Lymnaea Acuminata Research Articles

Laboratory Assessment of Molluscicidal Activities of Cannabis sativa, Acacia nilotica, and Tinospora cordifolia Against Snail Host of Fasciola spp.

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.

Molluscicidal Efficacy of Essential oils of Syzygium aromaticum Clove and Tachyspermum ammi Seeds against Lymnaea acuminata, a Vector Snail

In eastern Uttar Pradesh, fascioliasis, an endemic zoonotic disease, is quite prevalent. Essential oils that are produced from various plants are extremely important to human health. The current study found that the essential oils from Tachyspermum ammi seeds and Syzygium aromaticum cloves are effective herbal molluscicides against the vector snail Lymnaea acuminata. Syzygium aromaticum cloves and Tachyspermum ammi seeds are used to extract their essential oils using both conventional and unconventional techniques, such as solvent extraction (SE) and hydrodistillation (HD). The results section makes it evident that both of the essential oils from Syzygium aromaticum clove and Tachyspermum ammi seeds have a high level of molluscicidal activity (24-hour LC50 values are 3.01 and 2.35), particularly against the vector snail Lymnaea acuminata. The current investigation unequivocally showed that the exposed vector snails to the essential oils are extremely harmful. The aim of the present investigation is to establish the molluscicidal activity of the essential oils of Syzygium aromaticum clove and Tachyspermum ammi seeds against the vector snail Lymnaea acuminata.

Influence of Abiotic Factors and Umbelliferone Toxicity in Snail Attractant Pellets Against the Vector Snail <i>Lymnaea acuminata</i>

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.

Attraction of Umbelliferone in Snail Attractant Pellets (SAP) against the Snail Lymnaea acuminata: An Intermediate Host of Fasciola gigantica

Snail control method is one of the best ways to management of the fasciolosis. Snail attractant pellets (bait) containing attractant and molluscicide is the good alternative method for control of the Lymnaea acuminata, which is a known intermediate host of Fasciola gigantica. The result of the present study is to find the attraction of molluscicide umbelliferone in snail attractant pellets (SAP) against the Lymnaea acuminata, a vector of snail in different months of the year. Data shows that active molluscicidal component (umbelliferone) showed more attraction at lower concentration. On the contrary, at higher concentration, attraction of snail decreases significantly throughout the year. The attraction of snails declined significantly (P < 0.01) as the concentrations of molluscicide incorporated inside the pellets were increased and water temperature is low (i.e., in winter season). SAP containing 0.5% umbelliferone + starch attract maximum snails (46.0%) and 0.5% umbelliferone + proline, attract maximum snails (42.33%), in the month of June, whereas minimum attraction was observed in the month of January to March when SAP containing 7.0% umbelliferone + starch (6.23-8.1%) and when SAP containing 3.0 % umbelliferone + proline (7.33-9.45%).

In vitro use of Organic extracts of Tinospora cordifolia as anthelmintic against Fasciola gigantica larvae

This study aims to evaluate the in vitro anthelmintic larvicidal efficacy of Tinospora cordifolia against Fasciola gigantica larvae (sporocyst, redia, and cercaria). Fascioliasis caused high economic loss in cattle as well as in the human population. It can be controlled by the break of the life cycle of the Fasciola in the host snail Lymnaea acuminata. In vitro, exposure of dried stem powder (DSP), various organic extracts, and column purified extract (CPE) of T. cordifolia was observed upto 8h exposure at various concentrations against F. gigantica larva. The toxic effect of various preparations against larva was observed at 2, 4, 6, and 8h of the treatment. The column purified extract of dried stem powder of T. cordifolia against sporocyst, redia, and cercaria in 2h LC50 was 50.27, 55.26, and 53.11 mg/L and 8h LC50 was 48.20, 48.37, and 48.12 mg/mL, respectively. Maximum effects of column purified of T. cordifolia were observed against sporocyst larva (8h LC50 45.20 mg/L) of F. gigantica.

Molluscicidal Activity of Aqueous Extracts of Selected Medicinal Plants on Fresh Water Snails and Fish

