Skip to main content
. Author manuscript; available in PMC: 2011 Jun 1.
Published in final edited form as: Hepatology. 2010 Jun;51(6):1912–1921. doi: 10.1002/hep.23587

Figure 4. Silymarin inhibits microsomal triglyceride transfer protein (MTP) activity, apolipoprotein B (apoB) secretion, and infectious virus production.

Figure 4

A, Silymarin inhibits MTP activity in Huh7.5.1 cells. Chronically infected Huh7.5.1 cells (14 days post-infection) and uninfected cells were treated with the indicated μM doses of silymarin (SM) or as a positive control, 200 μg/ml naringenin (NN), and 24 hours later MTP activity was measured as described in the Materials and Methods. B, Silymarin inhibits apoB secretion from mock and HCV-infected cells. Huh7.5.1 cells were infected or mock-infected with JFH-1 at an m.o.i. of 0.01 for 96 hours before treatment with fresh medium containing DMSO, 10μM BMS-200150 (a small molecule inhibitor of MTP), or silymarin at the indicated μM doses for 5 hours. Culture supernatants were harvested, and apoB measured by ELISA. BMS=BMS-200150. C, De novo infectious virion production into culture supernatants is blocked by silymarin. Supernatants from panel B were diluted 1:20 and infectious titers were determined by focus forming unit assay on naïve Huh7.5.1 cells. BMS=BMS-200150. D, Treatment of infected cells for 5 hours does not inhibit intracellular HCV replication. Protein lysates were harvested from cultures described in panel B and equal amounts of total protein were blotted for NS5A. The positions of HCV NS5A and loading control GAPDH are indicated. D is the DMSO control, 40, 80, and 120 are the doses of silymarin in μM, and BMS is the MTP inhibitor BMS-200150. E, Silymarin blocks apoB secretion from primary human hepatocytes. Cells were treated with the indicated concentrations of SM for 24 hours before supernatants were harvested and apoB measured by ELISA. F, Silymarin blocks apoB secretion in HepG2 cells. Cells were treated with the indicated μM concentrations of silymarin for 5 hours before supernatants were harvested and apoB measured by ELISA. Inset, Silymarin blocks intracellular apoB levels. Cell lysates from HepG2 cells treated in panel F were probed for apoB by western blot. apoB100 and loading control GAPDH are indicated with arrows. M is the media control, D is the DMSO control, and 40, 80, and 120 are the doses of silymarin in μM.