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Background: The potential molluscicidal extracts, obtained from indigenous plants Cannabis sativa, Acacia nilotica, and Tinospora cordifolia, were tested for toxicity against freshwater pulmonate snail Lymnaea acuminata, an intermediate host of Fasciola hepatica. The organic extracts had a significant effect on young snails. Materials and Methods: All organic extracts and column-purified fractions gave median lethal concentrations (19–100.05 mg/L; 24 h) that fell well within the threshold level of 100 mg/L, set for a potential molluscicide by the World Health Organization. Results: The toxicity of T. cordifolia stem acetone extract (96 h LC50: 16.08 mg/L) was more pronounced compared with C. sativa leaf ethanol extract (96 h LC50: 16.32 mg/L) and A. nilotica leaf ethanol extract (96 h LC50: 24.78 mg/L). β-caryophyllene, gallic acid, and berberine were characterized and identified as active molluscicidal components. Co-migration of β-caryophyllene (retardation factor [Rf] 0.95), gallic acid (Rf 0.30), and berberine (Rf 0.23) with column-purified parts of Cannabis sativa, Acacia nilotica, and Tinospora cordifolia on thin-layer chromatography demonstrates same Rf value, that is, 0.95, 0.30, and 0.23, respectively. Conclusion: This study indicates that these extracts thus represent potential plant-derived molluscicides that are worthy of further investigations. [ABSTRACT FROM AUTHOR]

Background and Objective: Fasciolosis is a zoonotic disease, which is transmitted by Lymnaea acuminata snails of the Lymnaidae family and causes the disease in human and herbivorous mammals in all over the world. One of the suitable approaches for the control of fasciolosis is the snail control. The snail control by snail attractant pellets is a new technique because there is no any side effect on other biota/human/natural environment. Material and Methods: The influence of various abiotic factors and umbelliferone toxicity in bait against the vector snail Lymnaea acuminata was checked in different months of the years 2018-2019. Result: After 24h of molluscicide exposure, it was found that LC50 values 4.37, 4.22 and 5.66 % in SAP containing starch + umbelliferone and 4.02, 4.33, and 4.76 % in SAP containing proline + umbelliferone during May, June and July, respectively, were most effective treatments in killing the snails. While SAP containing starch + umbelliferone was 9.84% and proline + umbelliferone was 8.94% were minimum effective in January in 24h toxicity. Conclusion: This study indicates that various abiotic factors significantly changed the toxicity of umbelliferone; so, the snails can be controlled by snail attractant pellets containing umbelliferone will be applied in a particular month rather than the whole month of the year. [ABSTRACT FROM AUTHOR]

Phytotherapy of chlorophyllin formulations against Fasciola gigantica infected Lymnaea acuminata under sunlight exposure was highly toxic against redia and cercaria larvae. Binary combinations (1:1 ratio) of chlorophyllin (CHL) + freeze dried cow urine (FCU) were more toxic against cercariae (8 h LC50: 9.6 mg L−1) than single treatment with chlorophyllin (8 h LC50: 12.6 mg L−1) in sunlight. The larvicidal activity of sunlight exposed CHL against rediae (8 h LC50: 13.5 mg L−1) and cercariae (8 h LC50: 12.6 mg L−1) was more pronounced than laboratory conditions CHL treatment (rediae- 8 h LC50: 305.9 mg L−1; cercariae- 8 h LC50: 765.4 mg L−1). Larvicidal activity of FCU was less than CHL and CHL + FCU against both redia and cercaria. Chlorophyllin and its formulations were more toxic against redia and cercaria larvae in sunlight than laboratory conditions. CHL and its different formulations may be used as potent larvicides against Fasciola gigantica larvae. Chlorophyllin formulations will be economical, ecologically sounder and their use in aquatic environment will be safe.

Objective: The effect of chlorophyllin (CHL), CHL + freeze dried cow urine (FCU) and FCU on acetylcholinesterase (AChE) and cytochrome oxidase activity in the nervous tissue of the host snail Lymnaea acuminata, and parasitic cercaria larvae of Fasciola gigantica were studied. Methods: Whole cercaria larvae and snail nervous tissue was homogenized and supernatant was used as an enzyme source. Enzyme activity was measured in 10-mm path length cuvette using incubation mixtures and change in optical density was recorded. Results: Sublethal 4 h LC50 40% and 80% of these formulations in sunlight and laboratory conditions caused no significant change in AChE activity in the nervous tissue of host snail. It was noted that sublethal in vivo 8 h exposure to 40% and 80% of 4 h LC50 of single and binary combination of CHL+FCU, CHL and FCU significantly altered the AChE and cytochrome oxidase activity in the cercaria larvae. Binary combinations of CHL+FCU in sunlight were more effective in inhibiting both the enzymes. Conclusion: The present study reported that enzymes AChE and cytochrome oxidase were inhibited by chlorophyllin formulations and thus causing the larval death inside the snail body without affecting the snail itself which is an important bioindicator of aquatic ecosytem. [ABSTRACT FROM AUTHOR]

