Assessment of antitumor and antibacterial potential of Vipera latastei venom

• Autor(a) principal: Silva, André Jorge Teodoro da
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/30050
• topic: Cancer; Multi-resistant bacteria; Snake venom; Toxins; Vipera latastei; Antitumor potential; Antibacterial potential

Currently, cancer and the emergence of multi-resistant microorganisms represent a real threat to human health and therefore there is an urgent need for solutions that will be of added value in combating these problems. Thus, several studies have focused on the search for compounds that may constitute new therapeutic agents. Viperidae family presents a characteristic hemotoxic venom. Although it may be lethal or cause considerable damage to humans, venom is also a source rich in components with high therapeutic potential. In order to evaluate the bioactivity of Vipera latastei venom, the main objectives of this work were: a) to provide an overview of the venom and toxins produced by species belonging to the Viperidae family, reviewing its antimicrobial and antitumor potential, b) to evaluate the antitumor potential of V. latastei crude venom against melanoma cells, and c) to evaluate the antibacterial potential of the same venom. Through an extensive literature review, it was evidenced that venoms of vipers present a promising antitumor and antibacterial properties, and these activities are mainly associated to five of these families – SV-LAAO, Disintegrins, PLA2, SVMPs and C-type lectins. Several of these compounds are reported here, highlighting their therapeutic potential and mentioning some of the possible mechanisms of action. Furthermore, the composition of the venoms can be variable among species, which may contribute to the discovery of more compounds, and help in understanding the already known mechanisms of action. Regarding antitumor potential of the V. latastei crude venom, it was observed a significant decrease in cell viability of human melanoma MNT-1 and Human Keratinocyte HaCaT cells in a dose-dependent manner. However, this cytotoxic activity was not selective for tumor cells. Additionally, the venom induced changes in the cell cycle dynamics of the tumor cells. Nonetheless, no significant changes in the cell cycle of non-tumor keratinocytes (HaCaT) were observed. Furthermore, we also observed an increase in ROS generation, especially in tumor cells exposed to the venom. Regarding antibacterial activity, the venom inhibited the growth of all pathogenic bacteria tested in this study, revealing an interesting antibacterial activity. In general, this dissertation supports the idea that snake venoms are a promising source of new compounds of therapeutic interest, presenting the first studies on the bioactivity of V. latastei venom.