Bio-molluscicidal potential and biochemical mechanisms of clove oil and its main component eugenol against the land snail, Theba pisana.

The land snail, Theba pisana is a serious pest that adversely affects various crops in sustainable agriculture. Essential oils and their constituents represent an environmentally sound alternative to synthetic pesticides. Our study aimed to investigate the lethal and sub-lethal toxicity of clove oil and its main component eugenol to understand the mechanisms underlying its toxic action against T. pisana. The GC-MS profile of the clove oil composition was characterized. In the laboratory experiment, LD50 of clove oil and eugenol via the contact testing were determined after 48 and 72 h. Moreover, sub-lethal effects of clove oil or eugenol on the survivors following the exposure of snails to the 25 and 50% of the LD50/48 and 72 h were evaluated through using snail tissues for biochemical measurments. The GC-MS analysis showed that eugenol (64.87%) was the major constituent present in the oil. The results also showed that LD50 values at 48 and 72 h were 2006.5 and 1493.5 µg/g b.w for oil and 239.6 and 195.3 µg/g b.w for eugenol, respectively. Compared to control, the sub-lethal effects of clove oil or eugenol at 48 and 72 h showed a significant increase in reduced glutathione (GSH) levels. Catalase (CAT) and glutathione-S-transferase (GST) activities significantly elevated in oil- or eugenol-treated snails, except at low dose after 48 h. After two exposure times, snails exposed to oil or eugenol at both sub-lethal effects had considerably higher γ-glutamyltransferase (γ-GT) and aspartate aminotransferase (AST) activities. Moreover, markedly augmentation in alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities at all exposure times, with the exception of snails treated with low dose of eugenol after 48 h was observed. Both clove oil and eugenol at the tested doses caused a significant inhibition in acetylcholinesterase (AChE) activity at two exposure times. Our findings highlight the potential of clove oil and eugenol, as an efficient natural molluscicide alternative to its synthetic counterparts for snail control.

Molluscicidal and cercaricidal activities of the essential oil of Dysphania ambrosioides (L.) Mosyakin & Clemants: Implications for the control of schistosomiasis.

Schistosomiasis is one of the most important tropical diseases. A fundamental strategy to control its spread is the use of natural products against its vectors, which are snails of the genus Biomphalaria. The present study evaluated the chemical composition, the molluscicidal and cercaricidal effects, and the ecotoxicity of the essential oil from the aerial parts of Dysphania ambrosioides (L.) Mosyakin & Clemants (DAEO). The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Molluscicidal and cercaricidal activities were determined by the immersion method. Environmental toxicity was assessed from bioassays using Artemia salina larvae and Danio rerio fish. DAEO presented a 0.8% yield. The GC-MS analysis revealed the predominance of hydrocarbon monoterpenes in the oil. A total of 32 constituents was identified, with α-terpinene (50.69%) being the major compound, followed by p-cymene (13.27%) and ascaridole (10.26%). DAEO was active against adult Biomphalaria glabrata snails and demonstrated lethal effect against Schistosoma mansoni cercariae, with LC50 values of 25.2 (22.7-27.8) and 62.4 (61.8-62.9) µg/mL, respectively. Regarding toxicity to non-target aquatic organisms, the oil showed LC50 values of 86.9 (84.7-87.6) and 18.6 µg/mL (15.5-22.8) for A. salina and D. rerio, respectively. DAEO proved to be a promising natural product for the control of schistosomiasis, acting on both the vectors and the etiological agent of the disease. However, the use of the oil is safer in transmission sites where there are no non-target organisms, as it has showed toxicity to D. rerio fish.

Usnic acid potassium salt: an alternative for the control of Biomphalaria glabrata (Say, 1818).

In Brazil, the snail Biomphalaria glabrata is the most important vector of schistosomiasis due to its wide geographical distribution, high infection rate and efficient disease transmission. Among the methods of schistosomiasis control, the World Health Organization recommends the use of synthetic molluscicides, such as niclosamide. However, different substances of natural origin have been tested as alternatives for the control or eradication of mollusks. The literature describes the antitumor, antimicrobial and antiviral properties of usnic acid as well as other important activities of common interest between medicine and the environment. However, usnic acid has a low degree of water solubility, which can be a limiting factor for its use, especially in aquatic environments, since the organic solvents commonly used to solubilize this substance can have toxic effects on aquatic biota. Thus, the aim of the present study was to test the potassium salt of usnic acid (potassium usnate) with regard to molluscicidal activity and toxicity to brine shrimp (Artemia salina). To obtain potassium usnate, usnic acid was extracted with diethyl ether isolated and purified from the lichen Cladonia substellata. Biological assays were performed with embryos and adult snails of B. glabrata exposed for 24 h to the usnate solution solubilized in dechlorinated water at 2.5; 5 and 10 µg/ml for embryos, 0.5; 0.9; 1;5 and 10 µg/ml for mollusks and 0.5; 1; 5; 10 µg/ml for A. salina. The lowest lethal concentration for the embryos and adult snails was 10 and 1 µg/ml, respectively. No toxicity to A. salina was found. The results show that modified usnic acid has increased solubility (100%) without losing its biological activity and may be a viable alternative for the control of B. glabrata.

