Biomphalaria Alexandrina Snails Research Articles

Evaluation of Therapeutic Efficacy of Mucus and Tissue Extracted from Biomphalaria alexandrina Snails on Mice Infected with Schistosoma mansoni

Abstract Schistosomiasis is a neglected tropical disease with considerable morbidity. Praziquantel though safe and efficacious does not prevent reinfection and the emergence of drug resistance is of great concern. This study was done to evaluate the therapeutic efficacy of mucus and nucleoproteins extracted from Biomphalaria alexandrina snails on miracidia, cercariae and Schistosomamansoni adults in vitro and assess their in vivo effect on mice experimentally infected with Schistosoma mansoni through parasitological, pathological and biochemical parameters.The in vitro study proved that the mucus had a better lethal effect on cercariae than miracidia, on contrast to NPs which was better on miracidia. The mucus effect surpassed the NPs as regard the lethal effect on adults in vitro. The effect of mucus on S. mansoni females and males was almost equivocal except for the effect after 72 hours where 80 µg/ml caused 100% lethal effect on adult females. The effect of NPs on S. mansoni adult females was better than adult males at the highest used concentration of 100 µl/ml after 72 hours with a 60% lethal effect. However, at 48 hours the same concentration had a better lethal impact on males (25%) than females (20%). The in vivostudy proved that the combined NPs or mucus to PZQ added to the effect of individual PZQ considering its effect on ova count, oogram pattern and granuloma parameters. The histopathological results denoted a relevant potential for NPs when compared to the rest of the groups and the control though, the PZQ still showed the best findings. The effect of PZQ alone or combined with mucus or NPs was equivocal resulting in 100% TWB reduction. As regard oxidative stress markers, NO decreased level was best shown by combined PZQ and NPs, while, as regard GSH level, the individual PZQ showed the best increased level. This study concluded that mucus and NPs had cercaricidal, miracidial and antischistosomal effect in vitro and that their combination could be considered as a sharing therapeutic adding to PZQ potentiality in vivo for the treatment of schistosomiasis for further investigations.

Phyto-synthesized silver nanoparticles from Sargassum subrepandum: anticancer, antimicrobial, and molluscicidal activities.

In the realm of nanotechnology, the use of algae to produce nanoparticles is an environmentally friendly, sustainable, and economically viable strategy. In the present study, the brown macroalgae Sargassum subrepandum was utilized to effectively produce silver nanoparticles (AgNPs). Through various characterization techniques, the AgNPs' structural integrity was confirmed. AgNPs exhibited significant antimicrobial activity against Pseudomonas aeruginosa and Fusarium equiseti. AgNPs showed cytotoxic effects on the MCF-7 breast adenocarcinoma cell line with an IC50 of 12.5 µg/ml. Treatment with AgNPs resulted in a marked reduction in cell viability, alongside evident apoptotic and necrotic morphological changes in the cancer cells. Through molecular docking studies, a deeper understanding of the interaction between AgNPs and crucial proteins related to cancer has been achieved, AgNPs showed a promising molluscicidal action on Biomphalaria alexandrina snails, a Schistosoma mansoni intermediate host. The half-lethal dose (LC50) of AgNPs was determined to be 0.84 mg/L. The potential consequences of its administration include potential disruptions to the glycolysis profile, as well as potential impacts on the steroidal hormone's estrogen and testosterone and certain kidney function tests. This study highlights the diverse uses of algae-synthesized AgNPs, ranging from healthcare to environmental management, demonstrating their importance in advancing nano-biotechnological solutions.

