Anti-hepatitis B virus effects of the traditional Chinese herb Artemisia capillaris and its active enynes.

Ethnopharmacological relevance Artemisia capillaris (Yin-Chen) is a famous traditional Chinese medicine (TCM) for treating acute and chronic hepatitis in China. Enynes are one type of characteristic constituents in this herb, while their anti-hepatitis B virus (anti-HBV) properties have not been systemically investigated. Aim of the study This study is to reveal the active part of A. capillaris , and systemically investigate the enynes and their anti-HBV activity. Materials and methods The total extract and each fraction of A. capillaris were assayed for the anti-HBV activity to reveal the active part. Bioassay-guided fractionation using various chromatographic techniques yielded the enynes, whose structures were elucidated by spectroscopic analyses and ECD calculations. The anti-HBV properties inhibiting HBsAg and HBeAg secretions and HBV DNA replication were evaluated on HepG 2.2.15 cell line in vitro . Results ACT-2 and ACT-3 was revealed to be the respective active and toxic part of A. capillaris . Twelve enynes ( 1 – 12 ) involving four new ones ( 1 – 4 ) and two unusual enyne analogs ( 13 – 14 ) were isolated from the active part (ACT-2). All the isolates were assayed for their anti-HBV activity, and the preliminary structure-activity relationships were summarized based on the structural features. In particular, compound 4 could significantly inhibit the secretions of HBsAg and HBeAg, and HBV DNA replication with IC 50 values of 197.2 (SI > 5.1), 48.7 (SI > 20.5) and 9.8 (SI > 102) μM. Conclusions Enynes are responsible for the anti-HBV effects of A. capillaris . Hydroxyl and glycosyl groups are preferable for maintaining activity. This is the first time to systematically investigate the anti-HBV activity of enynes in A. capillaris , which provides valuable information for understanding the ethnopharmacological application of Yin-Chen. [ABSTRACT FROM AUTHOR]