Evaluation of antiviral activity of organic–polyoxometalate hybrids based on berberine against encephalomyocarditis virus <i>in vitro</i>

Polyoxometalates are promising inorganic drugs with antiviral activity but there is a cumulative risk to humans in the body. The polyoxometalates were encapsulated with Berberine from traditional Chinese herb may have lower cytotoxicity. Four organic-polyoxometalate hybrids (BR-POMs) based on Berberine were evaluated antiviral effects in vitro on BHK-21 and PK-15 cells based Encephalomyocarditis virus (EMCV) or Pseudorabies virus (PRV) infection model. The collected cells were used for quantitative PCR analysis. The supernatants were collected to quantify viral loads by TCID₅₀ assay in vitro. EC₅₀ and CC₅₀ were determined by dose-response experiments and the ratio (EC₅₀/CC₅₀) was used as a selectivity index (SI) to measure the antiviral activity. Results showed that BR-POMs all showed certain antiviral activity. BR-POMs did not exert toxicity against EMCV or PRV cells at the tested concentration (CC₅₀&gt; 40 μM). Notably, BR-EuSiW (EC₅₀ 15.07 μM, CC₅₀ 651.2 µM, SI 43.21) exerted antiviral action by acting on the virus biosynthesis stage and acted to inhibit virus proliferation in dose-dependent manner. This study highlights that organic-polyoxometalate hybrids can be a new strategy to find antiviral activity on EMCV.