Immunomodulatory and antioxidant properties of Sarcophaga argyrostoma larval hemolymph: utilizing the Biomphalaria alexandrina snail as a model

AbstractIn recent years, there has been a growing interest in exploring novel natural sources for antioxidant and anti-inflammatory agents, driven by the need for alternative therapeutic strategies with fewer side effects. This study investigates the potential of the Biomphalaria alexandrina snail as a valuable model organism to evaluate the antioxidant and anti-inflammatory properties of Sarcophaga argyrostoma larval hemolymph. The choice of B. alexandrina snails as a model is based on its ecological relevance and physiological similarities to other organisms, supporting well-established use in ecological and physiological research, as well as it provides a valuable platform for such investigations. Ultimately, this study may open avenues for the development of innovative and sustainable therapeutic interventions rooted in the rich biodiversity of the natural world. The experimental design involves the extraction of hemolymph from S. argyrostoma larvae, followed by a comprehensive analysis of its antioxidant capacity and anti-inflammatory effects using adult snails. Various biochemical assays, including total antioxidant capacity, immunomodulatory markers and histological investigation, will be employed to assess the bioactive potential of the hemolymph. The outcomes of this research can be attributed to the identification of the anti-oxidant and anti-inflammatory effects of hemolymph. This effect was observed through the reduction of oxidative stress and proinflammatory mediators, impacting the biological activities of the snails. The study is the first to shed light on the potential benefits of S. argyrostoma larval hemolymph using an animal model, showcasing its ability to mitigate oxidative and inflammatory responses within the biological context of the snails.

Biological, biochemical and genotoxicological alterations of Benzylamine on Biomphalaria alexandrina snails and its Schistosoma mansoni larvicidal potential

Biomphalaria spp. snails are freshwater gastropods that responsible for Schistosoma mansoni transmission. Schistosomiasis is a chronic illness that occurred in underdeveloped regions with poor sanitation. The aim of the present study is to evaluate the molluscicidal activity of benzylamine against B. alexandrina snails and it larvicidal effects on the free larval stages of S. mansoni. Results showed that benzylamine has molluscicidal activity against adult B. alexandrina snails after 24 h of exposure with median lethal concentration (LC50) 85.7 mg/L. The present results indicated the exposure of B. alexandrina snails to LC10 or LC25 of benzylamine resulted in significant decreases in the survival, fecundity (eggs/snail/week) and reproductive rates, acetylcholinesterase, albumin, protein, uric acid and creatinine concentrations, levels of Testosterone (T) and 17β Estradiol (E), while alkaline phosphatase levels were significantly increased in comparison with control ones. The present results showed that the sub lethal concentration LC50 (85.7 mg/L) of benzylamine has miracidial and cercaricidal activities, where the Lethal Time (LT50) for miracidiae was 17.08 min while for cercariae was 30.6 min. Also, results showed that were decreased significantly after exposure to sub lethal concentrations compared with control. The present results showed that the expression level of NADH dehydrogenase subunit 1 (ND1) genes and cytochrome oxidase subunit I (COI) in B. alexandrina snails exposed to LC10 or LC25 concentrations benzylamine were significantly decreased compared to the control groups. Therefore, benzylamine could be used as effective molluscicide to control schistosomiasis.

Study of the chemical composition and anesthetic effect of Cladophora glomerata extract on the physiological and hematological aspects of Biomphalaria alexandrina snails as biological models

Study of the chemical composition and anesthetic effect of Cladophora glomerata extract on the physiological and hematological aspects of Biomphalaria alexandrina snails as biological models

Activities of pumpkin seed oil against Biomphalaria alexandrina snails and the infective stages of Schistosoma mansoni with special emphasis on genotoxic and histopathological alterations.

Schistosomiasis is a serious health issue in tropical regions, and natural compounds have gained popularity in medical science. This study investigated the potential effects of pumpkin seed oil (PSO) on Biomphalaria [B.] alexandrina snails (Ehrenberg, 1831), Schistosoma [S.] mansoni (Sambon, 1907) miracidium, and cercariae. The chemical composition of PSO was determined using gas chromatography/mass spectrometry. A bioassay was performed to evaluate the effects of PSO on snails, miracidia, and cercariae. The results showed no significant mortality of B. alexandrina snails after exposure to PSO, but it caused morphological changes in their hemocytes at 1.0 mg/ml for 24 hours. PSO exhibited larvicidal activity against miracidia after 2 hours of exposure at a LC50 of 618.4 ppm. A significant increase in the mortality rate of miracidia was observed in a dose- and time-dependent manner, reaching a 100% death rate after 10 minutes at LC90 and 15 minutes at LC50 concentration. PSO also showed effective cercaricidal activity after 2 hours of exposure at a LC50 of 290.5 ppm. Histological examination revealed multiple pathological changes in the digestive and hermaphrodite glands. The PSO had genotoxic effects on snails, which exhibited a significant increase [p≤0.05] in comet parameters compared to the control. The findings suggest that PSO has potential as a molluscicide, miracidicide, and cercaricide, making it a possible alternative to traditional molluscicides in controlling schistosomiasis.

