AsianScientist (Oct. 8, 2014) – Research has validated the use of honeysuckle (Lonicera japonica) to treat viral infections, showing that it contains a plant microRNA (miRNA) which directly targets influenza A viruses (IAV) including H1N1, H5N1 and H7N9. This research has been published in Cell Research.
MiRNAs are a class of 19-24 nucleotide RNAs that do not encode for proteins. Instead, they bind to target messenger RNAs to inhibit protein translation. In previous studies, Professor Zhang Chen-Yu’s group at Nanjing University found that plant miRNAs can enter into the host blood and tissues via food-intake. More importantly, once inside the host, the food-derived exogenous miRNAs can regulate host physiology by regulating host “target” genes.
In the present study, they report a surprising finding that MIR2911 from a Chinese herb honeysuckle can suppress IAV infection. Firstly, MIR2911 was found to be selectively retained in the boiled decoction of honeysuckle, and delivered to mouse plasma and lung tissue after drinking.
Then, the authors showed that MIR2911 represses various influenza viruses by targeting PB2 and NS1, two genes that are known to be required for influenza viral replication. Moreover, both synthetic MIR2911 and endogenous MIR2911 in honeysuckle decoction showed effective protection of animals from H1N1 infection, and that such protection is dependent on the MIR2911-binding sites in the PB2 or NS1 genes. Finally, the also showed that MIR2911 is effective in suppressing the replication of influenza viruses H5N1 and H7N9, indicating a broad-spectrum anti-IAV effect of MIR2911.
The study is the first demonstration that a natural product can directly target a virus. Since Alexander Fleming discovered penicillin nearly a century ago, antibiotics have been developed to target various bacterial infections and have saved the lives of millions of people. However, no natural product that is effective against viral infection had been identified up till now.
As the first natural product directly targeting different IAVs, plant MIR2911 not only is the first active component identified in traditional Chinese medicine that directly targets various IAVs, but also may represent a novel type of natural product that effectively and directly suppresses viral infection. Furthermore, one of their ongoing studies shows that MIR2911 also directly targets Ebola virus, which is pandemic in West Africa and is becoming a crisis of public health.
These results also provide evidence that dietary exogenous miRNAs are able to be functionally absorbed by mammalian gastrointestinal tract and play an important regulatory role in a cross-kingdom manner.
The article can be found at: Zhou et al. (2014) Honeysuckle-Encoded Atypical MicroRNA2911 Directly Targets Influenza A Viruses.
Source: Nanjing University; Photo: Tony Alter/Flickr/CC.
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