Effet de l'extrait de Ginkgo biloba sur la barriere hemo-encephalique.

In: Presse Med (1986 Sep 25) 15(31):1498-501

The different methods used to explore the blood-brain barrier (made up of cerebral capillary vessels), and notably, at molecular level, isolated microvessel preparations, have greatly improved our knowledge in this particular field. Some of these methods could be used to evaluate the protective effects of therapeutic substances, such as Ginkgo biloba extract, on the blood-brain barrier.

Chaterjee G.:

Effects of Ginkgo biloba extract on cerebral metabolic processes.

In: Effects of GBE and Organic Cerebral Impairment, Paris, London, John Lilley, 1985.

Clostre F

[From the body to the cell membrane: the different levels of pharmacological action of Ginkgo biloba extract]

In: PRESSE MED 1986 Sep 25; 15(31):1529-38 (Published in FRENCH)

The pharmacological study of Ginkgo biloba extract has required numerous experiments over several years: diffe rent pathological models of cerebral ischaemia to evaluate its effects, and experiments at both cellular and molecular levels to determine its mechanisms of action. In experimental models of ischaemia, oedema and hypoxia, Ginkgo biloba extract reduced vascular, tissular and metabolic disturbances as well as their neurological and behavioural consequences. The pharmacological effects of Ginkgo biloba extract concern vascular, rheological and metabolic processes. Several membrane mechanisms seem to be involved: protection of the membrane ultrastructure against free radicals, modulation of some enzymatic systems and ionic pumps. The originality of the pharmacological properties of Ginkgo biloba extract lies in preferential focusing of its effects on ischaemic areas.

Creutzig A

[Is Ginkgo biloba extract EGb 761 clinically effective in intermittent claudication? (letter)]

In: Vasa (1993) 22(2):189-90 (Published in German)

Diwok M Kuklinski B Ernst B

[Superoxide dismutase activity of Ginkgo biloba extract]

In: Z Gesamte Inn Med (1992 Jul) 47(7):308-11 (Published in German)

The Ginkgo biloba extract is obtained from green leaves of the Ginkgo biloba tree. Preparations with this active substance are among others used for the treatment of disturbances of the cerebral function and arteriosclerotic diseases. In in-vitro and in-vivo studies antagonistic effects of radical scavenger and PAF (platelet activating factor) were described. In this study a concentration- depending superoxide dismutase activity of the Ginkgo biloba extract rokan liquid could be made evident.

Droy-Lefaix-M-T; Szabo-M-E; Doly-M

Ischaemia and reperfusion-induced injury in rat retina obtained from normotensive and spontaneously hypertensive rats: Effects of free radical scavengers.

In: International Journal of Tissue Reactions (1993)15(2): 85-91

The authors have studied the effects of free radical scavengers, superoxide dismutase (SOD) and extract of Ginkgo biloba (EGb 761, flavone-rich extract) on ion shifts (Na, K and Ca) induced by ischaemia and reperfusion in rat retina obtained from normotensive and spontaneously hypertensive rats. Eyes were subjected to 90 min of ischaemia by occlusion of the retinal artery, followed by 4 and 24 hours of reperfusion. SOD (15, 000 U/kg, i.v.) or EGb 761 (50 mg/kg, per os) was administered in a daily dose for 10 days. In the drug-free control groups, 90 min of ischaemia significantly increased tissue Na gains from their pre-ischaemic control values of 63 +- 7 mu-M/g dry weight (in retina obtained from normotensive rats) and 76 mu-M/g dry weight (in retina obtained from hypertensive rats) to 89 +- 9 mu-M/g dry weight and 101 +- 7 mu-M/g dry weight, respectively. During reperfusion, a further elevation was found in retinal Na in both the normotensive and hypertensive groups. Probably, because of the ischaemia-induced inhibition of Na-K-ATPase, retinal K loss was detected after ischaemia and reperfusion, respectively. An accumulation of retinal Ca was measured after ischaemia and reperfusion in the normotensive and spontaneously hypertensive groups. Both free radical scavengers significantly reduced the maldistribution of ions induced by ischaemia and reperfusion, but the effectiveness of drugs was more evident in normotensive than hypertensive groups. The present results indicate that the elimination of free radicals by free radical scavengers may reduce, probably via an indirect mode, the reperfusion-induced ionic imbalance and improve the ionic homeostasis in injured retinal cells obtained from normotensive and spontaneously hypertensive rats.