WINERY GRAPE-RESIDUE EXTRACT ASSOCIATED WITH POLYVINYLPYRROLIDONE DECREASES THE SEVERITY OF COLITIS INDUCED IN RATS BY 2,4,6-TRINITROBENZENESULFONIC ACID

Inflammatory bowel diseases (IBDs) are gastrointestinal disorders
that may lead to disability in life due to high-grade inflammation, ulceration or
necrosis, associated symptoms and needful surgeries. By 2025, an increase
in incidence is expected in developing countries, making important to discover
efficient ways to prevent these conditions. Recent studies have found
promising health effects on the utilization of specific polymers, capable of
promoting microencapsulation and increased efficiency of drugs or
polyphenols from plants. Therefore, the objective of this study was to
investigate the effects of a winery grape-residue extract (GR) associated with
polyvinylpyrrolidone (PVD), a polymer, in an animal model of IBD-like colitis.
GR was analysed regarding its total phenolic content. During three weeks, 51
male Wistar rats were utilized. Animals received, via gavage, during the whole
period, GR (400mg/kg) or PVD (300mg/kg) or GR-PVD or water. On week
two, rats received, via rectal, 2,4,6-trinitrobenzenesulfonic acid (TNBS) or
saline solution. The positive control group received, via gavage, mesalazine
(100mg/kg) during the final week. The disease activity index (DAI), colon
mass and lesions were evaluated. GR had 3% of total phenolics, then each
animal received about 3mg daily. Colitis was successfully induced, as seen by
high DAI, colon mass augmentation and prominent necrotic lesions (p<0,05).
Animals that received GR didn’t recover from colitis, possibly due to low
dosage of phenolics provided. Surprisingly, PVD alone decreased the length
of necrotic lesions (1.35±0.26 vs. 2.38±0.17cm;p<0,01). The GR-PVD
association provided even greater outcome, with rats presenting shorter
lesions and a percentage weight recovery (2.37±2.10 vs. -5.34±2.45%;p<0,05). Mesalazine had similar effects to GR-PVD. These results indicate that PVD, dissolved in water, on a dosage of 75mg per rat, acted by increasing the bioavailability of GR and/or have its own healing properties apparently not investigated so far. Future analysis will be performed to clarify these findings.