Exposure of Artemia salinato glyphosate and bioremediation by isotherapy

Artemia salina, an ecotoxicity bioindicator, isa microcrustacean belonging to the order Anostraca. Glyphosate is an herbicide widely used to control weeds. However, its intoxication can cause serious damage to human health and the balance of the environment, given its effects as an endocrine disruptor.Objective:verify the possible protection of the artemia exposed to glyphosate by the addition of its isotherapic into water, by means of the evaluation of the behavioral and morphological features of nauplii and of the physical properties of remedies andtreated water, to elucidate the involved mechanisms. Methods:Artemia salinacysts were kept in culture bottles containing artificial seawatercontaining glyphosate at LC 10 (lethal concentration 10%), to promote hatching within 48 hours. The isotherapic preparations were inserted in each bottle in a 10% of the total water volume. Part of the nauplii was distributed in transparent tubes, being 10 nauplii per tube and 6 tubes per group, for behavioral analysis, and part were collected for a detailed morphological analysis, under an optical microscope. About 80 to 270 nauplii were analyzed per group. The reserved water was divided into aliquots for physicochemical analysis, that is, evaluation of the water dipole behavior by Cartwright ́s method.Results:Gly 6cH presented selective effects on nauplii hatching (p=0.02) and on defected/healthy ratio (p=0.001), representing some protective action. This result was dependent of the salinity of water and presented correspondence with the effects on solvatochromic dyes, indicating that charges and ions can be critical factors involved in the mechanism of action. We concluded that the use of isotherapics could be a plausible tool to reduce the environmental impact of the indiscriminate use of glyphosate, since these results can be reproduced in further studies.

Environmental parameters modulate lead chloride toxicity on Artemia salina

Different environmental conditions can influence the effects of toxic agents on living beings. Recently, a series of experiments performed in Artemia salina submitted to different kinds of intoxication have shown that both, isotherapic and succussed watercan change Artemia salina ́s bio resilience at different levels. Moreover, it seems to vary according to the circalunar cycle. Objective:To verify if circalunar phases and water agitation can modify the toxicity of lead chloride on Artemia salina in vitro. Methodology:Artemia salina cysts were exposed to seawater containing 0.04% of lead chloride (equal to EC10 or 10% effective concentration, previously determined in a pilot study) in 96-well culture plates. Thirty-six experimental repetitions were performed in four series to observe the possible effects of adding stirred water, the so-called succussed water, and the moon phases. The hatched cysts were recorded after 48 hours using a digital microscope (1000x magnification) to identify the hatching percentage and the viability and mobility of the born nauplii. Results:The exposition of cysts to PbCl2 led to an increase in the hatching rate, and it was more evident during the full moon (p = 0.00014) The addition of succussed water into the seawater medium reduced this effect to the baseline levels. An increase in mobility was seen in nauplii born from exposed cysts during the full moon (p = 0.00077), but this effect was not affected by the treatment with succussed water. Discussion:Although the effects of lead chloride EC10 on the increase of nauplii hatching were expected, two environmental variables changed the sensitivity of cysts to this harmful stimulus. The circalunar cycle varied the hatching rate according to the moon phase, even in laboratory conditions, and the addition of succussed water into the medium reduced the hatching rate, even with different intensities according to the moon phase. The organization of nano and microbubbles generated after the succussion of water could be related to this protective effect and can explain, at least partially the effects of high diluted preparations on this biological context. Conclusion:Environmental factors, such as the circalunar cycle and products of water agitation, can modulate the adaptative control of hatching in Artemia salina exposed to lead chloride at EC10.

Mercury chloride toxicity attenuation of the Brine Shrimp Artemia Salinaafter treatment with Mercurius corrosivusas isotherapic

Isotherapics preparedfromtoxic substances have been described as attenuation factors for heavy metal intoxicationin aquatic animals. Herein, Artemia salinaand mercury chloride were usedas a model to identify treatment-related bioresilience. The aim was to describe the effects of Mercurius corrosivus(MC) in different potencies on Artemia salinacyst hatching and on mercury bioavailability. Artemia salinacysts were exposed to 5.0 µg/mL of mercury chloride during the hatching phase. MC6cH, 30cH, and 200cHwere prepared and poured into artificial seawater. Different controls were used (nonchallenged cysts and challenged cysts treated with water, succussed water, and Ethilicum 1cH). Four series of nine experiments were performed for4 weeks to evaluate the percentage of cyst hatchingconsidering all moon phases. Soluble total mercury (THg) levels and precipitated mercury content were also evaluated. Solvatochromic dyes were used to check for eventual physicochemical markers of MCbiological activity. Two-way analysis of variance (ANOVA) with mixed modelswas used for evaluating the effect of different treatments andthe simultaneous influence of the moon phases on the cystshatching rate, at both observation times (24 and 48 hours).When necessary, outliers were removed, using the Tukeycriterion.Thelevel of significance αwas set at 5%. Significant delay (p<0.0001) in cyst hatching was observed after treatment with MC30cH, compared with the controls. An increase inTHg concentration in seawater (p<0.0018) and of chlorine/oxygen ratio (p<0.0001) in suspended micro-aggregateswas also seen, with possiblerelation with mercury bioavailability. Specific interaction of MC30cH with the solvatochromic dye ET33 (p<0.0017) was found. The other observed potencies of Mercurius corrosivus6 and 200 cH were not significant in relation to the observed groups.The results werepostulated as being protective effects of MC30cH on Artemia salina, by improving its bioresilience.