RESUMO
BACKGROUND: An inverse relationship between selenium (Se) intake and cancer mortality is evident in humans. MATERIALS AND METHODS: In eighty patients who had been operated on for primary gastric cancer, serum Se and carcinoembryonic antigen (CEA) levels were measured preoperatively using a fluorometric and immunoradiometric assay (IRMA), respectively. RESULTS: The serum Se levels were 43+/-6.3 microg l(-1) in the patient group and 68.7+/-4.5 microg l(-1) in healthy individuals (p<0.001). The serum CEA was 12+/-1.9 U ml(-1) in the gastric cancer patients and 2.1 U ml(-1) in the control group (p<0.001). The Se tissue concentrations were 2,640+/-220 mg g(-1) in excised neoplastic tissue and 685+/-115 mg g(-1) in non-neoplastic tissue (p<0.001). An inverse correlation between Se and CEA serum levels was found (r=-0.782). There was no correlation between serum/tissue Se concentration and disease stage/histological type or gender in the patient group.
Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/sangue , Antígeno Carcinoembrionário/sangue , Neoplasias Intestinais/metabolismo , Selênio/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/secundário , Estudos de Casos e Controles , Feminino , Fluorometria , Humanos , Técnicas Imunoenzimáticas , Ensaio Imunorradiométrico , Neoplasias Intestinais/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Neoplasias Gástricas/patologiaRESUMO
Hypericum perforatum L. (St. John's wort) is a medicinal plant used for many pathologies, especially for the treatment of mild to moderate depression. In the present study we have investigated the cytotoxic activity of the locally collected (Epirus region) Hypericum perforatum L. against cultured T24 and NBT-II bladder cancer cell lines. The lipophilic extract of the herb, prepared using petroleum ether, induced apoptosis displaying LC(50) values at concentrations as low as 4 and 5 microg/mL. A fraction of this extract displayed 60 % cell growth inhibition at a concentration of 0.95 microg/mL. Evaluating the importance of various biologically active components of the extract, it was found that hypericins (hypericin, pseudohypericin, etc.) were identified only in the methanolic (lipophobic) extract of the herb, and not in the active lipophilic extract. In addition, hyperforin concentrations in the lipophilic extract and its most active fraction, were 0.94 microg/mL, and 0.17 microg/mL, respectively, while the active cytotoxic concentration of pure hyperforin appeared in the range of 1.8 microg/mL - 5.0 microg/mL. Therefore, pure hyperforin does not seem to contribute significantly to the cytotoxicity activity. Chlorophylls were identified in low, not significantly different, concentrations in all extracts and fractions and were not correlated to the biological activity. Owing to the combination of significant cytotoxic activity, natural abundance and low toxicity, the lipophilic extract of Hypericum perforatum holds the promise of being an interesting, new, antiproliferative agent against bladder cancer that deserves further investigation.