punicalagin and Inflammatory-Bowel-Diseases

Punica granatum L. (Lythraceae) inhibits cancer cell proliferation and apoptosis through the modulation of cellular transcription factors and signaling proteins. No pharmacological work is reported on the effects of P. granatum juice on the cellular signaling pathways involved in initiation and progression of inflammation. The present investigation evaluates the effect of P. granatum juice (PJ) and purified punicalagin (PW) on nuclear factor kappa B (NFκB) and the signaling pathways leading to its expression in colon inflammation. Male Sprague-Dawley rats were divided into six groups: positive and negative control, vehicle (50 % ethanol), standard (5-ASA 100 mg/kg, p.o.), PJ (400 mg/kg, p.o.), PW (4 mg/kg, p.o.). Colitis was induced with 2,4-dinitrobenzene sulfonic acid and animals were euthanized on 18th day. Colon samples collected were subjected to various histological assessment (CMDI, DAI), and biochemical parameters (MPO, MDA, SOD, NO). Gene expression study was carried out using RT-PCR for cytokines (TNF-α, IL-1β, IL-18 and NF-κβ). Pretreatment with PJ and PW significantly (p < 0.05) lowered the disease extent and severity as indicated by reduction in CMDI (2 ± 0.31) and DAI (1.83(#) ± 0.22) when compared with DNBS-treated rats (3.83* ± 0.17). Gene expression studies showed decreased mRNA levels of TNF-α, IL-18, and IL-1β in PJ and PW-treated groups. NF-κβ mRNA levels were found to be reduced 84 and 64 % by PJ and PW, respectively. These results suggest that P. granatum juice is more biologically active over punicalagin alone and can be potentially used for the treatment of inflammatory bowel disease.

Topics: Animals; Cytokines; Fruit and Vegetable Juices; Hydrolyzable Tannins; Inflammatory Bowel Diseases; Lythraceae; Male; NF-kappa B; Rats; Rats, Sprague-Dawley

This study aimed at evaluating the anti-inflammatory properties of a pomegranate fruit husk (PomH) polyphenolic extract, rich in punicalagin, using Caco-2 cells, an in vitro model of human intestinal epithelium. Differentiated cells in bicameral inserts were pretreated or not with a PomH extract or punicalagin, as reference, at the apical side, representing the intestinal lumen. Inflammation was then induced with a cocktail of cytokines (Il-1β, TNFα and IFNγ) and LPS. After 24 h incubation, 3 pro-inflammatory markers, i.e., interleukin (IL)-6, IL-8 and monocyte chemoattractant protein (MCP)-1, were assayed both at their gene transcription (qRT-PCR) and secretion (ELISA) levels. As previously described, the pro-inflammatory cocktail significantly stimulated these 3 markers, at the gene transcript and secretion levels. In inflamed cells, a significant down-regulation of the transcription of the genes encoding IL-6 and MCP-1 was observed in the presence of the PomH extract or punicalagin, while IL-8 transcription was unaffected. Both treatments also decreased the amounts of the 3 proteins with dose-response effects, but only in the apical compartment. A lowered ELISA response was also observed when either IL-6, IL-8 or MCP-1 were mixed with punicalagin in a cell-free culture medium, indicating a direct molecular interaction. In conclusion, the punicalagin-rich PomH extract tested showed anti-inflammatory properties in the Caco-2 in vitro intestinal model. It acted both on the pro-inflammatory gene transcription and protein levels, the later phenomenon being possibly due to a direct molecular trapping. These data suggest that pomegranate husk could be an interesting natural source contributing to prevent intestinal chronic inflammation.

Topics: Anti-Inflammatory Agents; Caco-2 Cells; Chemokine CCL2; Cytokines; Down-Regulation; Humans; Hydrolyzable Tannins; Inflammatory Bowel Diseases; Interleukin-6; Interleukin-8; Intestines; Lipopolysaccharides; Lythraceae; Phytotherapy