Molluscs have long been regarded as promising bioindicator and biomonitoring subjects for heavy metals as molluscs are highly tolerant to heavy metals and exhibit high accumulation in their body. In spite of several previous studies about the impact of cadmium on molluscs, little information exists in literatures concerning the toxic effects of cadmium on Lymnaea acuminata, especially pertaining to behavioral and hematological changes as these are considered effective bioindicators and biomonitoring variables for detecting heavy metals in polluted water bodies. In the present study, the median lethal concentrations of cadmium chloride to snail, Lymnaea acuminata, were estimated to be 9.66, 7.69, 6.26, and 5.54 mg/L at 24, 48, 72, and 96 h, respectively. For behavioral studies, variable test concentrations of cadmium from 0.00 to 10 mg/L were used. The clumping tendency, crawling activity, and touch reflex in the exposed snails were gradually decreased with higher concentrations at 72 and 96 h. For measuring the hemocyte numbers in the circulating hemolymph of snail during chronic cadmium exposure, two sublethal doses of cadmium (10 and 20% 96-h LC-0.55 and 1.11 mg/L, respectively) were used. A significant variation ( p < 0.05) from the control at all exposure times (7, 14, 21, and 28 days) was recorded at 1.11 mg/L concentration. The total count of circulating hemocytes was significantly reduced ( p < 0.05) compared to the controls at both concentrations of cadmium exposure at all time periods except 14 and 21 days exposure at 0.55 mg/L where values were non-significantly increased. In comparison between two sublethal doses, blood cells were significantly ( p < 0.05) lowered at 1.11 mg/L cadmium treatment. Considering the behavioral and hematological data, it seems possible to forecast the physiological state of snails in cadmium-contaminated water bodies and these findings can be used in determining the safe disposal level of cadmium in aquatic ecosystem. [ABSTRACT FROM AUTHOR]

Objective: To observe the toxicity of chlorophyllin against Lymnaea acuminata to control fasciolosis caused by liver fluke fasciola gigantica, very prominent in eastern region of Uttar Pradesh. Materials and Methods: Ten snails Lymnaea acuminata were placed in a glass aquarium containing 3 L of dechlorinated tap water. These snails were treated with different concentrations of chlorophyllin. Chlorophyll was extracted from spinach with the help of macerated leaves and kept for 2 h in 100% ethanol at 55ºC. Results: The results of the experiment showed that the photodynamically active chlorophyllin, at low concentration was able to kill the snails under exposure of solar radiation in summer season instead of winter season. In winter, extracted chlorophyllin toxicity against L. acuminata in sunlight (96 h LC50 91.82 mg L-1) /laboratory condition (96 h LC50 921.93 mg L-1) was less than pure chlorophyllin in sunlight (96 h LC50 12.05 mg L-1) /laboratory condition (96 h LC50 19.22 mg L-1), respectively. In summer, pure chlorophyllin was more toxic in sunlight (96 h LC50 3.90 mg L-1) than laboratory condition (96 h LC50 7.18 mg L-1). Pure chlorophyllin is more than five times toxic than synthetic molluscicides. Treatment of chlorophyllin caused no toxic effect against the fish (Colisa fasciatus). The result presented in this paper is found very beneficial and ecologically safe, as a photodynamic substance chlorophyllin, which found in every green plant. Conclusion: Phytotherapy of snails by photodynamic water soluble chlorophyllin to control fasciolosis can be used as potent molluscicides with low cost and easily biodegradable. [ABSTRACT FROM AUTHOR]

SUMMARY A food-borne trematode infection fascioliasis is one among common public health problems worldwide. It caused a great economic loss for the human race. Control of snail population below a certain threshold level is one of the important methods in the campaign to reduce the incidence of fascioliasis. The life cycle of the parasite can be interrupted by killing the snail or Fasciola larva redia and cercaria inside of the snail Lymnaea acuminata. In vitro toxicity of different binary combinations (1:1 ratio) of plant-derived larvicidal active components such as citral, ferulic acid, umbelliferone, azadirachtin and allicin against Fasciola redia and cercaria were tested. The mortality of larvae was observed at 2h, 4h, 6h and 8h of treatment. In in vitro condition azadirachtin + allicin (1:1 ratio) was highly toxic against redia and cercaria (8h LC50 0.006 and 0.005 mg/L). Toxicity of citral + ferulic acid was lowest against redia and cercaria larvae.

SUMMARY The molluscicidal activity of the leaf powder of Moringa oleifera and lyophilized fruit powder of Momordica charantia against the snail Lymnaea acuminata was time and concentration dependent. M. oleifera leaf powder (96 h LC50: 197.59 ppm) was more toxic than M. charantia lyophilized fruit powder (96 h LC50: 318.29 ppm). The ethanolic extracts of M. oleifera leaf powder and Momordica charantia lyophilized fruit powder were more toxic than other organic solvent extracts. The 96 h LC50 of the column purified fraction of M. oleifera leaf powder was 22.52 ppm, while that of M. charantia lyophilized fruit powder was 6.21 ppm. Column, thin layer and high performance liquid chromatography analysis show that the active molluscicidal components in M. oleifera leaf powder and lyophilized fruit of M. charantia are benzylamine (96 h LC50: 2.3 ppm) and momordicine (96 h LC50: 1.2 ppm), respectively. Benzylamine and momordicine significantly inhibited, in vivo and in vitro, the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activities in the nervous tissues of L. acuminata. Inhibition of AChE, ACP and ALP activity in the nervous tissues of L. acuminata by benzylamine and momordicine may be responsible for the molluscicidal activity of M. oleifera and M. charantia fruits, respectively.

