A botanical, phytochemical and ethnomedicinal review of the genus Mitragyna korth: Implications for products sold as kratom.
BACKGROUND
The genus Mitragyna (Rubiacaeae) has been traditionally used in parts of Africa, Asia and Oceania. In recent years, there has been increased interest in species of Mitragyna with the introduction of products to western markets and regulatory uncertainty.


OBJECTIVE
This paper reviewed the traditional ethnomedicinal uses of leaves for species belonging to the genus Mitragyna with reference to the botany and known chemistry in order to highlight areas of interest for products currently being sold as kratom.


METHODS
A literature search was conducted using Web of Science, Google Scholar, the Royal Museum for Central Africa, Internet Archive, Hathi Trust, and Biodiversity Heritage Library search engines in the spring of 2015, fall of 2016 and winter of 2017 to document uses of bark, leaf and root material.


RESULTS
Leaves of M. speciosa (kratom) had the most common documented ethnomedicinal uses as an opium substitute or remedy for addiction. Other species of Mitragyna were reportedly used for treating pain, however the mode of preparation was most often cited as topical application. Other uses of Mitragyna included treatment of fever, skin infections, and as a mild anxiolytic.


CONCLUSIONS
Mitragyna species have been used medicinally in various parts of the world and that there is significant traditional evidence of use. Modern products that include formulations as topical application of liniments, balms or tinctures may provide effective alternatives for treatment of certain types of pains. Future research is required to establish safety and toxicology limits, medicinal chemistry parameters and the potential for different physiological responses among varying genetic populations to support regulatory requirements for Mitragyna spp.
Natural Health Products and Food Research Group, British Columbia Institute of Technology, 4355 Mathissi Place, Burnaby, British Columbia, Canada V5G 4S8; Department of Biology, University of British Columbia, 3247 University Way, Kelowna, British Columbia, Canada V1V 1V7.
Paula N
PN
Brown
Natural Health Products and Food Research Group, British Columbia Institute of Technology, 4355 Mathissi Place, Burnaby, British Columbia, Canada V5G 4S8; Department of Chemistry, University of British Columbia, 3247 University Way, Kelowna, British Columbia, Canada V1V 1V7.
Jensen A
JA
Lund
Department of Chemistry, University of British Columbia, 3247 University Way, Kelowna, British Columbia, Canada V1V 1V7. Electronic address: susan.murch@ubc.ca.
Susan J
SJ
Murch
D000818:Animals; D020834:Ethnopharmacology; D006801:Humans; D008519:Medicine, Traditional; D032065:Mitragyna / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D019966:Substance-Related Disorders
D010936:Plant Extracts
7-hydroxymitragynine; Kratom; M. speciosa; Mitragyna; Mitragynine; Review