College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Wuhan Engineering Research Center of Bee Products on Quality and Safety Control, Wuhan 430070, China.
J Immunol Res. 2018 Sep 18;2018:7245956. doi: 10.1155/2018/7245956. eCollection 2018.
The effects of propolis on blood glucose regulation and the alleviation of various complications caused by diabetes have been widely studied. The main source of propolis in the northern temperate zone is poplar buds. However, there is limited research on the antidiabetic activity of poplar buds. In order to evaluate the effect of poplar buds on type-2 diabetes, crude extract and 50% fraction of poplar buds were used to feed streptozotocin-induced type-2 diabetic mice. The results showed that 50% fraction could increase insulin sensitivity and reduce insulin resistance, as well as decrease the levels of fasting blood glucose, glycated hemoglobin, and glycosylated serum proteins in diabetic mice. Compared with the model control group, the 50% fraction-treated group showed significant decreases of malondialdehyde (MDA) and increases of superoxide dismutase (SOD) in serum and liver homogenate. Moreover, 50% fraction could significantly decrease total cholesterol (TC), alleviate abnormal lipid metabolism, and enhance antioxidant capacity in the serum. For inflammatory factors, feeding of 50% fraction could also reduce the levels of interleukin 6 (IL-6), tumor necrosis factor (TNF-), monocyte chemotactic protein 1 (MCP-1), and cyclooxygenase-2 (COX-2) in liver homogenate. Taken together, our results suggest that crude extract and 50% fraction of poplar buds, particularly the latter, can decrease blood glucose levels and insulin resistance, and 50% fraction can significantly relieve dyslipidemia, oxidative stress, and inflammation caused by type-2 diabetes.
蜂胶对血糖调节以及缓解糖尿病引起的各种并发症的作用已得到广泛研究。北方温带地区蜂胶的主要来源是柳芽。然而，关于柳芽的降血糖活性的研究却很有限。为了评估柳芽对 2 型糖尿病的作用，用粗提物和 50%柳芽馏分喂养链脲佐菌素诱导的 2 型糖尿病小鼠。结果表明，50%馏分可提高胰岛素敏感性，降低胰岛素抵抗，并降低糖尿病小鼠的空腹血糖、糖化血红蛋白和糖化血清蛋白水平。与模型对照组相比，50%馏分组的血清和肝匀浆中丙二醛（MDA）水平降低，超氧化物歧化酶（SOD）水平升高。此外，50%馏分还可显著降低总胆固醇（TC），缓解异常的脂质代谢，并增强血清中的抗氧化能力。对于炎症因子，50%馏分的喂养也可以降低肝匀浆中白细胞介素 6（IL-6）、肿瘤坏死因子-α（TNF-α）、单核细胞趋化蛋白 1（MCP-1）和环氧化酶-2（COX-2）的水平。综上所述，我们的结果表明，柳芽的粗提物和 50%馏分，特别是后者，可以降低血糖水平和胰岛素抵抗，50%馏分还可以显著缓解 2 型糖尿病引起的血脂异常、氧化应激和炎症。