The molluscicidal activity of Bauhinia variegata leaf and Mimusops elengi bark was studied against vector snail Lymnaea acuminata. The toxicity of both plants was time and concentration-dependent. Among organic extracts, ethanol extracts of both plants were more toxic. Toxicity of B. variegata leaf ethanolic extract (96h LC50- 14.4 mg/L) was more pronounced than M. elengi bark ethanolic extract (96h LC50-15.0 mg/L). The 24h LC50 of column purified fraction of B. variegata and M. elengi bark were 20.3 mg/L and 18.3 mg/L, respectively. Saponin and quercetin were characterized and identified as active molluscicidal component. Co-migration of saponin (Rf 0.48) and quercetin (Rf 0.52) with column purified bark of M. elengi and leaf of B. variegata on thin layer chromatography demonstrate same Rf value i.e. 0.48 and 0.52, respectively. The present study clearly indicates the possibility of using M. elengi and/or B. variegata as potent molluscicide.

The present work was carried out to evaluate the molluscicidal activity of active ingredient Taraxerol with the acetone extract of Euphorbia tirucalli against Lymnaea acuminata snail. The (fecundity, hatchability and survivability) of snail L. acuminata exposed to this extract was studied. The effects of the tested extracts on life-history traits of harmful snail L. acuminata have also been evaluated, and this study also expounds the inhibitory effects of these extracts singly as well as in binary combination (1:1 ratio). It concluded that these herbal products act as a potential source of molluscicides, and that they would also have the advantage of easy availability, low cost, biodegradability and greater acceptance amongst users than synthetic pesticide.

The effect of sub-lethal feeding of bait formulations containing molluscicidal component of Ferula asafoetida (ferulic acid, umbelliferone), Syzygium aromaticum (eugenol) and Carum carvi (limonene) on biochemical changes in the ovotestis of snail Lymnaea acuminata were studied. Bait formulations feeding to L. acuminata were studied in clear glass aquaria having diameter of 30 cm. Baits were prepared from different binary combinations of attractant amino acid (valine, aspartic acid, lysine and alanine 10 mM) in 100 mL of 2% agar solution + sub-lethal (20% and 60% of 24h LC50) doses of different molluscicides (ferulic acid, umbelliferone, eugenol and limonene). These baits caused maximum significant reduction in free amino acid, protein, DNA, RNA levels i.e. 41.37, 23.56, 48.36 and 14.29% of control in the ovotestis of the snail, respectively. Discontinuation of feeding after treatment of 60% of 96h LC50 of molluscicide containing bait for next 72h caused a significant recovery in free amino acid, protein, DNA and RNA levels in the ovotestis of L. acuminata.

The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix) acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch) (Channidae {Ophicephalidae}), which shares the habitat with these snails, but the LC90 (24h) doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.

Fasciolosis is a food borne zoonosis, caused by the digenetic trematode Fasciola. Freshwater lymnaeid snails are the intermediate host of the trematodes. Chlorophyllin, a semi-synthetic derivative of chlorophyll and its formulations obtained from freeze dried cow urine (FCU) had their toxicity tested against redia and cercaria larvae of F. gigantica. The larvicidal activity of chlorophyllin and its formulations were found to depend on both, time and concentration used against the larvae. Toxicity of chlorophyllin + FCU (1:1 ratio) in sunlight against redia larva (8 h LC50: 0.03 mg/mL) was more pronounced than using just chlorophyllin (8 h LC50: 0.06 mg/mL). Toxicity of chlorophyllin + FCU in sunlight against redia (8 h LC50: 0.03 mg/mL) was higher than against cercaria (8 h LC50: 0.06 mg/mL). The larvicidal activity of chlorophyllin in sunlight (redia/cercaria larvae: 8 h LC50: 0.06 mg/mL) was more pronounced than under laboratory conditions (redia: 8 h LC50: 22.21 mg/mL/, cercaria 8 h LC50: 96.21 mg/mL). Toxicity of FCU against both larvae was lower than that of chlorophyllin and chlorophyllin + FCU. Chlorophyllin and its formulations + FCU were 357.4 to 1603.5 times more effective against redia/cercaria larvae in sunlight than under laboratory conditions. The present study has shown that chlorophyllin formulations may be used as potent larvicides against fasciolosis.

Introduction: Paper demonstrates effect of the active molluscicidal components arjunolic acid (Terminalia arjuna bark) and procynadine (Tamarindus indica seed) on the activity of acetylcholinesterase (AChE) and phosphatases (ACP/ALP) in the cerebral ganglion of snail Lymnaea acuminata. Materials and Methods: Kinetics of AChE/ACP/ ALP inhibition in the cerebral ganglion of snail Lymnaea acuminata was studied via in vivo (40% and 80% of 96 h LC50) and in vitro treatments (0.3 μg to 7.0 μg) of the column purified fractions, arjunolic acid and procynadine. Results: In vivo exposure of procynadine and arjunolic acid significantly inhibit acetylcholinesterase (AChE), acid phosphatase (ACP) and alkaline phosphatase (ALP) activities in the cerebral ganglion of L. acuminata exposed to 80% of 96h LC50. In in vitro treatment maximum inhibition in AChE/ACP/ALP activities in the cerebral ganglion of snail were noted when exposed to 7.0 μg of arjunolic acid and 0.9 μg of procynadine. Column purified fraction of T. arjuna bark and T. indica seed caused non-competitive and uncompetitive inhibition of AChE activity, respectively. Column purified fraction and arjunolic acid of T. arjuna bark caused uncompetitive inhibition of ACP while column purified fraction and procynadine of T. indica seed caused competitive inhibition. Competitivenon- competitive inhibition of ALP activity in the cerebral ganglion of L. acuminata was observed after treatment of column purified active components of both plants. Conclusions: The molluscicidal activity of T. arjuna bark (arjunolic acid) and T. indica seed (procynadine) against snail L. acuminata is due to the inhibition of AChE/ACP/ ALP. Their inhibition kinetics against AChE/ACP/ALP, were different in cerebral ganglion of snail. [ABSTRACT FROM AUTHOR]

