Determination of mitragynine in rat plasma by LC-MS/MS: application to pharmacokinetics

Beneficial and adverse health effects of kratom (Mitragyna speciosa): A critical review of the literature

Used in Southeast Asia for generations, kratom gained popularity in the United States and elsewhere over the past several decades. Derived from Mitragyna speciosa, kratom preparations including leaves, teas, powders, capsules, and extracts may yield stimulant, analgesic, and opioid-like effects that occur dose-dependently based on concentrations of kratom's key alkaloids, mitragynine and 7-hydroxymitragynine. Such effects are responsible for kratom's potential as a reduced-harm alternative to opiates and as a withdrawal treatment. But these properties are also associated with tolerance development and addictive potential. Given mitragynine and 7-hydroxymitragynine activity on cytochrome P450 isoforms and opioid receptors, adverse effects among polysubstance users are a concern. Current literature on the toxicology of kratom is reviewed, including product alkaloid concentrations, in vitro and in vivo data, epidemiological evidence, and human case data. The potential harms and benefits of kratom products are discussed within an exposure assessment framework, and recommendations for industry are presented. Current evidence indicates that kratom may have therapeutic potential in some persons and that products present few risks with typical, non-polysubstance use. However, few studies identified alkaloid doses at which adverse effects were expected in humans or animals. Such research is needed to inform future assessments of kratom's risks and benefits.

Development of a CZE-MS/MS method with dynamic pH junction sample pretreatment for analysis of kratom psychoactive alkaloids in urine

BACKGROUND

Kratom is a herbal substance belonging to the group of new psychoactive substances. It contains psychoactive indole alkaloids mitragynine and 7-hydroxymitragynine. At low doses, they act as psychostimulants and at higher doses they mediate an opioid-like effect. The increasing misuse of kratom requires the development of analytical methods that will accurately and reliably identify and quantify its psychoactive alkaloids in biological samples. Therefore, the development of effective, precise, and reliable green analytical methods that are easy to implement in practice is of great importance. On-line combination of capillary zone electrophoresis with tandem mass spectrometry (CZE-MS/MS) seems to be a promising solution.

RESULTS

We present a novel green approach based on capillary zone electrophoresis - tandem mass spectrometry (CZE-MS/MS) method with on-line dynamic pH junction sample pretreatment to identify and determine mitragynine and 7-hydroxymitragynine in urine samples. The separation was performed in a background electrolyte composed of 100 mM formic acid (pH 2.39). The dynamic pH junction was ensured by injection of a short plug of 12.5 % NH4OH before the sample. Under optimal conditions, the developed method was validated and parameters such as linearity (r2 > 0.99), precision (2.2-8.7 %), accuracy (89.2-102.5 %) or stability of the sample (86.6-114.7 %) met the defined FDA guideline criteria (%RSD and %RE values where within ±15 %). Introduction of a simple in-capillary preconcentration strategy based on dynamic pH junction enabled significant improvement in analytical signal intensity and also the applicability of the method. Applying the presented approach, high sensitivity was achieved as indicated by limit of detection values, which were 0.5 ng mL-1 and 2 ng mL-1 for mitragynine and 7-hydroxymitragynine, respectively. Greenness of the proposed approach was confirmed by the AGREE metrics (score 0.63). The application potential of the developed method was successfully verified using blinded urine model samples.

SIGNIFICANCE

For the first time a fully validated CZE-MS/MS method for kratom alkaloids determination was introduced. The presented novel method is a cheaper and more ecological alternative to conventionally used chromatographic techniques what was clearly confirmed by its greenness evaluation and comparison with previously published liquid chromatography (LC) approaches. In-capillary sample pretreatment (dynamic pH junction) has been demonstrated to be an effective and fast tool in bioanalysis, minimizing the number of pretreatment steps and the manipulation with the sample. Moreover, LOD values comparable to those obtained by LC methods were recorded. High potential for the implementation of this approach into the toxicology environment in the near future is expected.

Rapid mitragynine quantification and fingerprinting of products from Mitragyna speciosa Korth. leaf (Kratom) using high-performance thin-layer chromatography

INTRODUCTION

Kratom (leaves from Mitragyna speciosa Korth.; Rubiaceae) is a herbal medicine known for its analgesic properties and psychoactive effects. Kratom in Thailand is currently legal; however, it is prohibited in some countries and considered a narcotic plant.

OBJECTIVE

Our aim was to establish a reliable, simple, and rapid method for quantifying mitragynine in Kratom leaves and related products through a combination of high-performance thin-layer chromatography (HPTLC) and densitometry.

METHODOLOGY

A densitometric HPTLC method was developed and validated in terms of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, and robustness. The fingerprints of kratom leaves, Mitragyna spp., and related products were constructed.

RESULTS

For HPTLC, samples were applied to silica gel 60 F254 plates, and the mobile phase comprised n-hexane, ethyl acetate, and triethylamine (1:1:0.15, v/v/v). Densitometric detection was carried out under ultraviolet light at a wavelength of 226 nm. The validated method exhibited a range of 14.31-143.10 μg/mL, yielding a correlation coefficient of 0.9993. Spiked recovery rates were within a range of 98.3%-100.9%, and the LOD and LOQ were 3.80 and 11.53 μg/mL, respectively. Kratom samples were analyzed with the developed method, and the correlation coefficient was 0.9641, compared to the high-performance liquid chromatography-diode-array detection (HPLC-DAD) method. The HPTLC fingerprints displayed a distinctive pattern, facilitating discrimination among different plant parts and Mitragyna spp.

CONCLUSION

The established method offers the advantages of simplicity, ease of use, and speed of analysis, serving as a practical alternative for mitragynine quantification in kratom leaf and its related products.

Quantitative analysis of selected alkaloids of Mitragyna speciosa using 1H quantitative nuclear magnetic resonance spectroscopy

Mitragyna speciosa is a perennial plant native to Asia, well known for its psychoactive properties. Its major alkaloid mitragynine is known to have sedative and euphoric effects. Hence, the plant has been a subject of abuse, leading to addiction, necessitating efficient analytical methods to detect its psychoactive constituents. However, current chromatography-based methods for detecting the alkaloids are time consuming and costly. Quantitative nuclear magnetic resonance (qNMR) spectroscopy emerges as a promising alternative due to its nondestructive nature, structural insights, and short analysis time. Hence, a rapid and precise qNMR method was developed to quantify selected major psychoactive alkaloids in various parts of M. speciosa. Mitragynine, specioliatine, and speciogynine were quantified in relation to the integral value of the -OCH3 groups of the alkaloids and the internal standard 1,4-dinitrobenzene. The precision and reproducibility of the method gave a relative standard deviation (RSD) of 2%, demonstrating the reliability of the method. In addition, the method showed excellent specificity, sensitivity, high linearity range (R2 = 0.999), and limits of detection (LOD) and quantification (LOQ) values. The analysis revealed that the red-veined M. speciosa leaves contained higher levels of mitragynine (32.34 mg/g), specioliatine (16.84 mg/g) and speciogynine (7.69 mg/g) compared to the green-veined leaves, stem bark, or fruits.

