Screening for Neuraminidase Inhibitory Activity in Traditional Chinese Medicines Used to Treat Influenza.

OBJECTIVE: To screen for influenza virus neuraminidase inhibition and to provide a reference for the clinical treatment of influenza using traditional Chinese medicines (TCM). In this study, 421 crude extracts (solubilized with petroleum ether, ethanol, ethyl acetate, and aqueous solvents) were obtained from 113 TCM. The medicine extracts were then reacted with oseltamivir, using 2'-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid (MUNANA) as the substrate, to determine influenza virus neuraminidase activity using a standard fluorimetric assay. It was found that Chinese medicine extracts from Pyrola calliantha, Cynanchum wilfordii, Balanophora involucrata and Paeonia delavayi significantly inhibited neuraminidase activity at a concentration of 40 µg/mL. Dose-dependent inhibitory assays also revealed significant inhibition. The IC50 range of the TCM extracts for influenza virus neuraminidase was approximately 12.66-34.85 µg/mL, respectively. Some Chinese medicines have clear anti-influenza viral effects that may play an important role in the treatment of influenza through the inhibition of viral neuraminidase. The results of this study demonstrated that plant medicines can serve as a useful source of neuraminidase (NA) inhibitors and further investigation into the pharmacologic activities of these extracts is warranted.

[HPLC Analyzed the Iridoid Glycosides of Qingyedan Commonly Used in Folk Medicine in Yunnan].

Objective: To compare the contents of iridoid glycosides in Qingyedan medicinal materials,and to provide the scientific basis for using resources of Qingyedan and rationality of original plant medicinal. Methods: The contens of three iridoid glycosides,including swertiamarin,gentiopicroside and sweroside in Qingyedan medicinal materials were determined by HPLC. Results: The constituents of 30 samples in nine species were significant difference. And the contents of iridoid glycosides in Swertia bimaculata,Swertia tenuis and Swertia pubescens were reported for the first time. Conclusion: The results show that the contents of iridoid glycosides in Qingyedan medicinal materials have a significant difference due to the different species and producing areas. Therefore, these medicinal plants should not be used as alternative medicines for clinical application. Swertiamarin and sweroside can be selected as quality control components, this method is an effective method to identify and control the quality of Qingyedan materials.