Fasciolosis is a water and food-borne disease caused by the liver fluke Fasciola hepatica and Fasciola gigantica. This disease is widespread in different parts of the world. Lymnaeidae and Planorbidae snails are the intermediate hosts of these flukes. Snail population management is a good tool to control fasciolosis because gastropods represent the weakest link in the life-cycle of trematodes. Chlorophyll can be extracted from any green plant. Chlorophyllin was prepared from spinach in 100% ethanol by using different types of chemicals. The chlorophyll obtained from spinach was transformed into water-soluble chlorophyllin. In the present paper, toxicity of chlorophyllin against the snail Lymnaea acuminata was time and concentration dependent. The toxicity of extracted and pure chlorophyllin at continuous 4 h exposure of sunlight was highest with lethal concentration (LC50) of 331.01 mg/L and 2.60 mg/L, respectively, than discontinuous exposure of sunlight up to 8 h with LC50 of 357.04 mg/L and 4.94 mg/L, respectively. Toxicity of extracted chlorophyllin was noted in the presence of different monochromatic visible lights. The highest toxicity was noted in yellow light (96 h, LC50 392.77 mg/L) and the lowest in green light (96 h, LC50 833.02 mg/L). Chlorophyllin in combination with solar radiation or different wavelength of monochromatic visible lights may become a latent remedy against the snail L. acuminata. It was demonstrated that chlorophyllin was more toxic in sunlight. Chlorophyllin is ecologically safe and more economical than synthetic molluscicides which have the potential to control the incidence of fasciolosis in developing countries. [ABSTRACT FROM AUTHOR]

Adult Lymnaea acuminata (average length 20-22 mm) were collected locally from lakes and low-lying submerged fields from Gorakhpur. The chemoattraction studies were made in round glass aquaria measuring 30 cm in diameter and filled to a depth of 10 mm with 500 ml dechlorinated tap water. Each aquarium was divided into four concentric zones. At the starting time of the assay 10 snails were placed on the circumference of outermost zone 0. Snail attractant pellets (SAP) were added simultaneously in the center of central zone 3. SAP of different amino acids were prepared at concentrations of 10, 20, 50, 80 and 100 mM/2% agar solution and, subsequently, spread to a uniform thickness of 5 mm. After cooling, SAP were cut in small pieces of 5 mm in diameter. Lymnaea acuminata's attraction to amino acids was studied using different amino acid concentrations in SAP. Pellets containing amino acids with non-polar R groups (proline and tryptophan), a charged polar group (arginine) and uncharged polar R groups (serine, citrulline and asparagine) were tested. The snails were more attracted to the uncharged polar R group amino acid serine than to other groups of amino acids. The preferred amino acid concentration was 80 mM. The attraction of snails to different amino acids was concentration dependent. Snails could discriminate amongst the different amino acids at > or = 50 mM.

Objective: To test whether the larvicidal activity of citral against Fasciola varies by season. Methods: Mortality of Fasciola larva in different month of year (2011–2012) in in vitro and in vivo condition were observed at 2 h, 4 h, 6 h and 8 h exposure of citral. Results: In vitro toxicity of citral against redia was highest in between the June to August (8 h LC50: 2.58–2.62 mg/L), whereas against cercaria 8 h LC50 was in between 3.44–2.62 mg/L. Highest in vivo toxicity against redia was noted in between June to August (8h LC50: 4.20–5.09 mg/L). The lowest toxicity was observed from November to April. The highest temperature, free carbon dioxide, and lowest pH, dissolved oxygen were observed from June to August. Conclusions: The present study conclusively shows that varying a biotic factor can significantly alter the in vitro and in vivo toxicity of citral against sporocyst redia and cercaria larva.

Fasciolosis is an important cattle and human disease caused by Fasciola hepatica and Fasciola gigantica . One of the possible methods to control this problem is to interrupt the life cycle of Fasciola by killing its larva (redia and cercaria) in host snail. Molecular identification of cercaria larva of F. gigantica was done by comparing the nucleotide sequencing with adult F. gigantica . It was noted that nucleotide sequencing of cercaria larva and adult F. gigantica were 99% same. Every month during the year 2011–2012, in vivo treatment with 60% of 4 h LC 50 of phyto cercaricides citral, ferulic acid, umbelliferone, azadirachtin and allicin caused significant inhibition of acetylcholinesterase (AChE) and cytochrome oxidase activity in the treated cercaria larva of F. gigantica . Whereas, activity of both enzymes were not significantly altered in the nervous tissues of vector snail Lymnaea acuminata exposed to same treatments. Maximum reduction in AChE (1.35% of control in month of June) and cytochrome oxidase (3.71% of control in the month of July) activity were noted in the cercaria exposed to 60% of 4 h LC 50 of azadirachtin and allicin, respectively. [ABSTRACT FROM AUTHOR]

