Biomarkers of oxidative stress inBiomphalaria alexandrinasnails for assessing the effects of certain inorganic fertilisers

Molluscicidal activity of sodium hypochlorite against Biomphlaria alexandrina snails: Immunological and hepato-endocrine alterations with in silico docking study

Schistosomiasis is a tropical disease that widely neglected. Schistosoma mansoni reproduce asexually within the freshwater snail, Biomphlaria alexandrina. Sodium hypochlorite (NaOCl) is a widely used disinfectant, so its effect against gainst B. alexandrina snails was evaluated. The present results showed that NaOCl has a molluscicidal activity against adult B. alexandrina snails at LC50 1.25 ppm. Hemocytes displayed varied morphological forms after being exposed to the LC10 and LC25 concentrations of NaOCl in B. alexandrina snails, and the phagocytic index of B. alexandrina snail's hemocytes significantly increased. The phagocytic potency of exposed hemocytes to charcoal showed ruptured plasma membrane, engulfed particles, vacuolation in the cytoplasm and degeneration of nuclei. When B. alexandrina snails were treated with sublethal concentrations of NaOCl, transaminases (AST & ALT), alkaline and acid phosphatase activities were significantly increased. In contrast, the total protein, albumin concentrations, Testosterone (T) and 17β Estradiol (E) showed a significant decrease (p ≤ 0.05) as compared to the control groups. The molecular docking interaction showed high efficiency for the ligand, NaOCl against the receptor binding sites of the acid phosphatase, alanine aminotransferase, estrogen and testosterone. The present results showed that NaOCl could be used as an effective molluscicide against B. alexandrina snails but more attention should be paid to investigate the side effects on the non-target organisms living in the freshwater environment.

Assessing the molluscicidal and biochemical activities of New-Fort®, an inorganic fertilizer against Theba pisana snails

Terrestrial snails are a significant issue in agricultural production worldwide. The use of nitrogen - phosphorus - potassium (NPK) based fertilizers played an important role in meeting the food demand throughout the world, so its effectiveness against land snails needs to be investigated. This study was conducted to evaluate toxic lethal effect of New-Fort®, an inorganic NPK based fertilizer, in the field for 3, 7 and 10 days and in the laboratory for 24, 48 and 72 h against Theba pisana snails. Also, the impact of its sub-lethal doses (1/10, 1/5, 1/4 and 1/2 of 48 h-LD50) on biochemical parameters were determined under laboratory conditions. The results showed that the snails percent reduction in the field were 21.4, 61.0 and 80.0 % after 10 days' application of quarter, half and one field rate and the values of LD50 in the laboratory were 4.94, 4.56 and 4.24 mg/g b.w at 24, 48 and 72 h, respectively. New-Fort® sub-lethal doses caused a significant inhibition in catalase, γ-glutamyl transferase and acetylcholinesterase activities. It also elicited a significant elevation in glutathione S-transferase activity post exposure to 1/10 and 1/5 of LD50, whereas an opposite effect was occurred after exposure to 1/4 and 1/2 of LD50. Lipid peroxidation level was reduced in snails treated with 1/10 and 1/5 of LD50, whereas it increased in 1/4 and 1/2 of LD50- treated snails. Moreover, a significant inhibition in alkaline phosphatase activity at all tested doses, with the exception of 1/2 of LD50 was observed. An increase in alanine aminotransferase and aspartate aminotransferase activities were occurred after all tested doses exposure. Our findings highlighted on how biochemical changes can be exploited to better understand the mechanisms underlying New-Fort® fertilizer toxicity against the land snail, T. pisana, as well as how to benefit from NPK fertilizers application in snail control.

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

BACKGROUND

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.

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Certain compounds from fungal cultures could be safely used for biological control of Biomphalaria alexandrina snails.

Toxicological assessment of lambda-cyhalothrin and acetamiprid insecticides formulated mixture on hatchability rate, histological aspects, and protein electrophoretic pattern of Biomphalaria alexandrina (Ehrenberg, 1831) snails

Several formulated mixtures of pesticides are widely used in modern agriculture. Nevertheless, the agriculture runoff causes a serious damage to the aquatic ecosystem. Therefore, the present study aims to use B. alexandrina snails as bioindicators for 30 g/l lambda-cyhalothrin and 17 g/l acetamiprid as a formulated mixture insecticide. Results showed that it has a molluscicidal activity against snails at LC₅₀ 7.9 mg/l. The hatchability percent of both treated 1-day-aged and/or 3-day-aged groups were less than that of the control group. The sublethal concentrations of the tested insecticide caused a remarkable abnormal necrosis in male and female gametogenic cells, besides a severe damage in both secretory and digestive cells. The results of SDS-PAGE protein profiles of treated snails showed that the least number of protein bands was noticed in snail groups that subjected to LC₁₀ (6.6 mg/l) and LC₂₅ (7.2 mg/l) concentrations when compared to control protein fractions.