scholarly journals Zebrafish Embryo Toxicity of a Binary Mixture of Pyrethroid Insecticides: d-Tetramethrin and Cyphenothrin

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Janthri C. Mendis ◽  
Thejani K. Tennakoon ◽  
Chanika D. Jayasinghe

Pesguard FG161™, a mixture of d-tetramethrin and cyphenothrin (1:3 ratio), is extensively used to achieve rapid control of adult dengue vector, Aedes aegypti, during the disease outbreaks. Both d-tetramethrin and cyphenothrin are synthetic pyrethroids that are known to have adverse effects on non-mammalian organisms such as fish. The present study intended to use zebrafish embryo toxicity model to investigate the toxic effect of the above binary mixture on fish. Particularly, zebrafish embryo toxicity model provides an alternative to acute fish toxicity tests in terms of animal welfare perspective as the embryos are not considered live until 5 days after fertilization. The zebrafish embryos (2 hrs after fertilization) were exposed to a binary mixture of pyrethroids at different concentrations (d-tetramethrin: 0.01 – 1.20 μmolL-1 and cyphenothrin: 0.03 – 3.20 μmolL-1) for 24, 48, and 72 hrs at room temperature (26°C) according to the OECD guideline no. 236. Percentage mortality of embryos were calculated by observing the lethal endpoints and LC50 values were calculated for each time interval employing the probit analysis. This binary mixture was highly toxic to zebrafish embryos and was found to be concentration and time dependent. LC50 values at 24 hrs (d-tet: 0.58 μmolL-1, cyp: 1.74 μmolL-1) were significantly reduced in 48 hrs (d-tet: 0.11 μmolL-1, cyp: 0.33 μmolL-1) and 72 hrs (d-tet: 0.03 μmolL-1, cyp: 0.09 μmolL-1). Coagulation of embryos was the most common lethal effect observed and lack of somite formation and lack of heartbeat were also observed. The present study revealed that the binary mixture is highly toxic to zebrafish embryos even when based on nominal concentrations. Hence, extensive use of these pesticides could be detrimental to fish population and integrated vector control methods which involve the minimum use of insecticides are recommended. Further, this study highlights the applicability of zebrafish embryo toxicity model as an alternative method to investigate the toxicity of pyrethroids to fish.

2021 ◽  
Vol 22 (4) ◽  
pp. 1675
Author(s):  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
Zul Ilham ◽  
Adi Ainurzaman Jamaludin ◽  
Neil Rowan

Natural mycelial exopolysaccharide (EPS) and endopolysaccharide (ENS) extracted from bioreactor-cultivated European Ganoderma applanatum mushrooms are of potential high commercial value for both food and adjacent biopharmaceutical industries. In order to evaluate their potential toxicity for aquaculture application, both EPS (0.01–10 mg/mL) and ENS (0.01–10 mg/mL) extracts were tested for Zebrafish Embryo Toxicity (ZFET); early development effects on Zebrafish Embryos (ZE) were also analyzed between 24 and 120 h post-fertilization (HPF). Both EPS and ENS are considered non-toxic with LC50 of 1.41 mg/mL and 0.87 mg/mL respectively. Both EPS and ENS did not delay hatching and teratogenic defect towards ZE with <1.0 mg/mL, respectively. No significant changes in the ZE heart rate were detected following treatment with the two compounds tested (EPS: 0.01–10 mg/mL: 176.44 ± 0.77 beats/min and ENS: 0.01–10 mg/mL: 148.44 ± 17.75 beats/min) compared to normal ZE (120–180 beats/min). These initial findings support future pre-clinical trials in adult fish models with view to safely using EPS and ENS as potential feed supplements for supplements for development of the aquaculture industry.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Siti Rokhiyah Ahmad Usuldin ◽  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
Zul Ilham ◽  
Adi Ainurzaman Jamaludin ◽  
Nur Raihan Abdullah ◽  
...  

