Anti-hepatitis B virus effect of matrine-type alkaloid and involvement of p38 mitogen-activated protein kinase and tumor necrosis factor receptor-associated factor 6

The matrine-type alkaloid, oxymatrine inhibits hepatitis B virus (HBV) replication but very little is known about these effects in other matrine-type alkaloids, including sophoridine and sophocarpine. Therefore, we compared the in vitro anti-HBV effects of matrine, oxymatrine, sophocarpine, and sophoridine by treating an HBV-transfected cell line (HepG2.2.15) with 0.4-1.6 mM of the compounds for 24 or 72 h. The levels of the HBV surface antigen (HBsAg) and e antigen (HBeAg) in the culture medium, as well as the intracellular and extracellular HBV DNA levels, were determined. Metabolomic analysis and detection of the mRNA level of p38 mitogen-activated protein kinase (MAPK), tumor necrosis factor receptor associated factor (TRAF) 6, extracellular signal-regulated kinase (ERK) 1, NOD-like receptor family pyrin domain containing 10 (NLRP10), and caspase-1 were conducted in sophoridine-treated HepG2.2.15 cells. HepG2.2.15 cell exposure to 0.4-1.6 mM sophocarpine or sophoridine for 24 h reduced the HBsAg level of the medium more effectively than exposure to matrine and oxymatrine did, and reduced the HBeAg levels more effectively than these compounds did at 1.6 mM. Sophoridine (0.4-1.6 mM) reduced the cell medium HBV DNA levels more than the same concentrations of matrine, oxymatrine, or sophocarpine did. After 72 h, 0.4 and 0.8 mM sophoridine reduced HBsAg and intracellular HBV DNA levels more potently than matrine, oxymatrine, or sophocarpine did. Furthermore, sophoridine (0.8 mM) potently reduced the cell medium HBeAg levels while the metabolomic analyses revealed that HepG2.2.15 cells exposed to 0.8 mM sophoridine for 72 h exhibited reduced cycloleucine and phytosphingosine levels. In addition, the mRNA expression analyses revealed that HepG2.2.15 cells exposed to 0.8 mM sophoridine showed reduced levels of p38 MAPK, TRAF6, ERK1, NLRP10, and caspase-1. Sophoridine produced more potent anti-HBV effects than matrine, oxymatrine, and sophocarpine did. These effects may be related to the sophoridine-mediated reduction of p38 MAPK and TRAF6 levels. (C) 2016 Published by Elsevier B.V.