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Malathion Toxicity: Embryotoxicity and Survival of Hatchlings of Zebrafish (Brachydanio Rerio)
Abstract
Toxicity tests revealed that the hatchlings of Zebrafish (Brachydanio rerio) are more sensitive to malathion (an organophosphorus pesticide) as compared to the embryos. 72 … 168 hours LC50 values showed a gradual decrease as the exposure time was increased. Probable causes have been discussed.
... Malathion exposure during development causes skeletal abnormalities in fish and other aquatic vertebrates. Specifically, malathion results in skeletal malformations in developing zebrafish [13], medaka (Oryzias latipes) [14], sheepshead minnow (Cyprinodon variegates) [15], common carp (Gyprinus carpio) [16], and Atlantic silverside (Menidia menidia) [15]. Solomon [14] observed bent tails in medaka embryos exposed to malathion, likely caused by neuromuscular spasms. ...
... Zebrafish embryos exhibited pericardial edema and inhibited hatching when exposed to malathion [12]. Zebrafish embryos are more sensitive to malathion than unhatched zebrafish because mortality of developing zebrafish exposed to the same concentrations of malathion was greater after hatching than before hatching [13]. Juvenile common carp and half-banded hill trout (Barilius vagra) exhibited darkened skin after malathion exposure [16]. ...
... 24, 2005 L.W. Cook et al. embryos are more sensitive to malathion after initial development. Because the zebrafish do not need an external food source until the yolk sac is absorbed, Ansari and Kumar [13] suggested that the embryos are relatively resistant to toxins until their yolk sac is absorbed completely. When zebrafish embryos begin to consume food in their environment, their exposure to the toxin will increase. ...
Malathion is an organophosphorous pesticide widely used to control mosquitoes in urban areas and pests, such as boll weevils, in agricultural areas. Zebrafish, Danio rerio, are model organisms for developmental toxicology research because they are readily available, produce large numbers of clear embryos, and are sensitive to environmental changes. The nonlethal effects of malathion on developing zebrafish embryos, however, previously have not been analyzed quantitatively. We exposed zebrafish embryos to sublethal malathion concentrations to determine malathion's effects on a developing vertebrate. Zebrafish exposed to 0.5, 1.0, or 1.5 mg/L of malathion consistently elicited more rapid hatching from the chorion than zebrafish exposed to 2.0-, 2.5-, or 3.0-mg/L malathion concentrations. In addition, exposure to 2.0, 2.5, or 3.0 mg/L of malathion resulted in significantly shorter body length and eye diameters, indicating that malathion had teratogenic effects on zebrafish embryos. Malathion's action as an acetylcholinesterase inhibitor and the toxicity of the metabolites of malathion may be responsible for malathion's teratogenic effects on fish development.
... Embryo medium was renewed daily, and the embryos or larvae were analyzed with a stereoscopic microscope (Nikon SMZ645) at 2, 4, 6, 12, 24, and 48 h time points after exposure, looking at survival rates and spontaneous movements. 26,27 Alkaline comet assay ...
... 4,42,43,45 Even though Monceren 250 SC fungicide did not cause abnormal development in zebrafish embryos after exposure for 2 h, the survival rate of larvae was reduced by 40-45% postexposure, which is consistent with other studies in zebrafish. 26,27,46 In this work, we used Bleomycin as a positive control because it is a known genotoxic agent in vivo or in vitro that induces DNA strand breaks. 47 Zebrafish embryos exposed to 0.025 lg/mL Bleomycin for 2 h ...
... Embryo medium was renewed daily, and the embryos or larvae were analyzed with a stereoscopic microscope (Nikon SMZ645) at 2, 4, 6, 12, 24, and 48 h time points after exposure, looking at survival rates and spontaneous movements. 26,27 Alkaline comet assay ...
... 4,42,43,45 Even though Monceren 250 SC fungicide did not cause abnormal development in zebrafish embryos after exposure for 2 h, the survival rate of larvae was reduced by 40-45% postexposure, which is consistent with other studies in zebrafish. 26,27,46 In this work, we used Bleomycin as a positive control because it is a known genotoxic agent in vivo or in vitro that induces DNA strand breaks. 47 Zebrafish embryos exposed to 0.025 lg/mL Bleomycin for 2 h ...
