【摘要】：飼料中富含的多種營(yíng)養(yǎng)物質(zhì)(維生素、脂質(zhì)及蛋白等)在加工、儲(chǔ)存、運(yùn)輸特別是高溫環(huán)境條件下,容易被氧化導(dǎo)致飼料酸敗,影響飼料的適口性和營(yíng)養(yǎng)價(jià)值。飼料中添加適量的抗氧化劑能有效防止上述現(xiàn)象的發(fā)生,還能清除體內(nèi)多余的自由基,緩解動(dòng)物的氧化應(yīng)激,起到抗炎、抗病等效果,提高動(dòng)物機(jī)體的抗氧化性能。近年來(lái)研究發(fā)現(xiàn),抗氧化劑還可以通過(guò)清除下丘腦ROS水平,提高下丘腦促采食神經(jīng)元AgRP/NPY的蛋白表達(dá),促進(jìn)動(dòng)物的采食。為了篩選出能夠有效調(diào)控動(dòng)物采食量的抗氧化劑,并研究其作用機(jī)制,本文采用體外抗氧化試驗(yàn)(比較抗氧化劑清除DPPH自由基和羥自由基的能力)篩選出具有較強(qiáng)清除自由基能力的抗氧化劑,同時(shí)用昆明小鼠作為試驗(yàn)動(dòng)物,采用篩選出的抗氧化性能較強(qiáng)的抗氧化劑進(jìn)行飼養(yǎng)試驗(yàn),進(jìn)一步篩選出能提高小鼠采食量的抗氧化劑,在此基礎(chǔ)上研究其對(duì)小鼠體內(nèi)抗氧化相關(guān)指標(biāo)的影響以及提高小鼠采食量的調(diào)節(jié)機(jī)制,為抗氧化劑在生產(chǎn)中的推廣運(yùn)用提供試驗(yàn)依據(jù)。研究結(jié)果表明:(1)在本試驗(yàn)備選的抗氧化劑中,迷迭香酸的清除DPPH自由基和羥自由基能力比VC強(qiáng),原花青素、咖啡酸和丁香酸的清除DPPH自由基和清除羥自由基能力與VC相當(dāng)。(2)日糧中添加一定劑量的咖啡酸和丁香酸能顯著提高小鼠的日均采食量,0.5%原花青素能顯著促進(jìn)小鼠的平均日增重。迷迭香酸對(duì)小鼠的日均采食量和平均日增重?zé)o顯著影響。(3)日糧中添加0.5%原花青素、0.3%咖啡酸均能顯著提高小鼠的日均采食量,但對(duì)平均日增重?zé)o顯著影響。0.5%原花青素+0.3%咖啡酸能顯著提高小鼠的平均采食量和日增重,并能顯著降低小鼠下丘腦ROS水平;促進(jìn)促采食神經(jīng)元AgRP/NPY的蛋白表達(dá),提示原花青素和咖啡酸能通過(guò)降低小鼠下丘腦ROS影響下丘腦神經(jīng)元AgRP/NPY的表達(dá),提高小鼠的采食量。(4)日糧中添加0.5%原花青素、0.3%咖啡酸和0.5%原花青素+0.3%咖啡酸對(duì)小鼠機(jī)體內(nèi)抗氧化系統(tǒng)的主要指標(biāo)無(wú)顯著影響。綜上所述,原花青素和咖啡酸有較強(qiáng)的抗氧化能力,且日糧中添加0.5%原花青素和0.3%咖啡酸對(duì)小鼠體內(nèi)抗氧化能力無(wú)顯著影響,但能通過(guò)清除小鼠下丘腦ROS水平提高AgRP/NPY的蛋白表達(dá)水平,促進(jìn)小鼠采食。
[Abstract]:Many kinds of nutrients (vitamins, lipids and proteins), which are rich in feed, are easy to be oxidized in processing, storage and transportation, especially in high temperature environment, which affect the palatability and nutritional value of feed. The addition of appropriate amount of antioxidants in the feed can effectively prevent the occurrence of the above phenomena, eliminate the excess free radicals in the body, relieve the oxidative stress of animals, play the effects of anti-inflammation and anti-disease, and improve the antioxidant performance of the animal body. In recent years, it has been found that antioxidants can also increase the protein expression of AgRP/NPY in hypothalamic feeding neurons by clearing the level of hypothalamus ROS, and promote the feeding of animals. In order to screen antioxidants that can effectively regulate animal feed intake, and to study its mechanism, In this paper, antioxidants with strong scavenging ability of DPPH and hydroxyl radicals were screened by antioxidant test in vitro, and Kunming mice were used as experimental animals. The selected antioxidants with strong antioxidant properties were used to carry out feeding experiments to further screen the antioxidants that could increase the feed intake of mice. On this basis, the effects of antioxidants on the antioxidant related indexes in mice and the regulation mechanism of increasing the intake in mice were studied, which provided the experimental basis for the popularization and application of antioxidants in production. The results showed that: (1) among the antioxidants in this experiment, rosemary acid had stronger scavenging ability of DPPH free radical and hydroxyl radical than VC, proanthocyanidins, The scavenging effect of caffeic acid and eugenic acid on DPPH free radical and hydroxyl radical was similar to that of VC. (2) addition of caffeic acid and eugenic acid to diet could significantly increase the average daily gain of mice by 0.5% proanthocyanidins. Rosemary acid had no significant effect on daily intake and average daily gain of mice. (3) 0.5% proanthocyanidin 0.3wt% caffeic acid could significantly increase the daily intake of mice. But there was no significant effect on average daily gain. 0.5% procyanidin 0.3% caffeic acid could significantly increase the average intake and daily gain of mice, decrease the level of ROS in the hypothalamus of mice, and promote the protein expression of AgRP/NPY in the feeding neurons. These results suggest that proanthocyanidins and caffeic acid can affect the expression of AgRP/NPY in hypothalamic neurons by decreasing ROS in hypothalamus of mice. (4) the supplementation of 0.5% procyanidin 0.3% caffeic acid and 0.5% procyanidin 0.3% caffeic acid had no significant effect on the main indexes of antioxidant system in mice. In conclusion, proanthocyanidins and caffeic acid had strong antioxidant activity, and the supplementation of 0.5% procyanidin and 0.3% caffeic acid in diet had no significant effect on the antioxidant capacity of mice. But it can improve the expression of AgRP/NPY protein by eliminating the ROS level of hypothalamus of mice and promote the food intake of mice.
【學(xué)位授予單位】：華南農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：S816
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本文編號(hào)：2170753