Plantago ovata seeds (dietary fiber) might be as effective as mesalamine to maintain remission in ulcerative colitis.

Despite data favouring a role of dietary fat in colonic carcinogenesis, no study has focused on tissue n3 and n6 fatty acid (FA) status in human colon adenoma-carcinoma sequence. Thus, FA profile was measured in plasma phospholipids of patients with colorectal cancer (n=22), sporadic adenoma (n=27), and normal colon (n= 12) (control group). Additionally, mucosal FAs were assessed in both diseased and normal mucosa of cancer (n= 15) and adenoma (n=21) patients, and from normal mucosa of controls (n=8). There were no differences in FA profile of both plasma phospholipids and normal mucosa, between adenoma and control patients. There were considerable differences, however, in FAs between diseased and paired normal mucosa of adenoma patients, with increases of linoleic (p=0.02), dihomogammalinolenic (p=0.014), and eicosapentaenoic (p=0.012) acids, and decreases of a linolenic (p=0.001) and arachidonic (p=0.02) acids in diseased mucosa. A stepwise reduction of eicosapentaenoic acid concentrations in diseased mucosa from benign adenoma to the most advanced colon cancer was seen (p=0.009). Cancer patients showed lower a linolenate (p=0.002) and higher dihomogammalinolenate (p=0.003) in diseased than in paired normal mucosa. In conclusion changes in tissue n3 and n6 FA status might participate in the early phases of the human colorectal carcinogenesis. (Gut 1996; 38: 254-259)

The excess of genetic information in patients with Down syndrome (DS) produces an increase in the catalytic activity of superoxide dismutase (SOD1), an antioxidant enzyme coded on chromosome 21. It has been suggested that an increase in oxidative stress in DS patients may cause adverse effects in the cell membranes through the oxidation of polyunsaturated fatty acids (PUFAs). The aim of this study was to evaluate the cellular antioxidant system by determining the catalytic activity of the SOD1, glutathione peroxidase (GPx), catalase (CAT), and glutathione reductase (GR) enzymes and the concentrations of α-tocopherol in red blood cells (RBCs) in a group of 72 DS patients. The profile of fatty acids in the phospholipids of RBC membranes was also evaluated. The activity of the erythrocyte antioxidant enzymes is significantly higher in the DS group than in the control group (SOD1, 635 ± 70 U/g Hb vs 476 ± 67 U/g Hb; CAT, 1843 ± 250 U/g Hb vs 1482 ± 250 U/g Hb; GPx, 23.2 ± 5.3 U/g Hb vs 21.5 ± 3.6 U/g Hb; and GR, 9.32 ± 1.4 U/g Hb vs 6.9 ± 1.3 U/g Hb, respectively). No differences were observed in RBC α-tocopherol concentrations between the two groups studied. Long-chain n6 PUFA (C20:3n6, C20:4n6) concentrations were increased in DS patients, suggesting enhanced Δ-6-desaturase activity. The long-chain n3 PUFA (docosahexenoic acid) does not appear to be affected by increased oxidative stress, probably because of the existence of compensatory antioxidant mechanisms.