Clinical Toxicology
January 1, 2008
Kavita M. Babu, Christopher R. McCurdy, Edward W. Boyer
221 citations
Salvia divinorum and Kratom are unscheduled dietary supplements that activate opioid receptors and produce distinct psychoactive effects. Salvinorin A, from Salvia divinorum, is a highly selective kappa-opioid receptor agonist that causes visual hallucinations and synesthesia. Kratom's main alkaloid, mitragynine, acts as a partial opioid agonist with morphine-like effects, while its minor alkaloid 7-hydroxymitragynine is more potent than morphine. Both Kratom alkaloids activate supraspinal mu- and delta-opioid receptors, which explains their use by chronic narcotics users to ease opioid withdrawal. Despite widespread Internet availability, these substances elude traditional toxicologic monitoring, and the article aims to inform toxicologists and poison control specialists about them.
Brain sciences
August 28, 2025
Seif Abouheif, Ahmed Awad, Christopher R. McCurdy
1 citation
Indolethylamine N-methyltransferase (INMT) is an enzyme that adds a methyl group to compounds such as tryptamine, serotonin, and dopamine. Dysregulation of INMT activity is linked to neuropsychiatric disorders, neurodegeneration, and several cancers. This review describes the enzyme's structure, its role in disease, and methods to measure its activity, including both radiolabeled and non-radiolabeled assays. It also surveys natural and synthetic inhibitors of INMT that may have therapeutic value. The authors argue that INMT is an underexplored target for drug development and that integrating structural biology, disease pathology, and inhibitor profiling could advance therapeutic applications.
bioRxiv (Cold Spring Harbor Laboratory)
September 29, 2024
Sabrina Zequeira, Emely A. Gazarov, Alara A. Güvenli et al.
preprint
Acute cannabis smoke enhanced working memory accuracy in aged male rats but impaired it in aged females, with no effects in young adults of either sex. The same smoke had minimal effects on a hippocampus-dependent memory task regardless of age or sex. Chronic oral Δ9-tetrahydrocannabinol (Δ9THC) enhanced working memory in aged rats of both sexes while not affecting young adults, and did not affect spatial learning or memory in either age group. Minimal age differences in Δ9THC pharmacokinetics were observed. Cannabis and Δ9THC can attenuate working memory impairments that emerge in aging without exacerbating age-associated hippocampus-dependent cognitive decline.