title: Neurobiology of Kratom and its main alkaloid mitragynine.
abstract: Kratom or its main alkaloid, mitragynine is derived from the plant Mitragyna speciosa Korth which is indigenous to Southeast Asian countries. This substance has become widely available in other countries like Europe and United States due to its opium- and coca-like effects. In this article, we have reviewed available reports on mitragynine and other M. speciosa extracts. M. speciosa has been proven to have a rewarding effect and is effective in alleviating the morphine and ethanol withdrawal effects. However, studies in human revealed that prolonged consumption of this plant led to dependence and tolerance while cessation caused a series of aversive withdrawal symptoms. Findings also showed that M. speciosa extracts possess antinociceptive, anti-inflammatory, anti-depressant, and muscle relaxant properties. Available evidence further supports the adverse effects of M. speciosa preparations, mitragynine on cognition. Pharmacological activities are mainly mediated via opioid receptors as well as neuronal Ca2+channels, expression of cAMP and CREB protein and via descending monoaminergic system. Physicochemical properties of mitragynine have been documented which may further explain the variation in pharmacological responses. In summary, current researchs on its main indole alkaloid, mitragynine suggest both therapeutic and addictive potential but further research on its molecular effects is needed.
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Farah W
authors.initials: FW
authors.lastname: Suhaimi
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Nurul H M
authors.initials: NH
authors.lastname: Yusoff
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Rahimah
authors.initials: R
authors.lastname: Hassan
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Sharif M
authors.initials: SM
authors.lastname: Mansor
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Visweswaran
authors.initials: V
authors.lastname: Navaratnam
authors.affiliation: Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Müller
authors.affiliation: Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia. Electronic address: zurina_hassan@usm.my.
authors.forename: Zurina
authors.initials: Z
authors.lastname: Hassan
mesh_terms: D000818:Animals; D003072:Cognition Disorders / Q000139:chemically induced; D006801:Humans; D032065:Mitragyna / Q000737:chemistry*; D009446:Neurobiology; D064209:Phytochemicals; D011619:Psychotropic Drugs / Q000009:adverse effects*; D011957:Receptors, Opioid / Q000378:metabolism; D046948:Secologanin Tryptamine Alkaloids / Q000009:adverse effects*; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology
chemical_list: D064209:Phytochemicals; D011619:Psychotropic Drugs; D011957:Receptors, Opioid; D046948:Secologanin Tryptamine Alkaloids; C001801:mitragynine