The Anti-HBV Constituents from Traditional Chinese Medicine of Swertia mileensis

Hepatitis B virus (HBV) infection is a serious health problem worldwide, and the current treatment methods including vaccines, immunomodulators, interferons and nucleoside analogs are far from satisfactory. Traditional Chinese medicines (TCMs) with multi-component and multi-target properties might have advantages in treating HBV infection. Swertia mileensis, well-known in China under the name “Qing-Ye-Dan”, is a famous TCM for treating viral hepatitis [1]. In order to clarify its anti-HBV constituents, bioassay guided isolation resulted in a series of novel active lactones, swerilactones A-B (C₁₈), C-D (C₂₀), E-F (C₁₆), G (C₁₈), H-K (C₂₉), L (C₁₂) and M-O (C₁₃). Biogenetically, swerilactons A-D and H-K belong to secoiridoid dimers and trimers. Importantly, swerilactones H-K exhibited potent inhibition of HBV DNA replication, with IC₅₀ values ranging from 1.53 to 5.34 µm, equivalent to that of 3TC [2]. Preliminary mechanism investigation suggested that swerilactone H was targeted on HBV enhancer II different from nucleosides on HBV polymerase.

Acknowledgements: The work was supported by the National Natural Science Foundation of China and Yunnan Province (Grant No. U0832603), National Science Foundation of China for Distinguished Young Scholars (No. 81025023). References: [1] Gitlin N (1997) Clin Chem, 43: 1500 – 1506. [2] Geng CA, Wang LJ, et al. (2011) Chem Eur J, 17: 3893 – 3903.