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.

Spectroscopic techniques have shown that quaternary benzophenanthridine alkaloid~ (sanguinarine (Ia). chelerythrine (Ie), sanguilutine (If), sanguirubine (Ie), chelirubine (Ib), and cheli1utine (Id» are reduced by NADH or NADPH to their dihydro forms. The formation of the oxidized form of a coenzyme was demonstrated by HPLC. The kinetics of the reaction of sanguinarine with NADH has been studied rather in detail; the reaction was found to be reversible. its stoichiometry was 1 : 1. Reactivity of the tested alkaloids toward the coenzymes was given by reactivity of the imine bond. This was graded like pK values for the formation of the corresponding pseudobases and correlated with the energy of the lowest unoccupied molecular orbital of these compounds. The possible biological and pharmacological importance of the studied reactions is discussed.The quaternary benzophenanthridine alkaloids I a -If occur in various species of the families Papaveraceae, Fumariaceae, and Rutaceae l • These substances affect the metabolic processes in bacteria or animals and can act as, e.g., antibacterial, antitubular or antitumour substances 2 -6. The effects of these substances in vivo are closely related to their interactions with important macromolecular compounds of cells, especially with certain enzymes, such as NaJK -ATPase 7 , choline esterases 8 • 9 , and amino transferases lO • Interactions of these substances with biopolymers depend on their chemical reactivityll.12. The substances can readily react with -.sH groups of proteins and low-molecular-weight compounds, get converted (in moderately alkaline media) to pseudo-bases II, and can quite easily be reduced to the corresponding dihydro compounds III. All these reactions occur on the imine bond of the substances (Scheme 1), which is a natural site for attack by nucleophilic groups ref. 12 ).The objective of this paper is to describe the reactions of these substances with NADH and NADPH, i.e., with the reduced forms of nicotinamide adenine dinucleotide coenzymes present in considerable quantities in all cells. These reactions may be metabolically important in the parent plants and in the bacterial or animal cells, where these substances get as drugs.Collection Czechoslovak Chern. Commun. (VOI~ 51] (1986]

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Polyunsaturated fatty acids (PUFA) play an important role in reparative processes. The ratio of PUFAs n-3 to n-6 may affect wound healing. The study aimed to evaluate the effect of dietary supplementation with n-3 and n-6 PUFA in two proportions on skin wounds in laboratory rats. Adult male Wistar rats received 20% fat emulsion with a ratio of 1.4:1 (group A) or 4.3:1 (group B) for n-3:n-6 PUFAs at a daily dose of 1 mL/kg. The control group received water under the same conditions. The animals were supplemented a week before and a week after the skin excision performed on the back. The level of wound closure, various parameters of oxidative stress, and plasma fatty acids composition were evaluated. Wound tissue samples were examined by electron microscopy. The administration of fat emulsions led to significant changes in plasma polyunsaturated fatty acid composition. The increased production of reactive nitrogen species, as well as more numerous newly formed blood vessels and a greater amount of highly organized collagen fibrils in both groups A and B may indicate more intensive healing of the skin wound in rats supplemented with polyunsaturated fatty acids in high n-3:n-6 ratio.