Molluscicidal and larvicidal activities and essential oil composition of Cymbopogon winterianus.

UNLABELLED: CONTEXT. Cymbopogon winterianus Jowitt ex Bor (Poaceae), known as citronella grass, is an aromatic herbaceous plant and the essential oil extracted from this grass is used in cosmetics, perfumes, hygiene and cleanliness products worldwide. OBJECTIVE: This study investigated the composition and molluscicidal and larvicidal activities of the essential oil of C. winterianus cultivated in North Brazil. MATERIALS AND METHODS: The oil was obtained by hydrodistillation, analyzed by gas chromatography (GC) and GC-mass spectrometry and then its molluscicidal and larvicidal activities against snails (Biomphalaria glabrata) and hatched larvae of Artemia salina, respectively, were evaluated at concentrations from 10 to 1000 mg/L. RESULTS: The main constituents of oil were citronellal (26.5%), geraniol (16.2%), elemol (14.5%) and citronellol (7.3%). The molluscicidal test revealed significant lethal concentration (LC) values (LC90=97.0 mg/L, LC50=54.0 mg/L and LC20=22.0 mg/L), indicating the presence of molluscicidal compounds in the oil. In addition, the oil showed moderate larvicidal activity (LC50=181.0 mg/L) against the larvae of A. salina, which could justify its use in the aquatic environment without affecting other living organisms. DISCUSSION AND CONCLUSION: The results suggest that the oil of C. winterianus could be an effective alternative to control schistosomiasis, with an average margin of safety to other living organisms that coexist with snails.

Molluscicidal and leishmanicidal activity of the leaf essential oil of Syzygium cumini (L.) SKEELS from Brazil.

The chemical composition and biological potential of the essential oil extracted from Syzygium cumini leaves collected in Brazil were examined. GC/MS Analyses revealed a high abundance of monoterpenes (87.12%) in the oil. Eleven compounds were identified, with the major components being α-pinene (31.85%), (Z)-ß-ocimene (28.98%), and (E)-ß-ocimene (11.71%). To evaluate the molluscicidal effect of the oil, it was tested against Biomphalaria glabrata and the LC50 obtained was 90 mg/l. The essential oil also showed significant activity against Leishmania amazonensis, with an IC50 value equal to 60 mg/l. In addition, to evaluate its toxicity towards a non-target organism, the essential oil was tested against Artemia salina and showed a LC50 of 175 mg/l. Thus, the essential oil of S. cumini showed promising activity as a molluscicidal and leishmanicidal agent and might be valuable in combating neglected tropical diseases such as schistosomiasis and leishmaniasis. Further research is being conducted with regard to the purification and isolation of the most active essential-oil compounds.

Reports of metaldehyde and iron phosphate exposures in animals and characterization of suspected iron toxicosis in dogs.

OBJECTIVE: To describe reports of animals exposed to metaldehyde- and iron phosphate-containing molluscicides and characterize iron phosphate exposure incidents in dogs with clinical signs compatible with iron toxicosis. DESIGN: 2-part retrospective case series. SAMPLE: 1,500 reports of animals exposed to molluscicides containing metaldehyde (n … 1,285) or iron phosphate between 2001 and 2011 (n … 215; part 1) and a subset of 56 reports involving 61 dogs with suspected iron toxicosis (part 2). PROCEDURES: In part 1, a National Pesticide Information Center database was searched to identify reported exposures to metaldehyde- and iron phosphate-containing molluscicides before, during, and after a regulatory transition affecting metaldehyde product labeling beginning in 2006. Source of the report, number of animals, clinical signs, and deaths were evaluated. In part 2, reports involving potential iron toxicosis in dogs were additionally reviewed for signalment, circumstances of exposure, and product identification. RESULTS: Reports of metaldehyde exposures decreased each year between 2006 (n … 193) and 2011 (21), whereas reports of iron phosphate exposures increased between 2006 (n … 4) and 2010 (73); changes were not evaluated statistically. Animals had no clinical signs at the time of the call in 130 of 215 (60%) and 675 of 1,285 (53%) reports of iron phosphate and metaldehyde exposure, respectively. In dogs, 35 deaths were associated with metaldehyde exposure and no deaths were associated with iron phosphate exposure. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinary professionals should be aware of the potential for iron toxicosis following exposure to iron phosphate-containing molluscicides.

