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1.
PLoS Negl Trop Dis ; 13(10): e0007740, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31603908

RESUMO

Schistosomiasis is a serious worldwide parasitic disease. One of the best ways to control schistosomiasis is to control the population of Oncomelania hupensis snails. We sought to identify a high-efficiency biogenic molluscicide against Oncomelania with low toxicity, to avoid chemical molluscicide contamination and toxicity in aquatic organisms. We extracted quaternary benzo[c]phenanthridine alkaloids (QBAs) from Macleaya cordata fruits. Molluscicidal activity of the QBAs against Oncomelania was determined using bioassay. Our results showed that the extracted QBAs had a strong molluscicidal effect. In treatment of O. hupensis with QBAs for 48 h and 72 h, the lethal concentration (LC50) was 2.89 mg/L and 1.29 mg/L, respectively. The molluscicidal activity of QBAs was close to that of niclosamide (ethanolamine salt), indicating that QBAs have potential development value as novel biogenic molluscicides. We also analyzed physiological toxicity mechanisms by examining the activity of several important detoxification enzymes. We measured the effect of the extracted QBAs on the activities of glutathione S-transferase (GST), carboxylesterase (CarE), acid phosphatase (ACP), and alkaline phosphatase (AKP) in the liver of O. hupensis. We found that the effects of QBAs on detoxification metabolism in O. hupensis were time and concentration dependent. The activities of GST, CarE, AKP, and ACP in the liver of snails increased significantly in the early stage of treatment (24 h), but decreased sharply in later stages (120 h), compared with these activities in controls. GST, CarE, AKP, and ACP activity in the liver of snails treated with LC50 QBAs for 120 h decreased by 62.3%, 78.1%, 59.2%, and 68.6%, respectively. Our results indicate that these enzymes were seriously inhibited by the extracted QBAs and the detoxification and metabolic functions of the liver gradually weakened, leading to poisoning, which could be the main cause of death in O. hupensis snails.


Assuntos
Alcaloides/toxicidade , Frutas/química , Gastrópodes/efeitos dos fármacos , Moluscocidas/toxicidade , Papaveraceae/química , Fenantridinas/toxicidade , Extratos Vegetais/toxicidade , Fosfatase Ácida/efeitos dos fármacos , Fosfatase Ácida/metabolismo , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Carboxilesterase/efeitos dos fármacos , Carboxilesterase/metabolismo , China , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/metabolismo , Inativação Metabólica/efeitos dos fármacos , Fígado/metabolismo , Esquistossomose/prevenção & controle , Esquistossomose/transmissão
2.
Artigo em Inglês | MEDLINE | ID: mdl-31306804

RESUMO

Inhibition of acetylcholinesterase (AChE) activity has been widely used to assess the exposure and effects of anticholinergic environmental contaminants in several species. The aim of this study was to investigate if sublethal concentrations of the organophosphorous pesticide chlorpyrifos (CPF), a well-known AChE inhibitor, would also affect cholinesterases (ChE) in Gibbula umbilicalis and if this inhibition would result in an alteration of its behaviour, in an attempt to link the effects observed at the cellular level with effects at higher levels of ecological relevance. The biochemical properties of ChEs in this species were first characterized through the assessment of different enzymatic forms present in the sea snail, using different substrates and selective inhibitors. The results suggest that G. umbilicalis possess ChEs with characteristics of typical AChE, which should be the main form present. Additionally, in vitro and in vivo effects of CPF on AChE activity were investigated, along with effects on snails' behaviour: the ability of the snails to move/turn after exposure to the contaminant (flipping test). As expected, CPF inhibited AChE activity both in vitro and in vivo conditions. Moreover, the link between AChE activity inhibition and adverse effects on behavioural changes was established: AChE inhibition was positively correlated with the flipping test, indicating a mechanistic relationship between the two endpoints determined in in vivo exposures. This study highlights the importance of linking biochemical endpoints such as AChE activity with higher level endpoints like behavioural alterations, increasing the ecological relevance of the effects observed.


