Thebaine induces anaphylactic reactions via the MRGPRX2 receptor pathway on mast cells.

Morphine derivatives are clinically important anesthetic and sedative drugs, which often show anaphylactic side effects. Mas-related G-protein coupled receptor member X2 (MRGPRX2) triggers mast cell degranulation, which is important process in anaphylactic reactions. MRGPRX2-HEK293 and LAD2 cell membrane chromatographic (CMC) models were used to screen morphine derivatives binding to MRGPRX2. Furthermore, most morphine derivatives significantly enhanced Ca2+ mobilization. More importantly, thebaine was found to effectively promote histamine release. Thebaine induced the increased release of ß-hexosaminidase and high secretion level of cytokines, confirming that thebaine could further trigger anaphylactic reactions and promote subsequent inflammatory reactions. Moreover, the ability of thebaine inducing degranulation and the release of allergenic mediators in mast cells was significantly decreased after MRGPRX2 knockdown, which proved that MRGPRX2 is the key media for thebaine-induced anaphylactic reactions. Significant hind paw swelling and hypothermia in mice after injecting thebaine suggested that thebaine could trigger anaphylactic reactions in vivo.

A proposed approach to confirm heroin administration - Regional differences in heroin purity is a major factor.

In forensic toxicology, a marker of street heroin use is urgent especially in the absence of urinary 6-monoacetylmorphine. ATM4G, the Glucuronide of Acetylated product of Thebaine compound 4 Metabolite (ATM4), arising from byproducts of street heroin synthesis has been considered as a useful marker in some European studies. However, whether ATM4G is a universal marker particularly in Southeast Asia due to 'street' heroin with high purity, it's still unclear. To investigate putative markers for different regions, ATM4G and other metabolites including the Acetylated product of Thebaine compound 3 Metabolite (ATM3) and thebaol, also originated from thebaine were detected in 552 urine samples from heroin users in Taiwan. Results were compared with that from samples collected in the UK and Germany. Only a sulfo-conjugate of ATM4, ATM4S, was detected in 28 Taiwanese users using a sensitive MS3 method whilst out of 351 samples from the UK and Germany, ATM4G was present in 91. Thebaol-glucuronide was first time detected in 118. No markers were detected in urine following herbal medicine use or poppy seed ingestion. The presence of ATM4S/ATM4G might be affected by ethnicities and heroin supplied in regions. Thebaol-glucuronide is another putative marker with ATM4G and ATM4S for street heroin use.

Structural insights into thebaine synthase 2 catalysis.

Thebaine synthase 2 (THS2) that can transform (7S)-salutaridinol 7-O-acetate to thebaine catalyzes the final step of thebaine biosynthesis in Papaver somniferum. Here, the crystal structures of THS2 and its complex with thebaine are reported, revealing the interaction network in the substrate-binding pocket. Subsequent docking and QM/MM studies was performed to further explore the catalytic mechanism of THS2. Our results suggest that T105 may abstract the proton of C4-OH from the substrate under the assistance of H89. The resulting C4-O- phenolate anion then attacks the nearby C5, and triggers intramolecular SN2' syn displacement with the elimination of O-acetyl group. Moreover, the latter SN2' reaction is the rate-determining step of the whole enzymatic reaction with an overall energy barrier of 18.8 kcal/mol. These findings are of pivotal importance to understand the mechanism of action of thebaine biosynthesis, and would guide enzyme engineering to enhance the production of opiate alkaloids via metabolic engineering.

Effects of methyl jasmonate and phloroglucinol on thebaine and sanguinarine production in cell suspension culture of Persian poppy (Papaver bracteatum Lindl.).

The biosynthesis path engineering could be very promising for mass production of alkaloids by applying elicitors in the cell suspension culture of Persian poppy (Papaver bracteatum Lindl.). In this work, the effects of different concentrations of methyl jasmonate (MJ) and phloroglucinol (PG) on thebaine and sanguinarine productions in vitro were investigated. Roots as explant and supplementing 3 mg L-1 2,4-Dichlorophenoxyacetic acid with 0.5 mg L-1 Benzyl amino purine to modified MS medium were selected to achieve the most efficient combination for callus induction and production of callus fresh and dry weights. At 48 h after treatment, the addition of PG and MJ individually and in combination together significantly increased both thebaine and sanguinarine contents than the control. The results of high-performance liquid chromatography (HPLC) detection indicated that the highest production rate has been achieved through a synergic effect of two elicitors after 48 h. Results revealed that adding 200 µM of MJ and 100 mg L-1 PG increased thebaine and sanguinarine contents by 56.36 and 107.71-fold than control cells, respectively.

