Vitamin E and D regulation of allergic asthma immunopathogenesis

Abstract

Asthma occurs as complex interactions of the environmental and genetics. Clinical studies and animal models of asthma indicate dietary factors such as vitamin E and vitamin D as protective for asthma risk. In this review, we discuss opposing regulatory functions of tocopherol isoforms of vitamin E and regulatory functions of vitamin D in asthma and how the variation in global prevalence of asthma may be explained, at least in part, by these dietary components.

Keywords: Animal models; Asthma; Human; Vitamin D; α-Tocopherol; γ-Tocopherol.

Figure 1. α-tocopherol and γ-tocopherol

A) α-tocopherol differs from γ-tocopherol by one methyl group (arrows). B) Plasma γ-tocopherol (γ-T) and plasma α-tocopherol (α-T) in 1–2 reports/country and publication dates are indicated ^{, –}. Global asthma prevalence in 2004 and 2012 . C) Tocopherols were extracted from dietary oils (sunflower oil from Spectrum Organic Products, LLC; safflower oil from Spectrum; olive oil from Colavita; soybean oil from Crisco; corn oil from Mazola; grapeseed oil from Kusha, Inc; sesame oil from Lavita; peanut oil from Essentials by Supervalu; canola oil from Crisco; Sacha Inchi from Olivar). Extracted tocopherols were measured by HPLC with an electrochemical detector as previously described . ND, not determined.

Figure 2. Vitamin D Metabolism

Vitamins D2 or D3 circulate bound to vitamin D binding protein (DBP) which also transports 25-hydroxyvitamin D (25(OH)D) and 1-alpha-25- dihydroxyvitamin D (1,25(OH)D). Vitamin D hydroxylases include liver hydroxyvitamin D-25-hydroxylase (CYP2R1) and kidney 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1). Both 25(OH)D and 1-alpha-25-hydroxyvitamin D (1,25(OH)D) bind to vitamin D receptor (VDR) to induce vitamin D effects on tissues.