ABSTRACT
In the present study, we assayed the antioxidant properties of Ginkgo biloba (Gb) extract on rats submitted to 21 d of chronic hypoxia. Doses of 25 and 50 mg/kg were examined. Oxygenated free radical production measured by the chemiluminescence technique was significantly decreased in treated rats compared to control rats placed in similar experimental conditions, and this effect was more significant at the 50 mg/kg dose. On the other hand, no antioxidant enzyme activities of the drug were observed towards red blood cells. These results suggest that ginkgo biloba extract has a free radical scavenging action. These antioxidant properties could explain the beneficial hematological properties of Gb extract.
Subject(s)
Ginkgo biloba/chemistry , Hypoxia/metabolism , Plant Extracts/pharmacology , Animals , Free Radicals , Glutathione Peroxidase/metabolism , Luminescent Measurements , Male , Rats , Rats, Wistar , Superoxide Dismutase/metabolismABSTRACT
The influence of Vinburnine on red blood cell metabolism and hemoglobin oxygen affinity was investigated in normobaric rats (FiO2: 10%). Two periods of hypoxic exposure were performed (10-21 d). In each experimental series, rats were divided into two groups: Treated rats received a daily intraperitoneal injection of drug (4 mg/kg). Control rats in the same conditions of hypoxia received an isotonic saline solution. For a 10 d exposure period, Vinburnine does not affect red blood cell metabolism nor hemoglobin oxygen affinity. At 21 d period exposure, 2, 3 diphosphoglycerate (2, 3 DPG) and ATP amounts increase in treated rats. The rate of increase was 10% (p<0.05) and 28% (p<0.01), respectively. Red blood cell metabolism effect of Vinburnine was not accompanied by a modification in affinity hemoglobin oxygen (Hb-O2); no statistically significant difference was observed between treated rats and control rats concerning p50 (partial pressure oxygen at half hemoglobin saturation). Results suggest that Vinburnine has a metabolic effect corresponding to a glycolysis anaerobic stimulation, which can improve oxygen delivery to tissues and could explain the favorable hemoreological action of Vinburnine observed in a previous investigation.