Molluscicidal activities of six species of Bignoniaceae from north-eastern Brazil, as measured against Biomphalaria glabrata under laboratory conditions.

The molluscicidal profile and brine-shrimp bio-activity of the ethanolic extracts of plants from the Bignoniaceae family were determined. The six extracts investigated were of the stems of Melloa quadrivalvis and Tabebuia aurea, and whole plants of Adenocalymma comosum, Arrabidaea parviflora, Cuspidaria argentea and Clytostoma binatum. When tested in the laboratory, with Biomphalaria glabrata as the test snail, all six extracts gave median lethal concentrations (9-54 microg/ml) that fell well below the upper threshold, of 100 mug/ml, set for a potential molluscicide by the World Health Organization.

Synthesis of pyrido[2,1-c][1,2,4]triazine,1,2,4 triazolo[4,3-a] pyridine and 2-(substituted-pyrazolyl)nicotinonitrile and their effect on Biomphalaria alexandrina snail enzymes.

The reaction of 2-hydrazino-4-(4-methoxyphenyl)-6-pheny-nicotinonitrile 3 with halo compounds yielded 4a-c,5,6. Heating 3 with carbon disulphide gave 7-(4-methoxyphenyl)-5-phenyl-3-thioxo-2,3-dihydro [1,2,4-] triazolo [4,3-a] pyridine-8-carboxylic amide 7. The behaviour of 3 towards some alpha,beta-unsaturated nitriles ,ethoxymethylene and ketene dithioacetal derivatives has been investigated, affording 9a-c,11a-c,13a-c,16a,b respectively. The activity of compounds 4a,5,6 and 7 have been investigated as molluscicidal.

Chemical constituents from Lippia sidoides and cytotoxic activity.

Eleven known compounds and a new prenylated naphthoquinone, lippsidoquinone (13), were isolated from ethanol extracts of Lippia sidoides. Their structures were established by a combination of 1D and 2D NMR, IR, and EIMS spectral data analysis. The cytotoxic properties of compounds 3--13 were evaluated against HL60, SW1573, and CEM cell lines. Only tectol (6) and lippsidoquinone (13) exhibited significant activity against human leukemia cell lines HL60 and CEM.

Synthesis of new uracil-5-sulphonamide-p-phenyl derivatives and their effect on Biomphalaria alexandrina snail's nucleoproteins.

In continuation of the previous work (Fathalla, 1992) on the synthesis of some heterocycles containing uracil moiety, we report herein the incorporation of uracil moiety into cyanopyridine thione, thiosemecarbazone, semicarbazone, cyanopyridine, aminocyano pyridine, isoxazoline, pyrazoline, pyrimidine, triazolo pyrimidine, pyran, selena and thiazole derivatives which might modify their biological activities. The biological studies revealed that the chemical compound III f showed high molluscicdal activity than other compounds. The profile of the nucleoprotein extracted from chemically (compound IIIc, e, f and g) treated or UV-irradiated B. alexandrina snails did not show appreciable differences when compared to non-treated (native) snails by using SDS-PAGE, where no obvious qualitative or quantitative differences were observed. Immunization of experimental animals with the nucleoprotein extracted from native, chemically (compound III f & g) treated or physically treated B. alexandrina snails induced significant protection against challenge with normal S. mansoni cercariae, as compared to the non-immunized challenged control. As well as, a decrease in the number of granuloma formation and the size range of granuloma was also observed in immunized animals. It is concluded that, compounds III f and g have a potent molluscicidal activity. They also induced chemical modification comparable to that induced by physical treatment in the snail's nucleoprotein, which could possibly be used in immunization against S. mansoni infection.