Assuntos
Acetilcolinesterase/metabolismo , Clorpirifos/toxicidade , Inibidores da Colinesterase/toxicidade , Moluscocidas/toxicidade , Caramujos/metabolismo , Poluição Química da Água/efeitos adversos , Animais , Organismos Aquáticos/metabolismo
3.
Invert Neurosci ; 19(3): 7, 2019 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-31352500

RESUMO

Biomphalaria alexandrina and Lymnaea natalensis snails are the intermediate hosts of schistosomiasis and fasciolosis. The aim of the present study is to evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against these snails and how it affected its tissues and the biological system. Chlorophyllin was extracted from deep-frozen Moringa oleifera leaves, and then it was transformed into water-soluble chlorophyllin. The present results showed that it had a molluscicidal activity on B. alexandrina snails (LC50 17.6 mg/l; LC90 20.9 mg/l) and L. natalensis snails (LC50 4.3 mg/l; LC90 6.8 mg/l). Exposing B. alexandrina snails to the sublethal concentrations (LC0, LC10, and LC25) resulted in a significant reduction in their survival rates. Regarding its effect on biochemical parameters, chlorophyllin significantly reduced the acetylcholinesterase activity, protein content, and alkaline and acid phosphatase activity in B. alexandrina nervous tissue compared to the control group. Histopathological changes occurred in the digestive gland of treated B. alexandrina snails where cells lost their nuclei, vacuolated, degenerated, and ruptured, and the lumen increased. Photosynthesizing materials like chlorophyllin are new approaches to control schistosomiasis and fasciolosis in developing countries by affecting their intermediate host. These materials were cheap and environmentally safe to replace the synthetic molluscicides for snail control.


Assuntos
Clorofilídios/toxicidade , Moluscocidas/toxicidade , Caramujos/efeitos dos fármacos , Animais , Vetores de Doenças , Fasciolíase/prevenção & controle , Extratos Vegetais/toxicidade , Esquistossomose/prevenção & controle
4.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(2): 107-108, 2019 May 21.
Artigo em Chinês | MEDLINE | ID: mdl-31184037

RESUMO

Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, and control of Oncomelania snails is an important measure to control and interrupt the transmission of schistosomiasis. Therefore, snail control plays a very critical role in the national schistosomiasis control programmes of China. Pyriclobenzuron, which was recently developed by National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, is the latest great advance in the research on molluscicides and is expected to solve the problem of toxicity to fish, which is worthy of expanding experiments.


Assuntos
Erradicação de Doenças , Moluscocidas/toxicidade , Compostos Orgânicos/toxicidade , Esquistossomose , Caramujos , Animais , China , Pesquisa/tendências , Schistosoma japonicum , Esquistossomose/prevenção & controle , Caramujos/efeitos dos fármacos , Caramujos/parasitologia
5.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(2): 115-120, 2019 Apr 30.
Artigo em Chinês | MEDLINE | ID: mdl-31184039

RESUMO

OBJECTIVE: To evaluate the molluscicidal activity of a novel molluscicide pyriclobenzuron against Oncomelania hupensis robertsoni in the mountain regions of Yunan Province, and test its toxicity to fish, so as to provide scientific evidence for the extensive application of this molluscicide in schistosomiasis-endemic foci of Yunan Province. METHODS: In the laboratory and snail-breeding field of Dali Prefecture, Yunnan Province, the molluscicidal activity of 5% wettable powder of pyriclobenzuron sulphate (25% PBU) against O. hupensis robertsoni was assessed by using the immersion and spraying method, and the acute toxicity of 25% PBU to carp fries was tested, while 25% wettable powder of niclosamide ethanolamine salt (50% WPNES) served as a control. RESULTS: The 1-, 2- and 3-day 25% PBU LC50 and LC90 values were 0.47, 0.25 and 0.23 mg/L, and 1.54, 0.61 and 0.49 mg / L for O. h. robertsoni by using the immersion method in laboratory, and immersion with 25% PBU at 1.0 mg / L for 1 day achieved a comparable molluscicidal efficacy in relative to 50% WPNES at 1.0 mg/L. Spraying with 25% PBU at 4.0 g/m2 achieved 1-, 3- and 7-day snail mortalities of 64.23%, 96.67% and 100.00% in laboratory, respectively, which were not significantly different from those caused by treatment with 50% WPNES at 1.0 g/m2 (all P values > 0.05). One-day field immersion with 25% PBU at doses of 1, 2 and 4 g/m3 resulted in snail mortalities of 90.00%, 93.33% and 100.00%, respectively, which were not significantly different from those caused by treatment with 50% WPNES at 1.0 g/m3 (all P values > 0.05), and 3-day field spraying with 25% PBU at doses of 2.0 and 4.0 g/m2 caused snail mortalities of 86.36% and 87.72%, respectively, which were not significantly different from those caused by 50% WPNES treatment (both P values > 0.05). The 24-, 48- and 72-hour LC50 values of 25% PBU to carp fries were 29.38, 24.62 and 23.38 mg/L, respectively, and no fish death was observed within 72 hours of exposure to 25% PBU at a concentration of 17.5 mg/L and lower. CONCLUSIONS: 25% PBU is a novel, highly potent and environment-friendly molluscicide that is feasible in fish ponds, and the recommended dose is 1 g/m3 for field immersion and 2 g/m2 for field spraying in schistosomiasis-endemic areas of Yunnan Province.


