Differentiation of Mitragyna speciosa, a narcotic plant, from allied Mitragyna species using DNA barcoding-high-resolution melting (Bar-HRM) analysis.

Mitragyna speciosa (Korth.) Havil. [MS], or "kratom" in Thai, is the only narcotic species among the four species of Mitragyna in Thailand, which also include Mitragyna diversifolia (Wall. ex G. Don) Havil. [MD], Mitragyna hirsuta Havil. [MH], and Mitragyna rotundifolia (Roxb.) O. Kuntze [MR]. M. speciosa is a tropical tree belonging to the Rubiaceae family and has been prohibited by law in Thailand. However, it has been extensively covered in national and international news, as its abuse has become more popular. M. speciosa is a narcotic plant and has been used as an opium substitute and traditionally used for the treatment of chronic pain and various illnesses. Due to morphological disparities in the genus, the identification of plants in various forms, including fresh leaves, dried leaf powder, and finished products, is difficult. In this study, DNA barcoding combined with high-resolution melting (Bar-HRM) analysis was performed to differentiate M. speciosa from allied Mitragyna and to assess the capability of Bar-HRM assays to identify M. speciosa in suspected kratom or M. speciosa-containing samples. Bar-HRM analysis of PCR amplicons was based on the ITS2, rbcL, trnH-psbA, and matK DNA barcode regions. The melting profiles of ITS2 amplicons were clearly distinct, which enabled the authentication and differentiation of Mitragyna species from allied species. This study reveals that DNA barcoding coupled with HRM is an efficient tool with which to identify M. speciosa and M. speciosa-containing samples and ensure the safety and quality of traditional Thai herbal medicines.

[Discrimination of Kratom Products by an Improved PCR-RFLP Method].

In Japan, mitragynine, 7-hydroxymitragynine and Mitragyna speciosa Korth. (M. speciosa, "Kratom") were controlled as Designated Substances under the Pharmaceutical and Medical Device Act from March 2016. In this study, the origins of 16 Kratom products obtained from the illegal drug market in Japan were investigated by DNA analyses and LC-MS analyses. When the PCR-restriction fragment length polymorphism (RFLP) was performed using the restriction enzyme XmaI (as reported by Sukrong et al. to be able to distinguish M. speciosa), the same DNA fragment patterns were obtained from all 16 products. On the other hand, as a result of the identification of the plant species of each product by nucleotide sequence analyses, the sequences of M. speciosa were detected in only 14 products. Despite the facts that mitragynine and 7-hydroxymitragynine were detected also in the other two products by the LC-MS analyses, M. speciosa DNAs were not amplified from these products by the PCR. Moreover, the DNA amplicons of the other psychotropic plant (Mesembryanthemum sp., e.g. "Kanna") were detected. This plant PCR amplicon has the restriction site for the XmaI at the same position of the M. speciosa PCR amplicon and it is difficult to distinguish "Kratom" and "Kanna" by the conventional PCR-RFLP. When the restriction enzyme XhoI was used simultaneously with the Xmal, the specific DNA fragment was only observed from the M. speciosa amplicon and it was possible to distinguish both species using this improved PCR-RFLP method. This method is useful to identify the origin of Kratom products distributed in the illegal drug market.

The Scheduling of Kratom and Selective Use of Data.

Kratom is a traditional drug from Southeast Asia that has been an emerging new substance in the United States. On August 30, 2016, the DEA announced the intention to emergency schedule kratom into Schedule I. To support this decision, the DEA cited an increase in drug seizures of kratom and an increase in calls to poison control concerning kratom. However, a short time later, on October 12, 2016, the DEA withdrew the intent to schedule kratom after public and congressional backlash. The withdrawal by the DEA was somewhat unprecedented. To better understand both decisions, the current article examines the evidence the DEA cited to support their decision to emergency schedule kratom and the degree and type of media coverage of kratom to determine if a media-driven drug panic occurred.

The botanical origin of kratom (Mitragyna speciosa; Rubiaceae) available as abused drugs in the Japanese markets.

Kratom is the leaves of Mitragyna speciosa (Rubiaceae). Recently, kratom has been sold in street shops or on the Internet in Japan for the purpose of abuse due to its opium-like effects. In this study, we investigated the botanical origin of the commercial kratom products using the internal transcribed spacer (ITS) sequence analysis of rDNA in preparation for future regulation of this product. In addition, a previously reported method to authenticate the plant, utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was applied to the same products in order to estimate the method's accuracy and utility. The ITS sequence analysis of the commercial kratoms revealed that most of them were derived from M. speciosa or closely related plants, while the others were made from the same tribe plant as M. speciosa. The reported PCR-RFLP method could clearly distinguish kratoms from the other psychoactive plants available in the Japanese markets and also from related plants. The authentication method is considered to be useful for the practical regulation of the plant due to its wide range of application, high accuracy and simplicity.

Molecular analysis of the genus Mitragyna existing in Thailand based on rDNA ITS sequences and its application to identify a narcotic species: Mitragyna speciosa.

In Thailand, there are four Mitragyna species; M. speciosa, M. hirsuta, M. diversifolia, and M. rotundifolia. One, M. speciosa, is a narcotic plant and has medicinal importance for its opium-like effect. Since the use of M. speciosa has been forbidden in Thailand, the leaves of M. diversifolia or others are frequently used as substitutes but are not considered as effective. Therefore, accurate authentication of M. speciosa is essential for both medicinal and forensic purposes. The nucleotide sequences of internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (rDNA) of the Mitragyna species were analyzed. The whole length of ITS1-5.8S-ITS2 region was 608 bp in M. speciosa, 607 bp in the other species. Nineteen sites of nucleotide substitutions and 3 sites of 1-bp indels were observed, and M. speciosa showed specific sequence differed from the others. Based on the ITS sequences, a distinctive site recognized by a restriction enzyme XmaI in M. speciosa was found and then PCR-restriction fragment length polymorphism (RFLP) analysis was established to differentiate M. speciosa from the others. By the method, a 409-bp PCR fragment of ITS1-5.8S (partial) rDNA region from M. speciosa was cleaved into two fragments of 119 bp and 290 bp while the other species remained undigested. This method provides an effective and accurate identification of M. speciosa.