RESUMO
Corticosteroids have been used extensively since cortisone was first synthesized in the 1950s, but it leads to the development of numerous side effects. Parsley is one of the most effective medicinal herbs. It has antioxidant and free radical scavenging activities. The present study was designed to evaluate the toxic effect of the chronic use of prednisolone on the histological structure of the liver and lung and the protective effect of parsley oil against the changes induced by prednisolone. Twenty-five adult male albino rats were used. They were divided into three groups: group I was the control group; group II received 2 mg/kg/day prednisolone once daily for 1 month; and group III received parsley oil 0.6 ml/kg/day once daily followed by prednisolone after 2 h for 1 month. The liver and the lung were dissected out and processed for light and electron microscopic examination. In addition, a statistical study was carried out for determining the thickness of the interalveolar septum. In group II, some hepatocytes showed vacuolations and fatty changes and other hepatocytes revealed apoptotic changes. Lung tissue revealed sloughing of the bronchiolar epithelium. Hemorrhage and cellular infiltration were seen in airway spaces. Moreover, there was highly significant thickening of the interalveolar septa. Apparent increase in atypical type II pneumocytes with hyperchromatic nuclei was seen. Electron microscopy revealed vacuolated hyperchromatic type II pneumocytes. In group III, liver cells were normal except for some vacuolations in the cytoplasm. The lung continued to reveal significant increase in thickness of the interalveolar septa. Some type II pneumocytes showed hyperchromatic features. Electron microscopy revealed type II pneumocytes with a few lamellar bodies. Compared with the liver, the dose of parsley and its duration of treatment with respect to the lung should be markedly higher to have a significant effect, as the destructive effect of prednisolone on the lung is greater than that on the liver