AbstractNatural mycelial biomass (MB) and exopolysaccharides (EPS) of Malaysian tiger milk mushroom Lignosus rhinocerus are considered high-end components due to their high commercial potential value in drug discovery. This study aims to evaluate the toxicity of the mushroom extracts’ generated in a bioreactor using the zebrafish embryo toxicity (ZFET) model assay as a new therapy for treating asthma. Both MB and EPS extracts, at concentrations 0.16–10 mg/mL, were tested for ZFET and early development effects on Zebrafish Embryos (ZE) during 24–120 h post-fertilisation (HPF). Findings revealed that MB was deemed safe with an LC50 of 0.77 mg/mL; the EPS were non-toxic (LC50 of 0.41 mg/mL). Neither MB nor EPS delayed hatching nor teratogenic defects in the treated ZE at a 2.5 mg/mL dose. There were no significant changes in the ZE heart rate after treatments with MB (130 beats/min) and EPS (140 beats/min), compared to that of normal ZE (120–180 beats/min). Mixing both natural compounds MB and EPS did not affect toxicity using ZFET testing; thus, intimating their safe future use as therapeutic interventions. This represents the first study to have used the ZFET assay on MB and EPS extracts of L. rhinocerus for future health applications.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Cenk Yucel

Abstract Background The two-spotted spider mite, Tetranychus urticae (Koch) (Acari: Tetranychidae), is a widely distributed plant-feeding pest that causes significant yield losses in a wide range of crops. Newly developed or improved environmentally friendly biocontrol agents serve as an alternative to traditional pest control tools. Experiment of the effects of 2 local fungal isolates of Beauveria bassiana (BGF14 and BCA32) was carried out against T. urticae under laboratory conditions. Results Both tested isolates had lethal effect in a short time after application, and this effect increased as time progressed. BGF14 and BCA32 isolates caused T. urticae mortality rates ranging from 25.88 to 61.92 and 32.36 to 62.03% when applied at the concentrations between 1×105 and 1×108 conidia/ml, respectively. According to the Probit analysis performed on the effect of fungi on T. urticae adults, the LC50 values of BGF14 and BCA32 isolates on the 7th day after inoculation were 2.6×106 and 6.3×104 conidia/ml, respectively, and the LT50 values for both fungi applied at a concentration of 108 conidia/ml were 2.14 and 2.23 days, respectively. Conclusions The 2 isolates of B. bassiana (BGF14 and BCA32) had the potentials to suppress T. urticae population and can be recommended as promising biocontrol agent candidates for control of T. urticae.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 652 ◽  
Author(s):  
Wang Lee ◽  
Eungwang Kim ◽  
Hyun-Ju Cho ◽  
Taejoon Kang ◽  
Bongsoo Kim ◽  
...  

A silver nanoparticle is one of the representative engineered nanomaterials with excellent optical, electrical, antibacterial properties. Silver nanoparticles are being increasingly used for medical products, water filters, and cosmetics, etc. However, silver nanoparticles are known to cause adverse effects on the ecosystem and human health. To utilize silver nanoparticles with minimized negative effects, it is important to understand the behavior of silver nanoparticles released to the environment. In this study, we compared toxicity behaviors of citrate-stabilized silver nanoparticles with polyethylene glycol coated silver nanoparticles in two different ionic environments, which are aquatic environments for developing zebrafish embryo. Depending on the composition of the ionic environment, citrate-stabilized silver nanoparticles and polyethylene glycol coated silver nanoparticles exhibited different behaviors in dissolution, aggregation, or precipitation, which governed the toxicity of silver nanoparticles on zebrafish embryos.


Author(s):  
Emi Fazlina Hashim ◽  
Irence John ◽  
Intan Faraha A Ghani ◽  
Mohammad Noor Amal Azmai