Biomonitoring of manganese metal pollution in water and its impacts on biological activities of Biomphalaria alexandrina snail and larvicidal potencies

Metal pollution has many dangerous environmental and human health consequences due to the bioaccumulation in the tissues. The present study aims to measure the bioaccumulation factor of the manganese (Mn) heavy metal in Biomphalaria alexandrina snails’ tissues and water samples. The current results showed the concentration of Mn heavy metal in water (87.5 mg/l) and its bioaccumulation factor in Helisoma duryi tissue was higher than that in tissues of Physa acuta and B. alexandrina snails. Results showed that 87.5 mg/l Mn concentration had miracidicidal and cercaricidal activities. Also, this concentration decreased the mean total number of the hemocytes after exposure for 24 h or 48 h, while increasing both the mean mortality and phagocytic indices of the hemocytes of exposed snails. It caused alterations in the cytomorphology of the hemocytes of exposed snails after 24 or 48 h, where the granulocytes had irregular cell membranes and formed pseudopodia. Besides, levels of testosterone (T) and estradiol (E) were increased after exposure to 87.5 mg/l Mn metal compared to the control group. Also, it increased MDA (malonaldehyde) and TAC (total antioxidant capacity) contents, while decreasing SOD (superoxide dismutase). Besides, it caused significant histopathological damages in both hermaphrodite and digestive glands, represented in the degeneration of the gonadal, digestive, secretory cells, and the connective tissues. Therefore, B. alexandrina might be used as a sensitive bioindicator of pollution with Mn heavy metal to avoid ethics rules; besides, they are readily available and large in number.

The efficiency of N-heterocylic analogs against Biomphalaria alexandrina snails infected with Schistosoma mansoni; immune responses, histological structure and protein pattern

The efficiency of N-heterocylic analogs against Biomphalaria alexandrina snails infected with Schistosoma mansoni; immune responses, histological structure and protein pattern

The Molluscicidal Activity of Green Synthesized Copper Oxide–Based Annona squamosa Seed Extract Nanoparticles on the Feeding Behavior, Biochemical, Molecular, and Immunohistochemical Alterations of Biomphalaria alexandrina Snails

Because of their low ecological impact, plant molluscicides have garnered much attention. The work aimed to find out if Annona squamosa (AS) seed extract has a molluscicidal impact on Biomphalaria alexandrina snails and enhances this extract by adding CuO nanoparticles (NPs). Using a scanning electron microscope (SEM), transmission electron microscope (TEM), and PANalytical X’Pert PRO X-ray diffractometer (XRD), the presence of the green A. squamosa-based CuO NPs (AS-CuO NPs) was confirmed. After 24 h of exposure, the half-lethal concentration (LC50) of AS-CuO NPs was more toxic to mature B. alexandrina than the aqueous extract of AS seeds (LC50: 119.25 mg/L vs. 169.03 mg/L). The results show that snails exposed to sublethal doses of AS-CuO NPs at LC10 or LC25 (95.4 or 106.7 mg/L, respectively) had much higher glucose levels and alkaline phosphatase activity than those not exposed. Nevertheless, there was no discernible change in the protein content in general or glycogen phosphorylase production. Histological and immunohistochemical analysis showed that snails exposed to A. squamosa-derived CuO NPs LC10 had shrinking digestive tubules and degeneration as well as vacuolation of many digestive, secretory, ova, and sperm cells, with PCNA expressing positively in the hermaphrodite gland and digestive tubule cells. The toxic profile of green CuO NPs produced by A. squamosa may damage the biological activity of B. alexandrina snails; thus, this compound could be used as a molluscicidal base. Furthermore, B. alexandrina proved to be a useful biomarker of nanomaterial contamination.

