<bold>Thymoquinone ameliorates pulmonary vascular damage induced by</bold>Escherichia coli-<bold>derived lipopolysaccharide via cytokine downregulation in rats</bold>

Our study investigated the ameliorative effects of thymoquinone (TQ) on the pulmonary blood vessels which were injured after intratracheal administration of Escherichia coli-derived lipopolysaccharide (LPS) in a rat model. Forty rats (150 +/- 50 g) were randomly divided into four groups equally. The first group was intratracheally administered LPS (Escherichia coli O55:B5) at a dose 200 g. The second group was co-administered intraperitoneal injection of TQ and LPS daily for one week. The third group was provided intraperitoneal injection of 1 mg of TQ. The fourth group was administered normal saline intratracheally at the rate of 200 l. The results revealed that cytokine level of interleukin-1 beta (IL-1) and tumor necrosis factor alpha (TNF) in serum was reduced in TQ-treated rats. Immunohistochemical study showed that expression of NF-kB was countered in the lung tissue by the application of TQ. In addition, the lesion score for various pathological aberrations were checked when rats were treated with TQ. From the results of the present study, it was concluded that TQ has an ameliorative effect on the pulmonary blood vascular damage via rearrangement of the cytokines in response to LPS injury in the rat model.