Formation of multiple ion types during MALDI imaging mass spectrometry analysis of Mitragyna speciosa alkaloids in dosed rat brain tissue

Mitragyna speciosa, more commonly known as kratom, has emerged as an alternative to treat chronic pain and addiction. However, the alkaloid components of kratom, which are the major contributors to kratom's pharmaceutical properties, have not yet been fully investigated. In this study, matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry was used to map the biodistribution of three alkaloids (corynantheidine, mitragynine, and speciogynine) in rat brain tissues. The alkaloids produced three main ion types during MALDI analysis: [M + H]+, [M - H]+, and [M - 3H]+. Contrary to previous reports suggesting that the [M - H]+ and [M - 3H]+ ion types form during laser ablation, these ion types can also be produced during the MALDI matrix application process. Several strategies are proposed to accurately map the biodistribution of the alkaloids. Due to differences in the relative abundances of the ions in different biological regions of the tissue, differences in ionization efficiencies of the ions, and potential overlap of the [M - H]+ and [M - 3H]+ ion types with endogenous metabolites of the same empirical formula, a matrix that mainly produces the [M + H]+ ion type is optimal for accurate mapping of the alkaloids. Alternatively, the most abundant ion type can be mapped or the intensities of all ion types can be summed together to generate a composite image. The accuracy of each of these approaches is explored and validated.

An insight review on the neuropharmacological effects, mechanisms of action, pharmacokinetics and toxicity of mitragynine

Mitragynine is one of the main psychoactive alkaloids in Mitragyna speciosa Korth. (kratom). It has opium-like effects by acting on μ-, δ-, and κ-opioid receptors in the brain. The compound also interacts with other receptors, such as adrenergic and serotonergic receptors and neuronal Ca2+ channels in the central nervous system to have its neuropharmacological effects. Mitragynine has the potential to treat diseases related to neurodegeneration such as Alzheimer's disease and Parkinson's disease, as its modulation on the opioid receptors has been reported extensively. This review aimed to provide an up-to-date and critical overview on the neuropharmacological effects, mechanisms of action, pharmacokinetics and safety of mitragynine as a prospective psychotropic agent. Its multiple neuropharmacological effects on the brain include antinociceptive, anti-inflammatory, antidepressant, sedative, stimulant, cognitive, and anxiolytic activities. The potential of mitragynine to manage opioid withdrawal symptoms related to opioid dependence, its pharmacokinetics and toxic effects were also discussed. The interaction of mitragynine with various receptors in the brain produce diverse neuropharmacological effects, which have beneficial properties in neurological disorders. However, further studies need to be carried out on mitragynine to uncover its complex mechanisms of action, pharmacokinetics, pharmacodynamic profiles, addictive potential, and safe dosage to prevent harmful side effects.

Development and validation of a gradient HPLC-UV method for mitragynine following in vitro skin permeation studies

Mitragynine is a promising candidate for pain relief and opiate replacement but the investigations for drug delivery are lacking. This study aims to investigate the potential of mitragynine to be delivered through the skin with an emphasis on developing and validating a gradient HPLC-UV analytical method to determine mitragynine in the samples collected during in vitro skin permeation studies. The optimised method involves a gradient elution using a C18 column with a mobile phase comprising acetonitrile and 0.1 %v/v of formic acid (0-1 min: 30:70 to 70:30 (v/v) and hold up to 4 min; 4-6 min: return to 30:70 (v/v) and hold up to 10 min) at a flow rate of 1.2 mL/min. This method was validated based on the standards set by the International Council on Harmonisation guidelines. The method showed mitragynine elution at ∼ 4 min with adequate linearity (R2 ≥ 0.999 for concentration ranges of 0.5-10 and 10-175 μg/mL) and acceptable limits of detection and quantification at 0.47 and 1.43 μg/mL, respectively. The analytical performance is robust with excellent precision and accuracy. This method was used to evaluate the in vitro skin permeation of mitragynine (5 %w/v) from simple solvent systems over 48 hr. The results showed a cumulative amount of mitragynine permeated at ∼ 11 μg/cm2 for dimethyl sulfoxide and ∼ 4 μg/cm2 for propylene glycol. The study not only addressed the issues of the currently available HPLC-UV methods that limit the direct application but also affirmed the potential of mitragynine to be delivered through the skin.

Respiratory effects of oral mitragynine and oxycodone in a rodent model

RATIONALE

Kratom derives from Mitragyna speciosa (Korth.), a tropical tree in the genus Mitragyna (Rubiaceae) that also includes the coffee tree. Kratom leaf powders, tea-like decoctions, and commercial extracts are taken orally, primarily for health and well-being by millions of people globally. Others take kratom to eliminate opioid use for analgesia and manage opioid withdrawal and use disorder. There is debate over the possible respiratory depressant overdose risk of the primary active alkaloid, mitragynine, a partial μ-opioid receptor agonist, that does not signal through ß-arrestin, the primary opioid respiratory depressant pathway.

OBJECTIVES

Compare the respiratory effects of oral mitragynine to oral oxycodone in rats with the study design previously published by US Food and Drug Administration (FDA) scientists for evaluating the respiratory effects of opioids (Xu et al., Toxicol Rep 7:188-197, 2020).

METHODS

Blood gases, observable signs, and mitragynine pharmacokinetics were assessed for 12 h after 20, 40, 80, 240, and 400 mg/kg oral mitragynine isolate and 6.75, 60, and 150 mg/kg oral oxycodone hydrochloride.

FINDINGS

Oxycodone administration produced significant dose-related respiratory depressant effects and pronounced sedation with one death each at 60 and 150 mg/kg. Mitragynine did not yield significant dose-related respiratory depressant or life-threatening effects. Sedative-like effects, milder than produced by oxycodone, were evident at the highest mitragynine dose. Maximum oxycodone and mitragynine plasma concentrations were dose related.

