Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy.
Biomarkers Unit, Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Rome, Italy.
Cell Biochem Funct. 2024 Aug;42(6):e4105. doi: 10.1002/cbf.4105.
Prediabetes is a risk state that defines a high chance of developing diabetes and cardiovascular disease. Oxidative stress mediated by hyperglycemia-induced production of reactive species could play a crucial role in this context. In the present study, we investigated whether the anion exchange capability mediated by AE1 (SLC4A1), which is sensitive to oxidative stress, was altered in human red blood cells (RBCs) obtained from prediabetic volunteers. In addition, we assessed the precise composition of bioactive compounds and the potential benefits of finger lime juice extract (Citrus australasica, Faustrime cultivar) in counteracting oxidative stress-related functional alterations. Human RBCs from normal and prediabetic volunteers were incubated with 50 µg/mL juice extract for 2 h at 25°C. Juice extract restored alterations of the anion exchange capability mediated by AE1 and prevented the structural rearrangements of AE1 and α/β-spectrin in prediabetic RBCs. AE1 functional and structural alterations were not associated with an increase in lipid peroxidation or protein oxidation at the level of the plasma membrane. An increased production of intracellular ROS, which provoked the oxidation of hemoglobin to methemoglobin, both reverted by juice extract, was instead observed. Importantly, juice extract also induced a reduction in glycated hemoglobin levels in prediabetic RBCs. Finally, juice extract blunted the overactivation of the endogenous antioxidant enzymes catalase and superoxide dismutase and prevented glutathione depletion in prediabetic RBCs. These findings contribute to clarifying cellular and molecular mechanisms related to oxidative stress and glycation events that may influence RBC and systemic homeostasis in prediabetes, identify AE1 as a sensitive biomarker of RBC structural and function alterations in prediabetes and propose finger lime juice extract as a natural antioxidant for the treatment and/or prevention of the complications associated with the prediabetic condition.
糖尿病前期是一种高危状态，定义为发生糖尿病和心血管疾病的几率较高。高血糖诱导活性氧产生引起的氧化应激在此过程中可能发挥关键作用。在本研究中，我们研究了从糖尿病前期志愿者获得的人红细胞（RBC）中，由 AE1（SLC4A1）介导的阴离子交换能力是否发生改变，AE1 对氧化应激敏感。此外，我们评估了生物活性化合物的精确组成以及手指莱檬（Citrus australasica，Faustrime 品种）汁提取物在对抗与氧化应激相关的功能改变方面的潜在益处。将正常人 RBC 和糖尿病前期志愿者 RBC 与 50μg/mL 果汁提取物在 25°C 下孵育 2 小时。果汁提取物恢复了 AE1 介导的阴离子交换能力的改变，并防止了糖尿病前期 RBC 中 AE1 和 α/β- spectrin 的结构重排。AE1 功能和结构的改变与质膜水平的脂质过氧化或蛋白质氧化的增加无关。相反，观察到细胞内 ROS 产生增加，这导致血红蛋白氧化为高铁血红蛋白，这两种情况均被果汁提取物逆转。重要的是，果汁提取物还降低了糖尿病前期 RBC 中糖化血红蛋白的水平。最后，果汁提取物减弱了内源性抗氧化酶过氧化氢酶和超氧化物歧化酶的过度激活，并防止了糖尿病前期 RBC 中谷胱甘肽的耗竭。这些发现有助于阐明与氧化应激和糖化事件相关的细胞和分子机制，这些机制可能影响糖尿病前期的 RBC 和全身稳态，确定 AE1 为糖尿病前期 RBC 结构和功能改变的敏感生物标志物，并提出手指莱檬汁提取物作为治疗和/或预防与糖尿病前期相关并发症的天然抗氧化剂。