Actividad molusquicida del Paraiso (Melia azedarach L.) (Meliaceae) sobre Lymnaea cubensis, molusco vector de Fasciolosis / Molluscicidal activity of Paraiso (Melia azedarach L.) (Meliaceae) on Lymnaea cubensis, host snail of Fasciolosis

A Fasciolosis constitui em diversas regiöes fonte importante de perdas econômicas, e quando näo se adotam medidas de controle de seus hospedeiros (moluscos), junto a condiçöes ecológicas favoráveis, pode ocorrer o aparecimento de casos isolados de Fasciolosis humana. Dentro dos métodos alternativos para o seu controle está o uso de extratos vegetais e se tem pretendido avaliar o provável emprego do suco extraíso do fruto e sementes do Paraiso (Melia azedarach L.), no controle de Lymnaea cubensis, principal vetor da Fasciolosis em Cuba. Diferentes concentraçöes do suco extraído do fruto e semente do Paraiso (Melia azedarach L.) foram testadas para determinar as doses médias letais (DL50) e máxima (DL90) usando um programa computadorizado PROBIT-LOG. Sete séries experimentais foram realizadas, usando 72 moluscos em cada uma. Para determinar a influência sobre a freqüência cardíaca foram testados três grupos de 10 moluscos, dois foram tratados com as CL50=0,88627 e CL90=1,7641, respectivamente, enquanto que o terceiro foi considerado como controle. Observou-se uma marcada influência de ambas as doses sobre a freqüência cardíaca do molusco estudado. Os resultados foram alentadores, pois demonstraram um potencial uso dessa planta no controle de moluscos näo desejados

Phenobarbital-type P-450 inducers protect rats against metaldehyde toxicity.

The mechanism of metaldehyde toxicity is unclear. It may be due to the compound itself or, at least in part, to acetaldehyde resulting from the hydrolysis of metaldehyde in the stomach. In this study, we orally dosed rats with twice the LD50 of metaldehyde following no pretreatment (control) or pretreatment with 1 of 3 different cytochrome P-450 inducers either phenobarbital or o,p'-DDD (inducers of cytochromes P-450 IIB and IIIA) or 3-methylcholanthrene (an inducer of P-450 IA). Our results show strong protection against metaldehyde poisoning afforded by the phenobarbital-DDD P-450 inducers, but only weak protection with 3-methylcholanthrene pretreatment. Acetaldehyde administered at the same molarity failed to produce the clinical signs of metaldehyde toxicity and no clinical differences were observed between any of the pretreated groups.

Estudo ecotoxicológico do látex moluscicida da coroa-de-cristo (euphorbia milii var histopii) / Study on the ecotoxicity ot the molluscicida latex of \"crow-of-thorns\" (Euphorbua milli var histopii)

Investiga a toxicidade do látex à organismos näo-alvo do ecossistema aquático. A toxicidade aguda do látex liofilizado para caramujos do gênero Biomphalaria e para organismos näo-alvo foi avaliada através do sistema de exposiçäo estático. Os resultados (CL50 ou CE com o intervalo de confiança 95 por cento) foram os seguintes: letalidade para peixes: "paulistinha" (brachydanio rerio) - 24 horas = 1,15 (1,00-1,31) mg/l; 48 horas = 0,96 (0,84-1,070 mg/l e "guppy" (poecilia reticulata) - 24 horas = 1,71 (1,51-1,87) mg/l; 48 horas = 1,39 (1,18-1,55) mg/l. Imobilizaçäo para microcustáceos: daphnia similis - 24 horas = 1,04 (0,86-1,24) mg/l 48 horas = 0,37 (0,28-0,47) mg/l e ceriodaphnia dubia - 24 horas = 1,45 (1,06-2,03) mg/l; 48 horas = 1,06 (0,89-1,41) mg/l. Letalidade para o microcustáceo de águas salinas artemia sp.-24 horas = 24,23 (15,90-44,23) mg/l; 48 horas = 0,94 (0,67-1,25) mg/l. Letalidade para o oligoqueta tubifex tubifex siolii - 24 horas = 0,65 (0,58-0,71) mg/l; 48 horas = 0,31 (0,21-0,44) mg/l. Letalidade para insetos (larvas de primeiro e terceiro estágios de aedes aegypti, aedes fluviatilis e anopheles albitarsis); > 100 mg/l. Leatalidade para caramujos-alvo: biomphalaria tenagophila - 24 horas = 0,13 (0,09-0,19) mg/l; 48 horas = 0,08 (0,06-0,12) mg/l e biomphalaria glabrata - 24 horas = 0,26 (0,19-0,34) mg/l; 48 horas = 0,13 (0,10-0,17) mg/l. Letalidade para caramujos näo-alvo: helisoma duryi - 24 horas = 0,20 (0,13-0,35) mg/l; 48 horas = 0,10 (0,05-013) mg/l e pomacea sp.-24 horas = 12,46 (9,89-15,14) mg/l; 48 horas = 10,51 (8,39-12,66) mg/l. O látex näo inibiu o crscimento das algas clorofíceas slenastrum capricornutum e chlorella vulgaris. O látex também näo demonstrou efeito inibitório (em concentraçoes até 100 mg/l) para as bactérias escherichia coli, pseudomonas aeruginose a pseudomonas putida. Paralelamente foram realizados testes com a niclosamida para fins comparativos. Foi avaliada a estabilidade da atividade moluscicida da soluçäo aquosa de látex exposta a luz visível. Soluçoes de látex (10mg/l) em água destilada foram expostas luz visível (5000 lux) por 24, 48 e 96 horas. Soluçoes de látex fresco (10mg/l) e de látex protegido da luz (10mg/l) foram utilizadas como controles. Foram preparadas diluiçoes de 0,5 e 1,0 mg/l para testar a atividades moluscicida das soluçoes contra biomphalaria glabrata....