CONCLUSIONS

Consistent with mitragynine's pharmacology that includes partial µ-opioid receptor agonism with little recruitment of the respiratory depressant activating β-arrestin pathway, mitragynine produced no evidence of respiratory depression at doses many times higher than known to be taken by humans.

In vitro and in vivo pharmacology of kratom

Kratom products have been historically and anecdotally used in south Asian countries for centuries to manage pain and opioid withdrawal. The use of kratom products has dramatically increased in the United States. More than 45 kratom alkaloids have been isolated, yet the overall pharmacology of the individual alkaloids is still not well characterized. The purpose of this chapter is to summarize in vitro and in vivo opioid activities of the primary kratom alkaloid mitragynine and its more potent metabolite 7-hydroxymitragynine. Following are experimental procedures described to characterize opioid receptor activity; receptor binding and functional assays, antinociceptive assays, operant conditioning assays, and respiratory plethysmography. The capacity of kratom alkaloids to confer tolerance and physical dependence as well as their pharmacokinetic properties are also summarized. The data reviewed here suggest that kratom products and mitragynine possess low efficacy agonist activity at the mu-opioid receptor in vivo. In addition, kratom products and mitragynine have been demonstrated to antagonize the effects of high efficacy mu-opioid agonists. The data further suggest that 7-hydroxymitragynine formed in vivo by metabolism of mitragynine may be minimally involved in the overall behavioral profile of mitragynine and kratom, whereas 7-hydroxymitragynine itself, at sufficiently high doses administered exogenously, shares many of the same abuse- and dependence-related behavioral effects associated with traditional opioid agonists. The apparent low efficacy of kratom products and mitragynine at mu-opioid receptors supports the development of these ligands as effective and potentially safe medications for opioid use disorder.

Clinical Pharmacology of the Dietary Supplement, Kratom (Mitragyna speciosa)

Kratom (Mitragyna speciosa) consists of over 40 alkaloids with two of them, mitragynine (MG) and 7-OH-mitragynine (7-OH-MG) being the main psychoactive compounds. MG and 7-OH-MG each target opioid receptors and have been referred to as atypical opioids. They exert their pharmacologic effects on the μ, δ, and κ opioid receptors. In addition, they affect adrenergic, serotonergic, and dopaminergic pathways. Kratom has been touted as an inexpensive, legal alternative to standard opioid replacement therapy such as methadone and buprenorphine. Other uses for kratom include chronic pain, attaining a "legal high," and numerous CNS disorders including anxiety depression and post-traumatic stress disorder (PTSD). Kratom induces analgesia and mild euphoria with a lower risk of respiratory depression or adverse central nervous system effects compared to traditional opioid medications. Nonetheless, kratom has been associated with both physical and psychological dependence with some individuals experiencing classic opioid withdrawal symptoms upon abrupt cessation. Kratom use has been linked to serious adverse effects including liver toxicity, seizures, and death. These risks are often compounded by poly-substance abuse. Further, kratom may potentiate the toxicity of coadministered medications through modulation of cytochrome P450, P-glycoprotein, and uridine diphosphate glucuronosyltransferase enzymes (UGDT). In 2016 the U.S. Drug Enforcement Administration (DEA) took steps to classify kratom as a federal schedule 1 medication; however, due to public resistance, this plan was set aside. Until studies are conducted that define kratom's role in treating opioid withdrawal and/or other CNS conditions, kratom will likely remain available as a dietary supplement for the foreseeable future. This article is protected by copyright. All rights reserved.

A PSGL-1 glycomimetic reduces thrombus burden without affecting hemostasis

Events mediated by the P-selectin/PSGL-1 pathway play a critical role in the initiation and propagation of venous thrombosis by facilitating the accumulation of leukocytes and platelets within the growing thrombus. Activated platelets and endothelium express P-selectin, which binds P-selectin glycoprotein ligand-1 (PSGL-1) that is expressed on the surface of all leukocytes. We developed a pegylated glycomimetic of the N terminus of PSGL-1, PEG40-GSnP-6 (P-G6), which proved to be a highly potent P-selectin inhibitor with a favorable pharmacokinetic profile for clinical translation. P-G6 inhibits human and mouse platelet-monocyte and platelet-neutrophil aggregation in vitro and blocks microcirculatory platelet-leukocyte interactions in vivo. Administration of P-G6 reduces thrombus formation in a nonocclusive model of deep vein thrombosis with a commensurate reduction in leukocyte accumulation, but without disruption of hemostasis. P-G6 potently inhibits the P-selectin/PSGL-1 pathway and represents a promising drug candidate for the prevention of venous thrombosis without increased bleeding risk.

Pharmacokinetics of Eleven Kratom Alkaloids Following an Oral Dose of Either Traditional or Commercial Kratom Products in Rats

Kratom, Mitragyna speciosa Korth., is being widely consumed in the United States for pain management and the reduction of opioid withdrawal symptoms. The central nervous system (CNS) active alkaloids of kratom, including mitragynine, 7-hydroxymitragynine, and numerous additional compounds, are believed to derive their effects through opioid receptor activity. There is no literature describing the systemic exposure of many of these alkaloids after the consumption of kratom. Therefore, we have developed and validated a bioanalytical method for the simultaneous quantitation of 11 kratom alkaloids (mitragynine, 7-hydroxymitragynine, corynantheidine, speciogynine, speciociliatine, paynantheine, corynoxine, corynoxine-B, mitraphylline, ajmalicine, and isospeciofoline) in rat plasma. The validated method was used to analyze oral pharmacokinetic study samples of lyophilized kratom tea (LKT) and a marketed product, OPMS liquid shot, in rats. Among the 11 alkaloids, only mitragynine, 7-hydroxymitragynine, speciociliatine, and corynantheidine showed systemic exposure 8 h postdose, and the dose-normalized systemic exposure of these four alkaloids was higher (1.6-2.4-fold) following the administration of the commercial OPMS liquid. Paynantheine and speciogynine levels were quantifiable up to 1 h postdose, whereas none of the other alkaloids were detected. In summary, the method was successfully applied to quantify the exposure of individual kratom alkaloids after an oral dose of traditional or commercial products. This information will contribute to understanding the role of each alkaloid in the overall pharmacology of kratom and elucidating the pharmacokinetic differences between traditional and commercial kratom products.

