Effect of folic acid and vitamin B12 on the expression of PPARγ, caspase-3 and caspase-8 mRNA in the abdominal aortas of rats with hyperlipidemia

Abstract

Hyperlipidemia may lead to endothelial injury, due to its effects on homocysteine and vascular endothelial growth factor in the serum, and the mRNA expression levels of peroxisome proliferator-activated receptor-γ (PPARγ), and caspase-3 and -8 in the vascular wall. In order to prevent and mitigate the high-fat state that results from endothelial injury, this study examined the effect of folic acid (FA) and vitamin B12 (VB12) on the expression of PPARγ and caspase-3 and 8 mRNA in the abdominal aortas of rats with hyperlipidemia. Sixty 4-week-old healthy male Sprague Dawley rats were randomly divided into five groups (each n=12): the normal control (NC), high-fat diet (HL), FA, VB12 and FA+VB12 groups. Following one week of adaptive feeding, the FA, VB12 and FA+VB12 groups were subject to the intraperitoneal injection of FA (0.5 mg/day), VB12 (0.05 mg/day) and FA+VB12 (0.5 mg/day and 0.05 mg/day), respectively, while fed a high-fat diet. The rats in the NC group were injected intraperitoneally with 0.9% NaCl solution (0.5 ml/day) and fed a normal diet, whereas those in the HL group were fed a high-fat diet only. A reverse transcription-polymerase chain reaction (RT-PCR) assay demonstrated that at the end of week 12, the FA treatment had effectively increased the PPARγ mRNA level, while reducing the caspase-3 and -8 mRNA levels, compared with the high-fat diet treatment (P<0.05). The effect of FA on the expression of PPARγ and caspase-3 and 8 was enhanced when used in combination with VB12 (P<0.05). These results revealed that the application of FA, alone or in combination with VB12, improves and mitigates the high-fat state that results from endothelial injury.