Cytotoxic and antibacterial dihydrochalcones from Piper aduncum.

Bioactivity-guided fractionation of a CH2Cl2 extract from the leaves of Piper aduncum afforded three new dihydrochalcones, piperaduncins A [3], B [4], and C [5], as well as two known dihydrochalcones, 2',6'-dihydroxy-4'-methoxydihydrochalcone [1] and 2',6',4-trihydroxy-4'-methoxydihydrochalcone [2] (asebogenin), together with sakuranetin, anodendroic acid methyl ester, and the carotenoid lutein. The structures of the isolates were elucidated by spectroscopic methods, mainly 1D- and 2D nmr spectroscopy. The proposed stereochemistry for compound 4 was deduced by NOESY spectroscopy and the corresponding energy minimum was established by molecular modelling calculations and translated into a 3D structure.

Molluscicidal acridone alkaloids from Angostura paniculata: isolation, structures, and synthesis.

Two novel acridone alkaloids, cuspanine [1] and cusculine [2], were isolated from the CH2Cl2 extract of the leaves of Angostura paniculata (Rutaceae). Their structures were established as 1-hydroxy-2,3,5,6-tetramethoxy-9-acridone for 1 and 1,2,3,5,6-pentamethoxy-9-acridone for 2 by means of spectroscopic studies, in particular nmr. These structural assignments were confirmed by synthesis, using a direct metallation method as a key reaction. Both alkaloids exhibited moderate molluscicidal activity against an aquatic snail, Biomphalaria glabrata, and cytotoxicity against several types of carcinoma cell lines.

Evaluation of temporal, seasonal and geographic stability of the molluscicidal property of Euphorbia splendens latex

Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscacidal principle, with LD90 values of 1.14 ppm (spring), 1.02 ppm (fall), 1.09 ppm (winter), and 1.07 ppm (summer) that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador), demonstrating geographic stability of the molluscacidal effect. The molluscacidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate) and lyophilized, was stable for up to 124 days at room temperature (in natura) and for up to 736 days in a common refrigerator at 10 to 12 degrees C (lyophilized product). A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasis

Toxicological study of the molluscicidal latex of Euphorbia splendens: irritant action on skin and eye.

Aqueous solutions of the molluscicidal latex of Euphorbia splendens are irritant to the rabbit eye in concentrations higher than 0.35% and to the rabbit skin in concentrations higher than 0.5%. Although this irritant potential does not preclude its use as a molluscicide, special precautions are recommended for handling and application of the product and the hazard of skin tumor-promoting potential should be carefully investigated before its use for schistosomiasis vector control.

Biochemical studies on the terrestrial snail, Eubania vermiculata (Müller) treated with some pesticides.

The in vivo effects of methomyl, thiodicarb and metaldehyde on total soluble proteins, total lipids and glycogen content, in addition, the activity of glutamic oxaloacetic transaminase, (GOT), (GPT) glutamic pyruvic transaminase and catalase (CAT) enzymes of terrestrial E. vermiculata snails was studied. The experimental snails were treated with low concentration of 0.2% brain bait w/w of the pesticides for a period of 1,3,5,7 and 10 days. The results showed that methomyl and thiodicarb lead to significant reduction in total soluble proteins, lipids, and glycogen content, while significant increases in the activity of all enzymes tested were noted. Metaldehyde treatment showed no significant effect on total soluble proteins, lipids and GOT level, whereas a significant increase in GPT and CAT enzymes was observed. Also, metaldehyde resulted a significant reduction in glycogen content of snails.