Mechanisms and Factors Responsible for the Entrance of Toxicants in the Human body and their Harmful Effects
Jorge D. Rebolledo
Columbia Southern University
The purpose of this paper is to make a short historical reference in the field of Toxicology and how this area of science has develop starting from centuries ago until our present. It is also the intention of this paper to explain how the toxics enter our body, how they are absorbed and the mechanisms responsible for that.
As stated by E. Monosson, some define Toxicology as the study of toxic materials, including the clinical, industrial, economic, and legal problems associated with them. Although toxicology—as a formally recognized scientific discipline—is relatively new (with major developments in the mid-1900s), the science itself is thousands of years old. Consider the potential results of early trial and error experiences of hunter-gatherers for whom identifying a toxic plant or animal was a life or death situation. Some of the most poisonous substances known today are naturally produced chemicals including ricin from castor beans or tetrodotoxin from the puffer fish. Early humankinds’ careful observations of such plants or animals with toxic characteristics as frogs, containing curare, were put to use not only for avoidance of toxic substances but for weaponry as well. Many naturally-derived poisons were likely used for hunting, as medicinal (the Egyptians were aware of many such toxic substances as lead, opium and hemlock as early as 1500 BCE). Use extended eventually to political poisonings as practiced, for example, by the early Greeks and Romans. With time, poisons became widely used and with great sophistication. Notable poisoning victims include Socrates, Cleopatra, and Claudius. One of the more interesting stories resulting from a combination of both ancient history and current toxicological research, is the story of King Mithridates, king of Pontus (120-63 BC) who according to toxicology legend was so afraid that he might be a casualty of political poisoning, is said to have concocted a potion from a great number of herbs for his own consumption. It is believed he understood that by consuming small amounts of potential poisons, he might protect himself from any would-be poisoner. That is, he believed in the effectiveness of hormesis. Apparently, his plans worked so well that he gained a name for himself as one so mighty he could not be killed. Unfortunately, it is said that when circumstances were such that he desired to kill himself, he was unable to do so by ingesting poison and had to be run through by a sword instead. Whether or not the story is true, it has led current day scientists to speculate upon the ingredients of his potion. It is believed that some herbs that he may have used, for example, St. Johns Wort could truly have contributed to detoxification of some other poisons. Recent studies have demonstrated that St. Johns Wort (often used as an herbal remedy) can increase the metabolism or breakdown of certain drugs and chemicals. This early story of toxicology relates a very important concept—that all animals have some kind of intrinsic ability for detoxifying a number of naturally-occurring toxicants in small doses (so that, in some cases low doses of chemicals may pass through the body without causing harm. From this we derive the concept of a chemical threshold), and that these processes can be altered by exposure to other chemicals. The question remains as to how adept animals, including humans, are at detoxifying many of the newer industrial chemicals or mixtures of industrial or industrial and natural chemicals. Additionally, it is well known that in some cases, detoxification of chemicals can produce even more toxic compounds. Pre-Industrial Toxicology
As declared by E. Monosson, as humans...