Worldwide, millions of people suffer from hepatitis B virus (HBV) infection, putting them at a high risk of death from liver cirrhosis and cancer. Although effective anti-HBV drugs have been developed, current drugs have some limitations, as most of them have a risk of significant side effects. Therefore, the discovery of safe and effective anti-HBV drugs is still needed. Natural compounds are considered sources of novel, safe and effective therapeutics. In this study, we screened a library of Kampos, traditional herbal medicines, for suppression of HBV production. Among them, we found that maoto reduced extracellular HBV DNA but not extracellular HBsAg during HBV infection, suggesting that it suppressed HBV production by interfering with HBV nucleocapsid incorporation into viral particles. Furthermore, we revealed that maoto reduced the expression of a host gene, Tropomyosin β chain (TPM2), whose downregulation also suppressed HBV production, similarly to maoto. Since the safety of maoto has been already confirmed, maoto can be considered a candidate anti-HBV agent if the effect is confirmed in vivo. In addition, our findings also suggest TPM2 as a novel molecular target for the development of anti-HBV agents.

在世界范围内，数百万人患有乙型肝炎病毒（HBV）感染，使他们处于因肝硬化和癌症而死亡的高风险中。尽管已经开发出有效的抗HBV药物，但是当前的药物存在一些局限性，因为它们中的大多数都有明显的副作用风险。因此，仍然需要发现安全有效的抗HBV药物。天然化合物被认为是新颖，安全和有效的疗法的来源。在这项研究中，我们筛选了传统草药Kampos库，以抑制HBV产生。其中，我们发现maoto在HBV感染过程中降低了细胞外HBV DNA的水平，但没有降低细胞外HBsAg的水平，这表明它通过干扰HBV核衣壳掺入病毒颗粒而抑制了HBV的产生。此外，肌球蛋白β链（TPM2），其下调也抑制了HBV的产生，类似于maoto。由于已经确认了maoto的安全性，因此，如果已确认该效果，则可以认为maoto是抗HBV候选药物体内。此外，我们的发现还表明，TPM2作为抗HBV药物开发的新型分子靶标。