Aqueous Extract of Tomato (Solanum lycopersicum L.) and Ferulic Acid Reduce the Expression of TNF-α and IL-1β in LPS-Activated Macrophages

Abstract

Acute inflammation is essential for defending the body against pathogens; however, when inflammation becomes chronic, it is harmful to the body and is part of the pathophysiology of various diseases such as Diabetes Mellitus type 2 (DM2) and Cardiovascular Disease (CVD) among others. In chronic inflammation macrophages play an important role, mainly through the secretion of proinflammatory cytokines such as Tumor necrosis factor (TNF)-α and Interleukin (IL)-1β, explained in part by activation of the Toll-like receptor 4 (TLR4), a signaling pathway which culminates in the activation of Nuclear factor (NF)-κB, an important transcription factor in the expression of these proinflammatory genes. On the other hand, the benefits on health of a diet rich in fruit and vegetables are well described. In this work, the effects of aqueous extract of tomato and ferulic acid on the expression of proinflammatory cytokines in LPS activated monocyte-derived THP-1 macrophages were investigated. In addition, using Western blot, we investigated whether the inhibition was due to the interference on activation of NF-κB. We found that both the tomato extract and ferulic acid presented inhibitory activity on the expression of TNF-α and IL-1β cytokine by inhibiting the activation of NF-κB. The current results suggest that tomatoes and ferulic acid may contribute to prevention of chronic inflammatory diseases.

Keywords: NF-κB; inflammation; macrophages; proinflammatory cytokines.

Figure 1

Gene expression kinetics of TNF-α (A) and IL-1β (B). It is observed that the peak of expression for both cytokines was 4 h.

Figure 2

Aqueous tomato extract and ferulic acid inhibit expression of TNF-α (A) and IL-1β (B) in LPS-activated macrophages. LPS, lipopolysaccharide. ** significant at the p < 0.01 level, *** significant at the p < 0.001 level.

Figure 3

Kinetics of activation of NF-κB in LPS-activated macrophages. It is observed that the peak of NF-κB activation occurred at 30 min after the challenge with LPS.

Figure 4

Extract tomato and Ferulic Acid inhibit the activation of NF-κB in LPS-activated macrophages. LPS, lipopolysaccharide; DMSO, dimethylsulfoxide, * significant at the p < 0.05 level, ** significant at the p < 0.01 level.