A comparative account of coelomocyte of earthworm ecotypes with reference to its morphology, morphometry, density, phagocytosis, autofluorescence, and oxidative status.

Earthworms inhabit different strata of moist soil. Epigeic and endogeic earthworms prefer superficial and inner stratum of soil respectively, whereas, semiaquatic species are distributed around hydrated soil near ponds and lakes. Coelomocytes, the chief immunoeffector cells of coelomic origin, perform diverse physiological functions like phagocytosis, maintenance of cellular homeostasis, and acid-base balance of coelomic fluid, graft rejection, elicitation of cytotoxic, and oxidative responses under the challenges of pathogens and toxins. The present study aims to analyze selected morphological and functional parameters in three differentially adapted Indian earthworms of nonsimilar habitats. Coelomocytes of Glyphidrilus tuberosus (Stephenson, 1916) (semiaquatic), Perionyx excavatus (Perrier, 1872) (epigeic), and Eutyphoeus orientalis (Beddard, 1883) (endogeic) were isolated for morphological and morphometric analyses and subjected to determination of phagocytic, oxidative, and cytotoxic responses. Activities of phenoloxidase, pro, and antioxidant enzymes, and autofluorescence were determined in the extruded coelomocytes of earthworms of three contrasting habitats. The differential result may be correlated with species-specific responses and variation in habitat preference and related adaptation.

Metal accumulation and morphofunctional damage in coelomocytes of earthworm collected from industrially contaminated soil of Kolkata, India.

The current study is aimed to assess the ecotoxicological effects of toxic metals and seasonal shift of the physicochemical characteristics of soil in an endogeic earthworm Metaphire posthuma of industrially contaminated soil of Calcutta leather complex. The accumulation of cadmium, chromium, lead and mercury was quantitated in whole earthworms and coelomocytes. The accumulation of metals was derived to be high in the coelomocytes than whole earthworms. Morphofunctional shift in coelomocytes indicated a high level of metal toxicity in soil inhabitants. The shift in differential coelomocyte count and cellular damage including intense cytoplasmic vacuolation and membrane blebbing of coelomocytes of M. posthuma of contaminated soil were suggestive to a state of immunocompromisation in the same species. Shift in the generation of nitric oxide and activity of inducible nitric oxide synthase indicated a possible immunosuppression in earthworm. Depletion in the acetylcholinesterase activity of coelomocytes indicated neurotoxicity of metals leached from the dumped wastes in Calcutta leather complex. Integrated biomarker response based analysis was carried out to assess the biomarker potential of experimental endpoints of M. posthuma to monitor metal toxicity in soil.

Effects of copper oxide nanoparticle on gill filtration rate, respiration rate, hemocyte associated immune parameters and oxidative status of an Indian freshwater mussel.

Waterbodies of India support a wide range of molluscs including Lamellidens marginalis, a pearl forming edible mussel of ecological significance. Report of copper oxide nanoparticle toxicity in Indian molluscs is limited in scientific literature. L. marginalis is a gill respiring filter feeder, which is toxicologically vulnerable to exposure of copper oxide nanoparticles liberated from electrical, textile and polymer industries. Experimental exposure of copper oxide nanoparticles for 7 days yielded a decrease in gill filtration rate, respiration rate, total count and phagocytic response of hemocytes, the chief immunoeffector cells of L. marginalis. Nanoparticle exposure resulted in decrease of phagocytic response of mussel hemocytes. Decrease in nitric oxide generation and phenoloxidase activity were recorded in L. marginalis exposed to 0.5, 1 and 5 mg copper oxide nanoparticles per litre of water for 7 and 14 days. Superoxide anion generation in hemocytes was increased under the exposure of copper oxide nanoparticles. Increase in superoxide anion and decrease in the activities of superoxide dismutase and catalase were indicative to oxidative stress in mussels. Copper oxide nanoparticle induced shift in filtration and respiration rate along with the hemocyte associated immune parameters were suggestive to an acute immunophysiological stress in L. marginalis. We estimated the functional performance of gill and physiological status of aquatic respiration in L. marginalis exposed to copper oxide nanoparticles. A parallel set of estimation of each parameter was carried out in L. marginalis exposed to identical copper sulphate concentrations to record and compare the ionic toxicity of copper in the same specimen.

Shift in phagocytosis, lysosomal stability, lysozyme activity, apoptosis and cell cycle profile in the coelomocytes of earthworm of polluted soil near a tannery field of India.