This study aimed to determine the lethal concentration (LC50) of Terminalia catappa leaves extract on three cyprinid species; carp (Cyprinus carpio), goldfish (Carassius auratus) and tiger barb (Puntigrus tetrazona) through the acute toxicity test. The leaves of T. catappa were extracted with methanol and prepared in various immersion concentrations (40, 80, 100, 150, 200, 250, 300, and 350 mg/L). These extracts were immersed in the aquarium and left for 24 h before performing the acute toxicity test. The water quality was also analyzed before and after adding the extract immersions into the aquarium. The acute toxicity test conducted for 96 h with 10 fishes of each cyprinid species (4.0-6.0 cm length) in 30 L water capacity aquarium. The mortality of each cyprinid species was recorded at 24 h time interval and LC50 of the extracts throughout 96 hours was determined through the probit analysis application. Specifically, the LC50 of T. catappa leaves extract were 349.89, 338.65 and 318.48 mg/L exhibited for carp, goldfish and tiger barb, respectively. A high concentration range of any plant-based extract has the potential to become toxic to particular fishes. Thus, it is an effort from this study to identify the safety margin of T. catappa leaves extract before its therapeutic values can be further manipulated and elucidated in aquaculture research.


1997 ◽  
Vol 80 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Cao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li

Abstract The stability of 8 synthetic pyrethroids in 9 crops during storage for 90 days were studied. The 8 pyrethroid insecticides were highly persistent in the 6 grains during storage. But their stabilities in 3 kinds of fruits and vegetables were different from those in the 6 grains: Most of them were degraded. Florisil purification conditions were studied with 6 batches of Florisil from 3 countries at various extents of deactivation and amounts. The best conditions of Florisil purification found in this present research agree with those found 1 year ago. The efficiencies of acetonitrile and acetone to extract the 8 pyrethroids from 6 fruit and vegetable samples were compared. The extraction efficiency of acetone was competitive with that of acetonitrile for the 6 fruit and vegetable samples. Method performance was evaluated by 6 analysts from different areas. The ruggedness tests demonstrate further that the proposed method is simple, accurate with good precision, and suitable for multiresidue analysis of pyrethroids in various agriculture products.


1983 ◽  
Vol 66 (4) ◽  
pp. 1009-1012
Author(s):  
Radhakrishnan Sundararajan ◽  
Ram Parkash Chawla

Abstract Thin layer chromatography employing silver nitrate-impregnated alumina G plates has been extended for the routine detection and confirmation of the identity of halogenated synthetic pyrethroid insecticides. Of the solvent systems tried, maximum resolution was achieved by using n-hexane-benzene (45+ 55) and n-hexane-chloroform (60 + 40), which gave distinct separations of the cis- and trans-isomers of permethrin and cypermethrin from fenvalerate and decamethrin. Possible interference of HCH isomers and DDT and its analogs can also be checked by a concurrent run of the sample mixture in these 2 systems. A minimum of 50 ng each of cis- and trans-permethrin and cypermethrin isomers and fenvalerate and decamethrin can be positively detected. Using this technique, the minimum detectable limit of permethrin was 0.1 ppm in the cleaned up extracts of tomato plant and fruit and soil samples.


2015 ◽  
Vol 27 (1) ◽  
pp. 201 ◽  
Author(s):  
C.-W. Kim ◽  
R.-E. Go ◽  
K.-C. Choi

Synthetic pyrethroids (SP) are the most common pesticides in recent use, which are used as indoor pest control. The widespread use of SPs has resulted in extensive exposure to wildlife and human. Recently some SPs are suspected as endocrine disrupting chemicals (EDC) and have been assessed for their potential estrogenicity by various assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LCT) and cypermethrin (CP), the most commonly used pyrethroid insecticides in Korea, using BG-1 ovarian cancer cells expressing oestrogen receptors (ER). To evaluate the estrogenic activities of two SPs, LCT and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT–PCR). In MTT assay, LCT (10–6 M) and CP (10–5 M) significantly induced the growth of BG-1 cancer cells, 1.61 ± 0.1 and 1.45 ± 0.06 times, respectively, as 17β-oestradiol (E2, 10–9 M, 2.73 ± 0.25 times) did. LCT or CP-induced cell growth was reversed to a control level (DMSO) by addition of ICI 182 720 (10–8 M), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT–PCR results showed that transcriptional level of ERα expression was significantly down-regulated by LCT and CP as in case of E2. Taken together, these results indicate that LCT and CP may possess estrogenic potentials to stimulate ovarian cancer cells expressing ERs via an ER-dependent manner, and these collective results confirm the carcinogenicity of these SP, LCT and CP, in ER-positive cells or tissues.


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