Toxicological, hepato-renal, endocrine disruption, oxidative stress and immunohistopathological responses of chitosan capped gold nanocomposite on Biomphalaria alexandrina snails

The present investigation aimed to synthesize chitosan‑gold nanocomposites (Ch-AuNPs) with gamma radiation, then to evaluate its toxic effect on the freshwater snails Biomphalaia alexandrina. Results showed that Ch-AuNPs is spherical shaped with average size 12 nm. It had a toxic effect against B. alexandrina snails with LC50 20.43 mg/l. Exposure of B. alexandrina snails to LC10 7.51 or LC25 13.63 mg/l of Ch-AuNPs, reduced the survival, reproductive and fecundity rates; total protein and albumin; both testosterone (T) and 17β Estradiol (E) levels; SOD and CAT activities of exposed snails while increased the activities of transaminases (AST & ALT), uric acid, creatinine, TAC and MDA levels compared to the control group. Results were supported by histopathological and immunohistopathological alterations of the digestive and hermaphrodite glands. In conclusion B. alexandrina could be used as a model to screen the negative impact of nanomaterials. Also, Ch-AuNPs could be used as a molluscicidal agent.

Histopathological, Immunohistochemical, Biochemical, and In Silico Molecular Docking Study of Fungal-Mediated Selenium Oxide Nanoparticles on Biomphalaria alexandrina (Ehrenberg, 1831) Snails

Daphnia magna and freshwater snails are used as delicate bioindicators of contaminated aquatic habitats. Due to their distinctive characteristics, selenium oxide nanoparticles (SeONPs) have received interest regarding their possible implications on aquatic environments. The current study attempted to investigate the probable mechanisms of fungal-mediated selenium nanoparticles' ecotoxicological effects on freshwater Biomphalaria alexandrina snails and Daphnia magna. SeONPs revealed a toxicological impact on D. magna, with a half-lethal concentration (LC50) of 1.62 mg/L after 24 h and 1.08 mg/L after 48 h. Survival, fecundity, and reproductive rate were decreased in B. alexandrina snails exposed to SeONPs. Furthermore, the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were markedly elevated, while albumin and total protein levels decreased. Histopathological damage in the hermaphrodite and digestive glands was detected by light, electron microscopy, and immunohistochemistry studies. The molecular docking study revealed interactions of selenium oxide with the ALT and AST. In conclusion, B. alexandrina snails and D. magna could be employed as bioindicators of selenium nanomaterial pollution in aquatic ecosystems. This study emphasizes the possible ecological effects of releasing SeONPs into aquatic habitats, which could serve as motivation for regulatory organizations to monitor and control the use and disposal of SeONPs in industry.

Toxicological effects of Saponin on the free larval stages of Schistosoma mansoni, infection rate, some biochemical and molecular parameters of Biomphalaria alexandrina snails

Saponins have been used as biopesticides. The objective of the present study is to investigate the toxic effects of Saponin against Biomphalaria alexandrina snails. Results showed that Saponin exhibited a molluscicidal activity against adult B. alexandrina snails at LC50 (70.05 mg/l) and had a larvicidal effect on the free larval stages of Schistosoma mansoni. To evaluate the lethal effects, snails were exposed to either LC10 (51.8 mg/l) or LC25 (60.4 mg/l) concentrations of Saponin. The survival, the infection rates, protein, albumin, and total fat levels were decreased, while glucose levels were increased in exposed snails compared to control snails. Also, these concentrations significantly raised Malondialdehyde (MDA) and Glutathione S Transferase (GST) levels, whereas reduced Superoxide dismutase (SOD) activity and the total antioxidant capacity (TAC) in exposed snails. Furthermore, these concentrations resulted in endocrine disruptions where it caused a significant increase in testosterone (T) level; while a significant decrease in Estradiol (E2) levels were noticed. As for Estrogen (E) level, it was increased after exposure to LC10 Saponin concentration while after exposure to LC25 concentration, it was decreased. Also, LC10 and LC25 concentrations of Saponin caused a genotoxic effect and down-regulation of metabolic cycles in the snails. In conclusion, Saponins caused deleterious effects on the intermediate host of schistosomiasis mansoni. Therefore, B. alexandrina snails could be used as models to screen the toxic effects of Saponins in the aquatic environment and if it was used as a molluscicide, it should be used cautiously and under controlled circumstances.

