Components of aloe vera extracts show antiviral activity against influenza A

Researchers at the Korea Institute of Oriental Medicine investigated the antiviral activities of the bioactive components of Aloe vera. They reported their findings in an article published in The American Journal of Chinese Medicine.

• Previous studies have found that the ethanolic extract of Aloe vera (AVE) has significant anti-influenza activity, but the mechanisms underlying this activity and the constituents responsible for it have not yet been elucidated.
• In an earlier study, the researchers reported that AVE treatment significantly reduced the replication of green fluorescent protein-labeled influenza A virus in Madin-Darby canine kidney (MDCK) cells.
• They also noted that post-treatment with AVE inhibited expression of viral matrix protein 1 (M1), matrix protein 2 (M2) and hemagglutinin (HA).
• In the present study, the researchers found that AVE inhibited autophagy induced by influenza A in MDCK cells.
• They also identified quercetin, catechin hydrate and kaempferol as the active antiviral components of AVE.
• Post-treatment with the three compounds markedly inhibited M2 viral mRNA synthesis and M2 protein expression.
• Docking simulation suggested that the binding affinity of quercetin, catechin hydrate and kaempferol for the M2 protein may be higher than that of known M2 protein inhibitors.

Based on these findings, the researchers concluded that Aloe vera is an effective antiviral agent against H1N1 and H3N2 because it contains active compounds that can inhibit influenza virus-induced autophagy.

Journal Reference:

Choi JG, Lee H, Kim YS, Hwang YH, Oh YC, Lee B, Moon KM, Cho WK, Ma JY. ALOE VERA AND ITS COMPONENTS INHIBIT INFLUENZA A VIRUS-INDUCED AUTOPHAGY AND REPLICATION. The American Journal of Chinese Medicine. 2019;47(06):1307–1324. DOI: 10.1142/s0192415x19500678