Crystal structure of thebaine 6-O-demethylase from the morphine biosynthesis pathway.

Thebaine 6-O-demethylase (T6ODM) from Papaver somniferum (opium poppy), which belongs to the non-heme 2-oxoglutarate/Fe(II)-dependent dioxygenases (ODD) family, is a key enzyme in the morphine biosynthesis pathway. Initially, T6ODM was characterized as an enzyme catalyzing O-demethylation of thebaine to neopinone and oripavine to morphinone. However, the substrate range of T6ODM was recently expanded to a number of various benzylisoquinoline alkaloids. Here, we present crystal structures of T6ODM in complexes with 2-oxoglutarate (T6ODM:2OG, PDB: 5O9W) and succinate (T6ODM:SIN, PDB: 5O7Y). Both metal and 2OG binding sites display similarity to other proteins from the ODD family, but T6ODM is characterized by an exceptionally large substrate binding cavity, whose volume can partially explain the promiscuity of this enzyme. Moreover, the size of the cavity allows for binding of multiple molecules at once, posing a question about the substrate-driven specificity of the enzyme.

A Regio- and Diastereoselective Anodic Aryl-Aryl Coupling in the Biomimetic Total Synthesis of (-)-Thebaine.

The biosynthesis of thebaine is based on the regioselective, intramolecular, oxidative coupling of (R)-reticuline. For decades, chemists have sought to mimic this coupling by using stoichiometric oxidants. However, all approaches to date have suffered from low yields or the formation of undesired regioisomers. Electrochemistry would represent a sustainable alternative in this respect but all attempts to accomplish an electrochemical synthesis of thebaine have failed so far. Herein, a regio- and diastereoselective anodic coupling of 3',4',5'-trioxygenated laudanosine derivatives is presented, which finally enables electrochemical access to (-)-thebaine.

Measurement of some Benzylisoquinoline Alkaloids in Different Organs of Persian Poppy during Ontogenetical Stages.

Papaver bracteatum, a perennial species, has been known as a rich source of thebaine and a potential alternative to Papaver somniferum for the production of codeine and some semisynthetic antagonist drugs. In this study, ion mobility spectrum (IMS) of the root, leaf, bottom part of stem, upper part of stem, capsule wall, petal, and capsule content during developmental stages of P. bracteatum including annual rosette, perennial rosette, bud initiation, pendulous bud, preflowering, and lancing were investigated. The IMS revealed thebaine, papaverine, and noscapine as the major components of the extracted alkaloids. Based on the results of the study it appears that, at least in part, there is a competition among the biosynthesis pathways of papaverine, noscapine, and morphinan alkaloids from a common source. Root and capsule wall were the most potent organs for extraction of thebaine, while lancing stage was the best developmental stage for thebaine exploitation. However, it seems that total biomass of root and capsule wall plays a key role in the final selection of favorite organ. Although papaverine and noscapine in the stem at preflowering stage had the most quantity, significant amounts were found in the capsule wall. In general, total alkaloid content of leaf was lower than the other plant parts.

A cluster of acute thebaine poisonings from non-food grade poppy seeds in the Australian food supply.

