Cytotoxicity and genotoxicity of coronaridine from Tabernaemontana catharinensis A.DC in a human laryngeal epithelial carcinoma cell line (Hep-2)

Walace Fraga Rizo,Ana Lúcia Fachin,Paulo Sérgio Pereira,Leonardo Pereira Franchi,Vanessa Colnaghi,Juliana Simões Martins,Catarina Satie Takahashi,Mozart Marins,Rene Oliveira Beleboni,Luis Eduardo Ferreira

doi:10.1590/s1415-47572013005000010

Abstract

Cancer has become a major public health problem worldwide and the number of deaths due to this disease is increasing almost exponentially. In the constant search for new treatments, natural products of plant origin have provided a variety of new compounds to be explored as antitumor agents. Tabernaemontana catharinensis is a medicinal plant that produces alkaloids with expressive antitumor activity, such as heyneanine, coronaridine and voacangine. The aim of present study was firstly to screen the cytotoxic activity of the indole alkaloids heyneanine, coronaridine and voacangine against HeLa (human cervix tumor), 3T3 (normal mouse embryo fibroblasts), Hep-2 (human laryngeal epithelial carcinoma) and B-16 (murine skin) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); and secondly to analyze the apoptotic activity, cell membrane damage and genotoxicity of the compound that showed the best cytotoxic activity against the tumor cell lines tested. Coronaridine was the one that exhibited greater cytotoxic activity in the laryngeal carcinoma cell line Hep-2 (IC50 = 54.47 μg/mL) than the other alkaloids tested (voacangine IC50 = 159.33 g/mL, and heyneanine IC50 = 689.45 μg/mL). Coronaridine induced apoptosis in cell lines 3T3 and Hep-2, even at high concentrations. The evaluation of genotoxicity by comet assay showed further that coronaridine caused minimal DNA damage in the Hep-2 tumor cell line, and the LDH test showed that it did not affect the plasma membrane. These results suggest that further investigation of coronaridine as an antitumor agent has merit.

Highlights

The advances in oncology have led to more effective treatments and cure, cancer continues to be one of the leading causes of human death (Jemal et al, 2011)
In view of the better cytotoxic activity presented by coronaridine, we evaluated apoptosis induction, cell membrane damage and genotoxicity of this compound in human laryngeal carcinoma (Hep-2) cells and in normal mouse embryo fibroblasts (3T3)
The MTT colorimetric assay was used to evaluate the cytotoxicity of the three alkaloids isolated from T. catharinensis in different tumor cell lines (Table 1)

Summary

Introduction

The advances in oncology have led to more effective treatments and cure, cancer continues to be one of the leading causes of human death (Jemal et al, 2011). The toxicity of chemotherapeutic agents is a decisive treatment factor, in immunocompromised patients (Geard, 1992). The development of new cytotoxic compounds is important, and evaluation of the genotoxic activity of the compounds in non-tumor cells is necessary, to assure that the treatment is safe and has no serious side effects. Fucic et al (1998) reported that few chemotherapeutic agents induce secondary tumors in patients with cancer. In addition to playing an important role in the control of various vital processes, apoptosis forms the basis of various cancer treatment strategies, in which apoptosis is induced in tumor cells in response to treatment with cytotoxic agents (Grivicich et al, 2007; Sayers, 2011). The cell content is released, causing damage to neighboring cells and an inflammatory reaction at the site of injury (Kelekar, 2005)

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Conclusion