Determination of Psychoactive Mitragynine Drug in Suspected Kratom Species Collected from Various Geographical Areas in the Philippines: A Pilot Study on Existing Local Plant-based New Psychoactive Substance (NPS)

Kratom is a tropical tree indigenous to South East Asian countries and has been traditionally used by natives to increase work efficiency and treat selected illnesses. However, the United Nations Office on Drugs and Crime (UNODC) classified kratom,  Mitragyna speciose , as a plant-based New Psychoactive Substance (NPS) that must be monitored worldwide, due to increasing reports of abuse. Many countries, including the Philippines, do not put restrictions on the said plant species including its major psychoactive drug, mitragynine. Under this prevailing provision, a research exploration was carried out to determine the distribution of kratom trees, locally known as “mambog”, in the Philippines and authenticate species identity of collected specimens through chemical determination of mitragynine and DNA analysis. Various samples, specifically leaves, twigs, barks and roots, from claimed kratom species in selected regions of Luzon and the Mindanao Islands of the Philippines were sampled and preserved accordingly before subjecting them to instrumental analysis using Gas-Chromatograph Mass Spectrometer (GC-MS) and DNA barcoding. During the field exploration, it was well documented that claimed kratom trees are mostly present in wetland areas at low altitudes, and sometimes co-exist with local bangkal (genus  Nauclea ) trees. Interestingly, while locals identified some of the collected species as kratom through botanical assessment, mitragynine was not detected in some selected sampling sites. Remarkably, among tree parts collected, only leaves and twigs showed evidence of mitragynine suggesting further disparity among kratom tree parts. On the other hand, DNA barcoding technique was utilized to discern the species level identities of claimed kratom trees in the field, which revealed that acquired plant specimens that were found positive for mitragynine were suggested to be  Mitragyna speciosa , the specific kratom species being monitored by the UNODC. Given that the present laboratory findings confirmed the existence of kratom  Mitragyna speciosa  in the country, it is of great importance for the Philippine government to implement strict monitoring and scientific evaluation on the potential threats of the said plant-based NPS. Preliminary results can also assist law makers to possibly develop regulations in the future, since this paper is a pilot forensic study for kratom found in the Philippines.