ABSTRACT
This chapter discusses the antiviral evaluation of crude extracts. Babbar et al. have reported their screening of more than 2000 plant extracts for their ability to protect cultured cells or chick embryos against NDV and vaccinia viruses. Babbar et al. presented the results on 1864 plant extracts, of which 7 contained significant antiviral activity. Interferon itself was for a long time considered an 'antiviral' compound before its multiple real functions. The three major systems of traditional medicine in India, namely, the Ayurvedic, Siddha and Unani systems, have standard treatments for clinical jaundice, including that due to viral hepatitis. These treatments consist of oral administration of one or more dried plant extracts, in the form of tablets or capsules. The preinfection protocol and the virucidal protocol revealed fewer activities. Thus the most frequent activities, for both aqueous and ethanolic extracts, were those that probably interfered directly with virus replication.