DARK Classics in Chemical Neuroscience: Kratom

The psychoactive plant kratom is a native plant to Southeast Asia, and its major bioactive alkaloid is mitragynine. Mitragynine exerts its analgesic properties by acting on the opioid receptors. One of its active metabolites, 7-hydroxymytraginine, is found to be 40 times more potent than mitragynine and 10 times more potent than morphine. Interestingly, current research suggests that mitragynine behaves as an atypical opioid agonist, possessing analgesic activity with less severe side effects than those of typical opioids. Although Thailand and Malaysia have criminalized the use, possession, growing, or selling of kratom due to its abuse potential, kratom still remains unregulated in the United States. The U.S. Drug Enforcement Agency (DEA) listed kratom as a "drug of concern" in 2008 with the intent to temporarily place mitragynine and 7-hydroxymitragynine onto Schedule I of the Controlled Substances Act. However, responses from the general public, U.S. Congress, and Kratom Alliances had the DEA retract their intent. Kratom is currently marketed in the United States as a dietary or herbal supplement used to treat chronic pain, anxiety, and depression with over $207 million in annual sales in the United States alone. Here, we will review the traditional and medicinal uses of kratom along with the synthesis of its bioactive ingredients and their pharmacology, metabolism, and structure-activity relationships. The importance in society of this currently controversial substance will also be discussed.

Pharmacokinetics and pharmacodynamics of mitragynine, the principle alkaloid of Mitragyna speciosa: present knowledge and future directions in perspective of pain

Mitragyna speciosa, commonly known as Ketum or Biak in Malaysia and Kratom in Thailand, is a native plant to Southeast Asia and has various pharmacological benefits. Mitragynine (MG) is the principal alkaloid found in the leaves of Mitragyna speciosa and has been reported to be responsible for the plant's therapeutic actions. Traditionally, local communities use Kratom preparations for relief from different types of pain. The potential analgesic effects of MG using rodent models have been reported in literatures. We have reviewed the published analgesic and pharmacokinetic studies and all of these findings showed the routes of drug administration, doses employed, and type of vehicles used to solubilize the drug, varied considerably; hence this posted difficulties in predicting the drug's pharmacokinetic-response relationship. A rational approach is warranted for accurate prediction of dose-response relationship; as this is essential for the development of MG as an alternative medicinal drug for pain management. PKPD modeling would serve as a better method to understand the dose-response relationship in future MG preclinical and clinical studies.

Biomedical analysis of New Psychoactive Substances (NPS) of natural origin

New psychoactive substances (NPS) can be divided into two main groups: synthetic molecules and active principles of natural origin. With respect to this latter group, a wide range of alkaloids contained in plants, mainly from Asia and South America, can be included in the class of NPS of natural origin. The majority NPS of natural origin presents stimulant and/or hallucinogenic effects (e.g. Catha edulis and Ayahuasca, respectively) while few of them show sedative and relaxing properties (e.g. kratom). Few information is available in relation to the analytical identification of psychoactive principles contained in the plant material. Moreover, to our knowledge, scarce data are present in literature, about the characterization and quantification of the parent drug in biological matrices from intoxication and fatality cases. In addition, the metabolism of natural active principles has not been yet fully investigated for most of the psychoactive substances from plant material. Consequently, their identification is not frequently performed and produced metabolites are often unknown. To fill this gap, we reviewed the currently available analytical methodologies for the identification and quantification of NPS of natural origin in plant material and, whenever possible, in conventional and non-conventional biological matrices of intoxicated and dead subjects. The psychoactive principles contained in the following plants were investigated: Areca catechu, Argyreia nervosa, Ayahuasca, Catha edulis, Ipomoea violacea, Mandragora officinarum, Mitragyna speciosa, Pausinystalia yohimbe, Piper methisticum, Psilocybe, Rivea corymbosa, Salvia divinorum, Sceletium tortuosum, Lactuca virosa. From the results obtained, it can be evidenced that although several analytical methods for the simultaneous quantification of different molecules from the same plants have been developed and validated, a comprehensive method to detect active compounds from different natural specimens both in biological and non-biological matrices is still lacking.

In silico investigation of mitragynine and 7-hydroxymitragynine metabolism

Objective

Mitragynine is the main active compound of Mitragyna speciose (Kratom in Thai). The understanding of mitragynine derivative metabolism in human body is required to develop effective detection techniques in case of drug abuse or establish an appropriate dosage in case of medicinal uses. This in silico study is based upon in vivo results in rat and human by Philipp et al. (J Mass Spectrom 44:1249–1261, 2009).

Results

Gas-phase structures of mitragynine, 7-hydroxymitragynine and their metabolites were obtained by quantum chemical method at B3LYP/6-311++G(d,p) level. Results in terms of standard Gibbs energies of reaction for all metabolic pathways are reported with solvation energy from SMD model. We found that 7-hydroxy substitution leads to changes in reactivity in comparison to mitragynine: position 17 is more reactive towards demethylation and conjugation with glucuronic acid and position 9 is less reactive towards conjugation with glucuronic acid. Despite the changes, position 9 is the most reactive for demethylation and position 17 is the most reactive for conjugation with glucuronic acid for both mitragynine and 7-hydroxymitragynine. Our results suggest that 7-hydroxy substitution could lead to different metabolic pathways and raise an important question for further experimental studies of this more potent derivative.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4461-3) contains supplementary material, which is available to authorized users.

Pharmacokinetics of mitragynine, a major analgesic alkaloid in kratom (Mitragyna speciosa): A systematic review

BACKGROUND AND OBJECTIVE

Kratom (Mitragyna speciosa) is a tropical tree found in southern Thailand and northern states of the Malay Peninsula. Kratom is commercially available and used as an alternative to treat opioid withdrawal. Mitragynine is the major indole alkaloid found in kratom leaves. This review aimed to summarize available pharmacokinetic information about mitragynine.

METHODS

PubMed, Scopus, and Web of Science were systematically searched from their inceptions to June 2018. All types of pharmacokinetic studies of mitragynine were included for further systematic review.

RESULTS

Seventeen articles were reviewed. Mitragynine is a lipophilic weak base passively transported across the intestinal wall and blood brain barrier. 85-95% is bound to plasma protein and extensively metabolized by phase I and particularly phase II enzymes. Actions on CYP enzymes are unlikely to impact drug metabolism at concentrations likely to exist in kratom-consuming humans. In rats and humans, mitragynine is rapidly absorbed after orally administration (T_max˜1.5 h, C_max˜0.3-1.8 μM). V_d was 37-90 L/kg; t_1/2 was 3-9 hr; mostly excreted as metabolites in urine. Bioavailability was estimated as 21%. It also rapidly penetrated and redistributed in brain. A quality assessment tool tailored for pharmacokinetic studies was also created which rated some studies of lower value.

