Effect of wheat bran fiber on vitamin status of weaning rats with alimentary polyhypovitaminosis
AbstractEffect of wheat bran on the vitamin status of rats adequately provided with vitamins or insufficiently supplied with vitamins has been investigated. 32 male Wistar weaning rats (initial body mass – 49–67 g) were randomly divided into 4 groups and fed with complete semi-synthetic diet, containing 100 or 20% of vitamin mixture with or without addition of wheat bran (5% of diet mass) for 35 days. The animals of the control group received 100% of vitamin mixture without adding of wheat bran; 2 group – received those diet with wheat bran; 3 deficient group – 20% of vitamin mixture with full exclusion of vitamins Е, В1 and В2 ; 4 group – 20% of vitamin mixture and wheat bran. The inclusion of wheat bran in full semi-synthetic diet has been accompanied by significant decrease of α-tocopherol liver content on 17% (р=0,006), significant increase of vitamin B1 liver level on the 16% (р=0,027) and blood plasma vitamin D elevation on 19% (р=0,017), as well as a tendency (р=0,059) to increase the liver level of vitamin B2 . Indicators of vitamin A status as well as plasma vitamin E concentration, liver and blood plasma MDA levels were not changed in this group rats. The 5-fold reduction of the vitamin mixture quota and the exclusion of vitamins E, B1 and B2 resulted in a significant (p<0,05) 1,6–1,8 fold decreased in animal body weight and liver mass and the manifestation of the deep external signs of vitamin deficiency. Young animals were more sensitive than adult animals to a lack of vitamins in the diet. Vitamin A (retinol palmitate) liver content in rats from this group was 25,1-fold reduced, vitamin E (α-tocopherol) – 2,1-fold, vitamins B 1 and B 2 – by 57 and 38% compared with animals received a complete control diet (p<0,05). Blood plasma concentration of vitamins A, E, D was 19–34% decreased. Adding of bran in vitamin deficit diet led to increased consumption of vitamin B1 – on 40%, vitamins B 2 and E – 21%, both due to their natural content in the bran, and as a result of increased eatability of the feed by 16% relative to deficient group due to improved taste of the diet. Enrichment of vitamin scarce diet with wheat bran led to an increase in body weight by 56%, the efficiency of the diet by 67%. This circumstance didn’t allow to reveal the effect of dietary fiber on the vitamin status of rats with polyhypovitaminosis. The significant (p<0,05) increase of retinol plasma level by 34% and liver and blood plasma tocopherol content by 17% and 22% and reduction of MDA blood plasma level by 24% took place in animals from this group compared to a group of rats receiving vitamin deficit diet without any effect on liver MDA level, liver vitamin A, B1 and B2 content and heart coenzyme Q10 level. The results obtained suggest that wheat bran inclusion in the diet of rats adequately supplied with vitamins may lead to а deficiency of vitamin E.
Keywords:alimentary polyhypovitaminosis, dietary fibers, vitamins, MDA, coenzyme Q10 , wheat bran, liver, blood plasma, rats