Effect Of Combinations Of Different Levels Of Three Antioxidants On Intestinal Tissue Structure And Function In Meat Duck

The study was conducted to investigate the effects of three antioxidants (po-lyphenols,α-lipoic acid, silymarin) combination of different levels on mucosa morphology and antioxidant function in intestine mucosa of ducks. This study consisted three parts.1. Effects of oxidative stress on mucosa morphology and function of ducksThis experiment intented to establish the oxidative stress model through the intraperitoneal injection of cumene hydroperoxide (CHPO) to duck. 20 Cherry Valley ducks (42-day-old) with body weight of 3.36±0.01kg were randomly assigned to two treatment groups by homologous pairs.Two groups (10 replicates per treatment and 1 duck per replicate) including CHPO group (basic diet + CHPO) and control group (basic diet + saline). The ducks of CHPO group were injected intraperito- eally with 30 mg/kg·BW CHPO for 5 days, whereas ducks in the control group were injected with an equivalent amount of sterile saline for 5 days. The samples of mucosa were collected by scraping the intestine with a scalpel as soon as the ducks were butcheried. The results showed that: (1) CHPO decreased intestinal mucosa protein content in duodenum and ileum of ducks (P<0.05),and decreased DNA content in duodenum of ducks (P<0.01). (2) CHPO reduced vilous height of jejunum (P<0.05), increased crypt depth of ileum (P<0.05), and reduced significantly vilous height/crypt depth of intestine (P<0.01). (3) CHPO increased MDA level, decreased the activity of SOD and GSH-Px,and decreased GSH/GSSG in mucosa. (4) CHPO decreased the activity of DAO (P<0.01), and decreas- ed the activity of invertase (P<0.01), maltase and lactase (P<0.05) in mucosa. Conlusion: oxidative stress was induced by intraperitoneal injection of CHPO. The oxidative stress can induce intestinal injury. 2. Effects and interaction of three antioxidants combinations of different levels on mucosa morphology, DNA and RNA content and RNA /DNA in intestinal mucosa of ducksThe experiment was conducted to evaluate the effects and interaction of three antioxidants combinations of different levels on mucosa morphology, DNA and RNA content and RNA/DNA in intestinal mucosa of ducks to investigate whether it can alleviate the oxidative stress and whether there's interaction effect of the three antioxidants.80 Cherry Valley ducks (28-day-old) with body weight of 1.76±0.01kg were randomly divided into 8 groups, each group of 10 repeats (ducks). In this experiment, cross-experimental design was used, including three factors, two levels of each factor. Basic diets were added in different levels of tea polyphenols (100 mg/kg and 150 mg/kg),α-lipoic acid (150 mg/kg and 300 mg/kg) and silymarin (100 mg/kg and 200 mg/kg), a total of eight processing dietary composition. In 42 days, the ducks were injected intraperitoneally with 30 mg/kg·BW CHPO for 5 days. The samples of mucosa were collected by scraping the intestine with a scalpel as soon as the ducks were butcheried on 50-day-old. The results showed that: (1)150 mg/kgα-lipoic acid increased mucosa protein content of three intestine segments (P<0.001). There was synergistic effect betweenα-lipoic acid and tea polyphenols in the increase of the mucosa protein content in duodenum (P<0.001,α-lipoic acid * tea polyphenols = 1.91). There was synergistic effect between silymarin and tea polyphenols in the increase of the mucosa protein content in ileum (P<0.005, silymarin * tea polyphe- nols = 50.27). 150 mg/kg tea polyphenols,150 mg/kgα-lipoic acid increased mucosa RNA content of three intestine segments (P<0.05). There was synergistic effect betweenα-lipoic acid and tea polyphenols in the increase of the mucosa RNA content in duodenum and ileum (P<0.001,α-lipoic acid * tea polyphenols = 0.42,0.34). 200 mg/kg silyma- in increased mucosa DNA content in duodenum and jejunum (P<0.05). There was synergistic effect between tea polyphenols andα-lipoic acid (P<0.05, tea polyphneols *α-lipoic acid = 0.42), tea polyphneols and silymarin (P<0.05,α-lipoic acid*silymarin = 0.3) in the increase of the mucosa DNA content in the duodenum. (2) 150 mg/kg tea polyphneols increased vilous height (P<0.05), vilous height/crypt depth (P<0.05), Villus surface area in ileum (P<0.05). 150 mg/kgα-lipoic acid decreased crypt depth, increased Villus width and Villus surface area in duodenum (P<0.05). Conlusion: The three antioxidants alleviated the structure and function of small intestinal injury of ducks caused by CHPO. There is a synergistic effect between tea polyphenols andα-lipoic acid,α-lipoic acid and silymarin.3. Effects and interaction of three antioxidants combinations of different levels on antioxidant function and the activity of DAO and disaccharidase in intestinal mucosa of ducksThe experiment was conducted to evaluate the effects and interaction of three antioxidants combinations of different levels on antioxidant function and the activity of DAO and disaccharidase in intestinal mucosa of ducks to investigate whether it can alleviate the oxidative stress and whether there's interaction effect of the three antioxidants. The experimental design was same to experiment 2. The results showed that: (1)150 mg/kg tea polyphneols,300 mg/kgα-lipoic acid and 100 mg/kg silymarin all have a trend of decrease MDA levels in intestinal mucosa (P>0.05). There was synergistic effect between tea polyphenols andα-lipoic acid(tea polyphenols *α-lipoic acid = -2.71), tea polyphneols and silymarin(tea polyphneols * silymarin = -4.99) in the decrease of MDA level in mucosa.100 mg/kg tea polyphneols,150 mg/kgα-lipoic acid and 100 mg/kg silymarin all increased the activity of SOD and GSH-Px in mucosa (P<0.05). There was no interaction among the three in the increase of the activity of SOD and GSH-Px. 300 mg/kgα-lipoic acid increased GSH/GSSG in mucosa (P<0.05). There was synergistic effect between tea polyphenols and silymarin (tea polyphenols * silymarin = 9.53). (2) 100 mg/kg tea polyphneols,150 mg/kgα-lipoic acid and 100 mg/kg silymarin all increased the activity of DAO in mucosa (P<0.05), but there was no significant interaction among the three. (3) 100 mg/kg tea polyphneols and 150 mg/kgα-lipoic acid increased the activity of invertase in mucosa (P<0.05). There would be synergistic effect among the three in the increase of the activity of invertase in mucosa (P=0.011,tea polyphneols *α-lipoic acid*silymarin = 2.21). 100 mg/kg silymarin increased the activity of maltase and lactase in mucosa (P<0.05), but there's no significant interaction among the three. Conlusion: The three antioxidants alleviated the effect on antioxidant function and activity of DAO and disaccharidase in small intestinal of ducks caused by CHPO. There is a synergistic effect among tea polyphenols,α-lipoic acid and silymarin.In short, CHPO lead to oxidative stress in ducks, and to produce intestinal oxidative damage. The combinations of tea polyphneols,α-lipoic acid and silymarin relieved the damage caused by CHPO in intestinal of ducks.The function mainly showed as: relieved the damage of mucosal structural (increased mucosa protein and DNA content), and antioxidant capacity of intestinal (decreased the level of MDA, increase of the activity of SOD and GSH-Px,increased the GSH/GSSG). There was synergistic effect between tea polyphenols andα-lipoic acid. Altogether 100 mg/kgtea polyphneols,150 mg/kgα-lipoic acid and 100 mg/kg silymarin were the best combinations.