Abstract

THE POSSIBLE PROTECTIVE EFFECT OF VITAMIN D AND E AGAINST DEVELOPMENT OF NONALCOHOLIC FATTY LIVER DISEASE IN MALE RATS

Isaad A. Helal*, Aziza KH. Omar and Amira M. Negm

ABSTRACT

Background: Non-alcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide. Vitamin D deficiency has been frequently reported in many causes of chronic liver disease and has been associated with the development of NAFLD. It is believed that oxidative stress is a main player in the development and progression of NAFLD. Vitamin E provides protection against oxidative stress and inhibits the fatty acid peroxidation of membrane phospholipids, in addition to anti-inflammatory properties. Objective: Studying the possible protective effects of vitamin D (VD) and vitamin E (VE) against cafeteria (CAF) diet induced NAFLD in male rats. Material and methods: Fifty adult male albino rats of local strain weighing 100-150 g were used. The rats were divided into 5 equal groups. Group I (control), Group II (CAF), Group III (VD+CAF), Group IV (VE+CAF), and group V (VD+VE+CAF). The body weight, liver weight, liver to body weight ratio, lipid profile and liver enzymes were estimated. Hepatic gene expression of sterol regulatory element binding protein-1c (SREBP-1c), Peroxisome proliferator-activated receptor-α (PPAR-α) and Nuclear factor-κB (NF-κB) were analysed by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Hepatic tissue levels of tumor necrosis factor-α (TNF-α) and malondialdehyde (MDA) were determined for all groups, in addition to histological examination of liver tissue. Results: The administration of vitamin D or vitamin E or both vitamins for CAF diet fed rats showed reduced body weight gain, liver weight with improved serum lipids and liver enzymes. Furthermore, there was downregulation of mRNA expression of SREBP-1c and NF-κB, whereas, PPAR- α was upregulated. TNF-α and MDA tissue levels also were decreased. These results were confirmed by the histological study which showed improvement when compared to CAF diet fed rats Conclusion: vitamin D and E supplementation protect against the CAF diet-induced hepatic steatosis. Thus, vitamin D and E administration may be a novel therapeutic strategy for NAFLD prevention.

Keywords: Cafeteria diet, Vitamin D, Vitamin E, Non-alcoholic fatty liver disease.