Determination of mycotoxins, alkaloids, phytochemicals, antioxidants and cytotoxicity in Asiatic ginseng (Ashwagandha, Dong quai, Panax ginseng).

Mycotoxins and selected hazardous alkaloids in the medicinal plants (Panax ginseng, Angelica sinensis, and Withania somnifera) and dietary supplements were determined. Purine alkaloids were found in majority of samples; however, isoquinoline alkaloids were less abundant than indole. The predominant alkaloids appear to be caffeine (purine group), harman (indole group) and berberine (isoquinoline). Examined medicinal plants and dietary supplements were contaminated by mycotoxins (especially ochratoxin A 1.72-5.83 µg kg-1), and many species of mold (e.g. Cladosporium, Eurotium, Aspergillus, Rhizopus, Penicillium). MTT cytotoxicity tests revealed that plant and supplements extracts exhibited medium or high cytotoxicity (only Dong quai-low). Moreover, antioxidant activity, total phenolics content and selected phytochemicals were analyzed by spectrophotometric and chromatographic methods. Quercetin and rutin were predominant flavonols (1.94-9.51 and 2.20-7.28 mg 100 g-1, respectively). Analysis of phenolic acids revealed-gallic acid, as the most abundant, except Panax ginseng, where ferulic acid was prevailing. The results were analyzed by chemometric methods (cluster analysis, ANOVA).

Photochemical behaviour of hydrolysed keratin.

An investigation into the influence of UV irradiation on keratin hydrolysates was carried out using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. It was found that the absorption of keratin hydrolysates in solution increased during irradiation of the sample, most notably between 250-280 and 320-410 nm. The increase in absorbance in the region 320-410 was because of the new photoproducts formed during UV irradiation of keratin hydrolysates. The fluorescence of keratin hydrolysates was observed at 328 nm after excitation at 270 nm. UV irradiation caused fluorescence fading at 328 nm, and after 60 min of irradiation, a new broad weak band of fluorescence, attributable to new photoproducts, emerged in the UV wavelength region with emission maximum between 400 and 500 nm. FTIR spectroscopy results showed degradation of keratin under UV irradiation. A slight increase in oxidized sulphur species was also observed. The results obtained suggest that UV irradiation can be used as modifying agent for preparation of keratin hydrolysates for cosmetic applications.

Mitochondrial dysfunction in Parkinson's disease.

Parkinson's disease (PD) is a progressive, neurodegenerative condition that has increasingly been linked with mitochondrial dysfunction and inhibition of the electron transport chain. This inhibition leads to the generation of reactive oxygen species and depletion of cellular energy levels, which can consequently cause cellular damage and death mediated by oxidative stress and excitotoxicity. A number of genes that have been shown to have links with inherited forms of PD encode mitochondrial proteins or proteins implicated in mitochondrial dysfunction, supporting the central involvement of mitochondria in PD. This involvement is corroborated by reports that environmental toxins that inhibit the mitochondrial respiratory chain have been shown to be associated with PD. This paper aims to illustrate the considerable body of evidence linking mitochondrial dysfunction with neuronal cell death in the substantia nigra pars compacta (SNpc) of PD patients and to highlight the important need for further research in this area.

Spectrofluorometric determination of 2- and 10-disubstituted phenothiazines.

Spectrofluorometric method for determination of promethazine hydrochloride, thioridazine hydrochloride and perazine dimaleate in the pure form and in drugs is described. Fluorescence excitation spectra of series of aqueous solutions were measured. The fluorescence signal was found to be a linear function of the promethazine hydrochloride (PTM) concentration in the range: 0.30-20.02 ppm, thioridazine hydrochloride (TR): (0.43-21.70 ppm and perazine dimaleate (PDM): 0.85-50.60 ppm. The excitation spectra were used for determination of phenothiazine derivatives in pharmaceutical formulations such as: Diphergan, Thioridazin and Pernazinum. The influence of K+, Na+, Mg2+ i Ca2+ cations on the fluorescence intensity of phenothiazine derivatives was also studied.

Quantitative determination of selected tricyclic biological active compounds by using capillary electrophoresis.

Five tricyclic antidepressants: imipramine hydrochloride, noxiptilin hydrochloride, hydroxyzine dihydrochloride, diethiazine hydrochloride and amitryptyline hydrochloride were determined by the capillary electrophoresis method. The determinations were performed by using a fused sillica capillary (60 cm x 50 microns i.d., effective length 53 cm). Acetate buffer (25 mM ammonium acetate and 1 mM acetic acid) in (1:1) methanol:water solution was used as an electrolyte. The determination voltage was 20 kV. The UV-detector at 214 nm was applied.