Assuntos
Moluscocidas , Caramujos , Animais , China , Moluscocidas/toxicidade , Caramujos/efeitos dos fármacos
6.
Chemosphere ; 234: 589-595, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31229720

RESUMO

This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress induced by applying micro-doses of molluscicides. Here, the potential of rarely used peroxidation (PI) and unsaturation (UI) coefficients were tested as biomarkers. These indices were calculated based on the FA profiles of foot and hepatopancreas tissues of H. pomatia L. Snails were treated with three molluscicides: metaldehyde, methiocarb, and potassium chloride, in three doses each (5, 10, or 15 µl, 0.01% w/v concentration), for 12 weeks, under laboratory conditions. Correlations were evaluated between frequently used oxidation status indicators (catalase, glutathione peroxidase, selenium-dependent peroxidase, superoxide dismutase, glutathione transferase, glutathione reductase, glutathione, carbonyl protein, and thiobarbituric acid reactive substances, in the form of MDA) and UI and PI ratios. These results confirmed that fatty acids could be directly used as biomarkers of exposure and oxidative physiological status in snails. Moreover, the UI and PI, calculated based on FAs, clearly reflected the current oxidation status in snails. These indices changed with the application of micro-doses of molluscicides. In conclusion, these indices could serve as sensitive biomarkers of chemical stress in snails.


Assuntos
Biomarcadores/análise , Ácidos Graxos/metabolismo , Peroxidação de Lipídeos , Moluscocidas/toxicidade , Animais , Biomarcadores/metabolismo , Exposição Ambiental , Hepatopâncreas/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia
7.
Infect Dis Poverty ; 8(1): 27, 2019 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-31014390

RESUMO

BACKGROUND: Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis. Some plant extracts have shown obvious molluscicidal activity, and a new compound Luo-Wei, also named tea-seed distilled saponin (TDS), was developed based on the saponins extracted from Camellia oleifera seeds. We aimed to test the molluscicidal activity of 4% TDS against the intermediate host snails in China and Egypt, and evaluate its environmental safety to non-target organisms. METHODS: In the laboratory, Oncomelania hupensis, Biomphalaria alexandrina and Bulinus truncatus were exposed to 4% TDS, and the median lethal concentration (LC50) was estimated at 24, 48 and 72 h. In the field, snail mortalities were assessed 1, 2, 3 and 7 d post-immersion with 2.5 g/m3 4% TDS and 1, 3, 7 and 15 d post-spraying with 5 g/m2 4% TDS. In addition, the acute toxicity of 4% TDS to Japanese quail (Coturnix japonica), zebrafish (Brachydanio rerio) and freshwater shrimp (Macrobrachium nipponense) was assessed by estimations of LC50 or median lethal dose (LD50). RESULTS: In the laboratory, the LC50 values of 4% TDS for O. hupensis were 0.701, 0.371 and 0.33 mg/L at 24, 48 and 72 h, respectively, and 4% TDS showed a 1.975 mg/L [corrected] 24 h LC50 against B. alexandrina, and a 1.396 mg/L 24 h LC50 against B. truncatus. Across all study regions, the pooled mortalities of O. hupensis were 72, 86, 94 and 98% at 1, 2, 3 and 7 d, following field immersion of 4% TDS at a dose of 2.5 g/m3, and were 69, 77, 85 and 88% at 1, 3, 7 and 15 d, following field spraying at 5 g/m2, respectively. 4% TDS had moderate toxicity to Japanese quail (7 d LD50 > 60 mg/kg) and to shrimp (96 h LC50 = 6.28 mg/L; 95% CI: 3.53-11.2 mg/L), whereas its toxicity to zebrafish was high (96 h LC50 = 0.15 mg/L; 95% CI: 0.14-0.17 mg/L). CONCLUSIONS: 4% TDS is active against O. hupensis, B. alexandrina and B. truncatus under laboratory and field conditions, and it may be a candidate molluscicide of plant origin.


