Dietary aloin, aloesin, or aloe-gel exerts anti-inflammatory activity in a rat colitis model. 
Aloe has been a very popular folk remedy for inflammation-related pathological conditions despite the lack of studies reporting its efficacy in vivo.  The present study evaluated the anti-inflammatory effects of aloe components (aloin, aloesin and aloe-gel) known to be biologically active in the rat model of colitis.  Male Sprague Dawley rats were fed experimental diets for 2 weeks before and during the induction of colitis.  Drinking water containing 3% dextran sulfate sodium (DSS) was provided for 1 week to induce colitis.  At the end of the experimental period, clinical and biochemical markers were compared.  Plasma leukotriene B(4) (LTB(4)) and tumor necrosis factor-α (TNF-α) concentrations were significantly decreased in all groups supplemented with aloe components compared to the colitis control group (p<0.05).  Animals fed both a 0.1% and 0.5% aloesin supplemented diet showed colonic myeloperoxidase (MPO) activities which were decreased by 32.2% and 40.1%, respectively (p<0.05).  Colonic mucosa TNF-α and interleukin-1ß (IL-1β) mRNA expressions were significantly reduced in all animals fed aloin, aloesin, or aloe-gel (p<0.05).  Dietary supplementation of aloe components ameliorates intestinal inflammatory responses in a DSS-induced ulcerative colitis rat model.  In particular, aloesin was the most potent inhibitor.  Further studies are required for a more complete understanding of the specific mechanism of the action of these supplements.