Tocopherol succinate, but not α-tocopherol or other vitamin E analogs, stimulates prolactin release from rat anterior pituitary cells in vitro

Abstract

We have previously reported the isolation of a vitamin E analog ( α -tocopherol succinate) from a green barley leaf extract, which stimulates the release of prolactin and growth hormone from rat anterior pituitary cells in vitro. In the present study, we tested the commercially available forms of a-tocopherol and also succinic acid. Normal anterior pituitary cells were treated with different commercially available forms of tocopherol (100 μ g/ml) and succinic acid (50 to 100 μ g/ml). Only α -tocopherol succinate caused a significant increase ( P α -tocopherol, δ-tocopherol, α -tocopherol acetate, α -tocopherol nicotinate, succinic acid disodium salt, and succinic acid butenedoic acid did not affect the prolactin release in vitro. The data demonstrate that of all the biologically active forms of vitamin E, only α -tocopherol succinate possesses the ability to enhance anterior pituitary hormone release in vitro.