RESUMO
OBJECTIVE: To observe the effects ofGynura segetum in rats with hepatic veno-occlusive disease (HVOD). METHODS: Sixty Sprague-Dawley rats were assigned to a blank control group, one of three Gynura segetum treatment groups (low-dose group, 5.0 g/kg; mid-dose group, 10 g/kg; high-dose group, 20 g/kg), or a pseudo-drug group (10 g/kg of pseudo-ginseng). After 28 days of treatment, effects on white blood cell count, coagulation, secreted factors from vascular endothelium, and histopathology of the spleen were observed and inter-group differences were statistically assessed. RESULTS: After the 4-week administration, all rats in the Gynura segetum treatment groups showed decrease in body weight, increases in numbers of leukocytes, neutrophils, lymphocytes, monocytes and eosinophils.decreases in platelets and platelet hematocrit, and increases in mean platelet volume and platelet distribution.In addition, the Gynura segetum treatments increased the prothrombin time, activated partial thromboplastin time, thrombin time, prothrombin ratio and international normalized ratio, but decreased the PT%, fibrinogen level and platelet aggregation.Serum levels of endothelin and nitric oxide were also elevated by the Gynura segetum treatments.All measured parameters showed significant differences from the control group (P less than 0.01 or less than 0.05).Finally, the splenic follicles were significantly reduced and the spleens showed an absence of germinal centers along with a large number of diffuse lymphocytes and reduced red pulp sinusoids. CONCLUSION: The Gynura segetum treatment has some toxic effects; it can reduce platelet count and platelet hematocrit, inhibit blood clotting time and platelet aggregation, increase the secretion of factors from the vascular endothelium and disrupt spleen histology.