Antiviral Activity Against Infectious Bronchitis Virus and Bioactive Components of Hypericum perforatum L.

Abstract

<i>Hypericum perforatum</i> L., also known as <i>Saint John's Wort</i>, has been well studied for its chemical composition and pharmacological activity. In this study, the antiviral activities of <i>H. perforatum</i> on infectious bronchitis virus (IBV) were evaluated <i>in vitro</i> and <i>in vivo</i> for the first time. The results of <i>in vitro</i> experiments confirmed that the antiviral component of <i>H. perforatum</i> was ethyl acetate extraction section (HPE), and results showed that treatment with HPE significantly reduced the relative messenger ribonucleic acid (mRNA) expression and virus titer of IBV, and reduced positive green immunofluorescence signal of IBV in chicken embryo kidney (CEK) cells. HPE treatment at doses of 480-120 mg/kg for 5 days, reduced IBV induced injury in the trachea and kidney, moreover, reduced the mRNA expression level of IBV in the trachea and kidney <i>in vivo</i>. The mRNA expression levels of IL-6, tumor necrosis factor alpha (TNF-α), and nuclear factor kappa beta (NF-κB) significantly decreased, but melanoma differentiation-associated protein 5 (MDA5), mitochondrial antiviral signaling gene, interferon alpha (IFN-α), and interferon beta (IFN-β) mRNA levels significantly increased <i>in vitro</i> and <i>in vivo</i>. Our findings demonstrated that HPE had significant anti-IBV effects <i>in vitro</i> and <i>in vivo</i>, respectively. In addition, it is possible owing to up-regulate mRNA expression of type I interferon through the MDA5 signaling pathway and down-regulate mRNA expression of IL-6 and TNF-α <i>via</i> the NF-κB signaling pathway. Moreover, the mainly active compositions of HPE analyzed by high-performance liquid chromatography/electrospray ionization-mass spectroscopy (ESI-MS) are hyperoside, quercitrin, quercetin, pseudohypericin, and hypericin, and a combination of these compounds could mediate the antiviral activities. This might accelerate our understanding of the antiviral effect of <i>H. perforatum</i> and provide new insights into the development of effective therapeutic strategies.