INTRODUCTION: Poppy seed tea is used for its opioid effects and contains multiple opium alkaloids, including morphine, codeine, papaverine, and thebaine. Animal studies indicate thebaine has strychnine-like properties, but there is limited literature describing human thebaine poisoning. We describe a cluster of acute thebaine poisoning in people ingesting tea made using poppy seeds with high thebaine content that entered the Australian food supply chain. METHODS: This is an observational study of patients poisoned after drinking poppy seed tea. Cases were identified by three prospective toxicovigilance systems: the Emerging Drug Network of Australia collaboration, the New South Wales Prescription, Recreational and Illicit Substance Evaluation program, and the Emerging Drugs Network of Australia Victoria study. We report characteristics of clinical toxicity in cases with reported ingestion of poppy seed tea and analytical confirmation of thebaine exposure. RESULTS: Forty cases presenting with multi-system toxicity following poppy seed tea ingestion were identified across seven Australian states/territories from November 2022 to January 2023. Blood testing in 23 cases confirmed high thebaine concentrations. All 23 were male (median age 35, range 16-71 years). All patients experienced muscle spasms. Rigidity was described in nine, convulsions in six, while rhabdomyolysis, acute kidney injury, and metabolic acidosis occurred in five patients. There were two cardiac arrests. The thebaine median admission blood concentration was 1.6 mg/L, with a range of 0.1-5.6 mg/L, and was the dominant opium alkaloid in all samples. Convulsions, acute kidney injury, metabolic acidosis, and cardiac arrest were associated with increasing median thebaine concentrations. Four patients were managed in the Intensive Care Unit, with two receiving continuous kidney replacement therapy (one also received intermittent haemodialysis) for kidney injury. There was one death. CONCLUSIONS: Thebaine toxicity, like strychnine poisoning, resulted in neuromuscular excitation characterized by muscle spasm, rigidity, and convulsions. Severe toxicity, including acute kidney injury, metabolic acidosis, and cardiac arrest, appears dose-dependent.

Toxicokinetics of thebaine in those consuming non-food grade poppy seeds as a tea.

INTRODUCTION: Thebaine is an alkaloid in poppy seeds that is neurotoxic to animals. Data on its clinical effects and toxicokinetics in people are minimal. In 2022, poppy seeds high in thebaine entered the Australian food market, and people consuming tea made from these poppy seeds developed poisoning. METHODS: Three patients who drank poppy seed tea and developed neuromuscular toxicity consented for thebaine to be quantitated in serial blood samples. Blood samples were analyzed by liquid chromatography with high-resolution mass spectrometry. RESULTS: Case 1: A man in his 60s presented with drowsiness, vomiting, malaise and myoclonus. He developed metabolic acidosis with hyperlactataemia, acute kidney injury requiring haemodialysis, convulsions, rhabdomyolysis, and was in the hospital for 18 days. The admission thebaine blood concentration was 2.1 mg/L, and the apparent elimination half-life was 14.8 h. Case 2: A man in his 30s presented with myoclonus, rigidity, vomiting, and dizziness. He developed metabolic acidosis with hyperlactataemia, acute kidney injury, and myalgias. The admission thebaine blood concentration was 4.1 mg/L, and the apparent elimination half-life was 11.6 h. Case 3: A man in his 30s presented with myoclonus, rigidity, clonus, diaphoresis, and abdominal pain. The admission thebaine blood concentration was 2.2 mg/L, and the apparent elimination half-life was 8.3 h. DISCUSSION: Neuromuscular toxicity, metabolic acidosis with hyperlactataemia, acute kidney injury, and gastrointestinal symptoms were prominent clinical features in these patients after drinking poppy seed tea. Effects persisted for days, and all survived, despite thebaine concentrations far exceeding those in published forensic reports, although human data are sparse. Compared to rats, the thebaine apparent elimination half-life is much longer in humans who develop symptoms at lower concentrations. CONCLUSIONS: Despite relatively high thebaine blood concentrations and moderate to severe poisoning, outcomes were favourable with early presentations. It is possible that acute kidney injury prolongs the apparent elimination half-life of thebaine.

Urine thebaine determination by liquid chromatography tandem mass spectrometry after poppy seed consumption.

Laboratories are challenged to distinguish whether a positive urine morphine result is due to heroin use or possible poppy seed consumption. Thebaine is an opium alkaloid that has been shown to be present in the urine of individuals who have consumed poppy seeds, as well as those who have used opium. It is not present in heroin. We present a sensitive, specific liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for thebaine. We show that thebaine is detectable after consumption of two different poppy seed-containing products for up to 72 h in urine. We discuss limitations of the assay and suggest how the test might best be used.

Selective and Simple Determination of Isoquinoline Alkaloids in Papaver Species by Ion Mobility Spectrometry.