CONCLUSION

Rudimentary pharmacokinetics of mitragynine was described in this systematic review. However, the discovered studies provided scant information on the role of metabolism and redistribution into tissues nor the rate of excretion.

Simultaneous quantification of ten key Kratom alkaloids in Mitragyna speciosa leaf extracts and commercial products by ultra-performance liquid chromatography-tandem mass spectrometry

Kratom (Mitragyna speciosa) is a psychoactive plant popular in the United States for the self-treatment of pain and opioid addiction. For standardization and quality control of raw and commercial kratom products, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of ten key alkaloids, namely: corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine, mitragynine, mitraphylline, paynantheine, speciociliatine, and speciogynine. Chromatographic separation of diastereomers, or alkaloids sharing same ion transitions, was achieved on an Acquity BEH C18 column with a gradient elution using a mobile phase containing acetonitrile and aqueous ammonium acetate buffer (10mM, pH 3.5). The developed method was linear over a concentration range of 1-200 ng/mL for each alkaloid. The total analysis time per sample was 22.5 minutes. The analytical method was validated for accuracy, precision, robustness, and stability. After successful validation, the method was applied for the quantification of kratom alkaloids in alkaloid-rich fractions, ethanolic extracts, lyophilized teas, and commercial products. Mitragynine (0.7%-38.7% w/w), paynantheine (0.3%-12.8% w/w), speciociliatine (0.4%-12.3% w/w), and speciogynine (0.1%-5.3% w/w) were the major alkaloids in the analyzed kratom products/extracts. Minor kratom alkaloids (corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine) were also quantified (0.01%-2.8% w/w) in the analyzed products; however mitraphylline was below the lower limit of quantification in all analyses.

Identification of five Mitragyna alkaloids in urine using liquid chromatography-quadrupole/time of flight mass spectrometry

Mitragyna speciosa (Kratom) is a psychoactive plant that has recently emerged as a recreational drug. Mitragyna alkaloids are not within the scope of traditional forensic toxicology screening methods, which may contribute to under-reporting. Solid phase extraction (SPE) and liquid chromatography-quadrupole/time of flight mass spectrometry (LC-Q/TOF-MS) were used to identify five alkaloids in urine. Target analytes included the two known psychoactive compounds, mitragynine and 7-hydroxymitragynine, in addition to speciociliatine, speciogynine, and paynantheine. Two deuterated internal standards (mitragynine-D₃ and 7-hydroxymitragynine-D₃) were employed. Using traditional reversed phase chromatography all compounds and isomers were separated in 10 min. The procedure was validated in accordance with the Scientific Working Group for Forensic Toxicology (SWGTOX) Standard Practices for Method Validation. Extraction efficiencies were 63-96% and limits of quantitation were 0.5-1 ng/mL. Precision, bias and matrix effects were all within acceptable thresholds, with the exception of 7-hydroxymitragynine, which is notably unstable and unsuitable for quantitative analysis. In this paper we present a simultaneous quantitative analytical method for mitragynine, speciociliatine, speciogynine and paynantheine, and a qualitative assay for 7-hydroxymitragynine in urine using high resolution mass spectrometry (HRMS).

Development of an immunochromatographic strip incorporating anti-mitragynine monoclonal antibody conjugated to colloidal gold for kratom alkaloids detection

A lateral flow-based immunochromatographic strip was developed for the rapid detection of mitragynine (MG), a dominant alkaloid found in the leaves of kratom. Monoclonal antibody (mAb) against MG (anti-MG mAb) was conjugated to colloidal gold and used as a recognition probe. MG-ovalbumin conjugate (MG-OVA) and goat anti-mouse IgG were immobilized on the strip to produce a test zone and control zone, respectively. Based on the principle of a competitive assay, MG in a test sample competed with MG-OVA resident in the test zone to bind with colloidal gold-anti-MG mAb, resulting in an inverse relation of color intensity at the test zone and MG amount. The limit of detection (LOD) of the immunochromatographic strip is determined at 1 mg/mL of MG by visual assessment and 0.60 mg/mL by Image J analysis. The developed immunochromatographic strip can determine MG in kratom cocktails and kratom leaf samples. It could serve as a rapid and simple diagnostic kit for the detection of MG in kratom samples.

Method validation in quantitative analysis of phase I and phase II metabolites of mitragynine in human urine using liquid chromatography-tandem mass spectrometry

A method using solid phase extraction and liquid chromatography-tandem mass spectrometry to quantitatively detect mitragynine, 16-carboxy mitragynine, and 9-O-demethyl mitragynine in human urine samples was developed and validated. The relevant metabolites were identified using multiple reaction monitoring in positive ionization mode using nalorphine as an internal standard. The method was validated for accuracy, precision, recovery, linearity, and lower limit of quantitation. The intra- and inter-day accuracy and precision were found in the range of 83.6-117.5% with coefficient of variation less than 13%. The percentage of recovery for mitragynine, 16-carboxy mitragynine, and 9-O-demethyl mitragynine was within the range of 80.1-118.9%. The lower limit of quantification was 1 ng/mL for mitragynine, 2 ng/mL for 16-carboxy mitragynine, and 50 ng/mL for 9-O-demethyl mitragynine. The developed method was reproducible, high precision and accuracy with good linearity and recovery for mitragynine, 16-carboxy mitragynine, and 9-O-demethyl mitragynine in human urine.

The medicinal chemistry and neuropharmacology of kratom: A preliminary discussion of a promising medicinal plant and analysis of its potential for abuse

The leaves of Mitragyna speciosa (commonly known as kratom), a tree endogenous to parts of Southeast Asia, have been used traditionally for their stimulant, mood-elevating, and analgesic effects and have recently attracted significant attention due to increased use in Western cultures as an alternative medicine. The plant's active alkaloid constituents, mitragynine and 7-hydroxymitragynine, have been shown to modulate opioid receptors, acting as partial agonists at mu-opioid receptors and competitive antagonists at kappa- and delta-opioid receptors. Furthermore, both alkaloids are G protein-biased agonists of the mu-opioid receptor and therefore, may induce less respiratory depression than classical opioid agonists. The Mitragyna alkaloids also appear to exert diverse activities at other brain receptors (including adrenergic, serotonergic, and dopaminergic receptors), which may explain the complex pharmacological profile of raw kratom extracts, although characterization of effects at these other targets remains extremely limited. Through allometric scaling, doses of pure mitragynine and 7-hydroxymitragynine used in animal studies can be related to single doses of raw kratom plant commonly consumed by humans, permitting preliminary interpretation of expected behavioral and physiological effects in man based on this preclinical data and comparison to both anecdotal human experience and multiple epidemiological surveys. Kratom exposure alone has not been causally associated with human fatalities to date. However, further research is needed to clarify the complex mechanism of action of the Mitragyna alkaloids and unlock their full therapeutic potential. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

