Nicotine, a naturally occurring compound present in the leaves of the tobacco plant (Nicotiana tabacum), falls within the category of alkaloids. Classified as a highly addictive stimulant for the central nervous system, nicotine is chemically characterized as a colorless to pale yellow liquid with a distinctive odor. Its molecular structure comprises a pyridine ring, a pyrrolidine ring, and a methyl group, forming a relatively small molecule with the molecular formula C₁₀H₁₄N₂. Known predominantly for its association with tobacco products such as cigarettes, cigars, and chewing tobacco, nicotine rapidly enters the bloodstream through smoking or chewing, leading to its swift access to the brain and subsequent physiological and psychological effects. Acting as an agonist for nicotinic acetylcholine receptors (nAChRs) throughout the nervous system, nicotine triggers the release of neurotransmitters, including dopamine, norepinephrine, and serotonin, resulting in pleasurable sensations and heightened alertness for users. Beyond its presence in tobacco, nicotine is found in select plants of the Solanaceae family, including tomatoes, potatoes, and eggplants, albeit in significantly lower concentrations. Despite its natural origins, nicotine is a highly addictive substance associated with risks such as cardiovascular diseases, respiratory problems, and specific cancers. Chemical products derived from nicotine, either through synthesis or extraction from tobacco plants, find applications in research, pharmaceuticals, and smoking cessation products like nicotine replacement therapies (NRT). The emergence of electronic cigarettes (e-cigarettes) and vaping devices has introduced alternative avenues for nicotine consumption. These devices heat a liquid solution containing nicotine, producing an inhalable aerosol. While the long-term health effects are still under study, they are generally considered less harmful than traditional tobacco products. Nevertheless, due to its addictive nature, caution is advised when approaching nicotine use, and quitting may present challenges that can be addressed with proper support and resources.