Monceren 250 SC is a commercial fungicide with the active ingredient 1-(4-chlorobenzyl)-1-(cyclopentyl)-3-phenylurea, also known as pencycuron. This compound inhibits the growth of fungi as Rhizoctonia solani that invades potato, rice, and cotton or as Pellicularia spp, which contaminates lettuce and tomato crops. In this study, we assessed genotoxicity or DNA damage by the alkaline comet assay in zebrafish blastula-stage embryos exposed to 250 to 1250 μg/mL of the Monceren fungicide or to Bleomycin (0.25 μg/mL) used as a positive control. Additionally, survival and spontaneous movement were monitored in embryos after exposure to different concentrations of fungicide. DNA damage was evaluated using three genotoxicity parameters of the alkaline comet assay: tail length, tail moment, and tail intensity. We found that Monceren 250 SC fungicide induces DNA damage, as shown by significant increases in the three genotoxicity parameters in zebrafish embryos compared with control embryos nonexposed to Monceren. Tail intensity was the more accurate parameter to evaluate genotoxicity levels in zebrafish embryos. At 48 h after exposure to the fungicide, the survival rate of larvae-embryos was reduced to 40-45%. This study shows that the Monceren 250 SC fungicide exerts genotoxic effects in zebrafish during early stages of development.
... The xenobiotic pollutants may disrupt reproductive endocrine functions by acting at the hypothalamus, pituitary, gonads and liver dysfunctions may result in rate of gonadal development and viability of gametes (Sebire et al., 2009). Even the organophosphorus pesticides (Malathion) have also been found to cause abortions in zebrafish (Ansari and Kumar, 1986), moreover, seven days exposure to 0.9 mg/L malathion resulted in marked atresia with loss of the characteristic spherical shape of the ovarian follicles. This means that development and growth of follicles were abruptly affected by malathion (Ansari and Kumar, 1986). ...
... Even the organophosphorus pesticides (Malathion) have also been found to cause abortions in zebrafish (Ansari and Kumar, 1986), moreover, seven days exposure to 0.9 mg/L malathion resulted in marked atresia with loss of the characteristic spherical shape of the ovarian follicles. This means that development and growth of follicles were abruptly affected by malathion (Ansari and Kumar, 1986). Pyrethroids are widely used in rice fields in some countries (Bao et al., 2007) but their application in paddy fields has been prohibited in China because of their high toxicity to aquatic animals (Koprucu and Aydin, 2004; Cakmak and Gorgon, 2003). ...
... Reproductive alterations in zebrafish exposed to malathion and dimethoate have been reported previously, although the mechanisms underlying these changes are not fully elucidated. For example, zebrafish exposed for 4 months to malathion at 500 μg/L had reduced GSI and resorption of oocytes, and, likely due to resorption, the fish failed to spawn (Ansari & Kumar, 1986). In common tank goby (Glossogobius giuris) exposed to malathion at 500 μg/L, secondary growth of primary oocytes was significantly repressed due to suppression of vitellogenesis (Narayanaswamy et al., 2015). ...
Oogenesis is the process by which a primary oocyte develops into a fertilizable oocyte, making it critical to successful reproduction in fishes. In zebrafish (Danio rerio), there are 5 stages of oogenesis. During the final step in oogenesis, oocyte maturation, the maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (MIH) activates the membrane progestin receptor (mPR), inducing germinal vesicle breakdown. Using in vitro assays, it has been shown that anthropogenic stressors can dysregulate MIH-induced oocyte maturation. However, it is unknown if the in vitro assay is predictive of reproductive performance after in vivo exposure. Here, we demonstrate that a known inhibitor of oocyte maturation, malathion, and a structurally related chemical, dimethoate, inhibit oocyte maturation. However, malaoxon and omethoate, which are metabolites of malathion and dimethoate, did not inhibit oocyte maturation. Malathion and dimethoate inhibited maturation to a similar magnitude when oocytes were exposed for 4 hours in vitro or 10 days in vivo, suggesting that the in vitro zebrafish oocyte maturation assay might be predictive of alterations to reproductive performance. However, when adult zebrafish were exposed to malathion for 21 days, there was no alteration in fecundity or fertility in comparison to control fish. This study supports the oocyte maturation assay as being predictive of the success of in vitro oocyte maturation after in vivo exposure, but it remains unclear whether inhibition of MIH-induced oocyte maturation in vitro correlates to decreases in reproductive performance. This article is protected by copyright. All rights reserved. © 2022 SETAC.
... 93,94 A group led by Prof. Badre Alam Ansari at Kashi Naresh Government Postgraduate College (KNGPGC), Gyanpur had research to understand the toxicity of Diazinon and Malathion on zebrafish's liver, ovary, brain, and skeletal parts. [95][96][97][98][99][100] Dr. Uma's group at Tamil Nadu Fisheries University (TNFU), Chennai proved that zebrafish is an alternative model for assessing the environmental chemical toxicity in the laboratory condition. They checked the toxic effect of Ivermectin and Cypermethrin on the embryos, indicating that low levels of these drug contaminations in the aquatic environment could affect the developmental stages of aquatic organisms. ...