Assuntos
Moluscocidas/administração & dosagem , Moluscocidas/toxicidade , Schistosoma/efeitos dos fármacos , Caramujos/efeitos dos fármacos , Caramujos/parasitologia , Animais , Biomphalaria , Bulinus , China , Egito , Dose Letal Mediana , Extratos Vegetais , Codorniz , Esquistossomose/prevenção & controle , Testes de Toxicidade
8.
Environ Sci Pollut Res Int ; 26(8): 7960-7968, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30684178

RESUMO

Oxyfluorfen (Goal 24%EC) herbicide is widely used in agriculture for weed control. Biomphalaria alexandrina snails can be used as bioindicator of the chemical pollution in the aquatic environment. The objective of this study was to evaluate the molluscicidal activity of this herbicide on Biomphalaria alexandrina snails and how it affected its biological system. The present study revealed a molluscicidal effect of oxyfluorfen 24%EC on these snails at LC50 5.9 mg/l. After exposure of snails to the sub-lethal concentrations (LC0, LC10, or LC25) of this herbicide, the survival rates, reproductive rate (R0), and fecundity (Mx) of adult B. alexandrina snails were significantly decreased in comparison with the control group. Also, levels of testosterone and estradiol were decreased significantly. It caused alterations in the antioxidant system, where exposure to sub-lethal concentration of this herbicide caused significant increases in levels of lipid peroxide malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD), while it significantly decreased glutathione transferase (GST). Histopathological changes in the digestive gland included severe damage in the digestive cells, where, they lost their tips and some were degenerated, while the secretory cells increased in number. Regarding the hermaphrodite gland, there were losses of the connective tissues, irregular sperms, and the eggs degenerated. These findings concluded that B. alexandrina snails can be used as a bioindicator for pollution with pesticide in the aquatic environment.


Assuntos
Biomphalaria/fisiologia , Éteres Difenil Halogenados/toxicidade , Herbicidas/toxicidade , Animais , Antioxidantes , Disruptores Endócrinos/toxicidade , Genitália/efeitos dos fármacos , Dose Letal Mediana , Moluscocidas/toxicidade , Praguicidas , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade
9.
Chemosphere ; 222: 56-61, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30690401

RESUMO

Schistosomiasis japonica caused by Schistosoma japonicum infection is recognized as a considerable economic and public health concern in Asia. Oncomelania hupensis is the sole intermediate host of S. japonicum. The only molluscicide recommended by World Health Organization (WHO) since 1960s is relative toxic to other aquatic species. In this article, we evaluated the novel molluscicide PPU07 in field trials on their efficiency against O. hupensis and toxicity for local fish. 25% PPU07 sulfate WP exhibited similar molluscicidal effect at 2.0 g/m2 and 2.0 g/m3 in the spraying and immersion trials with the WHO recommended molluscicide niclosamide (1 g/m2 and 1 g/m3). The mortality rates reached 95% and 96%, respectively. Moreover, little toxicity was observed for local fish and other aquatic organisms at the effective molluscicidal concentrations. In all, 25% PPU07 sulfate WP is a promising molluscicide for snail control, particularly in semi-commercial or commercial aquaculture ponds.


Assuntos
Peixes/fisiologia , Moluscocidas/toxicidade , Caramujos/efeitos dos fármacos , Animais , Ásia , Niclosamida/toxicidade , Schistosoma japonicum/efeitos dos fármacos , Análise de Sobrevida
10.
Environ Sci Pollut Res Int ; 25(32): 32582-32590, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30242652

RESUMO

Several formulated mixtures of pesticides are widely used in modern agriculture. Nevertheless, the agriculture runoff causes a serious damage to the aquatic ecosystem. Therefore, the present study aims to use B. alexandrina snails as bioindicators for 30 g/l lambda-cyhalothrin and 17 g/l acetamiprid as a formulated mixture insecticide. Results showed that it has a molluscicidal activity against snails at LC50 7.9 mg/l. The hatchability percent of both treated 1-day-aged and/or 3-day-aged groups were less than that of the control group. The sublethal concentrations of the tested insecticide caused a remarkable abnormal necrosis in male and female gametogenic cells, besides a severe damage in both secretory and digestive cells. The results of SDS-PAGE protein profiles of treated snails showed that the least number of protein bands was noticed in snail groups that subjected to LC10 (6.6 mg/l) and LC25 (7.2 mg/l) concentrations when compared to control protein fractions.


