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1.
J Pharm Pharmacol ; 55(8): 1143-9, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12956905

RESUMO

Previous studies on the anticancer activity of protoberberine alkaloids against a variety of cancer cell lines were extended to human tumour HeLa and murine leukemia L1210 cell lines. An attempt was also made to investigate the relationship between the cytotoxic activity of berberine and its molecular mechanism of action. Cytotoxicity was measured in-vitro using a primary biochemical screening according to Oyama and Eagle, and the growth inhibition assay. The in-vitro cytotoxic techniques were complemented by cell cycle analysis and determination of apoptotic DNA fragmentation in L1210 cells. Berberine acted cytotoxically on both tumour cell lines. The sensitivity of leukemia L1210 cells to the berberine was higher than that of HeLa cells. The IC(100) was below 100 microg mL(-1) for HeLa cells and approached a 10 microg mL(-1) limit for the leukemia L1210 cells. For both cell lines the IC(50) was found to be less than 4 microg mL(-1), a limit put forward by the National Cancer Institute (NCI) for classification of the compound as a potential anticancer drug. In L1210 cells treated with 10-50 microg mL(-1) berberine, G(0)/G(1) cell cycle arrest was observed. Furthermore, a concentration-dependent decrease of cells in S phase and increase in G(2)/M phase was detected. In addition, apoptosis detected as sub-G(0) cell population in cell cycle measurement was proved in 25-100 microg mL(-1) berberine-treated cells by monitoring the apoptotic DNA fragmentation (DNA ladder) using agarose gel electrophoresis.


Assuntos
Berberina/farmacologia , Células HeLa/efeitos dos fármacos , Leucemia L1210/patologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Eletroforese em Gel de Ágar , Citometria de Fluxo , Inibidores do Crescimento/farmacologia , Humanos
2.
BMC Complement Altern Med ; 2: 2, 2002 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-11943071

RESUMO

BACKGROUND: As part of a study aimed at developing new pharmaceutical products from natural resources, the purpose of this research was twofold: (1) to fractionate crude extracts from the bark of Mahonia aquifolium and (2) to evaluate the strength of the antimutagenic activity of the separate components against one of the common direct-acting chemical mutagens. METHODS: The antimutagenic potency was evaluated against acridine orange (AO) by using Euglena gracilis as an eukaryotic test model, based on the ability of the test compound/fraction to prevent the mutagen-induced damage of chloroplast DNA. RESULTS: It was found that the antimutagenicity of the crude Mahonia extract resides in both bis-benzylisoquinoline (BBI) and protoberberine alkaloid fractions but only the protoberberine derivatives, jatrorrhizine and berberine, showed significant concentration-dependent inhibitory effect against the AO-induced chloroplast mutagenesis of E. gracilis. Especially berberine elicited, at a very low dose, remarkable suppression of the AO-induced mutagenicity, its antimutagenic potency being almost three orders of magnitude higher when compared to its close analogue, jatrorrhizine. Possible mechanisms of the antimutagenic action are discussed in terms of recent literature data. While the potent antimutagenic activity of the protoberberines most likely results from the inhibition of DNA topoisomerase I, the actual mechanism(s) for the BBI alkaloids is hard to be identified. CONCLUSIONS: Taken together, the results indicate that berberine possesses promising antimutagenic/anticarcinogenic potential that is worth to be investigated further.


Assuntos
Antimutagênicos/farmacologia , Berberina/análogos & derivados , Berberina/farmacologia , Mahonia , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Relação Dose-Resposta a Droga , Euglena gracilis/efeitos dos fármacos , Mahonia/química , Casca de Planta
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