Silibinin Inhibits HIV-1 Infection by Reducing Cellular Activation and Proliferation

PLoS One. 2012;7(7):e41832. doi: 10.1371/journal.pone.0041832. Epub 2012 Jul 25.

Abstract

Purified silymarin-derived natural products from the milk thistle plant (Silybum marianum) block hepatitis C virus (HCV) infection and inhibit T cell proliferation in vitro. An intravenous formulation of silibinin (SIL), a major component of silymarin, displays anti-HCV effects in humans and also inhibits T-cell proliferation in vitro. We show that SIL inhibited replication of HIV-1 in TZM-bl cells, PBMCs, and CEM cells in vitro. SIL suppression of HIV-1 coincided with dose-dependent reductions in actively proliferating CD19+, CD4+, and CD8+ cells, resulting in fewer CD4+ T cells expressing the HIV-1 co-receptors CXCR4 and CCR5. SIL inhibition of T-cell growth was not due to cytotoxicity measured by cell cycle arrest, apoptosis, or necrosis. SIL also blocked induction of the activation markers CD38, HLA-DR, Ki67, and CCR5 on CD4+ T cells. The data suggest that SIL attenuated cellular functions involved in T-cell activation, proliferation, and HIV-1 infection. Silymarin-derived compounds provide cytoprotection by suppressing virus infection, immune activation, and inflammation, and as such may be relevant for both HIV mono-infected and HIV/HCV co-infected subjects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-HIV Agents / pharmacology*
  • Biomarkers / metabolism
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / virology
  • Cell Proliferation / drug effects
  • HIV-1 / drug effects*
  • HIV-1 / physiology*
  • HeLa Cells
  • Humans
  • Silybin
  • Silymarin / pharmacology*
  • Virus Replication / drug effects

Substances

  • Anti-HIV Agents
  • Biomarkers
  • Silymarin
  • Silybin