Kaempferol: A Review of Current Evidence of Its Antiviral Potential

Abstract

Kaempferol and its derivatives are flavonoids found in various plants, and a considerable number of these have been used in various medical applications worldwide. Kaempferol and its compounds have well-known antioxidant, anti-inflammatory and antimicrobial properties among other health benefits. However, the antiviral properties of kaempferol are notable, and there is a significant number of experimental studies on this topic. Kaempferol compounds were effective against DNA viruses such as hepatitis B virus, viruses of the alphaherpesvirinae family, African swine fever virus, and pseudorabies virus; they were also effective against RNA viruses, namely feline SARS coronavirus, dengue fever virus, Japanese encephalitis virus, influenza virus, enterovirus 71, poliovirus, respiratory syncytial virus, human immunodeficiency virus, calicivirus, and chikungunya virus. On the other hand, no effectiveness against murine norovirus and hepatitis A virus could be determined. The antiviral action mechanisms of kaempferol compounds are various, such as the inhibition of viral polymerases and of viral attachment and entry into host cells. Future research should be focused on further elucidating the antiviral properties of kaempferol compounds from different plants and assessing their potential use to complement the action of antiviral drugs.

Keywords: antiviral actions; ethnobotany; kaempferol; kaempferol derivatives; physiopathology; traditional medicine.

Figure 1

Chemical structures of kaempferol and common derivatives mentioned in the text.

Figure 2

Summary of kaempferol antiviral effects on DNA and RNA viral infections.

Figure 3

Illustration of the action mechanisms of kaempferol and its derivatives on viral entry, replication and effects. A. Direct effect on viral molecules; B. Inhibition of viral attachment; C. Inhibition of polymerase activity; D. Inhibition of reverse transcription; E. Inhibition of viral proteins transcription; F. Inhibition of viral proteins activity; G. Down-regulation of the PI3K-Akt pathway; H. Up-regulation of AMPK signalling. DNA = deoxyribonucleic acid, RNA = ribonucleic acid, DNAP = deoxyribonucleic acid polymerase, RT = reverse transcriptase, AKT = protein kinase B, AMPK = adenosine monophosphate-activated protein kinase.