Silibinin attenuates oxidative metabolism and cytokine production by monocytes from preeclamptic women

Abstract

Silibinin is a polyphenolic plant flavonoid with anti-inflammatory properties. The present study investigated the effect of silibinin on oxidative metabolism and cytokine production - tumor necrosis factor-alpha (TNF-α), interleukin (IL)12, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, IL-10, and transforming growth factor beta (TGF-β₁) - by peripheral blood monocytes (PBM) from preeclamptic pregnant women. It is a case-controlled study involving women with preeclampsia (PE, n = 30) compared with normotensive pregnant (NT, n = 30) and with non-pregnant (NP, n = 30) women. Monocytes were obtained and cultured with or without silibinin (5 μM or 50 μM) for 18 h. Superoxide anion (O₂−) and hydrogen peroxide (H₂O₂) release were determined by specific assays, and cytokine levels were determined by immunoenzymatic assays (ELISA). Monocytes from preeclamptic women cultured without stimulus released higher levels of O₂₂, H₂O₂ and TNF-α, and lower levels of IL-10 and TGF-β₁ than did monocytes from NT and NP women. Treatment in vitro with silibinin significantly inhibited spontaneous O₂− and H₂O₂ release and TNF-α production by monocytes from preeclamptic women. The main effect of silibinin was obtained at 50 μM concentration. Thus, silibinin exerts anti-oxidative and anti-inflammatory effects on monocytes from preeclamptic pregnant women by inhibiting the in vitro endogenous release of reactive oxygen species and TNF-α production.

Keywords::

• cytokines
• monocytes
• oxidative stress
• preeclampsia
• silibinin

Acknowledgements

All authors would like to acknowledge the support of Funda o de Amparo à Pesquisa do Estado de São Paulo, Brazil, (FAPESP, grant no. 2008/07095-3).

Declaration of interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

Details of ethics approval

This study was approved by the Ethics Committee of the Botucatu Medical School, Sao Paulo State University (CEP no. 24/2007). All women involved in the study have given their written informed consent.