Assuntos
Biomphalaria/efeitos dos fármacos , Moluscocidas/toxicidade , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Proteínas/química , Piretrinas/toxicidade , Animais , Biomphalaria/anatomia & histologia , Biomphalaria/fisiologia , Composição de Medicamentos , Eletroforese em Gel de Poliacrilamida , Feminino , Masculino , Moluscocidas/química , Neonicotinoides/química , Nitrilos/química , Proteínas/metabolismo , Piretrinas/química
11.
Bull Environ Contam Toxicol ; 101(4): 428-433, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30167760

RESUMO

We used a comparative approach to investigate the effects of a copper-based pesticide (EarthTec® QZ) on embryos of an invasive snail (Bithynia tentaculata) and a native snail (Physa gyrina). Embryos were exposed to one of three treatments: control (0 mg/L Cu2+), low-dose (0.1 mg/L Cu2+), or high-dose (0.6 mg/L Cu2+), which reflect manufacturer-recommended low and medium 4-day molluscicide treatment concentrations. Exposure to 0.6 mg/L Cu2+ over 4 days generated 100% mortality in both invasive and native snail embryos; however, reducing the exposure time from 4 to 1 day resulted in 100% mortality in B. tentaculata but some hatching (7%) in P. gyrina. In contrast, embryos of both species exposed to 0.1 mg/L Cu2+ treatment for 4 days showed almost 100% survivorship. Further manipulations of Cu2+ concentrations and exposure times may yield regimes that maximize mortality in B. tentaculata while minimizing negative impacts on native species.


Assuntos
Cobre/toxicidade , Moluscocidas/toxicidade , Caramujos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Projetos Piloto , Rios , Caramujos/embriologia , Caramujos/crescimento & desenvolvimento , Especificidade da Espécie
12.
Acta Trop ; 188: 132-137, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30098309

RESUMO

The snail Biomphalaria glabrata is the most important vector for Schistosoma mansoni. Control of this vector to prevent the spread of schistosomiasis is currently performed with the application of a niclosamide molluscicide, which is highly toxic to the environment. Screening of substances that show embryotoxic molluscicidal potential as well as have detrimental effects on cercariae is very relevant for the control of schistosomiasis, as the efficacy of prevention of the disease is increased if it acts as a molluscicide as well as on the cercariae of S. mansoni. The aim of this work was to evaluate the effect of potassium usnate derived from usnic acid on different stages of embryonic development of B. glabrata and on S. mansoni cercariae. After 24 h of exposure, potassium usnate showed embryotoxic activity across all embryonic stages. The values obtained from the LC50 for the embryonic stages were the following: blastula 5.22 µg/mL, gastrula 3.21 µg/mL, trochophore 3.58 µg/mL, veliger 2.79, and hippo stage 2.52 µg/mL. Against S. mansoni cercariae, it had LC90 and 100% mortality at concentrations of 2.5 and 5 µg/mL in 2 h of exposure. In conclusion, this is the first report of potassium usnate toxicity on the embryonic stages of B. glabrata and cercariae of S. mansoni, and this study shows the potassium usnate as a promising agent for the control of mansoni schistosomiasis.


Assuntos
Benzofuranos/toxicidade , Biomphalaria/efeitos dos fármacos , Moluscocidas/toxicidade , Esquistossomose mansoni/prevenção & controle , Animais , Biomphalaria/embriologia , Vetores de Doenças , Potássio/toxicidade , Esquistossomose mansoni/transmissão
13.
Ecotoxicol Environ Saf ; 147: 1017-1022, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29976004

RESUMO

Freshwater snails are used as brilliant biomarkers of aquatic ecosystem pollution by chemical compounds. The objective of this study is to highlight the ecotoxicological impacts of the insecticide Match 5%EC (its active ingredient is lufenuron 5% EC) on Biomphalaria alexandrina snails the intermediate host of Schistosoma mansoni in Egypt. The present investigation recorded a remarkable molluscicidal effect of lufenuron 5% EC on these snails and there was a decrease in total number of their hemocytes after exposure. Three morphologically distinct populations of circulating hemocytes were identified (round small cells, granulocytes and hyalinocytes) and results showed that some hyalinocytes had a shrunk nucleus and some were degenerated. Significant increase of transaminases (ALT and AST), while, a decrease of the total protein and albumin content in hemolymph was recorded. The results of alkaline comet assay in the present study demonstrated that lufenuron 5% EC has a genotoxic effect especially when its concentration increases. It can be concluded that Biomphalaria alexandrina snails can be used as bio monitor to screen the deleterious effects of lufenuron 5% EC insecticide as a cause of the environmental pollution, and this insecticide can be used in controlling schistosomiasis because of its molluscicidal effects on B. alexandrina snails.