Fasciolosis is a food borne zoonosis, caused by the digenetic trematode Fasciola. Freshwater lymnaeid snails are the intermediate host of the trematodes. Chlorophyllin, a semi-synthetic derivative of chlorophyll and its formulations obtained from freeze dried cow urine (FCU) had their toxicity tested against redia and cercaria larvae of F. gigantica. The larvicidal activity of chlorophyllin and its formulations were found to depend on both, time and concentration used against the larvae. Toxicity of chlorophyllin + FCU (1:1 ratio) in sunlight against redia larva (8 h LC50: 0.03 mg/mL) was more pronounced than using just chlorophyllin (8 h LC50: 0.06 mg/ mL). Toxicity of chlorophyllin + FCU in sunlight against redia (8 h LC50: 0.03 mg/mL) was higher than against cercaria (8 h LC50: 0.06 mg/mL). The larvicidal activity of chlorophyllin in sunlight (redia/cercaria larvae: 8 h LC50: 0.06 mg/mL) was more pronounced than under laboratory conditions (redia: 8 h LC50: 22.21 mg/mL/, cercaria 8 h LC50: 96.21 mg/mL). Toxicity of FCU against both larvae was lower than that of chlorophyllin and chlorophyllin + FCU. Chlorophyllin and its formulations + FCU were 357.4 to 1603.5 times more effective against redia/cercaria larvae in sunlight than under laboratory conditions. The present study has shown that chlorophyllin formulations may be used as potent larvicides against fasciolosis. [ABSTRACT FROM AUTHOR]

The molluscicidal activity of Punica granatum Linn. (Punicaceae) and Canna indica Linn. (Cannaceae) against the snail Lymnaea acuminata was studied. The molluscicidal activity of P. granatum bark and C. indica root was found to be both time and dose dependent. The toxicity of P. granatum bark was more pronounced than that of C. indica. The 24 h LC50 of the column-purified root of C. indica was 6.54 mg/l whereas that of the column-purified bark of P. granatum was 4.39 mg/l. The ethanol extract of P. granatum (24 h LC50: 22.42 mg/l) was more effective than the ethanol extract of C. indica (24 h LC50: 55.65 mg/l) in killing the test animals. P. granatum and C. indica may be used as potent molluscicides since the concentrations used to kill the snails were not toxic for the fish Colisa fasciatus, which shares the same habitat with the snail L. acuminata.

Background & objectives: Indiscriminate use of synthetic pesticides has created serious problem for the aquatic flora and fauna, and also resulted in appearance of pesticide resistance in vector population. This study was designed to evaluate the biocontrol efficacy of aqueous and solvent extracts of mature leaves of Solanum nigrum L., against fresh water snail Lymnaea acuminata f. rufescens (Gray) (an intermediate host of parasites causing fasciolopsiasis) and larvae of Culex vishnui group (Reuben) (vector of Japanese encephalitis). Methods: Aqueous and solvent extracts of fresh, mature, green/shed dried leaves of S. nigrum were tested against adult L. acuminata and larvae of Cx. vishnui group. The lethal concentration was determined and the appropriate lethal concentration at 24 h of benzene extract was also studied on non target organisms such as Daphnia sp, Diplonychus annulatum and Chironomus circumdatus. A qualitative phytochemical analysis was carried out in search of active ingredient and the chemical nature of the active substance was also evaluated by infrared (IR) analysis. Results: In a 72 h bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5 and 3 per cent extract against larvae of Cx. vishnui group and L. acuminata, respectivela. In the benzene solvent extract, the maximum mortality was recorded at a concentration of 150 ppm against L. acuminata and at 50 ppm against larvae of Cx. vishnui group with LC50 values of 55.45 and 11.59 ppm, respectively at 72 h. The log probit analysis (95% confidence level) recorded lowest value at 72 h of exposure. Qualitative phytochemical analysis reported the presence of some biochemical compounds, such as saponin, lavonoids, steroid and tannin. Among these, the toxic compound was detected by IR analysis having Rf = 0.87 (showed 66.70% and 76.70% mortality of L. acuminata and larvae of Cx. vishnui group, respectively). IR analysis provided preliminary information about the aliphatic amide nature of the active ingredient. Interpretation & conclusions: The study results provide considerable scope in exploiting local indigenous plant resources for molluscicidal and mosquito larvicidal activities. [ABSTRACT FROM AUTHOR]

Piperonyl butoxide (PB) and MGK-264 were used to enhance the toxicity of the active components papain, arecoline and myristicin from the plants Carica papaya, Areca catechu and Myristica fragrans, respectively, against the vector snail Lymnaea acuminata. A time- and dose-dependent relationship was observed for the toxicity of these combinations. The toxic effects of these plant-derived molluscicides in combination with the synergists PB and MGK-264 were several times higher than the effect of the individual treatments. The highest degree of synergism was observed when MGK-264 was used in combination with C. papaya latex (10.47-fold increase) and PB was used with papain (8.35-fold increase). [ABSTRACT FROM AUTHOR]

Laboratory evaluation was made to access the seasonal variations in abiotic environmental factors temperature, pH, dissolved oxygen, carbon dioxide, electrical conductivity and ferulic acid toxicity in snail-attractant pellets (SAP) against the intermediate host snail Lymnaea acuminata in each month of the years 2010 and 2011. On the basis of a 24-h toxicity assay, it was noted that lethal concentration values of 4.03, 3.73% and 4.45% in SAP containing starch and 4.16, 4.23% and 4.29% in SAP containing proline during the months of May, June and September, respectively, were most effective in killing the snails, while SAP containing starch/proline + ferulic acid was least effective in the month of January/February (24-h lethal concentration value was 7.67%/7.63% in SAP). There was a significant positive correlation between lethal concentration value of ferulic acid containing SAP and levels of dissolved O2/pH of water in corresponding months. On the contrary, a negative correlation was observed between lethal concentration value and dissolved CO2/temperature of test water in the same months. To ascertain that such a relationship between toxicity and abiotic factors is not co-incidental, the nervous tissue of treated (40% and 80% of 24-h lethal concentration value) and control group of snails was assayed for the activity of acetylcholinesterase (AChE) in each of the 12 months of the same year. There was a maximum inhibition of 58.43% of AChE, in snails exposed to 80% of the 24-h lethal concentration value of ferulic acid + starch in the month of May. This work shows conclusively that the best time to control snail population with SAP containing ferulic acid is during the months of May, June and September. [ABSTRACT FROM AUTHOR]

