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  • Metabolism of 11′‐α‐ and 11...
    Montoya‐Arroyo, Alexander; Brand, Viola; Kröpfl, Alexander; Vetter, Walter; Frank, Jan

    Molecular nutrition & food research, 20/May , Letnik: 68, Številka: 10
    Journal Article

    Scope Tocomonoenols (T1) are little‐known vitamin E derivatives naturally occurring in foods. Limited knowledge exists regarding the cellular uptake and metabolism of α‐tocomonoenol (αT1) and none about that of γ‐tocomonoenol (γT1). Methods and results The study investigates the cytotoxicity, uptake, and metabolism of αT1 and γT1 in HepG2 cells compared to the α‐ and γ‐tocopherols (T) and ‐tocotrienols (T3). None of the studied tocochromanols are cytotoxic up to 100 µmol L−1. The uptake of the γ‐congeners is significantly higher than that of the corresponding α‐forms, whereas no significant differences are observed based on the degree of saturation of the sidechain. Carboxymethylbutyl‐hydroxychromans (CMBHC) are the predominant short‐chain metabolites of all tocochromanols and conversion is higher for γT1 than αT1 as well as for the γ‐congeners of T and T3. The rate of metabolism increases with the number of double bonds in the sidechain. The rate of metabolic conversion of the T1 is more similar to tocopherols than to that of the tocotrienols. Conclusion This is the first evidence that both αT1 and γT1 follow the same sidechain degradation pathway and exert similar rates of metabolism than tocopherols. Therefore, investigation into the biological activities of tocomonoenols is warranted. Metabolism of α‐ and γ‐tocomonoenols (T1), tocopherols (T) and tocotrienols (T3) in liver cells shows that their metabolism increases with increasing number of double bonds in sidechain (T < T1 ≪ T3) and with the methylation of the chromanol ring (α ≪ γ). The main product of T1 metabolism is carboxymethylbutyl‐hydroxychroman (CMBHC) and αT1 metabolism closely resembles that of α‐tocopherol.