Assuntos
Benzamidas , Biomphalaria/efeitos dos fármacos , Inseticidas , Moluscocidas/toxicidade , Animais , Biomphalaria/genética , Biomphalaria/fisiologia , Ensaio Cometa , Egito , Granulócitos/efeitos dos fármacos , Hemócitos/efeitos dos fármacos , Hemolinfa/efeitos dos fármacos , Hemolinfa/metabolismo , Controle de Pragas , Schistosoma mansoni
14.
Pestic Biochem Physiol ; 148: 151-158, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29891366

RESUMO

Pedunsaponin A, a novel molluscicidal compound isolated from Pueraria peduncularis, exhibits strong toxicity against Pomacea canaliculata. To determine the mechanisms of Pedunsaponin A toxicity, its effects on the organs and hemocytes of P. canaliculata were examined in this study. The results showed that Pedunsaponin A had significant toxic effects on different organs of the snail, including the lungs, gills, mantle, siphon tube, ventricle, pericardial cavity, hepatopancreas, kidneys, and the major symptom of this toxicity was the loss of cilia in the lungs and gills. Additionally, in further studies on the effects of Pedunsaponin A treatment, we found that the hemocyte count was changed and hemocyte morphology was damaged, which was primarily reflected by cytoplasm leakage, nuclei deformation, and significant reductions in the number of ribosomes and granulocyte mitochondria. Based on these results and considering that blood vessels are distributed in the lungs and gills, we hypothesized that Pedunsaponin A would first destroy the cilia, which disrupt physiological activities such as respiration, excretion and feeding, and then enter the hemolymph through blood vessels, disrupt the normal function of the hemocytes and destroy the snail immune system, eventually resulting in the death of the snail.


Assuntos
Cílios/efeitos dos fármacos , Gastrópodes/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Moluscocidas/toxicidade , Saponinas/toxicidade , Triterpenos/toxicidade , Animais , Vasos Sanguíneos/efeitos dos fármacos , Cílios/patologia , Gastrópodes/imunologia , Gastrópodes/fisiologia , Brânquias/irrigação sanguínea , Brânquias/patologia , Hemócitos/efeitos dos fármacos , Hemócitos/fisiologia , Hemolinfa/efeitos dos fármacos , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/patologia , Rim/efeitos dos fármacos , Rim/patologia , Pulmão/irrigação sanguínea , Pulmão/patologia , Mitocôndrias/efeitos dos fármacos , Pericárdio/efeitos dos fármacos , Pericárdio/patologia , Ribossomos/efeitos dos fármacos
15.
Acta Trop ; 179: 39-43, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29183853

RESUMO

This study reports the molluscicidal activity of usnic acid isolated from Cladonia substellata Vanio (lichen) on embryos at various stages of development and in adult mollusks of Biomphalaria glabrata. The toxicity of usnic acid was also evaluated through Artemia salina larvae mortality. Usnic acid was extracted with diethyl ether, isolated, purified, and its structure confirmed by analyzing the spectra of proton nuclear magnetic resonance. LC90 for 24 h of exposure were 1.62, 4.45, 5.36, and 4.49 µg mL-1 for blastula, gastrula, trocophore, and veliger embryonic stages, respectively, and 3.45 µg mL-1 for adult snails; LC50 of usnic acid against A. salina was 2.46 µg mL-1. LC90 assessed 7 days after exposure was 2.56 µg mL-1 for adult mollusks. In conclusion, these findings demonstrate that under laboratory conditions usnic acid has teratogenic and molluscicide potential to control the aquatic snail B. glabrata and may prove to be a promising candidate in the search for new molluscicide agents, but further detailed studies on its molluscicidal effect and possible environmental effects are needed.


