Lobeline

Lobeline is an alkaloid isolated from Lobelia inflata, commonly known as Indian tobacco. It is one of several active constituents of Lobelia species and belongs to the class of piperidine alkaloids. Lobeline has been studied for its potential effects on nicotinic acetylcholine receptors and as a pharmacological agent for nicotine dependence, but it is not approved as a medicine in major regulatory systems.

Lobeline occurs in Lobelia inflata and related species and can be isolated in free-base form or as salts such as lobeline hydrochloride for research and limited pharmaceutical uses. It is a multi-ring alkaloid with a piperidine moiety, and several stereoisomers exist due to chiral centers.

Lobeline acts as an agonist at nicotinic acetylcholine receptors, with activity at subtypes implicated in nicotine reinforcement. Through receptor activation, it can modulate the release of several neurotransmitters including dopamine and norepinephrine, and may influence reward pathways in animal models. The compound has also been studied for potential interactions with monoamine transporters. At higher doses, lobeline can cause adverse effects such as nausea, vomiting, dizziness, hypotension, and CNS symptoms.

There is limited and inconclusive clinical evidence supporting lobeline as a smoking cessation aid. Regulatory agencies have issued warnings about herbal products containing lobeline due to safety concerns; lobeline-containing products are not approved as prescription medications in most countries. People should avoid use in pregnancy or with certain concomitant medications that affect cholinergic or dopaminergic systems. More research is needed to establish efficacy and safety.