Poisons, hallucinogens, teratogens, pesticides, and xenobiotics—their sources, classification, chemistry, and metabolism

Abstract

Poison causes irritation, injury, illness, or death if a person tastes it, smells, and gets it on skin or in eye and may be solid, liquid, sprays, vapor or gases, etc., or even a good thing when used in a wrong way. Botulinum toxin is the deadliest substance known to man. Poison, toxin, and venom may be differentiated: any substance that has a noxious effect on living organisms is poison, a toxin is a poison produced by a living organism in nature and toxicants are synthesized chemical substances while venom is a toxin injected by a bite or sting from a living organism into another (delivery method). The poison is often used to describe any harmful substance, particularly corrosive substances, carcinogens, mutagens, teratogens and harmful pollutants, and to exaggerate the dangers of chemicals. Physical sources such as particulate radiation (alpha and beta particles) or electromagnetic waves (X-rays, γ-rays, UV-rays) may cause harmful effects on living organisms. Paracelsus wrote: “Everything is poison; there is poison in everything; only the dose makes a thing not a poison”. Some poisons exert their effects on the part they come in contact with (local effect), some exert their effect on one or more organ systems after absorption (systemic effect), while some poisons have both local and systemic effects (combined effect). General symptoms of poisoning include (i) sick feeling, (ii) diarrhea, (iii) stomach pain, (iv) drowsiness, dizziness or weakness, (v) high temperature (38 °C, 100.4 °F or above), (vi) chills (shivering), (vii) loss of appetite, (viii) headache, etc. Poisonous compounds may be useful either for their toxicity as pesticides in agriculture or in industry as chemical reagents, solvents or complexing reagents, but less common in household use. Hallucination is distortion in perceptions of reality caused by hallucinogens such as psychoactive agents like mescaline, psilocybin, ibogaine, LSD, etc. Most hallucinogens are alkaloids or related substances and may be smoked or snuffed, swallowed fresh or dried, drunk in decoctions and infusions, absorbed directly through the skin, placed in wounds or administered as enemas. Teratogens affect the development of an embryo or fetus and include radiation, maternal infections, maternal metabolic factors, exposure to 2,4-d spraying, chemicals, drugs, etc. A pesticide and weedicides are chemicals that prevent, destroy, or repel pests including insects, termites, nematodes, molluscs, mice and other rodents, weeds, fungi and microorganisms bacteria and viruses. Medicinal drugs are divided with respect to human organism are autobiogenous or natural, and (ii) xenobiotic or foreign. Biogenous drugs are involved in the conventional metabolic process while metabolic process of xenobiotics is subject to two major stages such as modification and conjugation. Metabolism of both biogenous substances and xenobiotics drugs is governed by the laws of enzyme kinetics. The metabolic conversion of xenobiotics is dependent on the occurrence of enzymes capable of catalyzing the conversion of these xenobiotics.