Actions of NO and INOS on Endotoxin Induced rat Acute Lung Injury and Effect of Rhubarb on Them

This study is to explore the actions of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) on endotoxin (lipopolysaccharide, LPS) induced rat acute lung injury (ALI) and effect of Rhubarb on them. LPS was injected into the sublingual vein of male Wistar rats to prepare ALI animal models. The rats were divided into 4 groups: LPS, control, Rhubarb, and dexamethasone. Macroscopic and histopathological examinations of the lung specimens were performed and the biological indexes of lung, including wet weight/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary vascular permeability and pulmonary alveolar permeability were observed. In the mean time, the contents of serum NO and the activities of lung tissue homogenate iNOS were measured. The results showed that in the LPS group, the injury and celluar infiltration in the pulmonary stroma and alveoli were more prominent than that in the control group. Lung wet weight/dry weight, the rate of neutrophils, protein content, pulmonary alveolar permeability, pulmonary vascular permeability were significantly increased (P<0.01); NO and iNOS were also markedly elevated (P<0.01). In the groups of dexamethasone and Rhubarb, the histopathological changes were significantly milder, and all the above biological indexes of lung injury and the contents of NO and the activities of iNOS were correspondingly decreased (P<0.05). The above data demonstrate that NO and the activities of iNOS play an important role in the onset of ALI; dexamethasone and Rhubarb interfering treatment can ameliorate lung injury and decrease the concentrations of NO and iNOS, showing that through inhibiting the levels of NO and the activities of iNOS, these 2 agents exert protective effect on ALI induced LPS.

Discrimination of the rare medicinal plant Dendrobium officinale based on naringenin, bibenzyl, and polysaccharides

The aim of this study was to establish a method for discriminating Dendrobium officinale from four of its close relatives Den- drobium chrysanthum, Dendrobium erystallinum, Dendrobium aphyllum and Dendrobium devonianum based on chemical composition analysis. We analyzed 62 samples of 24 Dendrobium species. High performance liquid chromatography analysis confirmed that the four low molecular weight compounds 4＇,5,7-trihydroxyflavanone （naringenin）, 3,4-dihydroxy-4＇,5-dime- tboxybibenzyl （DDB^2）, 3＇,4-dihydroxy-3,5＇-dimethoxybibenzyl （gigantol）, and 4,4＇-dihydroxy-3,3＇,5-trimethoxybibenzyl （moscatilin）, were common in the genus. The phenol-sulfuric acid method was used to quantify polysaccharides, and the mon- osaccharide composition of the polysaccharides was determined by gas chromatography. Stepwise discriminant analysis was used to differentiate among the five closely related species based on the chemical composition analysis. This proved to be a simple and accurate approach for discriminating among these species. The results also showed that the polysaccharide content, the amounts of the four low molecular weight compounds, and the mannose to glucose ratio, were important factors for species discriminaut. Therefore, we propose that a chemical analysis based on quantification of naringenin, bibenzyl, and polysaccha- rides is effective for identifying D. officinale.