Immunotoxicological Threats of Pollutants in Aquatic Invertebrates

Immunology deals with the physiological activity of organisms to defend against pathogen and toxin invasion. Invertebrates residing in aquatic ecosystems often face toxicological threat arises from habitat pollution. The aquatic habitat of invertebrates is in the precarious risk of pollution caused by diverse groups of environmental toxins. Immunotoxins have been considered as a special group of pollutants capable of affecting the immunological profile of organisms. Invertebrates residing in water bear ecological, economical, medicinal, industrial, nutritional and biotechnological significance. Global aquatic bioresource is largely composed of invertebrates belonging to multiple Phyla. These organisms, including insects, snails, clams, mussels, crabs and sponges, are physiologically dependent on innate immunological response for defense against pathogen and environmental contaminants. External physicochemical barriers of invertebrates act as primary line of defen against toxin entry. Principal barriers have been identified as shell, tunic, test, carapace, mucus, etc., in diverse species. Toxin-induced morphological damage of specialized immunocytes of invertebrates has been reported. Toxin-induced shift in density, surface adhesion efficacy and aggregation of blood cells or haemocytes have been identified as major xenobiotic stress in invertebrates. Various environmental toxins are capable of initiating alteration in the innate phagocytic response and cytotoxicity of blood cells. Lysosomes of invertebrate haemocytes are functionally involved in intracellular destruction of environmental pathogens. Toxins like arsenic, pyrethroid pesticides, azadirachtin and washing soda were reported to increase the relative fragility of lysosomal membranes of immunocytes. This often leads to impairment in the efficacy of invertebrates to destroy pathogen under the exposure of pollutants. Xenobiotics like pyrethroid pesticides have been recorded to affect apoptosis and necrosis of invertebrate immunocytes. Selected toxin-induced morphological damages of heart, gill, digestive gland, mantle and antennae may result in the overall impairment in homeostatic levels of invertebrates inhabiting the polluted environment. Global environment, in recent times, is under the serious threat of contamination by diverse chemical compounds of unknown or less known toxicity. A thorough ecotoxicological analysis at cellular and molecular levels needs to be carried out in invertebrates occupying the different realms of the planet in future

Immunogenic Modulations Induced by Prospective Anti-Malarial Herbal Extracts in Murine Model

Keeping in view the ever increasing problem of drug resistance and affordability of the antimalarial drugs by the poor mass, herbal medicines can become an important and alternative sustainable strategy for malaria treatment. Aqueous extracts of three Himalayan herbs― _Equisetum ravense_, _Artemisia vulgaris_ and _Centella asiatica_, with reported antimalarial property were screened for clinical efficacy against a local strain of _Plasmodium vivax_ antigen in murine model. _E. arvense_ extract was consistent in boosting phagocytic activity, nitric oxide generation, acid phosphatase and alkaline phosphatase activities in the peritoneal macrophages. The effectiveness of the rest herbals was discrete. A need for further detailed investigation to evaluate the clinical efficacy of these herbals seems essential

Expression analyses of interferon gamma, tumor necrosis factor alpha and inducible nitric oxide synthase in the hemocyte morphotypes of two commercially important Indian molluscs

Bellamya bengalensis and Lamellidens marginalis are the two common species of molluscs of Indian subcontinent which bear immense aquacultural prospect. These edible varieties of freshwater molluscs have nutritional, ecological, ethnomedicinal and industrial significance. Report of nonspecific immunological status of them is grossly inadequate in the current scientific literature. Hemocytes, the circulating blood cells of invertebrate molluscs play a pivotal role in cell mediated immunity. Information of existence of cytokines like IFNγ, TNFα and enzyme iNOS is very limited and controversial in molluscan hemocytes. We detected IFNγ, an immunomodulatory molecule and TNFα, a tumoricidal and apoptosis inducing cytokine in hemocyte morphotypes of molluscs B. bengalensis and L. marginalis by flow cytometry, iNOS had been detected in the hemocyte morphotypes of B. bengalensis and not in L. marginalis. We report the existence of IFNγ in molluscs for the first time. Comparative expression of IFNγ, TNFα and iNOS in hemocytes would provide a better information base to understand biology, evolution and immunological role of these molecules in molluscs and related metazoans