The zebrafish (Danio rerio) is a versatile model organism that has been used in biomedical research for several decades to study a wide range of biological phenomena. There are many technical advantages of using zebrafish over other vertebrate models. They are readily available, hardy, easy, and inexpensive to maintain in the laboratory, have a short life cycle, and have excellent fecundity. Due to its optical clarity and reproducible capabilities, it has become one of the predominant models of human genetic diseases. Zebrafish research has made rapid strides in the United States and Europe, but in India the field is at an early stage and many researchers still remain unaware of the full research potential of this tiny fish. The zebrafish model system was introduced into India in the early 2000s. Up to now, more than 200 scientific referred articles have been published by Indian researchers. This review gives an overview of the current state of knowledge for zebrafish research in India, with the aim of promoting wider utilization of zebrafish for high level biological studies.
... One possible reason is that fish embryos have a protective envelope called a chorion, which could minimize passing of toxicants into the embryos (Lillicrap 2010) that resulted in high concentration of MCP to cause 50 % mortality in the test population. Fish embryos are relatively resistant to toxins (Ansari and Kumar 1986) than newly hatched larvae exposed to zinc sulfate (Skidmore 1965) and ammonia (Stanley and Robert 1975). Fig. 4 Multiple malformations in the hatchlings after emerging from monocrotophos exposed embryos. ...
The present study examined the response of zebrafish embryos exposed to different concentrations (10, 20, 30, 40, 50, and 60 mg/L) of monocrotophos under static conditions for 96 h. We found that mortality had occurred within 48 h at all test concentrations, later insignificant mortality was observed. Monocrotophos (MCP) can be rated as moderately toxic to the Zebrafish embryos with a 96-h median lethal concentration (LC50) of 37.44 ± 3.32 mg/L. In contrast, it greatly affected the development of zebrafish embryos by inducing several developmental abnormalities like pericardial edema, altered heart development, spinal and vertebral anomalies in a concentration-dependent manner. A significant percent reduction in length by 9-48 % and heart beats by 18-51 % was observed in hatchlings exposed to LC10 and LC50 concentrations at 96 h when compared to controls. The process of looping formation of heart at embryonic stage was greatly affected by the LC50 concentration of MCP. The neurotoxic potentiality of MCP was assessed by using a marker enzyme, acetylcholinesterase in both in vitro and in vivo experiments. MCP was found to be the most potent inhibitor of AChE in vitro with an IC50 value of 4.3 × 10(-4) M. The whole-body AChE enzyme activity in vivo was significantly inhibited during the exposure tenure with the maximum inhibition of 62 % at 24 h.
... Pesticides produce numerous physiological and biochemical changes in fish and other aquatic species by influencing the activities of several antioxidant enzymes (Regoli and Principato 1995). Pesticides also affect basic genetic materials (DNA and RNA), total protein, total free amino acids, and carbohydrates (Ansari and Kumar 1986, 1988). This provided the impetus to investigate the toxic effects of sub-lethal exposure to lambda-cyhalothrin and Neemgold on different biochemical parameters in the gill, liver, and ovary of zebrafish, Danio rerio (Hamilton). ...
The aim of the present work was to study the effect of lambda-cyhalothrin and Neemgold on the total protein, total free amino acid, and nucleic acid contents in tissues (gill, liver, and ovary) of zebrafish, Danio rerio (Hamilton), after exposure to 96 h LC 10 , LC 20 , and LC 40 of lambda-cyhalothrin and the neem-based pesticide Neemgold. It was found that the total protein content was reduced to 38, 46, and 45% in gill, liver, and ovary, respectively, after lambda-cyhalothrin exposure for 21 days at the LC 40 dose. The total free amino acid content in the liver was enhanced to 172 and 154% of control (100%) after exposure to LC 40 of lambda-cyhalothrin and Neemgold, respectively. However, the total free amino acid content in the gill and ovary of treated fish was significantly reduced. In addition, DNA content was reduced to 45, 41, and 41% of controls (100%) in gill, liver, and ovary, respectively, after 21 days of exposure to LC 40 of lambda-cyhalothrin. The reduction in DNA content from the control was 51, 53, and 55% in gill, liver, and ovary, respectively, from Neemgold exposure at the same concentration (LC 40) and period as lambda-cyhalothrin. It was observed that all the changes were dependent on concentration as well as time. Similarly, significant reductions in RNA content were also observed in gill, liver, and ovary after lambda-cyhalothrin and Neemgold exposure. The probable causes are discussed.
