Effect of Chlorogenic Acid on Levels of Total Protein and Triglycerides, and Related Gene Expressions in Yellow Pond Turtle
This study discusses the effects of chlorogenic acid (CGA) on total protein and triglycerides levels, as well as the expression of metabolism-related genes in yellow pond turtle (Mauremys mutica). A total of 450 healthy, undamaged yellow pond turtle (initial body weight 125.47 ± 5.13 g) were randomly divided into five groups, with three replicates per group and 30 turtles per replicate. The turtles were fed a basic diet supplemented with 0 mg/kg (Con), 100 mg/kg (CGA1), 200 mg/kg (CGA2), 400 mg/kg (CGA4), or 800 mg/kg (CGA8) of CGA for 60 days. The results showed that 200 mg/kg of CGA significantly increased TP levels in both serum and liver, and reduced TG levels in serum, while 400 mg/kg of CGA significantly reduced TG levels in both serum and liver. RT-qPCR analysis revealed that 200 mg/kg of CGA significantly decreased the expression of the liver AKR1D1 gene, while significantly increasing the expression of PDIA4, DERL3, and CAPN9 genes. Furthermore, 400 mg/kg of CGA significantly downregulated the expression of AKR1D1 and P450 genes, while significantly increasing the expression of DERL3. Additionally, 800 mg/kg of CGA significantly upregulated the expression of the DERL3 gene. In conclusion, CGA enhances the ability of yellow pond turtle to synthesize TP in the liver, reduces TG levels in both serum and liver, upregulates the expression of PDIA4, DERL3, and CAPN9 genes, and downregulates the expression of AKR1D1 and P450 genes. The optimal addition amount of CGA in the diet of Chinese soft-shelled turtles is 200~400 mg/kg.
Chlorogenic Acid
杜仲(Eucommia ulmoides)是一种传统中药材,在《神农本草经》中早有记载,已有2000年的使用历史
黄喉拟水龟(Mauremys mutica)是一种硬壳淡水龟,隶属于龟鳖目(Testudines)、潮龟科(Geoemydidae)、拟水龟属(Mauremys),分布于日本、越南以及中国的中南部地区。目前,黄喉拟水龟是中国交易量最大的淡水龟类之一,也是一种重要的新兴水产养殖品种,在营养、药物、观赏和经济方面具有重要价值,市场前景广阔。在养殖过程中,养殖动物常常因为过量食用腐败变质的鱼、猪肠等饵料导致脂肪代谢异常、肝脏存储脂肪过多等问题
实验中使用的450只黄喉拟水龟购自中国南宁市碧艳龟鳖经营部,初始体重为125.47 ± 5.13 g。
实验所需的基础饲料原料购自佛山市顺德区全兴水产饲料有限公司。在饲料中分别添加0 (对照组,Con)、100 (CGA1)、200 (CGA2)、400 (CGA4)和 800 (CGA8) mg/kg的CGA,制成5组饲料,每组饲料营养成分如
原料组成(%) |
Con |
CGA1 |
CGA2 |
CGA4 |
CGA8 |
鱼粉 |
38 |
38 |
38 |
38 |
38 |
豆粉 |
10 |
10 |
10 |
10 |
10 |
花生饼 |
11 |
11 |
11 |
11 |
11 |
鱼油 |
4 |
4 |
4 |
4 |
4 |
磷脂 |
1 |
1 |
1 |
1 |
1 |
小麦粉 |
15 |
14.99 |
14.98 |
14.96 |
14.92 |
玉米粉 |
15 |
15 |
15 |
15 |
15 |
血粉 |
5 |
5 |
5 |
5 |
5 |
预混料 |
1 |
1 |
1 |
