Sunday, March 8, 2009

Chloroquine as antiviral agent !

We all knew that chloroquine derivatives are better known as antimalarials, but something new chloroquine can be used as antiviral agent? yes says a group of researchers lead by Dr. Moscona and that too against the two lethal viruses Hendra and Nipah.

The research is significant because of the fact that
the two henipaviruses that are the subject of the study are Hendra Virus (HeV) and Nipah Virus (NiV) emerged during the 1990s in Australia and Southeast Asia. (Spread via fruit bats, and they did cause potentially fatal encephalitis and respiratory disease in humans, with a devastating 75 percent fatality rate.) More recently, NiV outbreaks in Bangladesh involving human-to-human transmission have focused attention on NiV as a global health concern. One more interesting fact of this research is chloroquine is already an established drug for malaria and its the cheap drug too.

Like the avian flu, SARS, and Ebola viruses Hendra and Nipah are zoonotic pathogens (originating in certain animals but can jump between animal species and between animals and humans). There are currently no vaccines or treatments against the two henipaviruses, which are listed by the U.S. government as possible bioterror agents.

The aproach of this research group is interesting and also of greater importance because the mode of action of chloroquine is (as explained by the authors) it block the action of a key enzyme, called cathepsin L, which is essential to the virus's growth and maturation. Without this enzyme, newly formed Hendra or Nipah viruses cannot process the protein that permits the viruses to fuse with the host cell. Newly formed viruses then cannot spread the infection; in other words, they can invade, but cannot cause disease.

The authors also claim the fact that "several other zoonotic viruses depend on cathepsin L - most notably, Ebola. Our findings, and our methods, could easily be applied to the study of Ebola and other emerging diseases" .

Congrats Dr. Moscona and group for this acheivement. ...

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