Assuntos
Benzofuranos/toxicidade , Biomphalaria/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Líquens/química , Animais , Artemia/efeitos dos fármacos , Biomphalaria/embriologia , Larva/efeitos dos fármacos , Moluscocidas/toxicidade
16.
Pestic Biochem Physiol ; 143: 111-115, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29183578

RESUMO

In order to search new local plant molluscicides for the control of the vectors of schistosomiasis, leaves of Macleaya cordata (Willd) R. Br. were used to extract and separate alkaloid components by thinner acid method and column chromatography, and the molluscicidal effect of alkaloid components against snail Oncomelania hupensis was determined by bioassay. The results showed that 7 alkaloid components (AN1-7) were obtained after extracting and separating alkaloids from the leaves of M. cordata, where AN2 was found being the most toxic against snail O. hupensis with 48h LC50 and LC90 values of AN2 of 6.35mg/L and 121.23mg/L, respectively. Responses of some critical enzymes to AN2, including activities of Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), Aspartate transaminase (AST), Malic dehydrogenase (MDH) and Succinate dehydrogenase (SDH) in both cephalopodium and liver, were also detected through experiments, which also explored esterase isozyme (EST) exposed to AN2 in liver tissue. The results showed that AN2 significantly inhibited the activities of SDH, MDH and esterase isozyme, as AN2 significantly stimulated the activities of ALP, ALT and AST to increase at a low concentration (e.g. 25mg/L), while significantly inhibited the activities of these enzymes at a high concentration (100mg/L). These results indicated that AN2 not only inhibited protein synthesis, and respiratory chain oxidative phosphorylation, but also caused hepatocellular injury and reduced the detoxification ability of liver.


Assuntos
Alcaloides/toxicidade , Moluscocidas/toxicidade , Papaveraceae , Caramujos/efeitos dos fármacos , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Esterases/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Malato Desidrogenase/metabolismo , Extratos Vegetais , Folhas de Planta , Caramujos/enzimologia , Succinato Desidrogenase/metabolismo
17.
Environ Sci Pollut Res Int ; 24(36): 28072-28078, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28994007

RESUMO

Schistosomiasis is one of the neglected tropical diseases. It is a snail-borne trematode infection, and Biomphalaria alexandrina snails are the intermediate host of Schistosoma mansoni in Egypt. The objective of this study is to evaluate the molluscicidal activity of the aqueous seed extract of Moringa oleifera against B. alexandrina snails. The results showed that this aqueous extract was lethal for B. alexandrina snails (LC50 0.27 g/l; LC90 0.41 g/l). Exposure of snails to the sublethal concentrations of this aqueous extract caused a considerable reduction in survival rates and hatchability rates of eggs of these snails. Moreover, it negatively affected some biochemical aspects, where it increased the levels of transaminases (ALT and AST), while it decreased the concentrations of total protein, albumin, and globulin concentration. Histological examinations of the digestive gland of snails exposed to the sublethal concentrations of aqueous seed extract of M. oleifera revealed severe damage in the digestive cells, where they lost their tips and some were degenerated, while the secretory cells increased in number. Regarding the hermaphrodite gland, there were losses of connective tissues and irregular sperms, and the eggs were degenerated. These findings prove the potent activity of aqueous seed extract of M. oleifera against the intermediate hosts of Schistosoma mansoni and provide a considerable scope in exploiting local indigenous resources for snails' molluscicidal agents.


Assuntos
Biomphalaria/efeitos dos fármacos , Moluscocidas/toxicidade , Moringa oleifera/química , Extratos Vegetais/toxicidade , Animais , Egito , Moluscocidas/isolamento & purificação , Schistosoma mansoni/fisiologia , Sementes/química
18.
Parasit Vectors ; 10(1): 383, 2017 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-28793917