Novel Psychoactive Substances-Recent Progress on Neuropharmacological Mechanisms of Action for Selected Drugs

A feature of human culture is that we can learn to consume chemical compounds, derived from natural plants or synthetic fabrication, for their psychoactive effects. These drugs change the mental state and/or the behavioral performance of an individual and can be instrumentalized for various purposes. After the emergence of a novel psychoactive substance (NPS) and a period of experimental consumption, personal and medical benefits and harm potential of the NPS can be estimated on evidence base. This may lead to a legal classification of the NPS, which may range from limited medical use, controlled availability up to a complete ban of the drug form publically accepted use. With these measures, however, a drug does not disappear, but frequently continues to be used, which eventually allows an even better estimate of the drug's properties. Thus, only in rare cases, there is a final verdict that is no more questioned. Instead, the view on a drug can change from tolerable to harmful but may also involve the new establishment of a desired medical application to a previously harmful drug. Here, we provide a summary review on a number of NPS for which the neuropharmacological evaluation has made important progress in recent years. They include mitragynine ("Kratom"), synthetic cannabinoids (e.g., "Spice"), dimethyltryptamine and novel serotonergic hallucinogens, the cathinones mephedrone and methylone, ketamine and novel dissociative drugs, γ-hydroxybutyrate, γ-butyrolactone, and 1,4-butanediol. This review shows not only emerging harm potentials but also some potential medical applications.

Hepatotoxicity Induced by "the 3Ks": Kava, Kratom and Khat

The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.

Neurobiology of Kratom and its main alkaloid mitragynine

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.

An overview of recent developments in the analytical detection of new psychoactive substances (NPSs)

New psychoactive substances (NPSs), sometimes referred to as "legal highs" in more colloquial environments/the media, are a class of compounds that have been recently made available for abuse (not necessarily recently discovered) which provide similar effects to the traditional well studied illegal drugs but are not always controlled under existing local, regional or international drug legislation. Following an unprecedented increase in the number of NPSs in the last 5 years (with 101 substances discovered for the first time in 2014 alone) its, occasionally fatal, consequences have been extensively reported in the media. Such NPSs are typically marketed as 'not for human consumption' and are instead labelled and sold as plant food, bath salts as well as a whole host of other equally nondescript aliases in order to bypass legislative controls. NPSs are a new multi-disciplinary research field with the main emphasis in terms of forensic identification due to their adverse health effects, which can range from minimal to life threatening and even fatalities. In this mini-review we overview this recent emerging research area of NPSs and the analytical approaches reported to provide detection strategies as well as detailing recent reports towards providing point-of-care/in-the-field NPS ("legal high") sensors.

Determination of mitragynine in urine matrices by bar adsorptive microextraction and HPLC analysis

Bar adsorptive microextraction combined with liquid desorption followed by high performance liquid chromatography with diode array detection (BAµE-LD/HPLC-DAD) is proposed for the determination of the psychoactive alkaloid mitragynine (MG) in human urine matrices. By using a modified N-vinylpyrrolidone polymer (P2) sorbent phase, high selectivity and efficiency is achieved. Assays performed by BAµE(P2)-LD/HPLC-DAD on 25 mL water samples spiked at the 8.0 µg L(-1) level yielded average recoveries around 100% of MG, under optimized experimental conditions. The analytical performance showed good precision (RSD<15%), appropriated detection limits of 0.10 µg L(-1) and linear dynamic ranges (0.6-24.0 μg L(-1)) with convenient determination coefficients of 0.9924. By using the standard addition method, the application of the present methodology for the determination of MG in human urine matrices after Kratom consumer, allowed very good performances. The proposed methodology proved to be a suitable alternative to monitor MG in biological fluid matrices, showing to be easy to implement, reliable, sensitive and requiring low sample volumes, when compared with other sorbent-based methods.

Pharmacokinetics of mitragynine in man

BACKGROUND

Kratom, known botanically as Mitragyna speciosa (Korth.), is an indigenous tree in Southeast Asia. Kratom is currently easily available worldwide via special shops and the Internet to use as a drug of abuse, opioid alternative, or pain killer. So far, the pharmacokinetics of this plant has been studied only in animals, and there is no such study in humans. The major abundant active alkaloid in Kratom, mitragynine, is one of the promising new chemical substances to be developed as a new drug. The aim of this study was to examine the pharmacokinetics of mitragynine and assess the linearity in pharmacokinetics in chronic users.

METHODS

Since Kratom is illegal in Thailand, studies in healthy subjects would be unethical. We therefore conducted a prospective study by enrolling ten chronic, regular, healthy users. We adjusted the steady state in each subject by giving a known amount of Kratom tea for 7 days before commencement of the experiment. We admitted and gave different oral doses to subjects to confirm linearity in pharmacokinetics. The mitragynine blood concentrations at 17 times points and the urine concentrations during the 24-hour period were collected and measured by liquid chromatography-tandem mass spectrometry method.

RESULTS

Ten male subjects completed the study without adverse reactions. The median duration of abuse was 1.75 years. We analyzed one subject separately due to the abnormal behavior of blood concentration. From data of nine subjects, the pharmacokinetic parameters established were time to reach the maximum plasma concentration (0.83±0.35 hour), terminal half-life (23.24±16.07 hours), and the apparent volume of distribution (38.04±24.32 L/kg). The urine excretion of unchanged form was 0.14%. The pharmacokinetics were observed to be oral two-compartment model.

CONCLUSION

This was the first pharmacokinetic study in humans, which demonstrated linearity and was consistent with the oral two-compartment model with a terminal half-life of about 1 day. The pharmacokinetic linearity and parameters reported are necessary pharmacological information of Kratom, and there is a possibility for it to be developed medically as a pain killer or better opioid substitute in the future.

