Two in vitro trials were conducted to identify a peptide with antioxidant activity and immunoenhancement from cottonseed meal protein hydrolysate (CPH) for fish. Primary hepatocytes of Megalobrama amblycephala were treated with CPH. In experiment 1, CPH significantly increased aspartate aminotransferase (GOT), alanine aminotransferase (GPT), total superoxide dismutase (t-SOD), catalase (CAT), and lysozyme activities, as well as up-regulated SOD, CAT, antimicrobial peptides 1 (Leap 1) and Leap 2 mRNA levels (p < 0.05). However, CPH significantly down-regulated the expression of NADPH oxidase-2 (NOX2), Kelch-like-ECH-associated protein 1 (Keap1), NF-E2-related factor 2 (Nrf2) and BTB and CNC homolog 1 (Bach1) mRNA (p < 0.05) in fish hepatocytes. Experiment 2 showed that the molecular mass of CPH was distributed mainly in the 700-1024 Da range. Peptide 1 (P1) and P2 significantly decreased GOT and GPT activities in conditioned medium (p < 0.05); however, P4 and P6 did not affect GOT and GPT activities (p > 0.05). Furthermore, P4 significantly increased hepatocyte GOT, GPT, t-SOD, CAT levels and lysozyme activities (p < 0.05), up-regulated SOD, CAT, Leap1 and Leap2 mRNA expression levels, and down-regulated the expression of Nrf2 and NOX2 mRNA (p < 0.05) in fish hepatocytes. The above results indicated that CPH and P4 enhanced hepatocyte metabolism, as well as improved antioxidant capacities and innate immunity of blunt snout bream hepatocytes.

中文翻译：

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评价棉籽粕蛋白水解产物及其衍生肽对钝嘴鲷（Megalobrama amblycephala）肝细胞的抗氧化能力和免疫调节作用。

进行了两项体外试验，以从棉籽粉蛋白水解物（CPH）中鉴定出具有抗氧化活性和免疫增强作用的肽，以用于鱼类。用CPH处理睑板Mega的原代肝细胞。在实验1中，CPH显着提高了天冬氨酸转氨酶（GOT），丙氨酸转氨酶（GPT），总超氧化物歧化酶（t-SOD），过氧化氢酶（CAT）和溶菌酶的活性，并上调了SOD，CAT和抗菌肽1 （Leap 1）和Leap 2 mRNA水平（p <0.05）。但是，CPH明显下调了NADPH氧化酶2（NOX2），Kelch样ECH相关蛋白1（Keap1），NF-E2相关因子2（Nrf2）和BTB和CNC同源物1（Bach1）的表达。鱼肝细胞中的mRNA（p <0.05）。实验2表明，CPH的分子量主要分布在700-1024Da范围内。肽1（P1）和P2在条件培养基中显着降低GOT和GPT活性（p <0.05）；但是，P4和P6不会影响GOT和GPT活性（p> 0.05）。此外，P4显着增加肝细胞GOT，GPT，t-SOD，CAT水平和溶菌酶活性（p <0.05），上调SOD，CAT，Leap1和Leap2 mRNA表达水平，并下调Nrf2和NOX2 mRNA表达（p <0.05）在鱼肝细胞中。以上结果表明CPH和P4增强了钝嘴鼻肝细胞的肝细胞代谢，并提高了其抗氧化能力和先天免疫力。鱼肝细胞中的GPT，t-SOD，CAT水平和溶菌酶活性（p <0.05），上调SOD，CAT，Leap1和Leap2 mRNA的表达水平以及下调Nrf2和NOX2 mRNA的表达（p <0.05） 。以上结果表明CPH和P4增强了钝嘴鼻肝细胞的肝细胞代谢，并提高了其抗氧化能力和先天免疫力。鱼肝细胞中的GPT，t-SOD，CAT水平和溶菌酶活性（p <0.05），上调SOD，CAT，Leap1和Leap2 mRNA的表达水平以及下调Nrf2和NOX2 mRNA的表达（p <0.05） 。以上结果表明CPH和P4增强了钝嘴鼻肝细胞的肝细胞代谢，并提高了其抗氧化能力和先天免疫力。