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| Author(s): |
Flavia Renata Abe
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2017-12-08 |
| Examining board members: |
Danielle Palma de Oliveira;
Carolina Patricia Aires Garbellini;
Carlos Alexandre Sarabando Gravato;
Rhaul de Oliveira
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| Advisor: | Danielle Palma de Oliveira |
| Abstract | |
Synthetic dyes are widely used by textiles, cosmetic, food and pharmaceutical industries. However, several compounds have high inherent toxicity, and many are precursors of mutagenic and/or carcinogenic intermediates produced during metabolism. Thereby, the use of natural dyes became an alternative to the synthetic ones, in search of safe compounds for human and environmentl health. In this context, we aimed to investigate the toxicological and ecotoxicological potential of the natural dye erythrostominone (Ery), a naphthoquinone compound extracted from microorganism, using alternative methods to animal experimentation. Additionally, it was assessed the ecotoxicity of the Basic Red 51 (BR51), an azo synthetic dye used bu cosmetic and textile industries, and the Ery degraded (EryD) after exposure to light, aiming an easy alternative to industrial effluent treatments containing the dye. Ecotoxicological assessment was performed at different trophic levels: in the microcrutaceans Daphnia magna and in zebrafish (Danio rerio) early life stages. Toxicological assessment of Ery was also performed in human hepatocellular line (HepG2) as target organ of xenobiotic metabolism, and in equivalent human epidermis (EHE), a 3D model constructed with immortalized human keratinocytes (HaCaT), since dermal contact is expected due to potential use as cosmetic dye. Our results showed that Ery and BR51 are toxic for D. magna and zebrafish. BR51 induced alterations in immobility, reproduction, oxygen uptake and behavior of D. magna at concentrations up to 200-fold higher than those of Ery able to impair immobility, reproduction and behavior. However, for zebrafish embryos and larvae, both dyes showed toxic effects at close concentrations, with changes in embryo development and behavior, induction of pro-oxidant effects and changes in the energy balance of organisms. Interestingly, EryD showed no toxic effect on aquatic organisms, demonstrating that light was able to reduce and/or inactivate the toxicity of the initial chemical structure. For human cell lines, Ery showed to be cytotoxic to HepG2, with apoptosis being the main source of cell death. Ery also induced a delay in HepG2 cell cycle, particularly in the mitosis phase (G2/M), decreasing cell proliferation. On the other hand, Ery presented no genotoxic and mutagenic potential for HepG2 and did not induce cytotoxicity and genotoxicity after short-term exposure to EHE. In conclusion, Ery and BR51 are classified as toxic and very toxic to the aquatic environment, respectively. Ery also induces pro-apoptotic effects, which may be linked to the chemical structure of quinones. Therefore, Ery presents potential industrial applicability as an eco-friendly dye, highlighting the easy and rapid photodegradation, and the non-genotoxic and mutagenic effects for human cells. Further assessment of apoptosis mechanisms should be performed to ensure safety to human health (AU) | |
| FAPESP's process: | 13/14397-0 - Ecogenotoxicological evaluation of natural dye extracted from microorganism |
| Grantee: | Flavia Renata Abe |
| Support Opportunities: | Scholarships in Brazil - Doctorate |