Antiviral effect of Fufang yinhua jiedu (FFYH) granules against coronavirus and its potential mechanism

ABSTRACT

To investigate the effect of Fufang yinhua jiedu (FFYH) granules against coronavirus and its potential mechanism, we used Huh7, Huh7.5, H460, and C3A cell lines as in vitro models to evaluate the cytotoxicity and antiviral activity of FFYH by observation of cell pathogenic effect (CPE);and then the inhibitory effect of FFYH on the transcription expression of coronavirus RNA and inflammatory factor mRNA were evaluated by quantitive reverse transcription PCR (qRT-PCR);finally, the inhibitory effect of FFYH on the expression of coronavirus protein and its underlying mechanism against coronavirus were investigated by Western blot and immunofluorescence. Our results indicated that 50% toxic concentration (TC50) FFYH on Huh7, Huh7.5, H460, and C3A cells were 2 035.21, 5 245.69, 2 935.28 and 520 µg·mL-1, respectively;50% inhibitory concentration (IC50) of FFYH on HCoV-229E in Huh7 and Huh7.5 cells were 438.16 and 238.54 µg·mL-1 with safety index (SI) of 4.64 and 21.99, respectively;IC50 of FFYH on HCoV-OC43 in H460 cells was 165.13 µg·mL-1 with SI of 17.78. Moreover, FFYH not only could inhibit the replication of coronaviruses (HCoV-OC43 and HCoV-229E) through inhibiting the transcription of viral RNA and the expression of viral protein, but also effectively suppress the expression of inflammatory factors interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) and interleukin-8 (IL-8) at mRNA level caused by coronaviruses, which might be associated with the inhibitory effect of FFYH on mitogen-activated protein kinase (MAPK) pathway and the nuclear translocation of nuclear transcription factor-κB (NF-κB). In summary, our results demonstrated that FFYH exhibited a good in vitro anti-coronavirus effect, which provides a theoretical basis for its clinical use in the treatment of anti-coronavirus pneumonia.