Zoology Department, Faculty of Science, Damietta University, Damietta, Egypt.
Zoology Department, Faculty of Science, Port Said University, Port Said, Egypt.
Environ Sci Pollut Res Int. 2019 Jul;26(21):22061-22068. doi: 10.1007/s11356-019-05469-4. Epub 2019 May 29.
Human is exposed to traces of aluminum silicate (AlS), i.e., cosmetics, pesticides. Accumulation of aluminum compounds including AlS is associated with neuropathological diseases, e.g., Alzheimer's disease. The aim of the current study is to investigate the neuroprotective effects of propolis extracts in AlS-induced cerebellum intoxication in rats. Forty adult rats were randomly divided into four groups (n = 10). The first group served as a control; the second group treated with 200 ml propolis/kg bwt. every other day by stomach gavage tube, third group was intraperitoneally injected with AIS (20 mg/kg) twice a week for 8 weeks, and the fourth group received propolis extract and AIS. At the end of 8 weeks, the cerebellum was harvested for further ultrastructure, histological, and histochemical investigations. Using electron microscopy, the ultrastructure of the cerebellar cortex of AlS intoxicated rats showed Purkinje cells with an irregular euchromatic nucleus and extremely increased invagination of the nuclear envelope. In addition, the cytoplasm revealed numerous damaged mitochondria (> 20%) as well as swollen lysosomes (> 40%) compared to controls. These AlS-related ultrastructure changes were to some extent normalized to < 10% and < 30% in case of mitochondria and lysosomes, respectively, if rats were co-treated with propolis extract. Further, histopathological examination showed that AlS-exposed rats revealed abnormal Purkinje cells with irregular size and shrank shape, evidence of pre-necrotic stage in the form of nuclear pyknosis, and condensed and frequent darkly stained cells in cerebellar layers. However, propolis extract co-administration reversed from 35 to 25% (p < 0.05) these alterations. The carbohydrate and protein contents were reduced in case of AlS treatment and surprisingly propolis co-treatment was able to rescue these neurotoxic effects. Propolis extract might have neuroprotective effects against AIS-induced toxicity. Further studies are required to identify the mechanism of the pharmacological action and optimal settings for medical testing of propolis extract.
人类会接触到硅酸铝（AlS），例如化妆品、农药。铝化合物的积累包括 AlS 与神经病理学疾病有关，例如阿尔茨海默病。本研究的目的是研究蜂胶提取物对大鼠 AlS 诱导的小脑中毒的神经保护作用。40 只成年大鼠随机分为四组（n = 10）。第一组作为对照；第二组每天通过胃管灌胃 200ml 蜂胶/kg bwt；第三组每周腹腔内注射 AIS（20mg/kg）两次，共 8 周；第四组给予蜂胶提取物和 AIS。8 周后，收获小脑进行进一步的超微结构、组织学和组织化学研究。使用电子显微镜，AlS 中毒大鼠小脑皮质的超微结构显示，浦肯野细胞具有不规则的常染色质核和核膜极度增加的内陷。此外，与对照组相比，细胞质中受损的线粒体（>20%）和肿胀的溶酶体（>40%）明显增加。如果大鼠同时给予蜂胶提取物，这些与 AlS 相关的超微结构变化在某种程度上正常化，线粒体和溶酶体分别为<10%和<30%。此外，组织病理学检查显示，暴露于 AlS 的大鼠显示出浦肯野细胞异常，大小不规则，形状缩小，出现核固缩的坏死前阶段，小脑层中细胞密集且染色深。然而，蜂胶提取物的共同给药将这些变化从 35%逆转至 25%（p<0.05）。碳水化合物和蛋白质含量在 AlS 处理时降低，令人惊讶的是，蜂胶共同处理能够挽救这些神经毒性作用。蜂胶提取物可能对 AIS 诱导的毒性具有神经保护作用。需要进一步的研究来确定蜂胶提取物的药理作用机制和用于医学测试的最佳设置。
