Phylogenetic examination of crude drugs derived from Yunnanese Swertia plants.

Aiming to examine whether the genetic background of the crude drugs derived from four Yunnanese Swertia plants and their chemical constituent profiles correlate, we analyzed the nucleotide sequences of their nuclear ribosomal DNA regions including ITS1, 5.8S ribosomal RNA gene, and ITS2, together with those of Japanese S. japonica and S. pseudochinensis from Hebei Province. The result that two of the Yunnanese Swertia plants, S. binchuanensis and S. punicea, were genetically similar may explain their similarity in chemical constituent profiles. On the other hand, in spite of differences in chemical profile, S. decora and S. pseudochinensis were genetically close. The other Yunnanese Swertia plants, S. delavayi, and S. japonica, stood at intermediate positions between these two genetically similar pairs. The result suggests that although genetic background would have an influence, environmental factors, e.g., soil and weather conditions, might be critical for their production of secondary metabolites.

Studies on neurosteroids XVIII LC-MS analysis of changes in rat brain and serum testosterone levels induced by immobilization stress and ethanol administration.

The liquid chromatography-mass spectrometry (LC-MS) methods were developed and validated for the determination of testosterone (T) in the brain and serum of rats and of 5alpha-androstane-3alpha,17beta-diol (ADIOL), a metabolite of T, in the brain of rats. After derivatization of T with 2-hydrazino-1-methylpyridine and of ADIOL with p-nitrobenzoyl chloride, the detection sensitivities of T and ADIOL using LC-MS were increased 70- and 400-times superior to those of intact T and intact ADIOL, respectively. Those LC-MS methods are specific and reliable for the analysis of trace amounts of T and ADIOL in small amounts of samples. The animal studies using the developed methods showed that the brain and serum levels of T and the brain levels of ADIOL were not changed by stress or ethanol administration but the concentration ratio of the brain T to serum T in the stressed rats was higher than that in untreated rats. The low levels of endogenous AIDOL in brain of stressed and unrestrained rats found in this study demonstrated that the contribution to anesthetic and anxiolytic effects of ADIOL via gamma-aminobutyric acid type A receptors may be negligible.