J. Xenobiot., Volume 6, Issue 1 (June 2016) – 4 articles

Ecotoxicological effects of industrial chemicals (Rig wash, Oil eater, Nalco, Glycol™) and pesticides (Propoxur, Deltamethrin, Atrazine, Furadan) on Tilapia guineensis (fish) and Aporrectodea longa (earthworms) were tested using the Organisation for Economic Cooperation and Development (OECD) # 203 and 207 protocols. The water and soil ratings indicate that the test chemicals were toxic to the organisms. The estimated 96 hour lethal concentration LC₅₀ values for Rig wash, Oil eater, Nalco EC1304A/COT 505, Glycol, Propoxur, and Deltamethrin were 26.34±0.46, 6.02±0.30, 3.07±0.14, 1.31±0.01, 20.91±0 and 0.01±0 mg/l respectively. In the earthworm bioassay, the estimated 14-day LC₅₀ values for Rigwash, Oil eater, Nalco EC1304A/COT 505, Glycol, Atrazine and Furadan were 80.05±3.5, 151.55±10.7, 172.63±14.2, 63.72±2.43, 4.97±0 and 0.29±0 mg/kg respectively. Safety factors are arbitrarily built in around the LC₅₀ values in order to arrive at environmentally tolerable concentrations. The concentration of a chemical in the receiving environment should not exceed 10% of the L₅₀. The organisms exposed to the test chemicals showed significant difference when compared with the levels measured in the control group. The observed sensitivity of the test organisms to the chemicals indicates that adherence to standard safety limits/measures should be maintained during use and disposal of hazardous chemicals. This would ensure that the biotic components of the Nigerian Niger Delta ecosystem are prudently protected. Full article

We investigated the protective effect of gallic acid (GA) against methotrexate (MTX)-induced hepatotoxicity and nephrotoxicity. Male Wistar rats were randomized into five groups (n = 6/group): I, control; II, MTX-treated for seven days; III, pre-treated with GA for seven days, followed by MTX for seven days; IV, co-treated with MTX and GA for seven days and V, GA for seven days. MTX caused a significant increase (P<0.05) in plasma biomarkers of nephrotoxicity (urea, creatinine) and hepatotoxicity (Bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase) when compared with control. Furthermore, MTX caused a significant decrease in the activities of hepatic enzymic antioxidants (superoxide dismutase, catalase, glutathione S-transferase) and nonenzymic antioxidants (Vitamin C and glutathione), followed by a significant increase in hepatic malondialdehyde content. However, pretreatment and co-treatment with gallic acid ameliorated the MTX-induced biochemical changes observed. Taken together, GA protected against MTX-induced hepatotoxicity and nephrotoxicity in rats, by reducing the impact of oxidative damage to tissues. Full article

The blue mussel is a filter-feeding bivalve commonly used in ecotoxicological monitoring as a sentinel species. Due to climate change and the increase of temperature expected in marine environment, it is important to anticipate potential impacts on this species. The aim of this study was to investigate the immunocompetence of blue mussels acclimated to different temperatures and on the effects of increasing temperatures (5, 10 and 20°C). Different indices and gonad maturation stages were also determined throughout the experiments. Cell viability, phagocytosis, serum lysozyme activity and cyclooxygenase (COX) activity were evaluated as immune parameters. The cellular immunity was also evaluated after hemocytes exposure to various cadmium concentrations in vitro. The results obtained demonstrate modulation of hemocyte viability and the ability of these cells to phagocytize in absence of contaminants. After the exposure to cadmium, hemocytes showed greater viability at 5°C while maintaining a higher phagocytic competence. In addition, the lysozyme activity stayed stable at all tested temperatures, contrary to that of COX, which increased when the mussels were maintained at 20°C. The evaluation of indices demonstrated no reduction of general conditions during all the experiment despite the increase of temperature and the reduction of the digestive gland weight. Moreover, the lack of food does not affect gonad maturation and the spawning process. Full article

Pharmaceutical products and their wastes play a major role in the degradation of environment. These drugs have positive as well as negative consequences on different environmental components including biota in different ways. Many types of pharmaceutical substances have been detected with significant concentrations through various advanced instrumental techniques in surface water, subsurface water, ground water, domestic waste water, municipal waste water and industrial effluents. The central as well as state governments in India are providing supports by creating excise duty free zones to promote the pharmaceutical manufacturers for their production. As a result, pharmaceutical companies are producing different types of pharmaceutical products at large scale and also producing complex non-biodegradable toxic wastes byproducts and releasing untreated or partially treated wastes in the environment in absence of strong regulations. These waste pollutants are contaminating all types of drinking water sources. The present paper focuses on water quality pollution by pharmaceutical pollutants, their occurrences, nature, metabolites and their fate in the environment. Full article