[Double blind study of the hypoxia protective effect of a standardized Ginkgo biloba preparation after repeated administration in healthy subjects].

A randomised, placebo-controlled, double-blind, crossover study was run in 8 healthy, male subjects (mean age 27.3 +/- 2.6 years, mean BW 75.3 +/- 9.7 kg) to demonstrate a possible hypoxia-protective effect of standardised Ginkgo flavone glycosides after subchronical administration. After a 14-days' treatment with Ginkgo bilobae extract (Tebonin) performance of subjects was studied--concerning assessments of oculomotor and complex choice reaction system as well as simple cardiorespiratory parameters under multiple exposure to hypoxic hypoxia (10.5% oxygen, 89.5% nitrogen)--using oculodynamic methodology (ODT). Hypoxia increased the corneoretinal resting-potential of the eye and stimulated respiration. Both parameters were significantly reduced by verum administration. Under cumulative exposure to hypoxic hypoxia fixation time of saccadic eye movements and complex choice reaction time were significantly improved by Ginkgo flavone glycosides vs placebo. These results could be explained as a hypoxia-protective phenomenon--supporting the therapy of cerebral insufficiency.