Evaluation of extracts of Ginkgo biloba and its constituents on the fibrillogenesis and on the stability of collagen fibrils in vitro
Herbage, D.; Willems, R.; Flandin, F.
Phlebologie 44(4): 873-880
1991
ISSN/ISBN: 0031-8280 PMID: 1666679 Document Number: 374066
Extracts of Gingko biloba were studied with regard to their effect on collagen fibrillogenesis, reconstituted collagen fibrils, and collagen degradation by bacterial collagenase. The extracts EGba (total extract), EGbb (extract without terpenes), EGbc (extract without proanthocyanidines), EGbd (mixture of the ginkolides A, B, and C), and diosmin were used. EGba, EGbb, and EGbc significantly reduced both the latency period and solution turbidity during fibrillogenesis. EGba and EGbb further reduced latency times when they were incubated for 24 hours before fibrillogenesis. When incubated with pre-constituted collagen fibrils, EGba, EGbb, and EGbc, all of which contain flavonoids, had measurable levels of fixation to the collagen fibrils. Collagen fibrils incubated with EGba and EGbb had increased temperatures of denaturation. EGba, EGbb, and, to a lesser extent, EGbc inhibited collagen degradation by bacterial collagenase. EGbd and diosmin had no protective effects on collagen fibrils or fibrillogenesis. The collagen stabilizing and protecting action of the flavonoid fraction combined with the antiinflammatory action of the terpene fraction are responsible for the efficacy of Ginkgo biloba extract in the treatment of venous disease.