大豆蛋白抗氧性肽的研究

本文综述了国内外对大豆蛋白肽的抗氧性机理、生产工艺、理化特性的研究概况 。

Enzyme responses and lipid peroxidation in gills and hepatopancreas of clam Mactra vereformis, following cadmium exposure

To assess the toxicity of heavy metal pollution to marine intertidal shellfish, enzymatic responses and lipid peroxidation were investigated in the clam Mactra vereformis exposed to cadmium under laboratory conditions. Three antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx), two immune defense enzymes (acid phosphatase, ACP; alkaline phosphatase, ALP), and one lipid peroxidation product (malondialdehyde, MDA) were measured in the gills and the hepatopancreas of the clam exposed to 0, 25, 75, and 125 μg/L cadmium for 0, 1, 3, 5, and 7 d. The results show that the concentrations of antioxidant enzymes in the organs soared to a peak value on the first day and then decreased afterwards in most cases. CAT and GPx activities in the hepatopancreas were higher than in the gills, but the SOD activity was lower in the hepatopancreas. ACP activity was unchanged until Day 3 in the hepatopancreas and until Day 5 in gills, when it began to increase. ALP activity showed no significant relationship with Cd treatment. MDA concentrations increased in the two tissues after Cd exposure, peaked on Day 3 in gills, and on Day 5 in hepatopancreas. These observations show that changes in the activities of antioxidant enzymes and ACP reflect the time course of oxidative stress in the clam caused by Cd, and could be used as potential biomarkers for ecotoxicological bioassays of heavy metals.

The Toxic Mechanism of High Lethality of Herbicide Butachlor in Marine Flatfish Flounder,Paralichthys olivaceus

The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill （FG） ceils exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase （SOD）, catalase （CAT） and glutathione peroxidase （GPX）. Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.

Study on the Molecular Weight Composition and Antioxidant Activity of Peanut Bioactive Peptides

[ Objective] To prepare peanut bioactive peptides and analyze their molecular weight composition and antioxidant activity. [ Method ] The dialysis bag of 8.0, 3.5 and 1.0 kD were used to classify the hydrolyzate derived from alcalase and flavourzyme, peanut bioactive poptides of differ-ent molecular weight were obtained and then their scavenging capacity of free radicals was measured. The molecular weight composition was stud-ied by Tricine-SDS-PAGE.[Result] The content of peptides 〈 1.0 kD were 76.21% and 83.42% in the total hydrolyzate from alcalase and fla-vourzyme respectively. All hydrolyzate with different molecular grades showed free radical scavenging capacity, which was increased with the reduc- tion of molecular mass. The peptides 〈 1.0 kD exhibited higher radical scavenging capacity of （87.41 ±0.66） % （alcalase） and （67.88 ±0.48）% （ flavourzyme）, respectively. [ Conclusion] Peanut bioactive peptides had strong effect of antioxidant capacity, especially that 〈 1.0 kD, which had great prospect.

Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri

Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.

Antioxidant Activity of Peptides Obtained from Cotton Ground Oil-Cake Proteins

Antioxidant activity of the peptides derived from proteins of defatted cottonseed kernels and cotton ground oil-cake by their enzymatic hydrolysis with acidic （Asp. niger） and neutral proteinases （Bac. amyloliquefaciens） was studied. Antioxidant activity of the derived peptides depended on the used proteins and enzymes. The peptides derived by using of neutral proteinase possessed higher antioxidant activity, in comparison with the peptides derived by acidic proteinases.

Enrichment of Organic-Inorganic Se and Vitamin E in Quail Products and Its Effect on the Performances and Source of Antioxidant in Quails＇ Eggs

This study aimed to get an optimum level of combined organic selenium, inorganic selenium and vitamin E in obtaining the best production and reproduction of quails as well as the highest antioxidant level in quail eggs. Seven hundred twenty quails （360 females and 360 males） at the age of six weeks old were used in this research. Nine treatment diets were： To （commercial diet/control）, Tl （diet containing 0.46 ppm inorganic Se ＋ 43.50 ppm vitamin E）, T2 （diet containing 0.46 ppm inorganic Se ＋ 87.00 ppm vitamin E）, T3 （diet containing 0.92 ppm inorganic Se ＋ 43.50 ppm vitamin E）, T4 （diet containing 0.92 ppm inorganic Se ＋87.00 ppm vitamin E）, Ts （diet containing 0.46 ppm organic Se ＋ 43.50 ppm vitamin E）, T6 （diet containing 0.46 ppm organic Se ＋ 87.00 ppm vitamin E）, T7 （diet containing 0.92 ppm organic Se ＋ 43.50 vitamin E） and Ts （diet containing 0.92 ppm organic Se 0.92 ＋ 87.00 ppm vitamin E）. The design of the experiment was a factorial nested design. Any significant differences among the treatments were analyzed by using Duncan＇s test. The results of this study indicated that 0.92 ppm organic selenium ＋ 43.50 ppm vitamin E （T7） in general gave the highest content of selenium in meat, in egg albumin, and in egg yolk as well as hatchability. The antioxidants as represented by vitamin E and glutathione peroxidase enzyme in the quail eggs were significantly higher as compared to that of quails fed other treatment diets.

Effect of Zibushenjing Fang on skeletal development and brain tissue antioxidation in mice with kidney essence insufficiency: a mechanistic study

OBJECTIVE: To investigate the effects of Zibushenjing Fang (formula for tonifying the kidney essence) on skeletal development and brain tissue antioxidation in mice with kidney essence insufficiency. METHODS: Fifty male Kunming mice were randomly divided into five groups: normal group, model group, Jinkuishenqi Wan group, Zibushenjing Fang high dose group, and Zibushenjing Fang low dose group, with 10 mice in each group. The model of kidney essence insufficiency syndrome was established in all the mice except the normal group by using a cat to threaten the mice and by swimming until exhaustion daily which lasted about 21 days. Mice in the model group were administered 20 mL/ kg -1 · d -1 of normal saline intragastrically. The Jinkuishenqi Wan group was given 2.7 g/kg-1 · d-1 ofa solution of Jinkuishenqi Wan. The Zibushenjing Fang high dose group was given 20 g/kg -1 · d -1 and the Zibushenjing Fang low dose group was given 10 g/kg -1 · d -1 of a solution of Zibushenjing Fang.The general condition of all the groups was observed, including the quantity of food and water intake, swimming time, length of femur, and weight of the femur and musculus quadriceps femoris. The total superoxide dismutase (T-SOD), glutathione peroxi- dase (GSH-Px), and methane dicarboxylic aldehyde (MDA) activities in the brain tissues were detected. RESULTS: Zibushenjing Fang could improve the manifestation of kidney essence insufficiency, increase the quantity of food and water intake, swimming time, femur length, and femur and musculus quadriceps femoris weight. It could also regulate the activities of T-SOD, GSH-Px, and MDA in brain tissue. CONCLUSION: Zibushenjing Fang may play an important role in treating kidney essence insufficiency syndrome by promoting body development and improving brain tissue antioxidation.