Identification of natural compounds with antiviral activities against SARS-associated coronavirus

Abstract

More than 200 Chinese medicinal herb extracts were screened for antiviral activities against Severe Acute Respiratory Syndrome-associated coronavirus (SARS-CoV) using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay for virus-induced cytopathic effect (CPE). Four of these extracts showed moderate to potent antiviral activities against SARS-CoV with 50% effective concentration (EC50) ranging from 2.4 +/- 0.2 to 88.2 +/- 7.7 microg/ml. Out of the four, Lycoris radiata was most potent. To identify the active component, L. radiata extract was subjected to further fractionation, purification, and CPE/MTS assays. This process led to the identification of a single substance lycorine as an anti-SARS-CoV component with an EC50 value of 15.7 +/- 1.2 nM. This compound has a CC50 value of 14980.0 +/- 912.0 nM in cytotoxicity assay and a selective index (SI) greater than 900. The results suggested that four herbal extracts and the compound lycorine are candidates for the development of new anti-SARS-CoV drugs in the treatment of SARS.

In vivoandin vitroantiviral activity of five Tibetan medicinal plant extracts against herpes simplex virus type 2 infection

“…Three extracts (D. heterophyllum, D. tanguticum and S. mussotii) were found to be effective in encephalitis mice induced by HSV-2 infection. Many Chinese traditional medicinal plants showing anti-HSV activity were reported by Li et al (2005) and Cheng et al (2004). However, there is no report of anti-HSV activities for these Tibetan plant extracts in vitro and in vivo.…”

The study of chemical composition and pharmacological action of the alkaloid from plants of Lycoris Herb

“…The chemical composition of Lycoris type alkaloids havs anti-bacterial activity, some scholars have found that Crinine type alkaloids with broad-spectrum antimicrobial activity [31][32] , Crinine has inhibitory activity against Staphylococcus aureus; Crinine and ainarbellisine have anti-E.coli activity; The hippeastrine of Lycoris type alkaloids has anti-Candida albicans activity [33] ; The chemical composition of Lycoris type alkaloids have anti-viral activity, Lycoris type alkaloids has inhibition effect of flu virus, measles virus, polio virus and SARS virus [34] ; Haemanthidine of Crinine alkaloids have anti-transcriptional activity effect on HIV-1 virus, Homolycorine of Lycoris type alkaloids and Colchicine of Tazettine alkaloids also have anti-transcriptional activity [35] .…”

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“…Lycorine is also effective against Severe Acute Respiratory Syndrome-associated coronavirus (SARS-CoV) 103 . On the other hand, narciclasine inhibits protein synthesis at the step of peptide bond formation.…”