... Some of these chemicals like deltamethrin, cypermethrin, trimethrin have been reported to persist in the environment for many months or years [2]. These chemicals and their residues have been reported to cause chronic adverse effects in humans [3] and animals [4], especially fishes [5] which inhabit the aquatic environments like lakes, rivers leading to ecological degradation; deleterious effects on water taste and odor; lethal effects on non target organisms in agro-ecosystems and direct toxicity to the users [6,7]. ...
Cypermethrin is a synthetic pyrethroid which has been used widely as pesticides. Contaminations of the aquatic environment with organic pesticides have been reported to cause lethal and sub lethal effects in the organisms inhabiting the aquatic environment. Zebrafish embryo toxicity test (ZFET) was used to determine the toxic effects of cypermethrin in the present study. The LC50 value obtained for cypermethrin in the ZFET
was 0.05µg/l. Zebrafish embryos were exposed to various concentration of cypermethrin (0.001, 0.003, 0.01, 0.03and 0.05 µg/l) and the observations on the lethal, sub lethal and sublethal continuous endpoints were recorded. The results showed that the sub lethal and lethal effects of the zebra fish embryos increased with respect to an increase in the concentration of the cypermethrin. It is evident from this study that even low levels of cypermethrin contamination in the aquatic environment would affect the developmental stages of fishes inhabiting the aquatic systems.
... After three months of continuous exposure with both pesticides, the adult zebra fish were returned to normal water. Three batches of three mature females and six males were placed in 25 dm -3 glass aquaria and bred in the laboratory using the method by Ansari and Kumar (1986) for the observation of fecundity , viability, hatchability, and the survival of eggs laid by fishes. The parents were returned to the stock culture. ...
In the present research, both male and female zebrafish, Danio rerio (Hamilton), were exposed to 96-h LC5 values of Deltamethrin (0.016 µg dm -3) and Achook (0.025 µg dm -3) for three months. The fish were then returned to normal water and allowed to breed to permit observations of fecundity and hatchability. The results show significant reductions in fecundity and hatchability in comparison to the control group. Fecundity was reduced by 54.12% in the fish treated with Deltamethrin and by 17.81% in those treated with Achook. Significant decreases in hatchability of up to 49.7% were noted in the Deltamethrin group and of 36.9% in the Achook treated fish. The number of unhatched/dead eggs increased significantly (P < 0.05 for each case). It was concluded that low concentrations (96-h LC5 values) of both pesticides can have a significant impact on the reproduction of zebrafish.
The “Integrated Wastewater Discharge Standard” was implemented for water pollutant discharge in China’s pesticide industry, which has no control requirements for particular wastewater pollutants in the industry. In the standard, certain pollutants discharge limits are limited strictly or loosely, resulting in practical management implementation difficulties. In view of the highly selective targeting characteristics of organic pesticide active ingredients in fungicides, insecticides, and herbicides, a method for deriving discharge limits based on the water quality criteria for pesticides for the protection of nonsensitive species is established based on the idea of fully protecting aquatic organisms beyond sensitive objects. Through the use of malathion as an example, by screening its toxicity data in different species of aquatic organisms, the sequence point with the most significant change in the acute toxicity sensitivity of the species is taken as the variation point in the cumulative frequency of the sensitive and nonsensitive species to derive the water quality criteria, using the species sensitivity distribution method as the scientific basis for determining the discharge limits. After a comparative analysis of different simulation models, the sigmoid model, with the best fit, is selected to determine that the sensitive species hazard concentration (HC s ) of malathion to aquatic organisms in China is 46.4 µg/L, and the discharge limit derived from the HC s based on the relationship between the environmental capacity and emissions is rounded to 250 µg/L. Studies showed that the relationship between the emissions limit derived from the water quality criteria for protecting nonsensitive species and malathion limit stipulated in the “Environmental Quality Standards for Surface Water” conforms to the corresponding relationship of the quality standard and discharge standard, which can be achieved by current pollution control technology, combined with water quality improvement. The discharge limit offers the advantages of technical accessibility and economic rationality.