Molluscicidal effect of green synthesized silver nanoparticles using Azadirachta indica on Biomphalaria alexandrina snails and Schistosoma mansoni cercariae

Objective: To assess the molluscicidal effect of the eco-friendly green synthesized neem silver nanoparticles (neem-Ag NPs) against Biomphalaria alexandrina, the snail intermediate host for Schistosoma mansoni, and their cercaricidal potential.Methods: Methanol extracts from neem fruits were used for green synthesis of neem-Ag NPs. The neem-Ag NPs were characterized using UV-visible absorption spectra, dynamic laser light scattering technique, and transmission electron microscopy. The potential molluscicidal effect against adult and juvenile Biomphalaria alexandrina and the effect of the sub-lethal concentration on hatching of snail eggs and Schistosoma mansoni cercariae were evaluated.Results: The surface plasmon resonance of neem-Ag NPs showed a sharp absorption peak at λmax = 518 nm together with multiple peaks. The hydrodynamic diameter was (77.15±34.53) nm, the polydispersity index (0.338±0.000) and the zeta-potential −14.07 mV. Moreover, transmission electron microscopy showed that the average size of the nanoparticles was (27±2) nm. Agglomeration was evident and a light-colored capping layer could be seen coating the nanoparticles. Juvenile snails (LC50: 0.83 ppm) were more susceptible to neem-Ag NPs than adults (LC50: 1.07 ppm). In addition, neem-Ag NPs and neem at LC50 concentrations inhibited the egg-hatching of snails and showed cercaricidal activity in a time-dependent manner.Conclusions: Neem-Ag NPs have lethal activities against Biomphalaria alexandrina snails and their eggs, as well as Schistosoma mansoni cercariae. Hence, neem-Ag NPs could be a potential agent to control schistosomiasis.

TEM and LM assessment of Biomphalaria alexandrina snails’ immunotoxicity as a bio-monitor for water pollution by cuprous oxide nanoparticles and copper sulphate

TEM and LM assessment of Biomphalaria alexandrina snails’ immunotoxicity as a bio-monitor for water pollution by cuprous oxide nanoparticles and copper sulphate

Assessment of Amphora coffeaeformis and Scenedesmus dimorphus algae as immunostimulant agents on Biomphlaria alexandrina snails against Schistosoma mansoni

Schistosoma mansoni is the main factor of human schistosomiasis which is responsible for high rates of mortality. Recently, the use of alternative biological control agents has gained importance in disease control because the intensive use of molluscicides is very harmful to human health and poses risks to the environment. In the present work, the potential effect of two freshwater algae, Amphora coffeaeformis and Scenedesmus obtusus, on the immune response of Biomphalaria alexandrina snails against infection with S. mansoni was investigated. Two different concentrations 1 and 2 g L− 1 from each dried algal material were tested on snails before exposure to miracidial infection by one day. The use of Amphora coffeaeformis has a greater immunostimulatory effect than Scendesmus obtusus at a low concentration of 1.0 g L− 1. The tested algae affected the snail’s hemocytes and its immune response to S. mansoni as evidenced by a significant decrease in infection rate and cercariae production. In addition, increasing in total hemocyte count, the formation of vacuoles, the appearance of several pseudopodia, and the formation of coarse granules in hemocytes of infected snails treated with A. coffeaeformis. Intense tissue reactions were also observed. In conclusion, it was confirmed that these algae can be used as an immunostimulant in the prevention and control of S. mansoni.