Aim: To investigate the molluscicidal activity of aqueous extracts of Phyllanthus niruri and Euphorbia tirucalli on fresh water snails Lymnaea (Radix) acuminata and Indoplanorbis exustus (as target organisms) and on Channa punctatus fish ( as non target organism),sharing the same habitat.
 Methodology: The aqueous extracts of the stem bark and leaves of Phyllanthus niruri ( a tropical small herb, commonly known as a Bhumi Amla), belonging to the family Phyllanthaceae and the aqueous extracts of stem bark and latex of Euphorbia tirucalli (a semi-arid tropical plant, commonly called milk bush) of the family Euphorbiaceae, were investigated as plant origin molluscicides, against freshwater snails, responsible for causing fascioliasis, Lymnaea (Radix) acuminate and Indoplanorbis exustus, as well as on Channa punctatus ,using Singh and Agarwal method and POLO computer program.
 Results: A significant time and dose-dependent effect of aqueous extracts of both the plants against the freshwater snails were observed. Thus increase in exposure time, the LC50 of Phyllanthus niruri stem and leaf extracts were decreased from 267.89 mg DW/L (24h) > to 180.64mg DW/L (96h) against Lymnaea acuminata and 261.49 mg DW/L (24h)> to 136.40 mg DW/L (96h) against Indoplanorbis exustus. Likewise, the LC50 of aqueous extract of latex of Euphorbia tirucalli were decreased from 1.80 mg DW/L (24h) >to 0.65 mg DW/L (96h) against Lymnaea acuminata and 0.90 mg DW/L (24h)> to 0.28 mg DW/L (96h) against Indoplanorbis exustus, with the increase in exposure time. Its aqueous stem bark extract showed a similar pattern. These aqueous plant extracts at higher doses were also observed to be lethal to freshwater fish Channa punctatus, which share a common habitat with the freshwater snails, but the doses LC90, (24h) of snails didn’t cause any mortality to these fishes, thus indicating that these plant extracts can be safely used as molluscicides.

Efficacy of Essential Oils from Plant Origin Molluscicides against the Vector Snail Lymnaea acuminata

Efficacy of Essential Oils from Plant Origin Molluscicides against the Vector Snail Lymnaea acuminata

Joint Action of Two Pesticides and an Oxidase Inhibitor on The Snail Lymnaea Acuminata

Studies were conducted on synergism between an Organophosphate, Nuvan (dichlorvos) mixed with a carbamate, Sevin (carbaryl) in a 1:46 ratio against the snail Lymnaea acuminata. It was found that Sevin enhances the activity of Nuvan and thus the LC values ( LC10, LC50, LC90 ) obtained from this mixture were low as compared to Nuvan or Sevin alone. The acetylcholinesterase (AChE) inhibition was higher in case of Nuvan + Sevin (16.17%) as compared to Nuvan or Sevin (34.7% , 69.1%) alone. When Piperonyl Butoxide (PB), a mixed function oxidase inhibitor was given with Nuvan and Sevin in a 1:46:5 ratio, the LC value decrease still further. It appears that, in the tertiary mixture, while PB reduce the oxidative detoxification of Nuvan and Sevin the carbamate may also be preventing the hydrolysis of Nuvan may tertiary mixture lethal than of its components.

EFFICACY OF BINARY COMBINATION OF DELTAMETHRIN+MGK-264 ON LEVELS OF BIOCHEMICAL CHANGES IN THE SNAIL LYMNAEA ACUMINATA

Objective: The objective of the present study is the evaluation of the effect of the sublethal (40% and 60% of 48h LC50) binary combination (1:5 ratios) of molluscicides deltamethrin+MGK-264 on the endogenous levels of protein, amino acid and nucleic acid in different tissues of snail Lymnaea acuminata.
 Methods: The snails were treated with 1:5 mixtures of sub-lethal concentration of (40% and 60% of 48h LC50) deltamethrin+MGK-264 on the protein, amino acid and nucleic acid levels in gonadal, nervous and foot tissue of L. acuminata. In order to study the effect of withdrawal from treatment, the snails were first exposed to the above concentrations for 96h, after which they were transferred to freshwater. Water was changed every 24h for the next seven days, after which different biochemical parameters were estimated.
 Results: There was a significant change in the levels of protein (sublethal concentration of 60% of 48h LC50 after 96h) gonadal, nervous and foot tissues are 48.1, 12.1 and 14.5%, respectively, amino acid are 273, 234 and 252%, respectively, DNA are 25.1, 38.9 and 42.1%, respectively and RNA are 12.2, 30.7 and 30.5%, respectively. These changes were time and concentration-dependent. In the withdrawal experiment, the snails were treated for 96h to transfer in freshwater for 7 d, which caused significant recovery in all the biochemical parameters.
 Conclusion: The present study concluded that the high molluscicidal activity of deltamethrin+MGK-264 simultaneous decrease in the levels of proteins, DNA, RNA and increase in the level of amino acids.