1 |
1 |
绿原酸mg/kg |
0 |
0.01 |
0.02 |
0.04 |
0.08 |
营养成分组成(干物质) |
|||||
粗蛋白(%) |
45.34 ± 1.23 |
45.51 ± 2.01 |
46.09 ± 1.88 |
45.18 ± 1.72 |
45.64 ± 2.31 |
粗脂肪(%) |
8.35 ± 0.95 |
8.76 ± 0.73 |
8.19 ± 1.06 |
8.59 ± 0.67 |
8.81 ± 0.84 |
粗灰分(%) |
10.43 ± 1.03 |
10.38 ± 1.48 |
10.29 ± 0.96 |
10.51 ± 1.35 |
10.49 ± 1.58 |
喂食试验前7 d,所有黄喉拟水龟均暂时驯养在一个水泥池中,使其适应饲料和养殖环境。实验开始时,黄喉拟水龟禁食24小时。随机挑选健康无损伤、体重相近的黄喉拟水龟(n = 450, 125.47 ± 5.13 g),将其分批称重并按每箱30只的密度装入塑料箱(135 × 70 × 18厘米)中。试验期间,水温为(27.30 ± 1.10)℃。每次投喂量为黄喉拟水龟平均体重的2%,每天中午12:00投喂一次。投喂1 h后清理残余饲料,记录发病和死亡数。每个实验组依次投喂
每组随机选取10只龟,冷冻麻醉后采集尾静脉血,将血在4℃下放置5 h直至析出血清,然后在3000 ×g下离心10 min。收集血清样本并放置在−20℃保存。同时,解剖并快速取出肝脏样本,然后立即用液氮冷冻并在−80℃保存。
Gene symbol |
Forward primer sequence (5’-3’) |
Reverse primer sequence (5’-3’) |
β-actin |
TCGGGAATGAAAGGTTCCGG |
CTGCATTCTGTCAGCGATGC |
AKR1D1 |
TCTTCTTGCCGCTTTCATTCAGG |
TTCCCATCGCTCAGAGGTATGC |
P450 |
AGAGCATCCTCACCTTTCATTTATCC |
CTAGACCATTCACCACCACAACAG |
ACACA |
ACAGGCACCTTACCACAGATCC |
GGCAGGCAGTAACCATTCATCAC |
PDIA4 |
AGTCTGCCTGTTAGTGCTCCTC |
CACCTTCTTCTTCTTCTTCTCCTTGG |
DERL3 |
CAGCCGCCGCCTCAGTAG |
GACCAAAGCCGTTCTTCAGACAG |
CAPN9 |
GCGTTATAGAAGAGCATCCCAGAG |
GAGCAAGCCAGAATCACAGTCC |
实验数据采用Excel和SPSS 27.0软件进行统计分析,数据采用单因素方差分析,数据值以均数 ± 标准误(mean ± SEM)表示,采用LSD法进行多重检验比较差异显著性,P < 0.05表示差异显著。
如
组别 |
Con |
CGA1 |
CGA2 |
CGA4 |
CGA8 |
TP/(g/L) |
1.62 ± 0.22 |
2.51 ± 0.16 |
2.71 ± 0.12 |
2.36 ± 0.45 |
2.49 ± 0.41 |
TG/(mmol/L) |
1.13 ± 0.04a |
1.07 ± 0.07ab |
0.94 ± 0.05bc |
0.84 ± 0.04c |
1.04 ± 0.05ab |
注:同列中标有不同字母者表示组间有显著性差异(P < 0.05),标有相同字母者表示组间无显著性差异(P > 0.05),下同。
肝脏总蛋白及甘油三酯含量如
组别 |
Con |
CGA1 |
CGA2 |
CGA4 |
CGA8 |
TP/(g/L) |
4.02 ± 0.11b |
4.57 ± 0.21a |
4.69 ± 0.11a |
4.34 ± 0.14ab |
4.61 ± 0.16a |
TG/(mmol/gprot) |
1.18 ± 0.05a |
1.16 ± 0.03a |
1.07 ± 0.05ab |
0.93 ± 0.06b |
1.17 ± 0.08a |
绿原酸对黄喉拟水龟肝脏蛋白合成基因的影响如
由
目前,绿原酸对动物血清及肝脏TP含量影响的报道较少。本研究结果表明,在饲料中添加绿原酸后,CGA2组实验龟血清TP含量显著提高,CGA1、CGA2、CGA8组肝脏TP含量相较对照组均有显著提升,表明在饲料中添加绿原酸可提高黄喉拟水龟肝脏合成蛋白质的能力,有利于维持黄喉拟水龟正常的代谢和生理功能。TG含量是鉴定动物脂质代谢能力的关键生化指标,而在本研究中CGA2、CGA4组血清中的甘油三酯含量相较对照组显著下降,CGA4组肝脏中的甘油三酯含量相较对照组显著减少。该结果与以往的报道相似,如马建茸等的研究发现在高脂饲料中添加绿原酸可以显著减少花鲈(Lateolabrax maculatu)血清中TG的含量
提高中华鳖(Trionyx sinensis)肌肉中胶原蛋白的含量并降低胆固醇的含量。总之,向饲料中添加适量的绿原酸可以提高黄喉拟水龟血清和肝脏的TP并降低TG的含量。
肝脏是水生动物重要的代谢器官,参与蛋白质与脂质的代谢,以往研究表明绿原酸可以上调动物肝脏中脂质代谢基因的表达,如Jin
绿原酸可提高黄喉拟水龟肝脏合成总蛋白的能力、降低血清和肝脏中的甘油三酯含量,上调PDIA4、DERL3、CAPN9等蛋白代谢相关基因的表达、下调AKR1D1、P450等脂质代谢相关基因的表达。在本研究条件下,绿原酸在黄喉拟水龟饲料中最适添加量为200~400 mg/kg。
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*通讯作者。