grass carp as raw material, processing to extract all kinds of products and functional food. Grass carp antioxidant peptide is a kind production of them. The antioxidant activity of antioxidant peptides with a bioactive substance free radical scavenging by enzymatic hydrolysis of food protein prepared. The amino acid composition and structure of antioxidant peptides affect its activity. So we analyze the structural characteristics of antioxidant peptides by molecular biological technology. And we hope can make use of a single oral administration of the body of intervention to understand its antioxidant activity and metabolism in vivo with the purpose of To provide the theoretical basis for further study on the mechanism of antioxidation in vivo and in vitro.This paper optimized the process conditions of enzymatic preparation of antioxidant peptides from grass carp; Separation and purification of a grass carp antioxidant peptide monomer and identified the amino acid composition and sequence successfully. We have studied after oral administration, absorption and distribution of antioxidant peptide in mice, After a single oral dose of intervention, changes of oxidation index in blood of mice were analyzed. The main conclusions are as follows:1. Double enzyme optimum enzymatic hydrolysis preparation of antioxidant peptides for grass carp:Papain 800U/g, neutral protease 500U/g, pH 6.5, hydrolysis temperature is 50℃,hydrolysis temperature is 4h. The grass carp enzyme solution on DPPH radical scavenging rate is 93.50%, degree of hydrolysis is 35.63%,peptide obtain rate is 97.29%. Compared with the single enzyme hydrolysis not only improves the degree of hydrolysis and peptide obtain rate, but also improving the DPPH free radical scavenging rate.2. The solution obtained less than 3kDa the ability of the components of DPPH free radical scavenging by ultrafiltration separation of grass carp protease is the best. It DPPH radical scavenging rate is 89.27%. Component and after isolation and purification of HPLC end N-sequencing, we have found good antioxidant activity of peptide which had 4 amino acids, they are Tryptophan Glutamate Proline and Histidine. When the concentration is lmg/mL, WEPH’S DPPH free radical scavenging rate reached 73.52%. At the same time according to the amino acid composition of antioxidant peptide we cause with antioxidant activity.3. After a single intragastric administration of 2mg/kg, 0.1mL FITC-WEPH, the concentration of blood drug concentration indicated that the concentration of FITC-WEPH is highest after intragastric administration of 2h. Their absolute bioavailability is 10.49%. The distribution experiment showed that FITC-WEPH mainly distributed in the gastrointestinal in first 2h; The content of all organs in FITC-WEPH were decreased after 6h. FITC-WEPH in liver volume is high, slow metabolism, which suggests that FITC-WEPH is involved in the oxidative metabolism of the liver. A small amount of FITC-WEPH isalso found in the brain, that it can pass through the blood-brain barrier, the brain involved in normal metabolic activity.4. After a single intragastric administration of 2mg/kg, 0.1mL FITC-WEPH, it has influenced on the blood of mice the enzyme and MDA in blood. To show the activity of GSH-PX after treatment increased firstly and then decreased, reached a maximum of 391.78±29.85U/0.1mL after administration of 4h. After administration, the content of MDA decreased first and then increased, and the content of 2H was the lowest, which was 9.90±1.45mol/mL. After administration, the activity of T-SOD showed a trend of first increasing and then decreasing. After administration, the 2H reached the highest, which was 142.61±8.09U/mL. After administration, the GSH-PX activity increased first and then decreased and then increased. The maximum value of T-AOC was 10.566±2.05U/mL after administration.