| Transport of animals is an important part of the livestock production. Transport stress causes a series of negative impacts on production and health of animals. Transportation makes an imbalance between oxidation and antioxidant, and thus induces oxidative stress. Firstly, the current study evaluated the antioxidant capacity and characteristics of vitamin C, vitamin E, alpha lipoic acid, quercetin and Oregano Essential Oils (OEO). Then to provide the theoretical basis for livestock transport nutrition regulation of stress, we compared the effects of these antioxidants on transport stress in rats by setting up a model of transport stress in rats. The results are as follows:1. Evaluation of antioxidant effects and characteristics research of different antioxidants in vitro:DPPH scavenging activity of vitamin C, vitamin E, Quercetin and OEO was assaied. The IC50value of vitamin C, vitamin E, Quercetin and OEO was0.0059mg/ml,0.0249mg/ml,0.0051mg/ml and0.0687mg/ml respectively. The order of these antioxidants on DPPH scavenging activity was quercetin> VC> VE> OEO. By using rat liver homogenate lipid antoxidation model to compare the inhibition lipid antoxidation rate of these antioxidants, we showed that IC50of vitamin C, vitamin E, alpha lipoic acid, quercetin and OEO was0.255mg/ml,0.0052mg/ml,2.06mg/ml,0.0058mg/ml and0.067mg/ml respectively. The order of this five antioxidants is VE> quercetin> OEO> VC> alpha lipoic acid.2. Research of antioxidants on protective and anti-stress effects in rats of transport stress:Seventy male wistar rats,7to8weeks old, were randomly allocated into7groups of10replicates each. Stress control groups which fed with a basal diet, which other groups fed with a vitamin C diet (basal diet+1.5g/kg vitmin C), vitamin E diet (basal diet+1g/kg vitamin E), OEO diet (basal diet+100mg/kg OEO), quercetin diet (basal diet+1g/kg quercetin) or alpha lipoic acid diet (basal diet+2g/kg alpha lipoic acid). Experimental period was28days. At the end of the trial, all groups, except the no-stress control group, were treated using the same procedure (rats were placed in35℃shaker,60r/min,2h) to induce transport stress. Rats fed with basal diet and did not treat using the transportation procedure served as no-stress control. Rats were killed at the end of transport stress, then the samples were collected. Serum hormone level, activities of the antioxidant system of serum and liver, the morphological structure and the expressions of Hsps mRNA in rats jejunum tissue were determined. The results showed as follows: 1) The OEO group improve the body weight, average daily gain (ADG) and average daily feed intake (ADFI)(P <0.05), vitamin E group can increase the body weight (P<0.05), quercetin groups can increase ADFI (P <0.05).2) Transportation led to a significant decrease in body weight and significantly rise the body temperature (P <0.05). The body weight decreases in all antioxidants groups after transportation but have no significant difference compared with the stress control group (P>0.05). The body temperature of vitamin C group was higher than other groups (P<0.05).3) Cortisol and norepinephrine levels in serum were significantly increased in stress control group after transportation compare with no-stress control (P<0.05). Compare with the stress control group, vitamin E significantly reduces the norepinephrine levels (P <0.05).4) Compared with no-stress control group, Total Antioxidant Capacity (T-AOC) significantly reduced, the content of malondialdehyde (MDA) significantly increased, activities of glutathione peroxidase (GSH-Px) and Superoxide dismutase (SOD) significantly reduced in the stress control group (P<0.05), all antioxidants groups significantly increased activities of SOD, and decreased MDA production compared with the stress control group (P<0.05), T-AOC significantly increased in vitamin C, vitamin E, OEO groups, activities of GSH-Px significantly increased in vitamin E, quercetin, alpha lipoic acid, OEO groups (P<0.05).5) The antioxidative capability of liver in the rats of transportation and intervention effect of antioxidants:Compared with no-stress control group, activities of T-AOC, GSH-Px and SOD in the liver of stress contol group were significantly reduced, whereas MDA level was increased. Feeding a diet supplementation with VC, VE, quercetin or OEO significantly increased T-AOC activity, but reduced MDA level compared with stress control group (P <0.05). Quercetin or OEO supplementation significantly increased activities of SOD and GSH-Px compared with no-stress control group (P<0.05). Compared with the stress control group, the activities of SOD and GSH-Px in alpha lipoic acid group have no significant difference (P>0.05).6) Analysis antioxidants effect on mucosa morphology of jejunum in rats:compared with the no-stress control group, the stress control group significantly increased crypt depth, significantly decreased villous height and crypt depth ratio (VCR) and villous height (P<0.05). Vitamin E, Quercetin, a-lipoic acid and OEO groups can significantly increased the villous height (P<0.05); Vitamin C, vitamin E, Quercetin can decreased crypt depth (P<0.05); all the antioxidants can significantly increased VCR (P<0.05), but no significant difference in villous height, crypt depth, villous height and crypt depth ratio compared with no-stress control group (P>0.05)。7) Compared with no-stress control group, the stress control group could significantly raise the expressions of Hsp27, Hsp70, Hsp90mRNA in rats jejunum tissue(P<0.05). All antioxidants groups can significantly weaken the expressions of Hsp27, Hsp70, Hsp90mRNA in rats jejunum tissue compared with the stress control group(P<0.05).In summary, the conclusions of the present study are:(1) Quercetin and vitamin E have a better effect on DPPH radical scavenging and inhibition of lipid antooxidation in vitro.(2) Vitamin E, quercetin and OEO can increase animal feed intake and body weight, improve the growth performance of the rats.(3) Antioxidants can reduce the lipid peroxidation of transportation rats, increase the activities of GSH-Px and SOD, improve the antioxidant ability. In this study, alpha lipoic acid play a radical scavenging ability, and inhibit lipid oxidation in animals; OEO on the total antioxidant capacity enhancement effect is obvious; quercetin, vitamin C, vitamin E also can inhibit the lipid oxidation and enhance the activities of antioxidant enzymes; these five antioxidants have certain resistance to transportation stress in rats. Comprehensive index determination, vitamin E, quercetin and OEO have a better effects in transportation stress resistance in transportation stress rats. |
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