Copyright of Revista do Instituto de Medicina Tropical de São Paulo is the property of Instituto de Medicina Tropical de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We assessed the lethality of a bait containing both Iimonene and an attractant (starch or proline) against the pest snail Lymnaea acuminata for every month of the year 2010-2011. Simultaneously, levels of temperature, pH, dissolved oxygen, carbon dioxide and electrical conductivity in test water were measured. In 24 h toxicity assays, carried out in May, June and July, lethal concentration (LC50) values of 3.99, 4.47 and 4.44% were obtained for bait containing proline 4- Iimonene, and values of 5.45, 4.41 and 5.60% were obtained for bait containing starch 4- Iimonene. A significant positive rank correlation was observed between different concentrations of Iimonene in bait and acetylcholinesterase activity in the nervous tissue of the snail. There was maximum inhibition (57.93%) of acetylcholinesterase activity in snails fed bait containing 80% of the 24-h LC50 of Iimonene 4- proline in May. Our results indicate that snail populations can be controlled by a Iimonene bait formulation applied in a specific month rather than all the year round. [ABSTRACT FROM AUTHOR]

Copyright of Revista do Instituto de Medicina Tropical de São Paulo is the property of Instituto de Medicina Tropical de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Snail is one of the important components of aquatic ecosystem it act as intermediate host of Fasciola species. The life cycle of parasite can be interrupted by killing the vector snail or Fasciola larva (sporocyst, redia and cercaria) inside the snail body. Effect of abiotic factors on the toxicity of umbelliferone against Fasciola larvae in different months of the year 201 1 -201 2. In highest in vivo toxicity is noted of umbelliferone against, redia and cercaria larva was noted in month of May and July (redia - 8h LC50=0.93, and 0.89 mg/L; cercaria - 8h LC50=0.70 and 0.92 mg/L). In in vitro treatment highest toxicity against redia and cercaria larva was absorbed June, July and August (redia - 8h LC50= 0.26, 0.30 and 0.28 mg/L; cercaria - 8h LC50=0.09, 0.1 1 and 0.1 8 mg/L). The lowest toxicity was observed the month of November to January. The highest temperature, free carbon dioxide, and lowest pH, dissolved oxygen were observed in the months of June to August. The present study conclusively shows that variant abiotic factor can significantly alter the in vitro and in vivo toxicity of umbelliferone against sporocyst redia and cercaria larva. [ABSTRACT FROM AUTHOR]

Effect of sublethal (20% and 60% of 24h LC50) feeding of molluscicides (eugenol, ferulic acid, umbelliferone and limonene) in bait containing binary combination (1 :1 ratio) of amino acids (valine, aspartic acid, lysine and alanine) on the, hatchability and survival of young snails of Lymnaea (Radix) acuminata (Lamark) was studied. I t was observed that the different amino acid combinations of bait formulation with molluscicides significantly reduced the reproductive capacity (fecundity, hatchability and survival of young snails) of the snail Lymnaea acuminata. Maximum in reduction of fecundity was observed in valine + aspartic acid + ferulic acid (28.89% of control). In withdrawal group there is a significant recovery observed in all feeded group (85.95% of control). [ABSTRACT FROM AUTHOR]

Comparative histopathological effects were observed on the digestive glands (hepatopancreas) of freshwater snail species, Vivipara bengalensis and Lymnaea acuminata infected with single (furcocercous cercariae) and double infection of digenean trematode larvae (gymnocephalous cercariae + metacercariae), respectively. Digestive glands of both the snail species revealed degenerative changes in their digestive gland tubules. The latter became irregular in shape, reduced in size with enlarged lumen and inter-tubular space besides rupturing of digestive tubules. These changes were correlated with the size and types of trematode larvae, single or double infection and degree of parasitemia. Autolytic necrosis of numerous tubules was found in digestive glands infected with double and very severe single infection. None of the tubules was found to be invaded by sporocyst, redia and cercaria. However, metacercariae were seen to invade digestive tubules of Lymnaea species. [ABSTRACT FROM AUTHOR]

The article reports on a research related to determination of lethal concentration 50 (LC50) values of eugenol, a molluscicide, against a snail Lymnaea acuminata, concomitantly determining several other parameters such as temperature, dissolved oxygen (DO) and dissolved carbon dioxide (DCO). It mentions that positive correlation between the LC50 value of eugenol containing snail attractant pellets and DO level and pH was observed, while DCO showed negative correlation.

Copyright of Revista do Instituto de Medicina Tropical de São Paulo is the property of Instituto de Medicina Tropical de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Effect of active molluscicidal components of Sapindus mukorossi and Terminalia chebula on the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of freshwater snail Lymnaea acuminata were studied. In vivo and in vitro exposure of saponin (active component of S. mukorossi pericarp) and tannic acid (active component of T. chebula) significantly inhibited the AChE, ACP and ALP activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that saponin and tannic acid caused competitive and competitive–non-competitive inhibition of AChE, respectively. Saponin also caused competitive and competitive–non-competitive inhibition of ACP and ALP, respectively, whereas tannic acid caused competitive–non-competitive inhibition of ACP and ALP. Thus the inhibition of AChE, ACP and ALP by saponin and tannic acid in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of S. mukorossi and T. chebula. [Copyright &y& Elsevier]

