Freshwater snails are used as sensitive biomarkers of aquatic ecosystem pollution. The potential impacts of zinc oxide nanoparticles (ZnONPs) on aquatic ecosystems have attracted special attention due to their unique properties. The present investigation was designed to evaluate the possible mechanisms of ecotoxicological effects of ZnONPs on freshwater snail Biomphalaria alexandrina. ZnONPs showed molluscicidal activity against B. alexandrina snails, and the LC50 was 145 μg/ml. Two tested concentrations of ZnONPs were selected: The first concentration was equivalent to LC10 (7 μg/ml), and the second was equivalent to LC25 (35 μg/ml). Exposure to ZnONPs (7 and 35 μg/ml) for three consecutive weeks significantly induced malondialdehyde and nitric oxide with concomitant decreases in glutathione and glutathione-S-transferase levels in hemolymph and soft tissues of treated snails. Moreover, ZnONPs elicited a significant decrease in total protein and albumin contents coinciding with enhancement of total lipids and cholesterol levels as well as activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hemolymph and soft tissues of treated snails. This study highlights the potential ecological implications of ZnONP release in aquatic environments and may serve to encourage regulatory agencies in Egypt to more carefully monitor and regulate the industrial use and disposal of ZnONPs.

Toxicological effects of zinc oxide nanoparticles: Ecotoxicological effect of sublethal exposure to zinc oxide nanoparticles on freshwater snail Biomphalaria alexandrina

Schistosomiasis remains a public health problem in the developing world. Biomphalaria alexandrina is the intermediate host of Schistosoma mansoni, with a widespread distribution in Egypt. In Egypt molluscicides have been important, but otherwise molluscicides have been of minor significance. They may, however, become important now that WHO talks about eradicating schistosomiasis in some countries and that WHO has finally accepted that snail control is important.The present study investigated the different effects of three commercial herbicidical compounds, Butralin (as Amex 48% EC), glyphosate isopropylammonium (Herphosate 48% SL) and Pendimethalin (Stomp 50% EC) on B. alexandrina. All three compounds were found to have a molluscicidal effect, with Pendimethalin the most toxic over the examined range of concentrations. In addition, at sublethal concentrations, these compounds reduced growth rates and reproductive output (numbers of eggs laid) in exposed B. alexandrina, and it reduced viability of...

The Impact of Three Herbicides on Biological and Histological Aspects of Biomphalaria alexandrina, Intermediate Host of Schistosoma mansoni

Sesbania sesban (L.) Merrill is the most productive multipurpose tree widely distributed in tropics and subtropics; and usually planted by smallholder farmers mostly for its fodder and soil improvement values. The objective of the present study was to review the various aspects (with emphasis on its importance) of S. sesban and generate comprehensive technical information for scholars who wish to study the plant in detail. Different parts ofS. sesban is reputed for various purposes such as weed control, phytoremediation, anti-inflammation and antioxidant effect, abortion and antifertility agent, antimicrobial activity, firewood source, livestock feed and pasture improvement, green manure, mosquito repellant, live support and Schistosoma control. Having these and other multiple uses, S. sesban can contribute to sustainable livelihoods by improving household food, nutrition and health security.

	 

	Key words: Sesbania sesban, phytoremediation, anti-inflammation, antioxidant,livelihood.

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Sesbania sesban (L.) Merrill: Potential uses of an underutilized multipurpose tree in Ethiopia

The present study was designed to assess the relationship between anti-schistosomal effect of the antimalarial drug mefloquine (Mef) and the oxidative stress status of Schistosoma man- soni infected mice. Forty mice were divided into eight groups (5 mice/group); control (I, II), infected (III, IV), Mef low dosage (200 mg/kg) (V, VI), and Mef high dosage (400 mg/kg) (VII, VIII). Mef (200 and 400 mg/kg) was administered orally as a single dose at days 14 and 35 post infection (PI). All mice were sacrificed after 8 weeks PI. Oral administration of Mef (200 or 400 mg/kg) at day 14 or 35 PI reduced the total worm burden by 84%, 78% and 94%, 85.7% respectively. Meanwhile, Mef treatment reduced egg load in the intestine and the liver. Following Mef (200 and 400 mg/kg) treatment to mice at day 14 or 35 PI, the oogram pattern showed complete disappearance of all immature and mature ova. Treatment of mice with Mef at the two tested doses significantly decreased the activities of ALT, AST, ALP and GGT enzymes as compared to infected untreated group. However, administration of Mef (200 and 400 mg/kg) at day 14 or 35 PI significantly (P < 0.05) decreased the MDA level and increased the levels of GSH and CAT as compared to infected untreated group. In conclusion, Mef is an effective curative anti-schistosomal and anti-oxi- dative drug as it alleviates the biochemical and the oxidative stress alterations. Also, Mef has schist-

The potential role of mefloquine against Schistosoma mansoni infection by prohibition of hepatic oxidative stress in mice

The present study aims to investigate the effect of curcumin on treatment of schistosoma mansoni infected mice. Sixty mice were used in this experiment were divided equally into four groups, the first kept as control, the second supplemented with curcumin, the third infected with schistosoma mansoni and the fourth infected and treated with curcumin. Our results emphasized on the presence of anemia, leucopenia, neutropenia and eosinophilia in infected groups either treated or non-treated with an improvement in the treated group. The biochemical parameters; ALT, AST, ALP, total protein, albumin, AFP, TNF- α and lipid profile (TC, TG, HDL-C &LDL-C) improved significantly in infected treated mice compared with infected one. By the same way, results showed an improvement of some anti-oxidant parameters (MAD, GSH, CAT and SOD) in Schistosoma mansoni infected treated mice.

