ABSTRACT
Astaxanthin (Asx), one of the carotenoids, is a red pigment in fish and Crustaceans, and possesses stronger reduction properties than conventional carotenoids, like beta-carotene. However, little is known about the biochemical properties and physiological functions of astaxanthin. The effects of astaxanthin and vitamin C on stressed rats were studied physiologically and biochemically. beta-Carotene and three kinds of astaxanthins, which were extracted from Haematococcus and Phaffia, and synthesized chemically, were used in these experiments. These rats given astaxanthins or beta-carotene had stress induced on the 12th day by immersing the rats in chest-level water at 20 degrees C for 24 h after fasting for 24 h. Rats given astaxanthins or beta-carotene prior to stressing were appreciably protected against the evolution of gastric ulcerations in relation to control rats. Ulcer indexes in particular were smaller with the rat group fed astaxanthin extracted from Haematococcus than the other groups. Next, the effects of Asx and/or vitamin C on the protection of evolution of gastric ulcer in stressed rats were persued by the same methods as described above. The results showed that rats given Asx or vitamin C were appreciably protected against the evolution of gastric ulcerations in relation to control rats. The effects were more intense, especially in rats simultaneously supplied Asx and vitamin C than in rats taking either Asx or vitamin C. It was suggested that the simultaneous supplementation of food substances with astaxanthin and vitamin C would supply enough antioxidants to offset stress-related injuries.
Subject(s)
Antioxidants/administration & dosage , Ascorbic Acid/administration & dosage , Stomach Ulcer/prevention & control , Stress, Physiological/complications , beta Carotene/analogs & derivatives , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Diet , Immersion , Male , Rats , Rats, Wistar , Stomach Ulcer/etiology , Triglycerides/blood , Xanthophylls , beta Carotene/administration & dosage , gamma-Glutamyltransferase/bloodABSTRACT
By breeding and feeding salt to spontaneously hypertensive rats (SHR) continuously over a long period (until 60 wk old), rats with systolic blood pressures (SBP) of over 270 mmHg were prepared. It was studied whether or not supplying large amounts of vitamin C (200 mg/rat/d) over this period might bring any beneficial effect to blood pressure. Moreover, physico-chemical studies were performed to measure the components and enzymes in the blood and urine at 53 and 60 wk-old, and biochemical studies on vitamin C were also carried out in this experiment. Male (14 rats: 7 wk-old, 100-105 g) and female (15 rats: 7 wk-old, 95-100 g) SHR were divided into three groups and bred continuously for 53 wk. The A group rats were given salt (2.5 g/100 g of diet), the B group rats were given salt and vitamin C (500 mg/100 mL of drinking water), and the C group rats were controls. The results showed almost the same tendencies between male and female rats. The body weights of the SHR in groups A and B were slightly lower than group C. The amount of food intake in groups A and B was almost the same as group C. The amount of water intake was, in the order from highest to lowest, group A, B and C. The SBP of group A rats exhibited the highest value among the three groups. The SBP of group B rats given vitamin C simultaneously with the salt resulted in a low blood pressure level close to that of the controls (group C). Furthermore, the DBP (diastolic blood pressure) also reflected the antihypertensive effect of vitamin C as well. The heartbeat of the rats was highest in group A, and was comparable to the value in the rats receiving vitamin C simultaneously with salt. For the tests on occult blood and protein in the urine, group A rats showed strong positive reactions, whereas the group B and C rats had decreased results for both tests. The organ weights of the liver, stomach, spleen, adrenal gland and kidneys per 100 g rat body weight were not different among the three groups. The values for the bilirubin content, and the enzyme activities of ALT and AST in the blood showed to be the highest in the male rats of group A. The values from the group B rats decreased near to the normal value like the control group. Vitamin C was found to decrease the blood pressure in SHR, and also to work effectively to protect liver and kidney functions even under the condition of very high blood pressure, as high as 250 mmHg.
