Studies On Preparation Method Of Alkaloids Fraction Of Folium Uncariae, Its Effect On Microglia Activation And Acute Toxicity

The leaves of gambirplants （Gouteng） are botanically from leaves of Uncaria rhynchophylla （Miq.） Jacks., U. sinensis （Oliv.） Havil., U. macrophylla Wall., U. hirsuta Havil. and U. sessilifructus Roxb. （Rubinacea family）. Since there is similarity in variety and content of alkaloids between Folium Uncariae and Ramulus Uncariae Cum Uncis, the leaf herb is a new medicinal resourse worthy to be developed. Thus, studies on the preparative method of the active fraction with high content of rhynchophyllic alkanoids from the leaves of U. rhynchophylla （Miq.） Jacks, its inhibitory activity of microglia activation and acute toxicity were carried out. The main contents are as follows.1. By means of the chromatographic methods of silica gel column, reversed-phase column. Sephadex LH-20 column and preparative HPLC, the preparative method, physico-chemical identification and spectral elucidation of five reference substances, including rhynchophylline, isorhynchophylline, corynoxeine, isocorynoxeine and vincoside lactam, were established. These studies provided material basis for quantitative analysis of extracts and alkaloids fraction of the leaves of U. rhynchophylla （Miq.） Jacks..2.The preparative method of the active fraction enriching rhynchophyllic alkanoids was established on the basis of systematical experiments on the methods of preparing the extracts and enriching rhynchophyllic alkanoids by means of macroporous resin using the contents and availability of rhynchophylline, isorhynchophylline, corynoxeine, isocorynoxeine and vincoside lactam as the review indexe. The result showed that the total contents of five marker compounds of the active fraction were more than 60%, with the crude extract being only 3.65%, which was 15 times higher than that of the crude extract. Thus, the established technology was simple, steady, practical for enriching alkaloids, which provided experimental data for developent of new drug of the fraction enriching rhynchophyllic alkanoids. 3. The effects of crude extracts of leaves and hooks of U. rhynchophylla （Miq.） Jacks. and active fraction enriching rhynchophyllic alkaloid on the NO production in LPS-activated primary rat microglial cells and their acute toxicity were investigated. The active fraction showed significant inhibitive effect in a dose-dependent way with IC₅₀ being 10.7mg/mL, while the inhibition of crude extracts was not shown. The result confirmed rationality and efficacy of the enriching methods from the pointview of the activity. The acute toxicity tests showed low toxcity of the two crude extracts with both maximally tolerated dose being 10g/kg, while the LD₅₀ of the active fraction was 1406.4±198.9mg/kg. The above results provided a toxicological data for the development of alkaloids fraction as well as the leaves of U. rhynchophylla （Miq.） Jacks.