Antioxidant Property of the Egyptian Propolis Extract Versus Aluminum Silicate Intoxication on a Rat's Lung: Histopathological Studies.

In this study, we evaluated the inflammatory responses induced by aluminum silicate (AS) cytotoxicity in rat lungs. The prophylactic effect of propolis extract was evaluated in 60 adult male albino rats. The rats were divided into six groups: (1) a normal, healthy control group; (2) a normal group fed with 200 mL of propolis extract/Kg; (3) a low-dose positive control group injected with 5 mg/kg of AS; (4) a treated group given propolis and a low dose of AS; (5) a high-dose positive control group injected with 20 mg/kg of AS; and (6) a treated group given propolis with a high-dose of AS. At the end of the two-month experiment, the rats' lungs were removed. For each pair of lungs, one portion was subjected to biochemical analysis and the other underwent hematoxylin and eosin (H&E) staining in order to study its histology. The rats that received AS doses displayed significant disorders in their antioxidant contents as well as in their enzymatic activities and their histopathological structures revealed severe damage to their lung tissues. Upon the rats being treated with propolis, the enzymatic and antioxidant contents improved and partial improvements in the lung structures appeared, including minimized congestion, a reduced hemorrhage of blood vessels and preserved bronchioles, alveolar ducts, and alveoli. The prophylactic effectiveness of propolis extract on the cytotoxicity of AS, owing to the antioxidant properties of propolis, were studied.

Impacts of Egyptian propolis extract on rat cerebellum intoxicated by aluminum silicate: histopathological studies.

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.