HPLC characterization of molluscicidal component of Tamarindus indica and its mode of action on nervous tissue of Lymnaea acuminata

BackgroundFasciolosis is a water-borne disease with gastropods snail (Lymnaea acuminata) act as key-link is still burden for mankind especially in developing countries. Snail control is one of the important tools to trim down the frequency of fasciolosis. ObjectiveTo evaluate the toxic effect and inhibitory potential of plant Tamarindus indica and their active constituent on the key enzyme of nervous tissue of snail L. acuminata. MethodThe present study deals with the chromatographic isolation and identification of molluscicidal component from Tamarindus indica bark and its effects on enzymes activities of vector snail L. acuminata. ResultThe toxicity study reveals that among all organic extract ethanol extract of T. indica bark (96 h LC50:127.4 mgL−1) was more effective than other organic extracts. The 96 h LC50 of column purified fraction of T. indica bark was 13.78 mgL−1 respectively. Saponin was isolated, characterized and identified as active molluscicidal component in the bark of T. indica by column chromatography, TLC and HPLC chromatographic methods. The in vivo and in vitro treatment of column purified fraction and saponin has significant inhibition in enzyme AChE, ACP and ALP activities. The study of inhibition kinetics indicates that inhibition of AChE and ALP is competitive, while ACP is uncompetitive in both the treatments. ConclusionThus inhibition of these enzyme activities by T. indica bark column purified fraction and saponin in the snail L. acuminata may be the cause of its molluscicidal activity which leads snail death.

Photoactivated chlorophyllin and acetylcholinesterase/ cytochrome oxidase activity in Fasciola gigantica cercaria larvae

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.

Studies on acute and chronic toxicity of cadmium to freshwater snail Lymnaea acuminata (Lamarck) with special reference to behavioral and hematological changes.

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 5.54mg/L at 24, 48, 72, and 96h, respectively. For behavioral studies, variable test concentrations of cadmium from 0.00 to 10mg/L were used. The clumping tendency, crawling activity, and touch reflex in the exposed snails were gradually decreased with higher concentrations at 72 and 96h. 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 LC50-0.55 and 1.11mg/L, respectively) were used. A significant variation (p<0.05) from the control at all exposure times (7, 14, 21, and 28days) was recorded at 1.11mg/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 21days exposure at 0.55mg/L where values were non-significantly increased. In comparison between two sublethal doses, blood cells were significantly (p<0.05) lowered at 1.11mg/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.

Chlorophyllin Treatment Against the Snail Lymnaea acuminata: A new tool in Fasciolosis Control

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 LC5019.22 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.

Seasonal Alterations in Oxidative Stress Biomarkers of Freshwater Snails: Bellamya bengalensis and Lymnaea acuminata from Malangaon Reservoir of Dhule District, Maharashtra, India

Objectives: Two freshwater snails Bellamya bengalensis and Lymnaea acuminata from Malangaon reservoir of Dhule district (Maharashtra, India) were examined to study biomarkers of oxidative stress with the investigation of antioxidant enzyme activities. Methods: The experimental snail species were collected seasonally and acclimatized in the laboratory. Their digestive glands were used to study the activities of oxidative biomarker enzymes like Lipid PerOxidation (LPO), Glutathione-S-Transferase (GST), reduced glutathione (GSH), SuperOxide Dismutase (SOD), CATalase (CAT) and Glutathione Peroxidase (GPx). All investigations were carried out on double beam spectrophotometer (Elico BL 200). Findings: It was observed that, LPO level in B. bengalensis was 0.63, 0.55and 0.60(nmol of MDA formed/mg protein) while in L.acuminata 0.74, 0.67 and 0.70 respectively in summer, monsoon and winter seasons. GST activity was 23.41,15.73 and 19.61 in B. engalensis while 26.29, 18.34 and 22.29 in L.acuminata. Level of GSH was 0.083, 0.117and 0.094 (μM/g wet tissue) in B. bengalensis while in L.acuminata it was 0.018, 0.056 and 0.026 (μM/g wet tissue) in three seasons. The level of SOD was 20.87, 24.83 and 23.33 (U/mg of protein) in B. bengalensis while in L. acuminata it was 18.32, 22.35 and 20.73 in three seasons. Level of CAT was 9.23, 13.20, and 11.56 (U/mg of protein) in B. bengalensis while in L.acuminata it was 7.02, 10.53 and 8.86 (U/mg of protein) respectively during three seasons. GPx movement was 6.57, 8.50 and 7.48 (mg of GSH utilized/min/mg protein) in B. bengalensis. It was 5.05, 8.07 and 7.04 (mg of GSH utilized/min/mg protein) in L.acuminata respectively in three seasons. The obtained data also showed the lowest levels of LPO and activities of GST and uppermost doings of SOD, CAT, and GPx and uppermost heights of GSH in two snail types in rainy period than summer and winter period. This designates that in summer, the snails were under more conservation stress than winter and rainy periods. Application: It was decided that changes in antioxidant enzymes and LPO and GST activity can be used as tool in ecological nursing packages.

Photomediated Larvicidal Activity of Pheophorbide a against Cercaria Larvae of Fasciola gigantica.

