Division of Biological Science, College of Science, Sookmyung Women's University, Seoul, Korea.
Nutr Res. 2013 Nov;33(11):942-51. doi: 10.1016/j.nutres.2013.07.011. Epub 2013 Sep 17.
Type 1 diabetes is an endocrinologic disorder characterized by uncontrolled glucose regulation and oxidative stress. Olive leaves have been studied extensively for their antioxidant activity and capacity to improve immune function. We hypothesized that olive leaf powder supplementation will be effective in inhibiting the oxidative stress and immune dysregulation in streptozotocin (STZ)-induced diabetic mice. Mice were assigned to 1 of 5 groups: control (C), STZ-induced diabetes (D), and STZ-induced diabetes supplemented with very low dose (VLOL), low dose (LOL), or high dose of olive leaf powder (HOL). Blood glucose in the VLOL and LOL groups was lower than that in the D group (P < .05). Insulin levels were increased in all experimental groups in comparison with that in the D group, (P < .05). Superoxide dismutase, glutathione peroxidase, and catalase activities were shown to decrease in the D group, whereas these were increased in the VLOL and LOL groups. Nitric oxide levels decreased in the VLOL and LOL groups, as compared with the D group. The messenger RNA expression levels of inducible nitric oxide synthase were significantly decreased in the VLOL and HOL groups, and interferon-γ levels were significantly decreased in the liver of the VLOL, LOL, and HOL groups compared with the levels in the D group. Interleukin-17 levels were significantly decreased in the VLOL and HOL groups. Th1 and Th17 cytokine levels were increased in the D group but decreased in all the experimental groups. Th2 cytokine levels were increased in all olive leaf-supplemented groups compared with those in the D group. These results indicate a reduction in the levels of proinflammatory cytokines, suggesting that olive leaves have the potential to provide therapeutic inhibition of diabetic complications.
1 型糖尿病是一种内分泌紊乱疾病，其特征是葡萄糖调节失控和氧化应激。橄榄叶因其抗氧化活性和改善免疫功能的能力而被广泛研究。我们假设橄榄叶粉补充剂将有效抑制链脲佐菌素（STZ）诱导的糖尿病小鼠的氧化应激和免疫失调。将小鼠分为 5 组中的 1 组：对照组（C）、STZ 诱导的糖尿病组（D）和补充极低剂量（VLOL）、低剂量（LOL）或高剂量橄榄叶粉的 STZ 诱导的糖尿病组（HOL）。与 D 组相比，VLOL 和 LOL 组的血糖水平较低（P<.05）。与 D 组相比，所有实验组的胰岛素水平均升高（P<.05）。D 组中超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性降低，而 VLOL 和 LOL 组中这些酶活性增加。与 D 组相比，VLOL 和 LOL 组的一氧化氮水平降低。与 VLOL 和 HOL 组相比，诱导型一氧化氮合酶的信使 RNA 表达水平显著降低，而 VLOL、LOL 和 HOL 组肝脏中的干扰素-γ水平显著降低。与 D 组相比，VLOL 和 HOL 组的白细胞介素-17 水平显著降低。D 组 Th1 和 Th17 细胞因子水平升高，但所有实验组均降低。与 D 组相比，所有添加橄榄叶的组 Th2 细胞因子水平升高。这些结果表明促炎细胞因子水平降低，表明橄榄叶具有提供治疗抑制糖尿病并发症的潜力。