Effect of Curcumin on Hematological, Biochemical and Antioxidants Parameters in Schistosoma Mansoni Infected Mice

Biological and biochemical parameters of Biomphalaria alexandrina snails exposed to the plants Datura stramonium and Sesbania sesban as water suspensions of their dry powder

Some snails of Biomphalaria alexandrina can resist the infection of Schistosoma mansoni so this study aimed to clearly this mechanism by using light and electron microscopy (EM) and determine the role of Nitric oxide in this mechanism. B. alexandrina snails used in this study were exposed individually to S. mansoni infection according to their response they were classified into susceptible group (shed cercariae) and resistant group (failed to shed cercariae). Snails not exposed to infection were included in this study as control group. Nitric oxide (NO) level was assayed directly in the soluble fraction of B. alexandrina haemolymph supernatants collected from each group of B. alexandrina snails were subjected to NO assay by the Greiss reaction. The level of NO in haemolymph of infected snails was significantly increased (p < 0.001) than both control and non infected snails groups, however, in non infected snails group had significantly (p < 0.05) compared to control group. This study when correlated the changes recognized by EM with NO level the pro apoptotic effect of high level of NO on the haemocytes. Characterization and identification of cell shape of haemocytes in both haemolymph and tissue were examined by light and electron microscopy. Examination of B. alexandrina snail's haemocytes revealed three types of different cells classified according to their shape and granular contents. These cells are granulocytes, amoebocytes and hyalineocytes. Electron microscope study also revealed the important role of granulocytes and amoebocytes as defense mechanism against snail infection. NO is considered an important anti parasite molecule; intra-molluscan stages of parasites switch off host NO defense response.

https://jesp.journals.ekb.eg/article_90714_9aa0a225b877d2e396f4d860e50cba8d.pdf

Ultrastructural Study on Biomphalaria Alexandrina Haemocytes Infected with Schistosoma Mansoni in Egypt and Its Correlation with Nitric Oxide Level

Alternations in parasitological, biochemical and molecular parameters of Biomphalaria alexandrina snails, intermediate host of Schistosoma mansoni, induced post exposure to the proposed snail biocontrol agent Phasmarhabditis hermaphrodita nematode

Background: The internal defense system of snails consists of both cellular and humoral components. Circulating haemocytes are the principle line of cellular defense. The susceptibility of fresh water snails of genus Biomphalaria to infection by Schistosoma mansoni (S. mansoni)is linked to the haemocytes present in the haemolymph. While the humoral component includes lysosomal enzymes, that helps in recognition of pathogens and parasites.
	 Material and Methods: In the present work, Biomphalaria alexandrina (B. alexandrina),snails were exposed individually to S. mansoni infection; according to their response they were classified into susceptible group (shed cercariae) and resistant group (failed to shed cercariae). Snails not exposed to infection were considered as control group. Flow cytometric analysis was carried out for detecting apoptosis of B. alexandrina haemocytes isolated from pooled haemolymph and tissue.
	     Results: This study is used to discriminate and count the percentage of viable, apoptotic, necrotic, and dead cells in haemolymph of all studied groups. Comparing to control group, we observed that viable cells were the most common cells that significantly decreased in both infected and non-infected groups (P<0.001, P<0.01 respectively), and showed significant decrease in infected in comparison with non-infected group (P<0.01).  The haemolymph in infected group showed that dead cells were the most common cells (more than the viable, apoptotic and necrotic cells). At the same time, the apoptotic cells showed decrease in the condensation and de- condensation of DNA. This means failure to restore DNA.
	Conclusions: There was a significant variation in the number of the cells between susceptible and resistant snails. In susceptible snailsthe defense process failed, this was confirmed with increase of the dead cells in the infected haemolymph. While in resistant snails the viable spreading cells described as immunological active, are predominantly found in the haemolymph and tissue.

https://ejhm.journals.ekb.eg/article_15818_f64905f7030f0eab202cabbb5d10702b.pdf

Basma M. Abou-El-Nour

Papers

Biological and biochemical parameters of Biomphalaria alexandrina snails exposed to the plants Datura stramonium and Sesbania sesban as water suspensions of their dry powder

Ultrastructural Study on Biomphalaria Alexandrina Haemocytes Infected with Schistosoma Mansoni in Egypt and Its Correlation with Nitric Oxide Level

Alternations in parasitological, biochemical and molecular parameters of Biomphalaria alexandrina snails, intermediate host of Schistosoma mansoni, induced post exposure to the proposed snail biocontrol agent Phasmarhabditis hermaphrodita nematode

Analysis of Circulating Heamocytes from Biomphalaria Alexandrina Following Schistosoma Mansoni Infection Using Flow Cytometry