The effect of sub-lethal feeding of bait formulations containing molluscicidal component of Ferula asafoetida (ferulic acid, umbelliferone), Syzygium aromaticum (eugenol) and Carum carvi (limonene) on biochemical changes in the ovotestis of snail Lymnaea acuminata were studied. Bait formulations feeding to L. acuminata were studied in clear glass aquaria having diameter of 30 cm. Baits were prepared from different binary combinations of attractant amino acid (valine, aspartic acid, lysine and alanine 10 mM) in 100 mL of 2% agar solution + sub-lethal (20% and 60% of 24h LC50) doses of different molluscicides (ferulic acid, umbelliferone, eugenol and limonene). These baits caused maximum significant reduction in free amino acid, protein, DNA, RNA levels i.e. 41.37, 23.56, 48.36 and 14.29% of control in the ovotestis of the snail, respectively. Discontinuation of feeding after treatment of 60% of 96h LC50 of molluscicide containing bait for next 72h caused a significant recovery in free amino acid, protein, DNA and RNA levels in the ovotestis of L. acuminata. [ABSTRACT FROM AUTHOR]

The present work was carried out to evaluate the molluscicidal activity of active ingredient Taraxerol with the acetone extract of Euphorbia tirucalli against Lymnaea acuminata snail. The (fecundity, hatchability and survivability) of snail L. acuminata exposed to this extract was studied. The effects of the tested extracts on life-history traits of harmful snail L. acuminata have also been evaluated, and this study also expounds the inhibitory effects of these extracts singly as well as in binary combination (1:1 ratio). It concluded that these herbal products act as a potential source of molluscicides, and that they would also have the advantage of easy availability, low cost, biodegradability and greater acceptance amongst users than synthetic pesticide. [ABSTRACT FROM AUTHOR]

Aim: Fascioliasis is an important helminth disease caused by Fasciola (F.) hepatica and F. gigantica of Asia and Africa. This disease belongs to the plant-borne trematode zoonoses. Human infection has been reported in 51 different countries from 5 continents. One of the possible approaches to control this problem is to interrupt the life cycle of the parasitic trematodes by eliminating the snail. Materials and Methods: Snails attractant pellets (SAP) were prepared from binary combination of carbohydrate + amino acid (20 mM) in 2% agar solution with active molluscicidal component Ferula asafoetida (ferulic acid, umbelliferone), Syzygium aromaticum (eugenol), Carum carvi (limonene). Attraction of snails to different combinations was studied by using clear glass aquaria having diameter of 30 cm. Each aquarium was divided into four concentric zones; zone-3 (central zone), zone-2 and zone-1 (middle zone) and zone-0 (outer zone) had a diameter of 13, 18, 24, and 30 cm, respectively. The behavioral responses of snails to these binary combinations of carbohydrate and amino acid in bait formulation were examined. The fraction of snails that was in contact with the SAP at different times was used as a measure of attraction. Results: Among all the binary combination of carbohydrate+amino acid+molluscicide after 2h of experient, highest attraction of snail (54.71%) was observed towards the SAP containing starch+histidine+limolene. Limonene+ starch+histidine containing SAP emerged as the strongest bait formulation (96h LC50 0.74%) against Lymnaea acuminata. Conclusions: The present study suggested that the molluscicides of plant origin could be used with varying degrees of success in bait formulation. [ABSTRACT FROM AUTHOR]

Abstract: The molluscicidal activity of Sapindus mukorossi and Terminalia chebula fruit powder against the vector snail Lymnaea acuminata was time and concentration dependent. The molluscicidal activity of T. chebula fruit powder (96h LC50:93.59mgL−1) was more pronounced than that of S. mukorossi fruit powder (96h LC50:119.57mgL−1). Ethanolic extracts of S. mukorossi and T. chebula fruit powder were more toxic than their other organic solvent extracts. The molluscicidal activity of ethanolic extract of S. mukorossi fruit powder (24h LC50:2.75mgL−1) was more effective than the ethanolic extract of T. chebula fruit powder (24h LC50:124.06mgL−1). The 96h LC50 of column-purified fraction of S. mukorossi fruit powder was 5.43mgL−1 whereas those of T. chebula fruit powder was 7.49mgL−1. Column, thin layer and high performance liquid chromatography analysis demonstrates that the active molluscicidal component in S. mukorossi and T. chebula is saponin (96h LC50:1.31mgL−1) and tannic acid (96h LC50:1.64mgL−1), respectively. These plants may be used as potent source of molluscicides against the snail L. acuminata. [Copyright &y& Elsevier]

Copyright of Revista do Instituto de Medicina Tropical de São Paulo is the property of Instituto de Medicina Tropical de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Calotropis procera, commonly known as 'Arka,' is a popular medicinal plant found throughout the tropics of Asia and Africa. It has been widely used in the Indian traditional medical system for the treatment of a variety of disease conditions due to the presence of four ursane-type triterpenoids: cardiac glycosides, alkaloids, flavonoids, tannins and saponins. This study evaluated the toxicity of aqueous, ethanolic, and chloroform extracts of different parts of plant C. procera against two species of harmful snails: Lymnaea acuminata and Indoplanorbis exustus. The toxicity of these extracts were both time- and dose-dependent. Aqueous extracts of all parts of C. procera were less toxic compared to the ethanol and chloroform extracts. The chloroform extracts of all plant parts were more toxic than aqueous and ethanol extracts. Chloroform extracts of root and latex exhibited 4.27 and 4.88 96h LC50 against Lymnaea acuminata and Indoplanorbis exustus, respectively. [ABSTRACT FROM AUTHOR]