Single and Combined Effects of Bisphenol A Exposure and Schistosoma mansoni Infection: Biochemical and Histological Implications on Biomphalaria alexandrina Snails

Single and Combined Effects of Bisphenol A Exposure and Schistosoma mansoni Infection: Biochemical and Histological Implications on Biomphalaria alexandrina Snails

A Study on the Bio-responses of a Freshwater Snail (Biomphalaria alexandrina) to Fungal-derived Compounds

Biomphalaria alexandrina snails, as transitional hosts of schistosomiasis, plays an essential part in the spread of the illness. Control of these snails by the substance molluscicides antagonistically influences the oceanic climate, causing poisonous and cancer-causing consequences for non-target life forms. Looking for new naturally safe substances that can treat schistosomiasis disease with minimal side effects on the environment and plants, fish wealth and do not affect vital human functions. Fifty fungal species were used to evaluate their activity against Biomphalaria alexandrina. Study the effect of the fungal extract on vital functions of Biomphalaria alexandrina and fish wealth. Purification of active substances and identification of their chemical structures. Cladosporium nigrellum and Penicillium aurantiogresium metabolites were effective against B. alexandrina snails, and the effects of promising fungal extracts sublethal concentrations (IC10 & IC25) on the levels of steroid sex hormones, liver enzymes, total protein, lipids, albumin and glucose were determined. Chemical analyses of this filtrate separated a compound effective against snails; it was identified. Protein electrophoresis showed that fungal filtrate affects the protein pattern of snails' haemolymph. Little or no mortality of Daphnia pulex individuals was observed after their exposure to sublethal concentrations of each treatment. Certain compounds from fungal cultures could be safely used for biological control of Biomphalaria alexandrina snails.

Assessment of Bacillus aerius and Bacillus toyonensis extracts as biocontrol agents against Biomphalaria alexandrina snails

Schistosomiasis is one of the most deleterious parasitic diseases in the world and it is transmitted by aquatic snails. Consequently, there is a continuous need to search for new molluscicides to control the snails. The present study aimed to evaluate the molluscicidal activity of two bacterial diethyl ether extracts against adult Biomphalaria alexandrina snails. The present study indicated that LC50 and LC90 values were 193.734 and 280.670 mg/L for Bacillus aerius extract and 88.814 and 103.653 mg/L for Bacillus toyonensis extract against B. alexandrina snails after 48 h of exposure. After a 21-day chronic exposure period, the results showed that the sublethal concentrations (LCo and LC10) of both B. aerius and B. toyonensis extracts significantly decreased the survival rates of B. alexandrina snails. Likewise, the sublethal concentration (LC10) caused biochemical changes, including aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase enzymes, total protein, albumin, globulin, urea and creatinine and induced histopathological alterations in the digestive and hermaphrodite glands of exposed snails after 21 days. Despite negative effects on snails, we did not observe substantial morality in Artemia salina, a crustacean, after exposure to both extracts emphasizing that these extracts may be safe on other non-target aquatic organisms. Ultimately, our research suggests that B. aerius and B. toyonensis extracts can be used as promising biocontrol agents of B. alexandrina snails.

Biochemical characterization and peptide mass fingerprinting of two glutathione transferases from Biomphalaria alexandrina snails (Gastropoda: Planorbidae)

