Herbal preparations represent very complex mixtures, potentially containing multiple pharmacologically active entities. Methods for global characterization of the composition of such mixtures are therefore of pertinent interest. In this work, chemometric analysis of high-performance liquid chromatography with photodiode-array detection (HPLC-PDA) data from extracts of commercial preparations of Hypericum perforatum (St. John's wort) that originate from several continents is described. The spectral HPLC profiles were aligned in the elution mode using correlation optimized warping in order to remove peak misalignment caused by retention time shifts due to matrix effects. Furthermore, the warping was assisted by HPLC-PDA-SPE-NMR-MS (SPE = solid-phase extraction) experiments that yielded 1H NMR and 13C NMR data (from 1H-detected heteronuclear correlations), as well as ESI-MS and HRMS data, which enabled the identification of all major mixture constituents. The preprocessed HPLC-PDA data were subjected to parallel factor analysis (PARAFAC), a chemometric method that is a generalization of principal component analysis (PCA) to multi-way data arrays. PCA of the peak areas obtained from the PARAFAC analysis was used to facilitate sample comparison and allowed straightforward interpretation of constituents responsible for the differences in composition between individual preparations. In addition, loadings from the PARAFAC analysis provided pure elution profiles and pure UV spectra even for coeluting peaks, thus enabling the identification of chromatographically unresolved components. In conclusion, PARAFAC analysis of the readily accessible HPLC-PDA data provides the means for unsupervised and unbiased assessment of the composition of herbal preparations, of interest for assessment of their pharmacological activity and clinical efficacy.

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NGF promotes the survival and enhances the neurotransmitter phenotype of basal forebrain and striatal cholinergic neurons in brain of rat. The objective of the present study was to determine whether stimulations of the cholinergic neuronal markers ChAT and high-affinity choline uptake are reflected in enhanced synthesis and release of ACh. Enhancement of ACh release in brain of adult and aged rats could result in increased cholinergic neurotransmission, and altered animal behavior. NGF (1.2 micrograms/d) was administered intracerebroventricularly for 2 weeks by osmotic minipump to male Fischer-344 rats aged 4 and 24 months. Cholinergic neuronal functional parameters were measured in frontal cortex, hippocampus, and striatum. In young adult rats, increased ChAT and choline uptake activities were accompanied by enhanced ACh synthesis, basal and depolarization-induced release of both endogenous and newly synthesized transmitter, with the largest effect generally being observed in striatum. In aged animals, the responses to NGF were less uniform. Whereas the pattern for changes in ChAT activity was similar to that seen in younger animals, choline uptake activity was increased only in frontal cortex and striatum. Coincidentally, ACh synthesis was also increased only in these two brain regions. ACh content of synaptosomes was not affected by age or NGF treatment, and the ACh levels in microwaved samples of striatum and basal forebrain were not affected by NGF treatment. However, profound deficits in both basal and evoked release of newly synthesized ACh were observed in the aged rats. NGF treatment had no significant effect on the basal release of newly synthesized ACh in aged rats.(ABSTRACT TRUNCATED AT 250 WORDS)