Effects of dietary fibers on hepatocyte apoptosis in rats with alimentary polyhypovitaminosis
The effect of dietary fibers (DF) of wheat bran on hepatocyte apoptosis in rats adequately provided with vitamins or insufficiently supplied with vitamins has been investigated. 48 male Wistar rats (initial body mass – 58,1±0,5 g) were randomly divided into 6 groups and fed with semi-synthetic diet, containing 100% or 20% of vitamin mixture (Vit) with or without addition of DF in the dose corresponding to the upper allowable level of its consumption (5% of diet mass) for 4 weeks. The animals of the 1 group received 100% of vitamin mixture (100% Vit); 2 group – 100% Vit + DF; 3 group – 20% of vitamin mixture with full exclusion of vitamins Е, В 1 and В 2 (20% Vit); 4 group – 20% of vitamin mixture and DF (20% Vit + DF). The next 5 days rats from vitamin-deficient groups were fed with diets supplemented with 80% of vitamins from their content in control group: (5 group – 20% Vit + 80% Vit; 6 group – 20% Vit + DF + 80% Vit). The suspension of hepatocytes was received by Becton Dickinson Medimachine System (USA). Hepatocyte apoptosis was assessed by the method of flow cytometry using Beckman Coulter FC 500 (USA) cytometer by stained cells with Annexin V-FITC/ 7-AminoActinomycin D Kit (Beckman Coulter, USA). In rats fed complete semi-synthetic diet supplemented with DF (100% Vit + DF) the hepatocyte apoptosis was higher by 22% (p<0,10) than that in rats of control group (4,99±1,82%). In rats fed diets with low vitamin content (groups: 20% Vit and 20% Vit + DF) the hepatocyte apoptosis was significantly higher (p<0,05) than that in the control group and reached 7,03±1,74 and 7,26±1,13% accordingly. Normalization of vitamin content in the diets of rats from deficient groups during 5 days had no effect on the severity of apoptosis regardless from presence (8,02±2,18%) or absence of the DF (8,04±1,66%). Adding DF in dose corresponding to the upper allowable level of consumption, on the background of adequate vitamin content in the diet is accompanied by a tendency to develop hepatocyte apoptosis, which may be the result of a direct action of short chain fatty acids generated from the DF and the deterioration of vitamin sufficiency.
Keywords:hepatocyte apoptosis, alimentary polyhypovitaminosis, dietary fibers