PP062. Silibinin modulates NF-kB pathway and proinflammatory cytokines production by mononuclear cells of preeclamptic women

Abstract

Introduction: Pre-eclampsia (PE) is a complication of human pregnancy characterized by hypertension and proteinuria after 20 weeks of gestation. In addition to increased activation of monocytes and granulocytes, there is an elevated production of proinflammatory cytokines in pregnant women with PE. The nuclear transcription factor-kB (NF-kB) is present in the cells of the immune system and is responsible for transcription of genes related to inflammation. Whereas the PE is associated with intense inflammatory response, the use of substances modulating the activity of NF-kB factor could be useful in alleviating the inflammation present in these patients. Silibinin is the main component of silymarin, a polyphenolic extract obtained from fruits and seeds of Sylibum marianum with potent hepatoprotective, anti-inflammatory and anti-fibrotic activities.

Objectives: The objective of this study was to assess whether silibinin modulates the activity of NF-kB and the production of inflammatory cytokines by mononuclear cells of patients with PE.

Methods: We evaluated 34 pregnant women with PE, 20 normotensive pregnant women (NT) and 15 non-pregnant women (NP). Mononuclear cells (PBMC) were obtained from peripheral blood and cultured in the presence or absence of silibinin (50uM) and stimulated with 1ug/mL of lipopolysaccharide (LPS) for 18h. The supernatant was employed for determination of tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1β) by enzyme immunoassay. The cells were also cultured for 30min to perform the extraction and determination of the nuclear activity of NF-kB.

Results: The results showed increased endogenous activation of NF-kB in PBMC of the PE group compared with the NT and NP groups. We also observed increased production of TNF-α and IL-1β by non-stimulated PBMC in the PE group compared with NT and NP groups. A positive correlation between NF-kB activity and endogenous production of TNF-α (r=0.6509; p=0.0047) or IL-1 b (r=0.5106; p=0.0304) was observed in the PE group. Silibinin showed an anti-inflammatory activity by inhibiting the spontaneous and LPS-stimulated NF-kB activation as well as the production of inflammatory cytokines in all the groups studied.

Conclusion: Patients with PE showed a greater activation of PBMC cells compared with NT women. Silibinin showed modulatory activity on the inflammatory response by downregulation of NF-kB activation as well as TNF-α and IL-10 production.

Financial support: FAPESP 2010/00776-0.