Previous studies based on animal models demonstrated that N-acetylcysteine (NAC) prevents oxidative stress and improves salivary gland function when the NAC supplementation starts simultaneously with insulin resistance (IR) induction. This study is the first to evaluate the effect of a 4-week NAC supply on the antioxidant barrier and oxidative stress in Wistar rats after six weeks of high-fat diet (HFD) intake. Redox biomarkers were evaluated in the parotid (PG) and submandibular (SMG) salivary glands and stimulated whole saliva (SWS), as well as in the plasma and serum. We demonstrated that the activity of salivary peroxidase and superoxide dismutase and total antioxidant capacity were significantly higher in PG, SMG, and SWS of IR rats treated with NAC. It appears that in PG and SMG of rats fed an HFD, N-acetylcysteine supplementation abolishes oxidative modifications to proteins (evidenced by decreased content of advanced oxidation protein products (AOPP) and advanced glycation end products (AGE)). Simultaneously, it does not reverse oxidative modifications of lipids (as seen in increased concentration of 8-isoprostanes and 4-hydroxynonenal vs. the control), although it reduces the peroxidation of salivary lipids in relation to the group fed a high-fat diet alone. NAC administration increased protein levels in PG and SMG but did not affect saliva secretion, which was significantly lower compared to the controls. To sum up, the inclusion of NAC supplementation after six weeks of HFD feeding was effective in improving the general and salivary gland antioxidant status. Nevertheless, NAC did not eliminate salivary oxidative stress and only partially prevented salivary gland dysfunction.

中文翻译：

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NAC补充高血糖大鼠可预防胰岛素抵抗的发展并改善抗氧化状态，但只能缓解普通和唾液腺的氧化应激

先前基于动物模型的研究表明，当NAC补充剂与胰岛素抵抗（IR）诱导同时开始时，N-乙酰半胱氨酸（NAC）可以防止氧化应激并改善唾液腺功能。这项研究是第一个评估在食用六周高脂饮食（HFD）后供应4周NAC对Wistar大鼠抗氧化屏障和氧化应激的影响的研究。在腮腺（PG）和下颌下腺（SMG）唾液腺和刺激的全唾液（SWS）中以及血浆和血清中评估了氧化还原生物标志物。我们证明，NAC处理的IR大鼠的PG，SMG和SWS中唾液过氧化物酶和超氧化物歧化酶的活性以及总抗氧化能力显着更高。似乎在喂了HFD的大鼠的PG和SMG中，N-乙酰半胱氨酸的补充消除了蛋白质的氧化修饰（由高级氧化蛋白产物（AOPP）和高级糖基化终产物（AGE）含量降低所证明）。同时，尽管与单独喂高脂饮食组相比，它减少了唾液脂质的过氧化作用，但它并不能逆转脂质的氧化修饰（如从8-异前列腺素和4-羟基壬烯醛的浓度增加所见）。 。NAC施用可增加PG和SMG中的蛋白质水平，但不影响唾液分泌，与对照组相比，唾液分泌显着降低。综上所述，HFD喂食六周后添加NAC可以有效改善唾液腺和唾液的抗氧化剂状态。不过，