Understanding the physicochemical properties of mitragynine, a principal alkaloid of Mitragyna speciosa, for preclinical evaluation

Varied pharmacological responses have been reported for mitragynine in the literature, but no supportive scientific explanations have been given for this. These studies have been undertaken without a sufficient understanding of the physicochemical properties of mitragynine. In this work a UV spectrophotometer approach and HPLC-UV method were employed to ascertain the physicochemical properties of mitragynine. The pK_a of mitragynine measured by conventional UV (8.11 ± 0.11) was in agreement with the microplate reader determination (8.08 ± 0.04). Mitragynine is a lipophilic alkaloid, as indicated by a logP value of 1.73. Mitragynine had poor solubility in water and basic media, and conversely in acidic environments, but it is acid labile. In an in vitro dissolution the total drug release was higher for the simulated gastric fluid but was prolonged and incomplete for the simulated intestinal fluid. The hydrophobicity, poor water solubility, high variability of drug release in simulated biological fluids and acid degradable characteristics of mitragynine probably explain the large variability of its pharmacological responses reported in the literature. The determined physicochemical properties of mitragynine will provide a basis for developing a suitable formulation to further improve its solubility, stability and oral absorption for better assessment of this compound in preclinical studies.

Evaluation of the cardiotoxicity of mitragynine and its analogues using human induced pluripotent stem cell-derived cardiomyocytes

Introduction

Mitragynine is a major bioactive compound of Kratom, which is derived from the leave extracts of Mitragyna speciosa Korth or Mitragyna speciosa (M. speciosa), a medicinal plant from South East Asia used legally in many countries as stimulant with opioid-like effects for the treatment of chronic pain and opioid-withdrawal symptoms. Fatal incidents with Mitragynine have been associated with cardiac arrest. In this study, we determined the cardiotoxicity of Mitragynine and other chemical constituents isolated using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Methods and Results

The rapid delayed rectifier potassium current (I_Kr), L-type Ca²⁺ current (I_Ca,L) and action potential duration (APD) were measured by whole cell patch-clamp. The expression of KCNH2 and cytotoxicity was determined by real-time PCR and Caspase activity measurements. After significant I_Kr suppression by Mitragynine (10 µM) was confirmed in hERG-HEK cells, we systematically examined the effects of Mitragynine and other chemical constituents in hiPSC-CMs. Mitragynine, Paynantheine, Speciogynine and Speciociliatine, dosage-dependently (0.1∼100 µM) suppressed I_Kr in hiPSC-CMs by 67% ∼84% with IC₅₀ ranged from 0.91 to 2.47 µM. Moreover, Mitragynine (10 µM) significantly prolonged APD at 50 and 90% repolarization (APD50 and APD90) (439.0±11.6 vs. 585.2±45.5 ms and 536.0±22.6 vs. 705.9±46.1 ms, respectively) and induced arrhythmia, without altering the L-type Ca²⁺ current. Neither the expression,and intracellular distribution of KCNH2/Kv11.1, nor the Caspase 3 activity were significantly affected by Mitragynine.

Conclusions

Our study indicates that Mitragynine and its analogues may potentiate Torsade de Pointes through inhibition of I_Kr in human cardiomyocytes.

Development of indirect competitive ELISA for quantification of mitragynine in Kratom (Mitragyna speciosa (Roxb.) Korth.)

Monoclonal antibody (MAb) against mitragynine (MG), an analgesic alkaloid from Kratom leaves (Mitragyna speciosa), was produced. MG was coupled to carrier proteins employing either 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), a zero-length cross linker or a 5-carbon length glutaraldehyde cross linker. To confirm the immunogenicity, the hapten numbers were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Preparation of the MAb was accomplished by the electrofusion method. Hybridoma 1A6 that was constructed from the fusion between splenocytes of EDC/NHS conjugate immunized mice and SP2/0-Ag14 myeloma cells was selected, cloned twice and expanded. The cross-reactivities (CRs) of this MAb 1A6 with a series of indole alkaloids were 30.54%, 24.83% and 8.63% for speciogynine, paynantheine and mitraciliatine, respectively. Using this MAb, an indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed with a measurement range of 32.92-250 μg/mL. Quantitative analysis of the MG contents in plant samples by icELISA correlated well with the standard high performance liquid chromatography method (R(2)=0.994). The MAb against mitragynine provided a tool for detection of MG in Kratom preparations.

Comparison of three chromatographic techniques for the detection of mitragynine and other indole and oxindole alkaloids in Mitragyna speciosa (kratom) plants

Leaves of the Southeast Asian plant Mitragyna speciosa are used to suppress pain and mitigate opioid withdrawal syndromes. The potential threat of abuse and ready availability of this uncontrolled psychoactive plant have led to the need for improved analytical techniques for the detection of the major active components, mitragynine and 7-hydroxymitragynine. Three independent chromatographic methods coupled to two detection systems, GC with MS, supercritical fluid chromatography with diode array detection, and HPLC with MS and diode array detection, were compared for the analysis of mitragynine and other indole and oxindole alkaloids in M. speciosa plants. The indole alkaloids included two sets of diastereoisomers: (i) paynantheine and 3-isopaynantheine and (ii) mitragynine, speciogynine, and speciociliatine. Two oxindole alkaloid diastereoisomers, corynoxine and corynoxine B, were also studied. The HPLC and supercritical fluid chromatography methods successfully resolved the major components with slightly different elution orders. The GC method was less satisfactory because it was unable to resolve mitragynine and speciociliatine. This separation was difficult by GC with a liquid stationary phase because these diastereoisomers differ only in the orientation of an interior hydrogen atom. The observed lack of resolution of the indole alkaloid diastereoisomers coupled with the likeness of the mass and tandem mass spectra, calls into question proposed GC methods for the analysis of mitragynine based on solely GC with MS separation and identification.

A simple HPLC-DAD method for the detection and quantification of psychotropic mitragynine in Mitragyna speciosa (ketum) and its products for the application in forensic investigation

Mitragyna speciosa, a native plant of Thailand and Malaysia known as 'ketum', is a plant of considerable interest. It exhibits strong antinociceptive effect and yet, acts like a psychostimulant. Due to the affordability and its ease of availability, the abuse of this plant as a substitute for other banned narcotics has become a major concern in many societies. In countries such as Thailand, Myanmar, Australia and Malaysia, the use of ketum is illegal. However, for a person to be charged for possessing or selling ketum, a reliable analytical method is needed in order to detect and identify the plant and its products. Mitragynine is the major alkaloid of ketum. This compound manifests its antinociceptive effects by acting on the opioid receptors. Since M. speciosa contain large quantity of mitragynine and it is exclusive to the species, the present analytical method is developed and validated for the purpose of screening ketum products based on this unique compound as the analytical marker. The method uses a HPLC-DAD system with Inertsil C8 (4.6 mm × 150 mm, 5 μm) as the column and a mixture of acetonitrile and formic acid, 50:50 (v/v), as the mobile phase. This method not only detects mitragynine, it can also be used to quantify the amount of mitragynine in the sample. The limit of detection is 0.25 μg/ml, while the limit of quantification is 0.50 μg/ml. The method is quick, simple and reliable with an accuracy of 97.27-101.74% and coefficient of variations of between 0.91 and 3.96%. The method has been tested and found suitable for the identification and quantification of mitragynine in dried plants, a variety of ketum extracts, as well as ketum drink obtained from the market.

