The content of the main flavonoids in the root of Scutellaria baicalensis Georgi cultivated in Central Europe was evaluated using the new simple RP-HPLC method with gradient of acetonitrile in mobile phase. The main components of the roots were baicalin (8.12% of dry root mass) and wogonin glucuronide (2.52%). The content of flavonoids was comparable with the content in plants cultivated in natural localities. Five main flavonoids were evaluated for their scavenging ability with DPPH radical-generating system and due to limited solubility only two flavonoids were investigated for their ability to scavenge hydroxyl radical by the aromatic hydroxylation method. The total extract was also tested in both the experimental arrangements. In experiments with DPPH, only baicalin and baicalein displayed a significant scavenging effect, while the production of OH radicals generated by UV photolysis of H(2)O(2) was considerable decreased in the presence of baicalin and wogonin glucuronide. After comparison with results obtained for the total extract, it was concluded, that the scavenging activity of the extract against DPPH is mainly derived from baicalin. On the other hand, baicalin, wogonin glucuronide and probably other flavonoids participate in scavenging OH radical.

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Chelidonium majus L. (Papaveraceae) is a well-known and widely-spread herb. So far about 30 alkaloids have been described in this species (1-7). A number of studies have been published dealing with the determination of these alkaloids using high performance liquid chromatography (8-12). No method, however, covered a complete separation of the alkaloids, including the minor components in C. majus. Our aim was to establish an appropriate method for the determination of the main as well as the minor alkaloids in this species.

Increased oxidative stress is indisputably an important mechanism of doxorubicin side effects, especially its cardiotoxicity. To prevent impairment of non-tumorous tissue and to improve the specificity in targeting the tumor tissue, new drug nanotransporters are developed. In many cases preclinical therapeutic advantage has been shown when compared with the administration of conventional drug solution. Three forms of doxorubicin -conventional (DOX), encapsulated in liposomes (lipoDOX) and in apoferritin (apoDOX) were applied to Wistar rats. After 24 h exposition, the plasma level of 4-hydroxy-2nonenal (4-HNE) as a marker of lipoperoxidation and tissue gene expression of thioredoxin reductase 2 (TXNRD2) and aldehyde dehydrogenase 3A1 (ALDH3A1) as an important part of antioxidative system were determined. Only conventional DOX significantly increases the level of 4-HNE; encapsulated forms on the other hand show significant decrease in plasma levels of 4-HNE in comparison with DOX. They also cause significant decrease in gene expression of ALDH3A1 and TXNRD2 in liver as a main detoxification organ, and a mild influence on the expression of these enzymes in left heart ventricle as a potential target of toxicity. Thus, 4-HNE seems to be a good potential biomarker of oxidative stress induced by various forms of doxorubicin. Key words Doxorubicin • Drug nanotransporters • Oxidative stress • 4-hydroxy-2-nonenal • Thioredoxin reductase 2 • Aldehyde dehydrogenase 3A1

BackgroundDetailed quantitative analysis of the effect of left ventricle (LV) hypertrophy on myocardial ischemia manifestation in ECG is still missing. The associations between both phenomena can be studied in animal models. In this study, rabbit isolated hearts with spontaneously increased LV mass were used to evaluate the effect of such LV alteration on ischemia detection criteria and performance.MethodsElectrophysiological effects of increased LV mass were evaluated on sixteen New Zealand rabbit isolated hearts under non-ischemic and ischemic conditions by analysis of various electrogram (EG) parameters. To reveal hearts with increased LV mass, LV weight/heart weight ratio was proposed. Standard paired and unpaired statistical tests and receiver operating characteristics analysis were used to compare data derived from different groups of animals, monitor EG parameters during global ischemia and evaluate their ability to discriminate between unchanged and increased LV as well as non-ischemic and ischemic state.ResultsSuccessful evaluation of both increased LV mass and ischemia is lead-dependent. Particularly, maximal deviation of QRS and area under QRS associated with anterolateral heart wall respond significantly to even early phase (the 1st-3rd min) of ischemia. Besides ischemia, these parameters reflect increased LV mass as well (with sensitivity reaching approx. 80%). However, the sensitivity of the parameters to both phenomena may lead to misinterpretations, when inappropriate criteria for ischemia detection are selected. Particularly, use of cut-off-based criteria defined from control group for ischemia detection in hearts with increased LV mass may result in dramatic reduction (approx. 15%) of detection specificity due to increased number of false positives. Nevertheless, criteria adjusted to particular experimental group allow achieving ischemia detection sensitivity of 89–100% and specificity of 94–100%, respectively.ConclusionsIt was shown that response of the heart to myocardial ischemia can be successfully evaluated only when taking into account heart-related factors (such as LV mass) and other methodological aspects (such as recording electrodes position, selected EG parameters, cut-off criteria, etc.). Results of this study might be helpful for developing new clinical diagnostic strategies in order to improve myocardial ischemia detection in patients with LV hypertrophy.