In a previous study, we demonstrated that exposure to an antifouling biocide, copper pyrithione (CuPT), early during life induced vertebral deformity in the larvae of a marine fish, the mummichog (Fundulus heteroclitus). Skeletal deformities may be caused by inhibition by of acetylcholiensterase (AChE) activity, and to elucidate the mechanism underlying the CuPT-associated vertebral deformity, we first examined whether CuPT, zinc pyrithione (ZnPT), and their degradation products could inhibit AChE activity in the fish. Two of the degradation products, 2,2'-dipyridyldisulfide [(PS)(2)] and 2,2'-dithiobispyridine-N-oxide [(PT)(2)], but neither CuPT nor ZnPT, exhibited prominent AChE-inhibiting activity. Secondly, thin-layer chromatography revealed that mummichog hepatic microsomes metabolized CuPT to produce (PS)(2) in a microsome-dependent manner. The AChE inhibition induced in CuPT-exposed fish is likely due to (PS)(2) that was produced through metabolism of acquired CuPT. (PS)(2) may cause therefore skeletal deformity in CuPT-exposed fish by means of its neuromuscular blocking properties, through a mechanism similar to that proposed for animals exposed to organophosphorous pesticides.
Four-month old adult siblings of zebrafish were exposed to four concentrations of diazinon for up to 168 h. DNA, RNA, protein and total free amino acid content were monitored in the liver. The DNA, RNA and protein contents were significantly reduced, whereas the amino acid content was significantly enhanced. All these changes showed dose- as well as time-dependent response.
Pesticides used for controlling insect pests of crops like cotton, maize, sugarcane, oil seeds and pulses may run off to adjoining aquatic ecosystem. The hazards of these pesticides to aquatic organisms are well documented (Murty 1986). However, there is little information on acute toxicity of the pesticides to different life stages of fresh water culturable fishes (Kaur and Toor 1977; Kaur and Cheema 1985; Von Westernhagen 1988). The objectives of this study, therefore, were to evaluate the toxicity of four pesticides to eggs, larvae and fry stages of Cyprinus carpio, and to compare the sensitivity of these stages. These data will support environmental hazards assessment of pesticides.
The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1-2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology.
The toxicity of an endrin formulation to spring chinook and coho salmon, rainbow trout, bluegill, mosquitofish, guppies, and the marine threespine stickleback was determined at 20° C. Coho salmon were the most sensitive, with a 96-hour TLm of 0.27 parts per billion endrin; sticklebacks were the most tolerant. A volume effect was demonstrated; bluegills died at lower concentrations of endrin in aquaria with the smallest number of fish. Temperature had a marked influence on toxicity of endrin to bluegills, the toxicity increasing with rise of temperature. Tolerance of endrin by marine threespine sticklebacks was about the same in waters of different salinities. Developing eggs and early larvae of the stickleback are more tolerant than fully developed fish.
Toxicity tests reveal that the zebrafish (Brachydanio rerio) is very sensitive to malathion, an organophosphorus insecticide, and 24 to 96-h LC50 values showed a gradual decrease as the exposure time was increased. Zebrafish exposed to long-term sublethal concentrations failed to spawn and invariably exhibited skeletal deformities. Possible causes of the reduced gonadosomatic index and skeletal deformities are discussed.
Exposure of early Fundulus embryos to concentrations of DDT and malathion up to 10 parts/1O6 had no gross developmental effects, Exposure to 10 parts/106 of carbaryl and parathion, however, caused developmental arrest prior to the initiation of heartbeat. When embryos were removed frorn carbaryl after three days of exposure most recovered and developed normally. Exposure for longer periods of time caused most embryos to develop a circulatory failure in which the heart remained a feebly beating thin tube and circulation was absent. In addition, blood pigment did not form. Other tissues, however, apparently continued developing fairly normally. Such embryos did not hatch. A similar syndrome developed in parathion-treated embryos after somewhat shorter times of exposure.
Zebrafish of eleven age groups were exposed to four concentrations of zinc sulphate (5, 10, 20 and 40 p.p.m. Zn) in soft water (CaCO3 10 p.p.m.) at 25d̀ C. In all four concentrations, newly laid eggs generally survived the longest time. Survival time decreased with age until hatching on the fourth day. Newly hatched fish (4–13 days old) survived the shortest time. Forty-day-old fish and adults (100 days old) survived slightly longer in the two highest concentrations. In the two lowest concentrations, 40-day-old fish survived as long as newly laid eggs, and many adults survived indefinitely. The threshold concentration of zinc was approximately 10 p.p.m. for adults and 1.3 p.p.m. for 40-day-old fish.
Acetylcholinesterase (AChE) activity in the nervous tissue (brain) of the fish Brachydanio rerio was significantly inhibited by exposure to the organophosphorus (OP) pesticide, malathion. The inhibition was dose- as well as time-dependent. The fish survived even when the activity of the enzyme was inhibited by 90%. There was a significant recovery in the activity of AChE when malathion stress was lifted.
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