From Kratom to mitragynine and its derivatives: physiological and behavioural effects related to use, abuse, and addiction

Kratom (or Ketum) is a psychoactive plant preparation used in Southeast Asia. It is derived from the plant Mitragyna speciosa Korth. Kratom as well as its main alkaloid, mitragynine, currently spreads around the world. Thus, addiction potential and adverse health consequences are becoming an important issue for health authorities. Here we reviewed the available evidence and identified future research needs. It was found that mitragynine and M. speciosa preparations are systematically consumed with rather well defined instrumentalization goals, e.g. to enhance tolerance for hard work or as a substitute in the self-treatment of opiate addiction. There is also evidence from experimental animal models supporting analgesic, muscle relaxant, anti-inflammatory as well as strong anorectic effects. In humans, regular consumption may escalate, lead to tolerance and may yield aversive withdrawal effects. Mitragynine and its derivatives actions in the central nervous system involve μ-opioid receptors, neuronal Ca²⁺ channels and descending monoaminergic projections. Altogether, available data currently suggest both, a therapeutic as well as an abuse potential.

Here today, gone tomorrow…and back again? A review of herbal marijuana alternatives (K2, Spice), synthetic cathinones (bath salts), kratom, Salvia divinorum, methoxetamine, and piperazines

Despite their widespread Internet availability and use, many of the new drugs of abuse remain unfamiliar to health care providers. The herbal marijuana alternatives, like K2 or Spice, are a group of herbal blends that contain a mixture of plant matter in addition to chemical grade synthetic cannabinoids. The synthetic cathinones, commonly called "bath salts," have resulted in nationwide emergency department visits for severe agitation, sympathomimetic toxicity, and death. Kratom, a plant product derived from Mitragyna speciosa Korth, has opioid-like effects, and has been used for the treatment of chronic pain and amelioration of opioid-withdrawal symptoms. Salvia divinorum is a hallucinogen with unique pharmacology that has therapeutic potential but has been banned in many states due to concerns regarding its psychiatric effects. Methoxetamine has recently become available via the Internet and is marked as "legal ketamine." Moreover, the piperazine derivatives, a class of amphetamine-like compounds that includes BZP and TMFPP, are making a resurgence as "legal Ecstasy." These psychoactives are available via the Internet, frequently legal, and often perceived as safe by the public. Unfortunately, these drugs often have adverse effects, which range from minimal to life-threatening. Health care providers must be familiar with these important new classes of drugs. This paper discusses the background, pharmacology, clinical effects, detection, and management of synthetic cannabinoid, synthetic cathinone, methoxetamine, and piperazine exposures.

UAE, MAE, SFE-CO2 and classical methods for the extraction of Mitragyna speciosa leaves

Mitragyna speciosa, a tropical plant indigenous to Southeast Asia, is well known for its psychoactive properties. Its leaves are traditionally chewed by Thai and Malaysian farmers and manual labourers as it causes a numbing, stimulating effect. The present study aims to evaluate alkaloid yield and composition in the leaf extracts. For this purpose we have compared several non-conventional extraction techniques with classic procedures (room temperature or under heating). Dried M. speciosa leaves belonging to three batches of different origin (from Thailand, Malaysia and Indonesia) were extracted using ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and supercritical carbon dioxide extraction SFE-CO(2), using methanol, ethanol, water and binary mixtures. The extracts were compared using an HPLC/ESI-MS analysis of mitragynine and four other related alkaloids which were present in the alkaloid fraction. The extraction technique influences both the raw product yield and the relative alkaloid content of M. speciosa leaves. Of the several methods tested, MAE in a closed vessel at 110 °C (60 W, methanol/water 1:1) gave the highest alkaloid fraction amount, while UAE with an immersion horn at 25 °C (21.4 kHz, 50 W, methanol) showed the best yield for mitragynine. This work may prove to be a useful contribution to forensic, toxicological and pharmacognosy studies. Although the potential applications of M. speciosa alkaloids clearly need further investigation, these results may facilitate the scaling-up of their extraction.

Intrahepatic cholestasis following abuse of powdered kratom (Mitragyna speciosa)

INTRODUCTION

Kratom (Mitragyna speciosa) is a common medical plant in Thailand and is known to contain mitragynine as the main alkaloid. According to an increase in published reports and calls at German poison control centers, it has been used more frequently as a drug of abuse in the western hemisphere during the last couple of years. Despite this increase, reports of severe toxicity are rare within the literature.

CASE REPORT

We describe a case of a young man who presented with jaundice and pruritus after intake of kratom for 2 weeks in the absence of any other causative agent. Alkaloids of M. speciosa were detected in the urine.

CONCLUSION

While M. speciosa is gaining in popularity among illicit drug users, its adverse effects remain poorly understood. This is the first published case of intrahepatic cholestasis after kratom abuse.

Seizure and coma following Kratom (Mitragynina speciosa Korth) exposure

Reports of toxicity secondary to Kratom are rare and lack of diagnostic testing in human specimens has prevented confirmatory explanation of observed clinical effects. We present a novel case of serious human toxicity following Kratom use confirmed via quantitative analysis of urine by high performance liquid chromatography coupled to electrospray tandem mass spectrometry. A 64 year-old male was witnessed to have a seizure at home following kratom consumption. Upon arrival to the emergency department (ED), the patient was unresponsive. While in the ED, the patient sustained a second seizure. He was intubated to protect his airway. The remainder of his hospital course was uneventful. A urine specimen was collected shortly after admission and sent for analysis. The mitragynine concentration in the urine was 167 ± 15 ng/ml. We report a rare case of Kratom toxicity characterized by a seizure and coma confirmed by urinary analysis of mitragynine by high performance liquid chromatography coupled to electrospray tandem mass spectrometry. The proposed mechanism for this reaction is unclear but suggested mechanisms include adenosine binding or stimulation of adrenergic and/or serotonergic receptors similar to tramadol.