What About Tomato Intake and the Regulation of Inflammation?
Authors: Godoy Maria Fernanda , Slobodianik Nora Haydee , Insani Ester Marina 
Published: November 2023

The effect of tomato intake on the intestinal immune system by means of a Wistar rat model in protein malnutrition status was evaluated.

Freeze‐dried tomato was added to the diet as a supplement (equivalent to +5% of α‐tocopherol – reference value from IDR AIN93‐) during 42 days. Four groups of well‐nourished rats at weaning were used; two of them were fed with a protein‐free diet until 25% of initial body weight loss. The re‐nutrition was achieved with an experimental diet containing 20% of casein (Re‐nourished group = R). The second group received the same diet plus tomato (RT group). Two well‐ nourished groups were fed 20% casein diet with and without tomato (CT and C) along all the experimental period.

IgA+ and IgE+ B cells, TCRγδ + T cells and lymphocytes CD25+ were evaluated by immunofluorescence on histological sections of small intestine (intestinal villi ‐ IV). TNFα was evaluated by ELISA in intestinal fluid. Statistics were performed using Duncan test.

In previous works, we demonstrate that the nutritional management of protein malnutrition (free protein diet ‐ re‐nourishing diet) generate an allergic model. Thus, also in this experience, IgE+ B cells in IV of R were significantly higher than in C. Tomato intake induced certain degree of allergenicity in C (IgE+ cells in CT>C). Interestingly, the tomato intakes by R did not produce significant difference in IgE+ cells, which denote a different capacity to mount an immunological response of well‐ and malnourished population (Table 1). In fact, IgA+ B cells (secretory branch) so as TCRγδ + (cell‐mediated branch) and CD25+ are involve to some extent, in the mechanism of oral tolerance. In CT group compared to C, IgA+ cells decreased in IV, probably due to an increased secretory process towards the intestinal cavity, and TCRγδ+ significantly increase in IV, in response to local stimuli (tomato). This process is successful in decreasing the inflammatory process evidenced by the significant decrease in TNFα (CT<C). The bioactive compounds present in tomato, such as lycopene, may contribute to this reduction in the inflammatory response.

Instead, R rats showed a different pattern. Previously we demonstrate that the IgA+ cells, strong depleted during the free‐protein diet period, could only be partially recovered during the re‐nutrition period. Here this is also evident being significantly lower in R vs. C. RT presented higher TNFα level than R (Fig. 1) ‐inflammatory response‐. In the re‐nourished groups only CD25+ cells, were able to respond to the antigen present in the local microenvironment. This may be due to the long term allergic state of R and the role of CD25+ cells in this process. In RT, the bioactives from tomato were not sufficient for slowing the inflammatory response.

Different immunological responses took place in well‐ and malnourished populations after tomato intake. It was successful for slowing the inflammatory state in well‐nourished but not in malnourished. These observations have to be taken into account for generalized nutritional recommendations.

Support or Funding Information

Supp. by PNBIO 1131022 and INTA, Res 1177‐14

Markers in IV. Different letters in the same column indicate significant differences at p<0.05.

Groups
IgA+
IgE+
TCRγδ+
CD25+

C
84 ± 5 A
23 ± 3 A
42±3 A
8 ± 1 A

CT
64 ± 5 B
34 ± 3 B
61±3 B
6 ± 1 A

R
68 ± 5 B
35 ± 3 B
43±3 A
19 ± 1 B

RT
57 ± 5 B
41 ± 2 B
48 ±3 A
24 ± 1 C