DL-Menthol
DL-Menthol (Racementhol) is an orally active, GABAaR positive allosteric modulator and UDP-glucuronosyltransferase (UGT) inhibitor that can cross the blood-brain barrier. DL-Menthol binds to GABAAR and exhibits an allosteric activation effect, enhancing GABA-mediated chloride influx and inhibiting neuronal excitability. DL-Menthol can induce surgical anesthesia in fish and inhibit the metabolic detoxification of tobacco carcinogens by human liver and intestinal UGT enzymes, resulting in reduced NNAL-N-Gluc production[1][2].