Snail attractant pellets (SAP) were prepared from binary combination (1:1) of amino acid (20mM) in 2% agar solution. Attraction of snails to different binary combinations with molluscicides was studies by using clear glass aquaria. The fraction of snails that were in contact with the SAP at 1h and 2h were used as a measure of attraction. These were tested on Lymnaea acuminata. The behavioral responses of snails to these binary combinations of amino acid were examined. The fraction of snails that were in contact with the SAP at different times was used as a measure of attraction. Among all the binary combinations of amino acid alanine + valine with molluscicides 0.7% eugenol attract maximum (39.50%) snail after 2h. Toxicity of these SAP containing different molluscicides are time and concentration dependent. SAP containing alanine + valine and limonene emerged as the strongest bait formulation (96h LC50 1.50%) against L. acuminata. [ABSTRACT FROM AUTHOR]

Lymnaea acuminata breeds round the year. The effect of pH, temperature, dissolved oxygen, carbon dioxide, light/dark period and clean/polluted water on the fecundity, hatchability and survival of young snails of L. acuminata were studied. It was observed that these environmental variant abiotic factors caused a significant variation in fecundity, hatchability and survival of young snails. Maximum reproduction of this snail was observed in the months of March to May. A significant positive correlation ( p < 0.05) between D.O. (3.1-7.7 ppm)/pH (7.01-8.96) of water with fecundity (6.0-196.33/20 snails), hatchability (54.69-96.91%) and survival (61.3-95.86%) of young snails was observed for each month and each interval of 24-72 h. In contrast, a significant negative correlation between dissolved CO2 (4.6-16.6 ppm)/temperature (16-37°C) of water was noted with fecundity, hatchability and survival of snails. Percent hatchability in the eggs in different regimens of water was between 96.91-54.69%. The hatching period was prolonged (2-14 days) in snail exposed to different groups of water compared to the control group (2-9 d). This study conclusively shows that variant abiotic factors in different months of the year can significantly alter the reproductive ability and development process in the snail Lymnaea acuminata. [ABSTRACT FROM AUTHOR]

Abstract: The molluscicidal activity of bark powder of Saraca asoca, leaf powder of Thuja orientalis against the snail Lymnaea acuminata was studied. The molluscicidal activity of all the plant products was found to be both time and concentration dependent. The 96h LC50 of T. orientalis leaf powder against L. acuminata was 250.5mg/l. Ethanol extracts were more toxic than other organic extracts. The ethanol extract of T. orientalis leaf (24h LC50: 32.74mg/l) was more effective than that of S. asoca bark (24h LC50: 82.38mg/l). The 24h LC50 of column purified fraction of T. orientalis leaf and S. asoca bark powder was 29.25 and 64.89mg/l, respectively. Saponin and thujone were identified as active molluscicide components in the bark of S. asoca and leaf of T. orientalis, respectively. The product of S. asoca and T. orientalis may be used as potent molluscicides. [Copyright &y& Elsevier]

Abstract: In the present study toxic effects of active molluscicidal component of Areca catechu and Carica papaya was studied on certain enzymes in the nervous tissue of freshwater snail Lymnaea acuminata. In in vivo and in vitro exposure of arecoline (active component of Areca catechu seed) and papain (C. papaya latex and seed) significantly inhibited the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that arecoline and papain caused competitive and uncompetitive inhibition of AChE, respectively, whereas arecoline caused competitive–non-competitive inhibition of ACP/ALP and papain caused non-competitive inhibition of ACP/ALP. Thus the inhibition of AChE, ACP and ALP by arecoline and papain in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of A. catechu and C. papaya, respectively. [Copyright &y& Elsevier]

Abstract: Snail control is one of the important methods in the campaign to reduce the incidence of fascioliasis and schistosomiasis. In order to achieve this objective, the method of bait formulation containing an attractant and a molluscicide is an appropriate approach to lure the target snail population to the molluscicide. In the present study snail attractant pellets (SAP) were prepared from binary combination of carbohydrates (10mM) and amino acids (20mM) in 2% agar solution. These were tested on Lymnaea acuminata, an intermediate host of the digenean trematodes Fasciola hepatica and Fasciola gigantica. The behavioral responses of snails to these binary combination were examined. The fraction of snails that was in contact with the SAP at different times was used as a measure of attraction. Among all the binary combination of carbohydrates; (sucrose+starch)—72.9%, binary combination of amino acids; (proline+serine)—48.0% and binary combination of carbohydrates and amino acids; (sucrose+serine)—69.5%, emerged as the strongest attractant pellets. Toxicity of these SAP containing different concentrations of molluscicides were used as bait against the snail, L. acuminata. Thymol containing SAP emerged as the strongest bait formulation (96h LC50 0.540%, 0.318% and 0.305%) against L. acuminata. [Copyright &y& Elsevier]

Effect of sublethal treatment of (40% and 60% of 48h LC50) of deltamethrin+MGK on phospholipid level and rate of lipid peroxidation in nervous and foot tissue of Lymnaea acuminata were studied. Maximum reduction in phospholipid (24.10%) level and increase in rate of lipid peroxidation (586.8%) were observed in foot tissue of snail exposed to 60% of 48h LC50 of deltamethrin+MGK 264 for 96h. Alterations in the levels of phospholipids and rate of lipid peroxidation were time and concentration dependent. Use of MGK-264 with deltamethrin increases the toxicity of deltamethrin and their action on membrane phospholipids and rate of lipid peroxidation. [Copyright &y& Elsevier]