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Despite the progress in using silver nano products in many fields, including medicine, food, and industry, their effects on the environment need more attention. Therefore, the current study aimed to assess the effect of silver/saponin nanocomposites (Ag/S NCs) for the first time on the aquatic environment by using freshwater clam, Caelatura aegyptiaca, as a fundamental bioindicator in the freshwater system. Following the preparation and characterization of Ag/S NCs by using atomic absorption spectrophotometer, UV–Vis spectrophotometer, X-ray diffraction, transmission electron microscopy, and acute toxicity study, we exposed the clam to three different doses of Ag/S NCs (12.5, 25 and 50 mg L−1) for consecutive 6 days. All Ag/S NCs concentrations caused a significant increase in malondialdehyde and nitric oxide while induced a notable decrease in glutathione and catalase levels in all studied organs. Moreover, the histological alternations were observed in gills, labial palp, and foot tissues, particularly at dose 50 mg L−1. From the results of our work, we concluded that toxicity of Ag/S NCs on freshwater clam leads to an oxidative stress response as well as histopathological changes. Besides, we assumed that Coelatura aegyptiaca could be used as a sensitive bioindicator for monitoring water pollution caused by different nanoparticles. Therefore, we do recommend performing further studies by using fresh clam to provide a better assessment for our aquatic environment to prevent water pollution locally and globally. [ABSTRACT FROM AUTHOR]

More research is needed to understand the interactions of nanoparticles (NPs) with aquatic organisms and their mechanism of toxic action. Zinc oxide nanoparticles (ZnONPs) are the most used engineered metal oxide NPs in consumer products. The present study was designed to evaluate the cytotoxicity, genotoxicity and digestive gland (DG) as well as gill histopathology of the freshwater molluscan bivalve Coelatura aegyptiaca following exposure to ZnONPs (2, 10 and 50 mg/L) for 6 consecutive days. Exposure to ZnONPs (10 and 50 mg/L) induced a significant increase in malondialdehyde, superoxide dismutase and nitric oxide with a concomitant decrease in reduced glutathione, glutathione-S-transferase and catalase levels in the haemolymph, DG and gills of the treated mussels. Following exposure to ZnONPs (50 mg/L), the DG exhibited gradual changes in glandular activity showing hypertrophy and hyperplasia in the glandular cells and irregularity of lamellae and swelling of filaments in the gills. The present investigation revealed that oxidative stress induction, genotoxicity in the haemocytes and histological alterations in the DG and gills of C. aegyptiaca could be the main mechanisms involved in ZnONPs toxicity in aquatic organisms. Thereby, it is suggested that ZnONPs should be applied with more precautions in relevant industries, and occupational health surveillance should be necessarily considered. [ABSTRACT FROM AUTHOR]

Bivalves can accumulate and concentrate most pollutants, even if they are present in somewhat low concentrations. The present study aimed to use freshwater bivalveas for the first time as vital indicator for silver/chitosan nanocomposites (Ag-CS NCs) in the freshwater environment. Following the preparation and characterization of Ag-CS NCs by using UV–vis spectrophotometer, X-ray diffraction, transmission electron microscopy, and acute toxicity study, the animals exposed to three different dose of nano chitosan (CS), AgNPs, and Ag-CS NCs (12.5, 25 and 50 mg/L) for consecutive 6 days. Ag-CS particles were in size range of 8–19 nm. The nominal concentrations for Ag-CS NCs were 12.5, 25 and 50 mg Ag L−1 were corresponding to measured concentration of AgNPs 0.37, 0.81, and 1.65 mg Ag L−1, respectively. All concentrations of Ag-CS NCs caused a significant increase in MDA and NO, while GSH and CAT levels decreased significantly in all organs. Histological investigation of the gills, labial palp and foot tissues showed alternation after exposure to Ag-CS NCs, especially at dose 50 mg/L. The present study showed that exposure to Ag-CS NCs caused oxidative stress responses in Coelatura aegyptiaca and histological changes in the organs. These physiological and histological changes observed after exposure to Ag-CS NCs were most likely the result of the action of AgNPs themselves while the effect of chitosan on these changes was negligible. We concluded that Coelatura aegyptiaca was a sensitive bio-indicator for monitoring of the past and the present water pollution by nanoparticles. [ABSTRACT FROM AUTHOR]

Objectives: With the development of sophisticated instruments for the isolation and elucidation of natural products structures from marine and freshwater organisms, major advances have been made in the discovery of aquatic derived therapeutics. Present investigations were carried out to evaluate cuttlefish (Sepia officinalis) ink extract (IE) and freshwater clam (Coelatura aegyptiaca) extract (CE) for their anticancer and antioxidant activities as compared to 5-flurouracil (5-Fu), in Ehrlich ascites carcinoma (EAC)., Methods: Sixty female Swiss albino mice were divided into five groups (n = 12). All groups except group I received EAC cells (5 × 10(6) cells/mouse i.p.) and this was taken as the 0th day. Group I served as saline control (5 ml/kg 0.9% NaCl w/v p.o). Group II served as EAC control. Rats of groups III, IV and V received IE, CE (200 mg/kg body weight i.p.), and reference drug (5-Fu, 20 mg/kg body weight i.p.), respectively., Results: The reduction in tumor volume, packed cell volume, tumor cell counts and increase in median survival time and percentage increase in life span in treated animals were observed. There was a significant increase in RBC count; Hb content in treated animals and reduction in total WBC count. There was a significant decrease in AST, ALT, ALP and liver MDA levels and increase in GSH, SOD and NO levels were observed in all treated animals., Conclusion: Both IE and CE were effective in inhibiting the tumor growth in ascitic tumor models. The biochemical, antioxidants and histopathological studies were also supported their antitumor properties.