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Our goal is to obtain a new food supplement -a chemopreventive preparation derived from selenium (Se)-enriched Lentinula edodes mycelium. In the present study the bioavailability of selenium from Se-enriched mycelium preparations was tested in vitro and in vivo. Three different preparations of selenated mycelium were compared: dried mycelium, lyophilized mycelium, and lyophilized-autolyzed mycelium. In vitro, estimated Se bioavailabilities were 60%, 82%, and 98%, respectively. In vivo bioavailability was determined in rats. As reference, sodium selenite and Se yeast formulations were used at an Se-equivalent dose. The pharmacokinetic data for tested mycelial preparations suggest a rapid but incomplete Se absorption, and rapid elimination, without risk of accumulation. The speciation of selenium in Se-enriched mycelial cultures was carried out by specific oxido-reduction reactions. For tested mycelium the main part of Se was in the 0 and IV oxidation states in inorganic form or combined in a lipid or carbohydrate structure, about 47% was in the -II state in Se-amino acids or in other undefined water-or alcohol soluble organic compounds. Differences in pharmacokinetic data for Se yeast and L. edodes mycelial formulations probably arise from differences in Se speciation. Our data suggest that formulations of selenized Lentinula edodes mycelium could be used in chemoprevention as food supplements.

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Injected intrathecally, bradykinin (BK) produced either hyperalgesia (0.15 µg) or antinociception (6.0 µg) in rats when thermal noxious stimuli were used. Similarly, des-Arg⁹-BK at the lower dose (0.15 µg) decreased, whereas at the higher dose (6.0 µg) it increased the threshold to thermal noxious stimuli; however, these effects were less pronounced than those of BK. The antinociception induced by BK was abolished by HOE 140, a B₂ receptor antagonist, injected intrathecally at a dose of 1.3 ng and was markedly attenuated by des-Arg¹⁰-HOE 140, a B₁ receptor antagonist (1.15 ng i.t.). The results obtained in this study showed that – depending on the dose used – BK and des-Arg⁹-BK could produce pro- as well as antinociceptive actions. Both B₂ and B₁ receptors are involved in the action of intrathecally applied BK.