ABSTRACT
Cyanobacteria are microorganisms found in different parts of the world. Some genera are cyanotoxins producers a sodium channel blockingneurotoxin (saxitoxins). Some homeopathic preparations have been identified as remedial action on toxicity models in Artemia salina. This study aimed to observe whether homeopathic products influence the toxicity ofR.raciborskiiextract onA.salinaby inducing cyst hatching arrest, anembryo bioresiliencemodel previously developed in our laboratory (Pinto et al., 2021; Mohammad et al., 2022). Thus, previous toxicity testswere carried out on cysts in 96-well plates, using different concentrations of the extract obtained from regular cultivation of R. raciborskii in HCl 0.05M, whose strain, named T3, is kept in the laboratory of Cyanobacteria at FURGS, Brazil.The standardization of toxin concentration was based on an established scale developed at FURGS, in which the number of T3 filaments is associated withspecific saxitoxin concentrationsdefined by chromatography. The concentration of 2.6 µg/L was chosen since it reducedthe cysthatching rate by 30%, the ideal level to observe embryo bioresilience. Then, a screeningstudy with 22 homeopathic preparations was tested blind in three experimental series, in duplicate,against threecontrols (unchallenged, water,and succussed water)for possible toxicity attenuationon Artemia salinacysts hatching rate. Homeopathic medicines were prepared in pure,sterile water from a stock homeopathic solution, one potency below the working potency. After the 1:100 dilution, 100 succussions were made using a robotic arm (Denise, Autic). The medicines were inserted into the seawater on a 10% basis. Due to the high sensitivity of A. salinato the circalunar variations, all experiments were performed during the first quarter moon. Statistical analysis was performed by two-way ANOVA followed by Tukey, with α=0.05. The most significant results indicative of bioresilience improvement were seen after the treatment with Nitric acidum6 cH, Plumbum metallicum6 cH, isotherapic 200 cH, and hydrochloric acid 1 cH being the last one used as a vehicle of the extracts. Thus, these preparations were chosen to be used in further experiments. In conclusion, the Artemia salinamodel has also beenuseful to study bioresilienceimprovement by homeopathic medicines after intoxication with saxitoxin.
Subject(s)
Artemia/virology , Biodegradation, Environmental , Homeopathic Vehicles , CyanobacteriaABSTRACT
O objetivo do trabalho é avaliar a eficiência da adsorção com carvão ativado em pó (CAP) e da cloração de cálcio na remoção de saxitoxinas. As saxitoxinas dispersas em água destilada foram produzidas por meio da extração de células viáveis de cianobactérias da espécie Cylindrospermopsis raciborskii. Os ensaios foram realizados em equipamento de jar test adaptado e empregando-se três tipos de CAP e hipoclorito de cálcio. Os tempos de detenção aplicados foram de duas horas para adsorção e 30 e 60 minutos para oxidação. Os resultados evidenciaram que a eficiência de remoção, para a adsorção, está intrinsecamente relacionada ao tipo de carvão e à dosagem empregada, obtendo maior eficiência para o CAP de madeira. Para oxidação, os dois tempos de contato e as dosagens avaliadas apresentaram eficiência praticamente constante, da ordem de 80 por cento, atendendo ao estabelecido pela Portaria 518.
This paper focuses on the evaluation of the saxitoxins removal by means of adsorption and oxidation. These toxins were produced through extraction of viable cells from cyanobacteria Cylindrospermopsis raciborskii. The tests were carried out in the batch scale with three different powdered activated carbons and calcium hypochlorite. The detention times were two hours for adsorption, and 30 and 60 minutes for oxidation tests. The results pointed out that the type and dosage of carbon are strongly related, and the wood carbon presented higher efficiency. The oxidation efficiency was approximately 80 percent for both evaluated detention times and distinct dosages, keeping practically constant for all tests according to the limit established by the Brazilian Drinking-water Legislation 518.