Antiproliferative activity and apoptosis induced by 6-bromo-2-(morpholin-1-yl)-4-anilinoquinazoline on cells of leukemia lines

Quinazolines are known to be multitarget agents with broad spectrum of biological activity. Aim: To investigate anticancer activity of newly prepared 6-bromo-2-(morpholin-1-yl)-4-anilinoquinazoline (BMAQ) towards L1210, HL-60 and U-937 leukemia cells. Materials and Methods: Growth inhibition of BMAQ-treated cells was determined by cell counting using trypan blue staining technique. Apoptosis and cell cycle profile changes were analysed using internucleosomal DNA fragmentation assay, fluorescence microscopy and flow cytometry. Activity of caspase-3 was determined using colorimetric method. Results: Cell proliferation assay showed that BMAQ caused significant decrease of cell number in a dose-dependent manner. BMAQ induced cell death by apoptosis, based on results from DNA fragmentation, fluorescence microscopy and caspase-3 assays. Conclusion: Presented results clearly demonstrate that BMAQ is a promising anticancer agent with significant antiproliferative and apoptotic activities towards leukemia cells in vitro.Квиназолины известны как химиопрепараты широкого спектра действия. Цель: на моделях лейкозных клеток линий L1210, HL-60 и U-937 изучить противоопухолевую активность нового препарата 6-бромо-2-(морфолин-1-ил)-4-аналиноиназолина (BMAQ). Методы: ингибирование роста клеток под действием BMAQ изучали путем подсчета количества клеток, окрашенных трипановым синим. Апоптоз и изменения профиля клеточного цикла исследовали с помощью флуоресцентной микроскопии, электрофореза ДНК и проточной цитометрии. Активность каспазы-3 определяли колориметрическим методом. Результаты: показано, что BMAQ вызывает значительное дозозависимое уменьшение количества лейкозных клеток. При этом клетки, обработанные BMAQ, погибают путем апоптоза, что дается образованием апоптотических телец, межнуклеосомной фрагментацией ДНК и активацией каспазы-3. Выводы: представленные результаты свидетельствуют о том, что BMAQ обладает антипролиферативной и проапоптотической активностью в отношении лейкозных клеток in vitro

Decrease in the production of beta-amyloid by berberine inhibition of the expression of beta-secretase in HEK293 cells

<p>Abstract</p> <p>Background</p> <p>Berberine (BER), the major alkaloidal component of <it>Rhizoma coptidis</it>, has multiple pharmacological effects including inhibition of acetylcholinesterase, reduction of cholesterol and glucose levels, anti-inflammatory, neuroprotective and neurotrophic effects. It has also been demonstrated that BER can reduce the production of beta-amyloid_40/42, which plays a critical and primary role in the pathogenesis of Alzheimer's disease. However, the mechanism by which it accomplishes this remains unclear.</p> <p>Results</p> <p>Here, we report that BER could not only significantly decrease the production of beta-amyloid_40/42and the expression of beta-secretase (BACE), but was also able to activate the extracellular signal-regulated kinase1/2 (ERK1/2) pathway in a dose- and time-dependent manner in HEK293 cells stably transfected with APP695 containing the Swedish mutation. We also find that U0126, an antagonist of the ERK1/2 pathway, could abolish (1) the activation activity of BER on the ERK1/2 pathway and (2) the inhibition activity of BER on the production of beta-amyloid_40/42and the expression of BACE.</p> <p>Conclusion</p> <p>Our data indicate that BER decreases the production of beta-amyloid_40/42by inhibiting the expression of BACE via activation of the ERK1/2 pathway.</p

Redox Regulation of the AMP-Activated Protein Kinase

Redox state is a critical determinant of cell function, and any major imbalances can cause severe damage or death

Different concentrations of berberine result in distinct cellular localization patterns and cell cycle effects in a melanoma cell line

Abstract Purpose Natural products represent a rich reservoir of potential small molecule inhibitors exhibiting antiproliferative and tumoricidal properties. An example is the isoquinoline alkaloid berberine, which is found in plants such as goldenseal (Hydrastis canadensis). Studies have shown that berberine is able to trigger apoptosis in different malignant cell lines, and can also lead to cell cycle arrest at sub-apoptotic doses. A particularly interesting feature of berberine is the fact that it is a fluorescent molecule, and its uptake and distribution in cells can be studied by flow cytometry and epifluorescence microscopy. To test the relationships between berberine uptake, distribution and cellular effect in melanoma cells, K1735-M2 mouse and WM793 human melanoma cells were treated with different concentrations of berberine, and alterations in cell cycle progression, DNA synthesis, cell proliferation, and cell death measured. Methods Cell proliferation was measured by sulforhodamine B assays, cell death by flow cytometry, berberine uptake and distribution by laser scanning confocal microscopy and flow cytometry, cell cycle progression by flow cytometry, and DNA synthesis, M-phase, and mitochondrial effects by immunolabeling and epifluorescence microscopy methods. Results In these melanoma cell lines, berberine at low doses (12.5–50 µM) is concentrated in mitochondria and promotes G1 arrest. In contrast, higher doses (over 50 µM) result in cytoplasmic and nuclear berberine accumulation, and G2 arrest. DNA synthesis is not markedly affected by low doses of berberine, but 100 µM is strongly inhibitory. Even at 100 µM, berberine inhibits cell growth with relatively little induction of apoptosis. Conclusion Berberine displays multiphasic effects in these malignant cell lines, which are correlated with the concentration and intracellular distribution of this alkaloid. These results help explain some of the conflicting information in the literature regarding the effects of berberine, and suggest that its use in clinical development may be more as a cytostatic agent than a cytotoxic compound