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Pharmacology is a science of medical drug and medication, including a substance's origin, composition, pharmacokinetics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.
Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. Factors that influence chemical toxicity include the dosage, duration of exposure, route of exposure, species, age, sex, and environment. Toxicologists are experts on poisons and poisoning. There is a movement for evidence-based toxicology as part of the larger movement towards evidence-based practices. Toxicology is currently contributing to the field of cancer research, since some toxins can be used as drugs for killing tumor cells. One prime example of this is ribosome-inactivating proteins, tested in the treatment of leukemia.
In vitro toxicity testing is the scientific analysis of the toxic effects of chemical substances on cultured bacteria or mammalian cells. In vitro testing methods are employed primarily to identify potentially hazardous chemicals and/or to confirm the lack of certain toxic properties in the early stages of the development of potentially useful new substances such as therapeutic drugs, agricultural chemicals and food additives.
Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with mutagenicity, all mutagens are genotoxic, but some genotoxic substances are not mutagenic. The alteration can have direct or indirect effects on the DNA: the induction of mutations, mistimed event activation, and direct DNA damage leading to mutations. The permanent, heritable changes can affect either somatic cells of the organism or germ cells to be passed on to future generations. Cells prevent expression of the genotoxic mutation by either DNA repair or apoptosis; however, the damage may not always be fixed leading to mutagenesis.
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Sean Ekins is a British pharmacologist and expert in the fields of ADME/Tox, computational toxicology and cheminformatics at Collaborations in Chemistry, a division of corporate communications firm Collaborations in Communications. He is also the editor of four books and a book series for John Wiley & Sons.
Toxicodynamics, termed pharmacodynamics in pharmacology, describes the dynamic interactions of a toxicant with a biological target and its biological effects. A biological target, also known as the site of action, can be binding proteins, ion channels, DNA, or a variety of other receptors. When a toxicant enters an organism, it can interact with these receptors and produce structural or functional alterations. The mechanism of action of the toxicant, as determined by a toxicant’s chemical properties, will determine what receptors are targeted and the overall toxic effect at the cellular level and organismal level.
References
- ↑ Williams, D.P.; Naisbitt, D.J. (2002). "Toxicophores: Groups and Metabolic Routes Associated with Increased Safety Risk". Current Opinion in Drug Discovery & Development. Curr. Opin. Drug. Discov. Devel. 5 (1): 104–115. PMID 11865664.
- ↑ Seal, Abhik; Passi, Anurag; Jaleel, Abdul; Wild, David J (May 2012). "In-silico predictive mutagenicity model generation using supervised learning approaches" (PDF). Journal of Cheminformatics. 4 (1): 10. doi: 10.1186/1758-2946-4-10 . PMC 3542175 . PMID 22587596.
- ↑ "Computational Toxicology: Superfund Research Program". National Institute of Environmental Health Sciences. 2009.
- ↑ "About the National Center for Computational Toxicology (NCCT)". Research Triangle Park, NC. 2005.
- ↑ "ToxCast: Advancing the next generation of chemical safety evaluation" . Retrieved March 10, 2014.
- ↑ "ACToR: Aggregated Computational Toxicology Resource" . Retrieved March 10, 2014.
- ↑ "CompTox Chemistry Dashboard" . Retrieved January 5, 2017.
- ↑ "Distributed Structure-Searchable Toxicity (DSSTox) Database Network" . Retrieved March 10, 2014.
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