Toxicology

Biography

Biography: S S Hundal

Abstract

The concept of stress in an organism that results in an internal physiological response in living organisms has been recognized and hypothesized to involve important adaptive changes that are necessary to restore homeostasis. Different conditions produce similar stress responses, and the ability of organisms to adapt to stress is regulated by the integration of the nervous, immune and endocrine systems; mediated by hormones and is ultimately played out at the level of cells and molecules. Stress plays a prominent role in cellular aging because the cells have to withstand and respond to major types of stress in their environment, including genotoxic and oxidative stress often leading to initiating a cell death program. Oxidative stress occurs when highly reactive molecules - free radicals - overwhelm the cell’s natural defenses against their attack. Under conditions of oxidative stress, cellular machinery fails and eventually impairs function by slowing down physiological processes. The different types of pollutants released to environment in every moment by the human activity enter different ecosystems from different pathways - industrial wastes, human disposal, toxic chemicals, sewages, radio nuclides, organic pollutants, air and trafficked pollutants - and their effects remain for a long period of time. These toxic elements eventually influence the human lives leading to the negative effects on human population growth and its expanding ecological footprint. Even though living organisms have long been subject to a myriad of evolutionary pressures arising from the environment and are consequently well adapted to respond to pressures, the current pace of environmental change is unprecedented and it is unknown whether the capacity of species to adapt to such changes and counteract their harmful and often combined effects may be exceeded. Information and data from reliable sources on this subject is extremely limited, making it difficult to understand the full extent of the effects of environmental change on wildlife health. Recent ecological studies have shown that oxidative status could have a significant impact on fitness components in wild animals, which can predict their chances of reproduction and survival in their natural habitat. Such important characteristics make markers of oxidative status informative tools to evaluate a priority of the individual perspectives of reproduction and survival as well as to assess the effect of human activities on the fitness of species of conservation concern and wildlife in general. Generally stress proteins are activated very early in the cascade of cellular events that follow toxic exposure and at concentrations below the lethal dose. The aim for using stress proteins as preferable biomarkers in environmental risk assessment is to prove that they can give initial information on the effects of pollutants in the shortest period of time. An attempt is being made to review and raise awareness of the conservation practitioners to use these markers of oxidative status to contribute to the success or the failure of reintroduction or translocation programmes; encourage conservation physiologists to enhance the success of conservation of wildlife and its management. This would also address the levels at which anthropogenic environmental change might affect wildlife health and identify potential deficits in reproductive parameters in the context of a rapidly changing environment.