VEGETABLE CONCENTRATES INTERACT WITH CANTHAXANTHIN TO AFFECT CAROTENOID BIOAVAILABILITY AND SUPEROXIDE-DISMUTASE ACTIVITY BUT NOT IMMUNE-RESPONSE IN RATS

We examined tomato paste and dried spinach powder as dietary sources o f lycopene and lutein and determined their interactions with canthaxan thin (CX) in water-soluble beadlets. Mature male rats, 10/group, were fed a basal diet containing 16% fat and 2 g per kg CX from beadlets (CX) or placebo beadlets (-CX) for 8 weeks. Tomato paste or spinach pow der was added to each of these diets at 0, 5 (low tomato, low spinach) and 15% (w/w) (high tomato, high spinach). The low and high levels of tomato paste and spinach powder contained 0.03 and 0.09 g lycopene an d 0.02 and 0.06 g lutein per kg of diet, respectively. CX was detected in liver and plasma. High tomato decreased liver CX concentrations 5- fold and plasma CX 2-fold; low tomato had no effect. Liver lycopene co ncentrations increased as the concentration of tomato paste increased in the diet. However, feeding CX dramatically decreased liver lycopene concentrations. Feeding high tomato and no CX lowered liver superoxid e dismutase activity. Neither dietary carotenoids nor CX treatment alt ered mitogenic response of splenic mononuclear cells to concanavalin ( Con A) or lipopolysaccharide (LPS). These data from rats illustrate ho w a carotenoid-rich food may influence the bioavailability of a carote noid supplement. Likewise, supplementation with a single purified caro tenoid may antagonize the bioavailability of carotenoids in food matri ces.