Toxin

Toxin are heterogeneous molecules that show toxic properties to other cells, organisms, and living beings in various mechanisms. The plant's toxic nature and seeds have also been well-known for centuries. Dating back to about 1500 BC, the first information and description of natural poisons originated in the Ebers Papyrus. It is now widely known that many plants content with poisonous substances. In 50 BC, Dioscorides classified toxins depending on their origin to animal, plant, and mineral toxins in his Materia Medica. A biological toxin is a poisonous substance having a protein structure. Thus, toxins are biomolecules produced by insects, plants, bacteria, fungi, vertebrates, and invertebrate animals. Toxins do not produce an infection. The toxins are mainly produced for self-defense but could harm other organisms by injection, absorption, ingestion, or inhalation. Toxins cause toxicity in other organisms’ cells by a variety of mechanisms. Some toxins cause disturbances in the functioning of organs and tissues due to damage to cell membranes. Such toxins cause permanent damage to health due to their irreversible nature. Some toxins might use for bioterrorism, and examples are botulinum, ricin, Clostridium perfrigens epsilon toxin, conotoxins, Shiga toxins, tetrodotoxins, saxitoxins, mycotoxins, and nicotine. By blocking protein synthesis, the well-known toxin ricin causes multiorgan toxicity, and botulinum leads to muscle paralysis by blocking acetylcholine in the peripheral nervous system. Some toxins can also act as carcinogens, eg, aflatoxins. [AKM Mahbub Hasan]

See also diphtheria toxin, tetanus toxin.