Anti-flu Effect of Compound Yizhihao Granule and Its Effective Components / 中草药·英文版

ABSTRACT

Objective To research the anti-influenza effect of active ingredients in Compound Yizhihao Granule (CYG). Methods The cytotoxicity and cytopathic effects (CPE) were observed under the phase-contrast microscope, besides 50% toxicity concentration (TC50) and 50% inhibitory concentration (IC50) were also calculated using Reed-Muench method, then the antiviral activity in vitro according to Selection Index (SI = TC50/IC50) was evaluated. In PR8 virus-infected mice, survival time, death rate, and lung index were observed in order to evaluate the protective effect. Besides, the effective ingredients were determined using HPLC method, and their contents were calculated by external standard method. Results CYG could inhibit the influenza virus-induced CPE, with IC50 of 4.6 mg/mL (equal to herbal extracts 262.2 μg/mL), and no direct cytotoxic effect at this concentration. PR8-infected mice were ig given CYG, the lung index and mortality were significantly reduced, and survival time was obviously prolonged. HPLC analysis indicated CYG contained many kinds of antivirus active components, including rupestonic acid, epigoitrin, and adenosine. Conclusion CYG is an effective natural anti-influenza medicine. Its antiviral effect should be the synergic effect of a variety of antiviral active ingredients.