Prebiotics such as fructans, and probiotics such as Lactobacilli or Bifidobacteria, or a combination of prebiotics and probiotics (synbiotics) are thought to be protective against colon cancer. Therefore, we studied whether the prebiotic inulin enriched with oligofructose (Raftilose-Synergy1 ^® , briefly, Synergy1, 10% of the diet), probiotics [ Bifidobacterium lactis (Bb12) and Lactobacillus rhamnosus (LGG), each at 5×10 ⁸ c.f.u./g diet] or synbiotics (a combination of the two) protect rats against azoxymethane (AOM)-induced colon cancer. Male F344 rats were divided into: Controls; PRE, which were fed a diet containing Synergy1; PRO, fed a diet containing LGG and Bb12; PREPRO, fed a diet containing Synergy1, LGG and BB12. Ten days after beginning the diets, rats were treated with AOM (15 mg/kg s.c. two times); dietary treatments were continued for the entire experiment. Thirty-one weeks after AOM, rats treated with Synergy1 (PRE and PREPRO groups) had a significantly lower ( P < 0.001) number of tumours (adenomas and cancers) than rats without Synergy1 (colorectal tumours/rat were 1.9 ± 1.7, 1.1 ± 1.1, 2.2 ± 1.4 and 0.9 ± 1.2 in Controls, PRE, PRO and PREPRO groups, respectively, means ± SD). A slight, not significant effect of probiotics in reducing malignant tumours was also observed ( P = 0.079). Caecal short-chain fatty acids (SCFA) were higher ( P < 0.001) in the groups treated with Synergy1. Apoptosis was increased in the normal mucosa of the PRO group, while no variation was observed in the tumours. Colonic proliferation was lower in the PRE group as compared with Controls. Glutathione S -transferase placental enzyme pi type expression, and to a lesser extent, inducible NO synthase were depressed in the tumours from rats in the PRE and PREPRO groups. Cycloxygenase-2 expression was increased in the tumours of control rats but not in those from PRE, PRO or PREPRO rats. In conclusion, prebiotic administration in the diet decreases AOM-induced carcinogenesis in rats.

p-Coumaric acid (3-(4-hydroxyphenyl)-2-propenoic acid; 4CA), is a ubiquitous plant metabolite with antioxidant and anti-inflammatory properties. The antiplatelet activity of this compound was analysed both ex vivo and in vitro. 4-CA, administered to rabbits for 2 weeks at the dose of 5 mg/kg, mixed with food, inhibited ADP-induced platelet aggregation without affecting blood coagulation. This effect was associated with a marked increase in plasma antioxidant activity, measured as ferric reducing ability of plasma, and with the reduction of thromboxane B₂ production. The antiplatelet effect was confirmed by in vitro experiments on human blood: 4CA (500 μm and 1 mm) reduced ADP-induced platelet aggregation (55·2 (se 4·01) % and 35·6 (se 2·35) % relative to basal level, respectively). 4CA was able to modify platelet function, measured with PFA-100™, a shear-inducing device that simulates primary haemostasis. 4CA interfered also with arachidonic acid cascade, reducing thromboxane B₂ production and lipopolysaccharide-induced prostaglandin E₂ generation (ic₅₀ 371 and 126 μm, respectively). The data show that 4CA is an antioxidant compound with good antiplatelet activity at doses that can be obtained with dietary intervention, suggesting possible applications for primary prevention of vascular disease.