Fasciolosis is a parasitic disease caused by Fasciola gigantica. The freshwater snail Lymnaea acuminata is the intermediate host of F. gigantica which cause endemic fasciolosis in the northern part of India. To investigate larvicidal activity of pure and laboratory extracted pheophorbide a (Pa) against cercaria larvae of F. gigantica, data were analyzed in different spectra of visible light, sunlight, and laboratory conditions. Photostimulation of chlorophyll derivative pheophorbide a (Pa) caused time and concentration dependent larvicidal activity against cercaria larvae of F. gigantica. Larvicidal activity of pure Pa under 650 nm and 400–650 nm (8 h LC50 0.006 mg/10 mL) was more pronounced than extracted Pa under same irradiations (650 nm LC50 0.12 mg/10 mL, 400–650 nm LC50 0.14 mg/10 mL). Lowest toxicity of pure (8 h LC50 0.14 mg/10 mL) and extracted Pa (8 h LC50 1.25 mg/10 mL) was noted under 400 nm. Pa was found to be toxic in laboratory conditions also. The results presented in this paper indicate that pheophorbide a possess potential larvicidal activity against Fasciola gigantica larvae in different wavelengths of visible light, sunlight, and laboratory conditions.

First record of a rare transversotrematid cercaria larva (Trematoda: Digenea) from Rajasthan, India: focus on seasonal occurrence and host-specificity of diverse cercariae.

During the survey of freshwater snail hosts and their digenean larval trematode parasites, a rare cercaria larva belonging to family Transversotrematidae and subclass Digenea (Trematoda) was recovered from the snail species Melanoides striatella tuberculata inhabiting perennial Som river of Udaipur district, Rajasthan, India. More than 28% mature specimens of these snails were found to be infected with transversotrematid cercaria larvae in the spring season. Body of this cercaria is large, bowl-shaped, biocellate, spinose, transparent and laterally extended having two pigmented eye spots, two hold fast organs extended from the junction of body and tail, large tail with two foliated furcal rami, and cyclocoel intestinal caeca. As far as the authors are aware, this is the first record of a transversotrematid larva from Rajasthan, India. Simultaneously, other forms of cercariae viz., amphistome, echinostome, monostome, gymnocephalous, furcocercous and xiphidiocercous cercariae were also recovered from fifteen species of pulmonate and operculate snails including Lymnaea acuminata f. patula, L. acuminata f. chlamys, L. acuminata f. typica, L. acuminata f. rufescens, L. luteola f. australis, L. luteola f. typica, L. luteola f. impura, Planorbis (Indoplanorbis) exustus, and Anisus (Gyraulus) convexiusculus, Faunus ater, Melania (Plotia) scabra, Thiara (Tarebia) lineata, Melanoides striatella tuberculata, Vivipara bengalensis race gigantica and V. bengalensis race mandiensis. The seasonal occurrence and host-specificity of diverse trematode cercaria larvae are also discussed besides the first record of a rare transversotrematid cercaria larva from Rajasthan, India.

Phytotherapy of chlorophyllin exposed Lymnaea acuminata: A new biotechnological tool for fasciolosis control

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 (8h LC50: 9.6mgL−1) than single treatment with chlorophyllin (8h LC50: 12.6mgL−1) in sunlight. The larvicidal activity of sunlight exposed CHL against rediae (8h LC50: 13.5mgL−1) and cercariae (8h LC50: 12.6mgL−1) was more pronounced than laboratory conditions CHL treatment (rediae- 8h LC50: 305.9mgL−1; cercariae- 8h LC50: 765.4mgL−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.

Toxicity of Chlorophyllin against Lymnaea acuminata at Different Wavelengths of Visible Light.

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.

Inhibition of acetylcholinesterase and cytochrome oxidase activity in Fasciola gigantica cercaria by phytoconstituents

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 4h LC50 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 4h LC50 of azadirachtin and allicin, respectively.

Enzyme inhibition by molluscicidal agents of Bauhinia variegata and Mimusops elengi in the nervous tissue of Lymnaea acuminata

Objective: To evaluate the effect of enzymatic activity in the nervous tissue of snail Lymnaea acuminata (L. acuminata) by Bauhinia variegata (B. variegata) and Mimusops elengi (M. elengi) and their active molluscicidal components quercetin and saponin. Methods: Treatment of sublethal concentration (40% and 80% of 96-h LC50) in vivo of column-purified fraction of B. variegata leaf and M. elengi bark and their molluscicidal agents quercetin and saponin inhibit the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP and ALP) activities in the nervous tissue of L. acuminata. Results: AChE activity was more inhibited than ACP and ALP in snail exposed to column- purified fraction of M. elengi bark and saponin. Among all the treatments the highest inhibition in AChE activity (27.77% ) was noted in snail L. acuminata exposed to 80% of 96-h LC50 of saponin at 96-h exposure period. Conclusions: It can be concluded from the present study that inhibition of AChE, ACP and ALP by B. variegata leaf (quercetin) and M. elengi bark (saponin) in snail L. acuminata could be the cause of snail mortality.