RESUMO

BACKGROUND: Schistosomiasis mansoni is one of the most important, but often neglected, tropical diseases transmitted by snails of the genus Biomphalaria. Control of the intermediate host snail plays a crucial role in preventing the spread of schistosomiasis. However, there is only one molluscicide, niclosamide, recommended by the World Health Organization. Niclosamide has been used for several decades but is toxic to non-target organisms. Therefore, it is necessary to optimize the scaffold of niclosamide and develop novel molluscicides with enhanced potency and decreased toxicity to non-target organisms. METHODS: In this study, a candidate compound was analyzed by nuclear magnetic resonance and mass spectrometry. The molluscicidal potential against Biomphalaria species and cercaricidal potential against S. mansoni were evaluated using the immersion method. Furthermore, the preliminary mechanism was studied through cellular enzyme tests and electron microscopy. RESULTS: 5-chloro-2-[(2-chloro-4-nitrophenyl)carbamoyl]phenyl-4-methoxybenzoate (salicylanilidate), a novel salicylanilide ester derivative, was derived from niclosamide. The 50% lethal concentration to B. glabrata, B. straminea and B. pfeifferi was 0.261 mg/l, 0.172 mg/l and 0.241 mg/l, respectively. The effective dose required to completely kill S. mansoni cercariae was 0.625 mg/l for salicylanilidate and 0.125 mg/l for niclosamide. However, salicylanilidate was approximately 100-fold less toxic to the fish Danio rerio than niclosamide. Furthermore, salicylanilidate reduced the enzymatic activities of nitric oxide synthase (NOS), lactate dehydrogenase (LDH) and acetylcholinesterase (AChE) in the snail, demonstrating that it could affect neurohypophysis transmission and energy metabolism. Severe swelling in the tentacle and deformation of cilia in the tentacle and mantle were observed through scanning electron microscopy. The results of transmission electron microscopy showed that salicylanilidate could damage critical organelles in hepatopancreas tissues, including degeneration of the endoplasmic reticulum and vacuolization in mitochondria. In addition, transcriptional levels of superoxide dismutase (SOD), acid phosphatase (ACP) and NOS in the hepatopancreas were significantly downregulated as shown by real-time quantitative polymerase chain reaction (RT-PCR). These results indicated that the hepatopancreas is a primary target organ of salicylanilidate. CONCLUSIONS: Salicylanilidate not only had deleterious effects on Biomphalaria species and S. mansoni cercariae but also showed very low toxicity to D. rerio, suggesting that it has broad potential applications.


Assuntos
Biomphalaria/efeitos dos fármacos , Biomphalaria/parasitologia , Vetores de Doenças , Moluscocidas/farmacologia , Salicilanilidas/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Fosfatase Ácida/genética , Fosfatase Ácida/metabolismo , Animais , Biomphalaria/enzimologia , Cercárias/efeitos dos fármacos , Cílios/efeitos dos fármacos , Cílios/patologia , Cílios/ultraestrutura , Descoberta de Drogas , Retículo Endoplasmático/efeitos dos fármacos , Hepatopâncreas/efeitos dos fármacos , L-Lactato Desidrogenase/antagonistas & inibidores , Microscopia Eletrônica de Varredura , Mitocôndrias/efeitos dos fármacos , Moluscocidas/toxicidade , Niclosamida/análogos & derivados , Niclosamida/toxicidade , Óxido Nítrico Sintase/antagonistas & inibidores , Salicilanilidas/toxicidade , Esquistossomose mansoni/prevenção & controle , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
19.
Artigo em Chinês | MEDLINE | ID: mdl-27356413

RESUMO

OBJECTIVE: To study the acute inhalation toxicity of 50% Luowei, a plant molluscacide, in rats. METHODS: Twenty adult Wistar rats, half male and half female, were given of 5000 mg/m³ of 50% Luowei through a dynamic inhalation device and the death and recovery of the rats were observed within 14 days, and LC50 was drawn. RESULTS: After exposure, the activities of the rats decreased and a few individual animals had scratching symptom, but the symptom disappeared after the exposure. No animals died during the whole observation period. Therefore, the acute inhalation LC50 was greater than 5000 mg/m³ for rats, and Luowei belonged to low toxicity level. CONCLUSIONS: 50% Luowei will not cause animal death if it is inhaled into animal body. However, people still need to wear protective equipment in production and use.


Assuntos
Moluscocidas/toxicidade , Administração por Inalação , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Dose Letal Mediana , Masculino , Ratos , Ratos Wistar
20.
Artigo em Chinês | MEDLINE | ID: mdl-26094431

RESUMO

OBJECTIVE: To evaluate the molluscicidal effect of black plastic film combined with carbon amide. METHODS: In Jiangdong Town, Jinhua City, the field with Oncomelania hupensis in the history was selected as experimental area and divided into 3 groups: Group One was administered with black plastic film combined with carbon amide; Group Two was administered with simple black plastic film; and Group Three was a control group. RESULTS: On the 3rd, 7th, 15th, 20th and 30th day after the experiment, the mortality rates of 0. hupensis of Group One were 86.0%, 88.0%, 100%, 100% and 100% respectively, which were significantly higher than those of the control group (all P < 0.05). The differences of mortality rates between Group One and Group Two were statistically significant on the 3rd and 7th day after the experiment (Group One was superior to Group Two). CONCLUSION: The bladk plastic film combined with carbon amide can improve the molluscicidal effect.


Assuntos
Amidas/toxicidade , Carbono/toxicidade , Moluscocidas/toxicidade , Controle de Pragas/métodos , Caramujos/efeitos dos fármacos , Animais , Controle de Pragas/instrumentação , Caramujos/fisiologia
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