Calcutta Leather Complex of the state of West Bengal, India has been designated as an industrially active zone with around 400 active tannery units. This area spanning 4.5 km2 is surrounded by human habitation. The soil of this region is contaminated with metal pollutants and exhibited an alteration in selected physicochemical parameters, namely cation exchange capacity, moisture content, pH, total nitrogen, total organic carbon and water holding capacity. Metaphire posthuma, a common variety of endogeic earthworm inhabiting this region is thus continuously exposed to these toxic metals. Coelomocytes, the chief immune effector cells of earthworm presented a shift in phagocytosis, lysosomal membrane stability, lysozyme and phosphatase activity, physiological apoptosis and cell cycle profile of M. posthuma sampled from the soil of tannery industry. Presence of high concentration of toxic metals and change in the physicochemical characteristics of soil led to a state of cellular stress and immunocompromisation in M. posthuma, a common inhabitant of soil of this region. Experimental endpoints bear ecotoxicological significance as biomarkers of physiological stress in earthworm for monitoring the health of soil around this tannery industrial zone.

Analysis of oxidative stress and cellular aggregation in the coelomocytes of earthworms collected from metal contaminated sites of industrial and agricultural soils of West Bengal, India.

Endogeic earthworm Metaphire posthuma (Valliant, 1868) is a common biological component of the tropical soil of India and other countries. The species is reported to influence fertility and porosity of soil and bear a high composting potential. Intensive agricultural, industrial, and mining activities increase the amount of toxic metals in soil causing physiological adversity in earthworm and other biotic components in soil. Coelomocytes, the chief immunoeffector cells of earthworm, perform diverse physiological functions under the challenge of toxins and pathogens. The experimental earthworms collected separately from soils with agricultural and tannery activities were subjected to quantitation of prooxidation and antioxidation parameters for estimation of oxidative stress. Total count, cellular aggregation, generation of reactive oxygen species (ROS), superoxide anion, nitric oxide, activities of phenoloxidase, superoxide dismutase, catalase and glutathione-s-transferase, and amount of total protein were estimated in the coelomocytes of M. posthuma as experimental end points of toxicity screening. Concentrations of cadmium, chromium, lead, and mercury were determined in the soil samples to assess the degree of toxic contamination. The increase in the amount of prooxidants and decrease in the activities of antioxidant enzymes indicated the signs of oxidative stress in the coelomocytes of the organism. Aggregation of circulating coelomocytes is considered as an immune response involved in pathogen encapsulation response as reported in many invertebrates. Decrease in coelomocyte aggregation in earthworm collected from contaminated sites suggested a state of inappropriate shift of the innate immune status. Toxin-induced oxidative stress and reductions in cell aggregation response are the signs of immunocompromisation of M. posthuma. Present findings bear a prospect of this experimental species as an indicator of soil pollution.

Immunotoxicity of copper nanoparticle and copper sulfate in a common Indian earthworm.

Copper oxide nanoparticles and copper sulfate are established contaminants of water and soil. Metaphire posthuma is a common variety of earthworm distributed in moist soil of Indian subcontinent. Comparative toxicity of copper nanoparticles and copper sulfate were investigated with reference to selected immune associated parameters of earthworm. Total count, phagocytic response, generation of cytotoxic molecules (superoxide anion, nitric oxide), activities of enzymes like phenoloxidase, superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase and total protein of coelomocytes were estimated under the exposures of 100, 500, 1000mg of copper oxide nanoparticles and copper sulfate per kg of soil for 7 and 14 d. A significant decrease in the total coelomocyte count were recorded with maximum depletion as 15.45 ± 2.2 and 12.5 ± 2 × 104 cells/ml under the treatment of 1000mg/kg of copper nanoparticles and copper sulfate for 14 d respectively. A significant decrease in generation of nitric oxide and activity of phenoloxidase were recorded upon exposure of both toxins for 7 and 14 d indicating possible decline in cytotoxic status of the organism. A maximum inhibition of superoxide dismutase activity was recorded as 0.083 ± 0.0039 and 0.055 ± 0.0057 unit/mg protein/minute against 1000mg/kg of copper nanoparticles and copper sulfate treatment for 14 d respectively. Activities of catalase and alkaline phosphatase were inhibited by all experimental concentrations of both toxins in the coelomocytes of earthworm. These toxins were recorded to be modifiers of the major immune associated parameters of M. posthuma. Unrestricted contamination of soil by sulfate and oxide nanoparticles of copper may lead to an undesirable shift in the innate immunological status of earthworm leading to a condition of immune compromisation and shrinkage in population density of this species in its natural habitat. This article is the first time report of immunological toxicity of nanoparticles and sulfate salt of copper in M.posthuma inhabiting the soil of India, an agriculture based country.