BackgroundThe freshwater snails Biomphalaria alexandrina (Gastropoda: Planorbidae) has public health importance of being an intermediate host of Schistosoma mansoni, the parasite species that causes intestinal schistosomiasis in humans. Glutathione transferases (GSTs) play an important role in detoxification of a broad range of compounds including secondary metabolites and exogenous compounds. Studying GSTs in snails may clarify their role in detoxification of molluscicides. ResultsTwo glutathione transferases (BaGST2 and BaGST3) were purified and characterized from B. alexandrina snails. BaGST2 and BaGST3 were electrophoretically homogeneous preparations with subunit molecular weight of 23.6 kDa and molecular weight of 45 kDa. Isoelectric focusing of BaGST2 revealed the presence of two components at pI 4.47 and 4.67, while BaGST3 showed one band at pI 4.17. The specific activity of BaGST2 and BaGST3 toward 1-chloro-2,4-dinitrobenzene (CDNB) was 19.0 and 45.2 μmol/min/mg protein following 146- and 346-fold purification, respectively. The catalytic pH optima, km values, and the activation energies for BaGST2 and BaGST3 were determined. BaGST2 and BaGST3 were significantly inhibited by hematin and Cibacron Blue and to a less extent by bromosulfophthalein, S-butyl-GSH, S-hexyl-GSH, and S-P-bromobenzyl-GSH. BaGST2 and BaGST3 showed high activity against ethacrynic acid as substrate, and they also exhibited peroxidase activity on cumene hydroperoxide. The two enzymes showed identical patterns of lysine-C digestion after high-performance liquid chromatography. The amino acid sequences of three peptide fragments and peptide mass fingerprinting of fourteen peptides were used to predict the primary structure of BaGST2. A polypeptide of 206 amino acids (with 7 gaps, 3 of which could not identified) was predicted for BaGST2. The theoretical subunit molecular weight of BaGST2 is 22.6 kDa, with pI of 8.58. BaGST2 has 65% sequence identity and 78% positive with Biomphalaria glabrata GST7. The overall structure of BaGST2 at the N-terminal domain is identical to the canonical GST N-terminal domain, having the typical thioredoxin-like fold with a βαβ-α-ββα motif, whereas the C-terminal domain is made from 6 α-helices. A conservative GST-N-domain includes glutathione binding sites Y11, L17, Q53, M54, Q65, and S66, while a variable GST-C domain contains electrophilic substrate binding site H99, R102, A103, F106, K107, L161, and Y167. Phylogenetic tree showed that BaGST2 was clustered in the sigma group with GSTs sigma class from invertebrates and vertebrates. ConclusionsWe have purified and characterized two GSTs from B. alexandrina snails. Our study broadens the biochemical information on freshwater snail GSTs by demonstrating the role of BaGSTs in defense mechanisms against structurally different electrophilic compounds. BaGST2 and BaGST3 have Se-independent peroxidase activity, which indicates their role in cellular antioxidant defense by reducing organic hydroperoxides in B. alexandrina. A polypeptide chain of 206 amino acids was predicted. The primary structure of BaGST2 showed 65% sequence identity with Biomphalaria glabrata GST7. Sequence analysis indicates that BaGST2 is a GST-N-sigma-like with a thioredoxin-like superfamily. Phylogenetic tree confirms that BaGST2 belongs to the sigma class of GSTs superfamily.

Toxicological impact of organophosphorus Chlorpyrifos 48%EC pesticide on hemocytes, biochemical disruption, and molecular changes in Biomphalaria alexandrina snails

Organophosphorus pesticides like Chlorpyrifos 48%EC were widely used to control agricultural pests. The present study aimed to evaluate the toxic effects of Chlorpyrifos 48%EC on B. alexandrina snails, the intermediate host of Schistosoma mansoni. After exposure of snails to serial concentrations to determine the LC50, thirty snails for each sublethal concentration (LC10 2.1 and LC25 5.6 mg/l) in each group were exposed for 24 h followed by another 24 h for recovery. After recovery random samples were collected from hemolymph and tissue to measure the impacts on Phagocytic index, histological, biochemical, and molecular parameters. The current results showed a toxic effect of Chlorpyrifos 48%EC on adult B. alexandrina snails after 24 h of exposure at LC50 9.6 mg/l. After exposure to the sub-lethal concentrations of this pesticide, it decreased the total number of hemocytes and the percentage of small cells, while increased the percentage of hyalinocytes. The granulocyte percentage was increased after exposure to LC10, while after LC25, it was decreased compared to the control group. Also, the light microscopical examination showed that some granulocytes have plenty of granules, vacuoles and filopodia. Some hyalinocytes were contained shrinked nuclei, incomplete cell division and forming pseudopodia. Besides, the phagocytic index of hemocytes was significantly increased than control in all treated groups. Also, these sub-lethal concentrations increased MDA and SOD activities, while, tissue NO, GST and TAC contents were significantly decreased after exposure. Levels of Testosterone (T) and Estradiol (E) were increased significantly after exposure compared with control group. The present results showed that the concentration of DNA and RNA was highly decreased after exposure to LC10, 25 than the control group. Therefore, B. alexandrina snails could be used as a bio monitor of the chemical pollution. Besides, this pesticide could reduce the transmission of schistosomiasis as it altered the biological system of these snails.