Mitragyna speciosa: Leaves of this plant, as kratom, are used as an "opium substitute" in southeast Asia, and it has been suggested to be entheogenic, in part based on content of indole alkaloids like mitragynine (Emboden 1979; Harrison McKenna 1989; Jansen & Prast 1988a; Jansen & Prast 1988b). Whole leaves of kratom are stimulating while mitragynine is a depressant (Shellard 1989), suggesting the pharmacological importance of secondary alkaloids. Further studies are needed to clarify kratom ethnopharmacognosy. Kratom or gra-tom is used as a stimulant and antidiarrheal in Thai ethnomedicine (Ponglux et al. 1989). Four African species of Mitragyna were devoid of mitragynine, but rich in other alkaloids (Shellard 1983).


References
Emboden WA. Narcotic Plants. Macmillan Publishing Co, New York. 1979.

Shellard E J. "The alkaloids of Mitragyna with special reference to those of Mitragyna speciosa, Korth": Bulletin On Narcotics, 1974 issue 2

Harrison McKenna K. Plant collecting in Thailand -- January 1989. Whole Earth Review 64:32-33. 1989.

Jansen KLR, Prast CJ. Ethnopharmacology of Kratom and the Mitragyna alkaloids. Journal of Ethnopharmacology 23(1):115-119. 1988.

Jansen KLR, Prast CJ. Psychoative properties of mitragynine (kratom). Journal of Psychoactive Drugs 20(4):455-457. 1988.

Shellard EJ. Ethnopharmacology of kratom and the Mitragyna alkaloids. Journal of Ethnopharmacology 25(1):123-124. 1989.

Ponglux D, et al. (editors) Medicinal Plants. Victory Power Point Corp, Bangkok Thailand. Preface K Manunapichu. 1991.

Shellard EJ. Mitragyna: A note on the alkaloids of African species. Journal of Ethnopharmacology. 8(3): 345-347. 1983.