Metabolic activation enhances the cytotoxicity, genotoxicity and mutagenicity of two synthetic alkaloids with selective effects against human tumour cell lines.

The pharmacological potential of drugs must be evaluated to establish their potential therapeutic benefits and side effects. This evaluation includes assessment of the effects of hepatic enzymes that catalyse their metabolic activation. Previously, our research group synthesized and characterized a set of synthetic 3-alkyl pyridine alkaloid (3-APA) analogues that cause in vitro cytotoxic, genotoxic, and mutagenic effects in various human cancer cell lines. The present study aimed to evaluate these activities with the two most promising synthetic 3-APAs (3-APA 1 and 3-APA 2) against cell lines derived from breast cancer (MDA-MB-231), ovarian cancer (TOV-21 G) and lung fibroblasts (WI-26-VA4) with and without metabolic activation (S9 fraction). The cytotoxicity of the compounds was evaluated employing MTT and clonogenic assays. In addition, comet assays, γH2AX immunocytochemistry labelling assays and cytokinesis-block micronucleus tests were carried out to evaluate the potential of these compounds to induce chromosomal damage. The results obtained in the MTT assay showed that compound 3-APA 2 exhibited high selectivity index (SI) values (ranging between 21.0 and 92.6). In addition, the cytotoxicity of the compounds was clearly enhanced by metabolic activation. Moreover, both compounds were genotoxic and induced double-strand breaks in DNA and chromosomal lesions with and without S9. The cancer cell lines tested showed higher genotoxic sensitivity to the compounds than did the non-tumour cell line used as a reference. The genotoxic and mutagenic effects of the compounds were potentiated in experiments with metabolic activation. The data obtained in this study indicate that compound 3-APA 2 is more active against the human cancer cell lines tested, both with and without metabolic activation, and can therefore be considered a candidate drug to treat human ovarian and breast cancer.

Ultrasound elastography in patients with fatty liver disease / Análise da elastografia por ultrassonografia em pacientes com esteatose hepática

Abstract Hepatic steatosis, or fatty liver disease, occurs due to the accumulation of lipids in hepatocytes. When it becomes chronic, lobular inflammation develops and the disease can evolve to hepatic fibrosis, liver cirrhosis, or hepatocellular carcinoma. Early diagnosis is desirable because patients diagnosed in the early stage of the disease respond better to treatment. In the early stages of fatty liver disease, the physical examination is often unremarkable. Fatty liver disease and hepatic fibrosis can be diagnosed and monitored through laboratory tests, imaging, and biopsy. Among the imaging methods, ultrasound stands out as an effective means of diagnosing and following patients with liver disease. Ultrasound used in conjunction with elastography (ultrasound elastography) has recently shown great utility in the follow-up of such patients. Ultrasound elastography studies the degree of deformation (stiffness) of an organ or lesion, so that when there is hardening, fibrosis, or cirrhosis of the liver, those alterations are well demonstrated. In this review article, we discuss the application of the different types of ultrasound elastography for liver studies: transient elastography, point shear wave elastography, and two-dimensional shear wave elastography. Although magnetic resonance elastography may also be used in the analysis of liver fibrosis, it will not be addressed in this article.

Resumo Esteatose hepática ocorre pelo acúmulo de lipídios nos hepatócitos, sua cronificação cursa com inflamação lobular e evolui com fibrose hepática, cirrose e carcinoma hepatocelular. O diagnóstico precoce do acometimento hepático é desejável em razão da melhor resposta terapêutica dos pacientes na fase inicial da doença. O exame físico nas fases iniciais da doença não apresenta alterações. O diagnóstico e o controle evolutivo da esteatose e fibrose hepática podem ser realizados por exames laboratoriais, exames de imagens e biópsia. Entre os exames de imagem, destaca-se a ultrassonografia (US) no diagnóstico e acompanhamento dos pacientes com doença hepática. Atualmente, a US associada à elastografia vem se destacando para acompanhamento desses pacientes. A elastografia por US estuda o grau de deformação (ou dureza) do órgão ou lesão, de modo que quando há endurecimento do fígado, por fibrose ou cirrose, essa alteração é bem demonstrada na elastografia por US. Neste artigo de revisão nos propusemos a discutir a aplicação dos diversos tipos de elastografia por US para estudo do fígado: elastografia transitória, point-shear wave elastography e 2D-shear wave elastography. A elastografia por ressonância magnética também pode ser utilizada na análise de fibrose hepática, mas não será abordada neste artigo.

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

ABSTRACT In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents.