The major aim of this study was to investigate the effect of rice protein (RP) on the activation of endogenous antioxidant defense in growing and adult rats. After 2 weeks, RP activated nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) by suppressing Kelch-like ECH-associated protein 1 (Keap1) and Cullin 3 (Cul3) in growing and adult rats. Compared with casein, the upregulation of antioxidant responsive element (ARE)-driven antioxidant expression levels (glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modulatory subunit, glutathione synthase, glutathione reductase, glutathione S-transferase, glutathione peroxidase, catalase, superoxide dismutase, heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1) were found in RP groups. Also, RP upregulated methionine sulfoxide reductase (MsrA, MsrB2, and MsrB3) expression levels in growing and adult rats. As a result, RP enhanced endogenous antioxidative capacities to reduce hepatic accumulations of malondialdehyde, protein carbonyl, and reactive oxygen species. This study demonstrates that RP exerts the endogenous antioxidant capacity in growing and adult rats, which is due to stimulating Msr antioxidant expression and activating Nrf2-ARE pathway. Results suggest that the antioxidant activity induced by RP is independent of age.

中文翻译：

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大米蛋白通过蛋氨酸亚砜还原酶和Nrf2抗氧化剂系统发挥内源性抗氧化能力，不受年龄的影响。

这项研究的主要目的是研究水稻蛋白（RP）对成年和成年大鼠内源性抗氧化剂防御的激活作用。2周后，RP通过抑制成年和成年大鼠中的Kelch样ECH相关蛋白1（Keap1）和Cullin 3（Cul3）来激活核因子类红细胞2（NF-E2）相关因子2（Nrf2）。与酪蛋白相比，抗氧化剂反应元件（ARE）驱动的抗氧化剂表达水平（谷氨酸半胱氨酸连接酶催化亚基，谷氨酸半胱氨酸连接酶调节亚基，谷胱甘肽合酶，谷胱甘肽还原酶，谷胱甘肽S的表达上调）在RP组中发现-转移酶，谷胱甘肽过氧化物酶，过氧化氢酶，超氧化物歧化酶，血红素加氧酶1，NAD（P）H：醌氧化还原酶1）。此外，RP上调了成年和成年大鼠的蛋氨酸亚砜还原酶（MsrA，MsrB2和MsrB3）表达水平。结果，RP增强了内源性抗氧化能力，以减少丙二醛，羰基蛋白和活性氧物种的肝积累。这项研究表明，RP在刺激成年大鼠和成年大鼠中发挥内源性抗氧化能力，这是由于刺激Msr抗氧化剂表达并激活Nrf2-ARE途径。结果表明，RP诱导的抗氧化活性与年龄无关。