Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic acid and choline deficiency in rats.

Yi-Qun Liu,Takahiro Inakuma,Xue-Song Xiang,Li-Cui Sun,Kimio Sugiyama,Zhen-Wu Huang,Tatsuya Miyashita,Zheng Jia,Feng Han

doi:10.1155/2014/904501

Abstract

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine β-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

Highlights

Nutritional strategies focused on lowering plasma homocysteine concentration are beneficial to human health, because elevated plasma homocysteine levels are considered to be an independent risk factor for cardiovascular disease [1,2,3]
Food intake, and relative liver weight were not affected by the addition of guanidinoacetic acid (GAA) and supplementation with betaine or spinach powder level (Table 1), except that the relative liver weight was slightly lower in those rats fed with 0.1% betaine or 5.52% spinach powder diet than the rats compared to the other diets
The GAAinduced hyperhomocysteinemia was significantly suppressed by supplementation with betaine or spinach powder in a dose-dependent manner, and it was completely suppressed by 11.0% of spinach powder supplementation

Summary

Introduction

Nutritional strategies focused on lowering plasma homocysteine concentration are beneficial to human health, because elevated plasma homocysteine levels are considered to be an independent risk factor for cardiovascular disease [1,2,3]. Plasma homocysteine is a risk factor for the development of cognitive impairment and Alzheimer’s disease [4]. It is a common amino acid, homocysteine occupies a pivotal position in the metabolism of the essential amino acid, methionine (Figure 1) [5]. The plasma homocysteine concentration is affected by various factors, such as nutritional, physiological, hormonal, pharmacological, lifestyle, disease, and genetic factors [1,2,3]. Among these factors, genetic and nutritional factors are deemed to have greater influence on plasma homocysteine

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