Inhibitory Effect of Ginkgo Biloba Extract on the Tonus of the Small Intestine and the Colon of Rabbits

Abstract

Ginkgo biloba is widely used in folk medicine. Patients very often use the plant preparation with no concern for purity. They also tend to increase the dosage by themselves and this may result in certain insufficiently researched acute effects. Due to this extremely widespread application, the aim of this work is an examination of the possible acute effects of Ginkgo bilobaon the motility of the small and the large intestine of rabbits. The effects of Gingium® - a standardized ginkgo biloba extract (GBE) [one milliliter preparation contained 8.8-10.8 mg ginkgo flavonol glycoside and 2.0-2.8 mg lactone ring-containing terpenes (ginkgolides and bilobalides)], on the tonus of isolated segments of the ileum and the colon of rabbits were examined. The experiments were carried out on isolated bowel incisions according to the Magnus method. Data was registered by physiography (Narco-Bio-System). Our results show that GBE (0.006 g/L, - 0.06 g/L) concentration-dependently reduces the tonus of the ileum and the colon of rabbits. Apart from that, GBE reduces the increase of the tonus of the ileum caused by acetylcholine (ACh), but does not change colon tonus intensified by ACh. This indicates that the effects of the used extract in the ileum are predominantly achieved through cholinergic mechanisms, while the relaxant effects in the colon are achieved in some other way.