Identification of opioid receptor subtypes in antinociceptive actions of supraspinally-admintstered mitragynine in mice

Suchitra, Thongpradichote; Matsumoto, Kinzo; Tohda, Michihisa; Takayama, Hiromitsu; Aimi, Norio; Sakai, Shin‐ichiro; Watanabe, Hiroshi

doi:10.1016/s0024-3205(98)00075-7

Cited by 135 publications

(93 citation statements)

References 23 publications

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“…administration of mitragynine is dominantly mediated by m-and d-opioid receptor subtypes, and that the selectivity of mitragynine for the supraspinal opioid receptor subtypes differs from that of morphine in mice. 34) Recently, Tsuchiya et al reported that mitragynine (1), similar to morphine, inhibits 2-deoxy-D-glucose-stimulated gastric acid secretion in urethane-anesthetized rats through opioid receptors. 35) The results of pharmacological evaluations of minor constituents, speciogynine (2), speciociliatine (3), paynantheine (4), and 7-hydroxymitragynine (5), are discussed in sections 5 and 6.…”

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confidence: 99%

Chemistry and Pharmacology of Analgesic Indole Alkaloids from the Rubiaceous Plant, Mitragyna speciosa

2004

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The leaves of a tropical plant, Mitragyna speciosa KORTH (Rubiaceae), have been traditionally used as a substitute for opium. Phytochemical studies of the constituents of the plant growing in Thailand and Malaysia have led to the isolation of several 9-methoxy-Corynanthe-type monoterpenoid indole alkaloids, including new natural products. The structures of the new compounds were elucidated by spectroscopic and/or synthetic methods. The potent opioid agonistic activities of mitragynine, the major constituent of this plant, and its analogues were found in in vitro and in vivo experiments and the mechanisms underlying the analgesic activity were clarified. The essential structural features of mitragynines, which differ from those of morphine and are responsible for the analgesic activity, were elucidated by pharmacological evaluation of the natural and synthetic derivatives. Among the mitragynine derivatives, 7-hydroxymitragynine, a minor constituent of M. speciosa, was found to exhibit potent antinociceptive activity in mice.

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confidence: 99%

Chemistry and Pharmacology of Analgesic Indole Alkaloids from the Rubiaceous Plant, Mitragyna speciosa

2004

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“…Mitragynine, a major indolecontaining constituent similar in structure to yohimbine [13], accounts for up to 66 % of the plant's alkaloid content [15,16]. It produces opioid-like effects predominantly via mu-and delta-opioid receptor agonism [5,13,17] in addition to modulation of the descending serotonergic and noradrenergic pathways [18]. In vitro characterization of mitragynine receptor binding in the central nervous system reveals the complexity with which Kratom acts (see Table 1) [10].…”

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confidence: 99%

Suspected Adulteration of Commercial Kratom Products with 7-Hydroxymitragynine

et al. 2016

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Introduction Kratom (Mitragyna speciosa), a plant native to Southeast Asia, has been used for centuries for its stimulant and opium-like effects. Mitragynine and 7-hydroxymitragynine, exclusive to M. speciosa, are the alkaloids primary responsible for Kratom's biologic and psychoactive profile, and likely contribute to its problematic use. We purchased several commercially available Kratom analogs for analysis and through our results, present evidence of probable adulteration with the highly potent and addictive plant alkaloid, 7-hydroxymitragynine. Methods A simple and sensitive LC-MS/MS method was developed for simultaneous quantification of mitragynine and 7-hydroxymitragynine in methanol extract of marketed Kratom supplements. Results We found multiple commercial Kratom products to have concentrations of 7-hydroxymitragynine that are substantially higher than those found in raw M. speciosa leaves. Conclusions We have found multiple packaged commercial Kratom products likely to contain artificially elevated concentrations of 7-hydroxymitragynine, the alkaloid responsible for M. speciosa's concerning mechanistic and side effect profile. This study describes a unique form of product adulteration, which stresses the importance of increased dietary supplement oversight of Kratom-containing supplements.

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“…Kratom (Mitragynia speciosa korth) is a medicinal herb indigenous to Southeast Asia whose components mitragynine and 7-hydroxymitragynine agonize the mu-opioid receptor with high affinity [1][2][3]. Recent findings suggest that kratom is purchased from internet sources by some of the 40 million Americans with chronic pain to self-manage opioid withdrawal [1].…”

Section: Introductionmentioning

confidence: 99%