O presente estudo verificou as alterações ocorridas na fisiologia de três espécies de Rhodophyta por meio da análise da concentração de pigmentos e de carboidratos não estruturais, avaliando comparativamente algas coletadas da natureza e após 28 dias de cultivo em laboratório. Outro objetivo do estudo foi determinar se as espécies mantêm o potencial antifúngico após o período de cultivo em laboratório, correlacionando as mudanças ocorridas na fisiologia com as de bioatividade. Após a realização de cultivo em laboratório os resultados indicaram a tendência de redução nas concentrações de pigmentos nas três espécies de macroalgas, principalmente para as ficobiliproteínas. Para os carboidratos não estruturais não foi observado padrão de resposta das macroalgas em relação às condições avaliadas. Os extratos das macroalgas Ochtodes secundiramea e Palisada flagellifera, após cultivo em laboratório, apresentaram aumento significativo do potencial antifúngico positivamente correlacionado com a alteração na concentração e nas razões de clorofila a e pigmentos acessórios. A aplicação de técnicas de cultivo em laboratório das macroalgas foi uma ferramenta eficiente para o conhecimento da fisiologia, obtenção de biomassa e de compostos com aplicação biotecnológica, sem impactar populações naturais.

The present study examined changes that took place in the physiology of three species of Rhodophyta by analysing the concentration of pigments and non-structural carbohydrates, comparatively evaluating algae collected from nature and after 28 days of laboratory cultivation. Another objective of the study was to determine whether the species retain their antifungal potential after the period of laboratory cultivation, correlating the changes in physiology and those from bioactivity. After carrying out laboratory cultivation, the results indicated a trend, in the three species of macroalgae, towards a reduction in pigment concentrations, mainly in the phycobiliproteins. For the non-structural carbohydrates no response pattern of the macroalgae was observed for the conditions evaluated. Extracts from the macroalgae, Ochtodes secundiramea and Palisada flagellifera, after laboratory cultivation showed a significant increase in antifungal potential which could be positively correlated with the change in concentration and ratios of chlorophyll-a and accessory pigments. Applying techniques of laboratory cultivation to macroalgae was an efficient tool for gaining knowledge of the physiology, and for obtaining biomass and compounds having biotechnological applications, without impacting on natural populations.

An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.

Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs) which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.