Immunopharmacological properties of the polysaccharide fraction isolated from Ginkgo bilobae folium

Many macromolecular compounds of the vegetal polysaccharidic type possess important immunostimulatory properties [1]. The crude macromolecular fraction was isolated from the leaves of Ginkgo biloba L. (codified as PGfol) harvested at the Botanical Gardens of Iasi, Romania. The hot water extract was partially purified and submitted to chemical and immunopharmacological studies. Purification started with anion-exchange-column chromatography, followed by HP-GPC. We found out that the polysaccharide fraction contains one macromolecular component with the molecular weight of 260.000D. The immunostimulatory activity of PGfol was further investigated by a series of tests on rats (after 7 days p.o. treatment with 100,0mg/kg): phagocytosis capacity of PMN cells by NBT test, serum complement activity and determination of the activity on spleenic T-lymphocyte [2]. In all experimental procedures Levamisole® (10,0mg/kg p.o.) was the reference compound; statistical significance was established by the Student's “t“ test. The results showed that PGfol has a good immunostimulatory activity, equal or higher to the Levamisole. The protection against Klebsiella pneumoniae 507 experimental infection was measured on mice after 10 days p.o. treatment with 10,0mg/kg PGfol; the survival rate after the treatment with PGfol was 72,7% compared to 68,7% of the control group.

References: [1] Flandroy, L. (1996) Biofutur, 159, 35–41. [2] Caesar, W. (1989) Dtsch. Apoth. Ztg. 129: 2430.