A compound derived from fats found in fish oils prevents death in influenza-virus-infected mice, even at advanced stages of disease, according to a study published Thursday in the journal Cell.

Flu viruses are a major cause of death and sickness around the world, and antiviral drugs currently do not protect the most seriously ill patients. The study offers a promising strategy for the treatment of patients with severe influenza virus infections.

Currently available antiviral drugs inhibit influenza virus replication, but they are not typically effective when given to patients as little as two days after infection. In an attempt to discover more effective drug targets for influenza, scientists have recently identified several genes and molecules that are crucial for influenza virus replication. However, until now it was not known whether naturally occurring lipids, such as those derived from omega-3 polyunsaturated fatty acids (PUFAs) found in fish oils, might also be involved in influenza virus infections.

To answer this question, researchers at Akita University in Japan screened for PUFA-derived lipids in influenza-virus-infected human lung cells. When they treated infected cells with these lipids, they found that protectin D1 (PD1) was the most effective at inhibiting the replication of viruses, including H5N1.

In addition, low levels of PD1 in the lungs of influenza-virus- infected mice were associated with severe infection and highly pathogenic viruses, such as H5N1. Treatment with PD1 in combination with an approved antiviral drug improved the survival of influenza-virus-infected mice and prevented death, even when given two days after infection.

"Our findings suggest that PD1 could serve as a biomarker as well as a much needed antiviral drug for severe and lethal influenza virus infections," the researchers said.

Source: Xinhuanet