In this study, a fast and precise method for determining three opium alkaloids (morphine, codeine, and thebaine) in different parts of some Papaver species was developed and validated with a low limit of detection (LOD) of 0.05 - 0.20 mg/L. The proposed method was based on three extraction steps by alkaline aqueous solution/chloroform/acidic aqueous solution and analysis by ion mobility spectrometry (IMS) and high-performance liquid chromatography (HPLC). After optimizing IMS parameters based on an experimental design, IMS was applied to analyze the extracts of seeds, stems, leaves, and capsules of seven Papaver species collected from different regions of Iran. All prepared samples were analyzed by HPLC and IMS at the same time. Then, the obtained results of the two instrumental methods were compared. The HPLC did not detect morphine in the prepared samples, while IMS results showed trace amounts of morphine in the capsules and leaves of four Papaver species. Other results were comparable and showed that IMS is more sensitive, affordable, and faster than HPLC for alkaloid analysis.

A novel self-aggregated gold nanoparticles based on sensitive immunochromatographic assays for highly detection of opium poppy in herbal teas.

Opium poppy abused in food has aroused public concerns due to its serious side effects. Effective monitoring is essential to fight the abuse crisis. Herein, we synthesized an easily prepared, affordable, accessible highly aggregated gold nanoparticles (AGNPs) performing in lateral flow immunoassay (LFIA) for detection opium poppy in herbal teas. Simultaneously, a LFIA based ontime-resolved fluorescent microspheres (TRFMs) was developed as contrastive method. In this study, morphine (MOR), codeine (COD) and thebaine (THE) were as the specific recognition markers of opium poppy. Results demonstrated the quantitative limits of detection were 0.0049/0.0053/0.084, 0.034/0.037/0.37 ng mL-1 for AGNPs/TRFMs-LFIA, respectively. The recoveries were 95%-107.5%/91%-106.7% with coefficient of variation was 1.6%-6.6%/1.8%-7.2%, indicating excellent accuracy and precision. Parallel experiments among AGNPs/TRFMs-LFIA and LC-MS/MS analysis showed good correlation. Overall, AGNPs-LFIA executed quantitative analysis within 15 min on the basis of simple treatment while providing a rapid and sensitive analysis strategy for illegal drugs abused.

In vitro evaluation of chromosomal damage and DNA strand breaks after treatment with the poppy seed alkaloid thebaine.

Thebaine is an alkaloid and can be found in poppy seeds in relatively high concentrations. Acute toxicity of thebaine is fairly high, but not much is known about chronic toxicity. To investigate the genotoxicity of thebaine, cytokinesis-block micronucleus test and comet assay were conducted in TK6 cells. In addition, effects of putative thebaine metabolites were analysed using metabolically active HepG2 cells and TK6 cells with S9 mix. FDA test and trypan blue test were used together with the frequency of mitotic and apoptotic cells to assess potential cytotoxicity of thebaine treatment. Micronucleus induction was observed after high doses (150 and 500 µM) of thebaine without metabolic activation in the presence of slight to moderate cytotoxicity. No effects were observed in the comet assay or after metabolic activation up to the highest dose of 500 µM. A potential protective effect on micronucleus induction after thebaine treatment was investigated via co-treatment with MMC and BaP in TK6 cells. Only after co-treatment with MMC, a reduction of micronucleus frequency was found. Overall, this study shows a potential of thebaine to induce genotoxic effects at high concentrations. The observation of cytotoxicity at these concentrations supports the hypothesis that genotoxicity may be caused by cytotoxic effects. Further studies will need to elucidate whether these effects are directly genotoxic or indeed result from cytotoxicity.

What do we know about health risks related to thebaine in food?

Opium alkaloids such as morphine and thebaine occur in the latex of Papaver somniferum varieties. Some varieties are used for both, pharmaceutical opium alkaloid generation and poppy seed production for food use. Poppy seeds can be contaminated with opium alkaloid-containing latex, e.g. during harvesting. In recent years, poppy seed contamination with opium alkaloids, including thebaine, gave repeatedly reasons for concern in Europe. So far, risk assessments regarding opium alkaloids in poppy seeds were mainly based on the morphine level, whereas other opium alkaloids thereunder thebaine could not be finally evaluated due to lack of data. However, available limited data indicate that thebaine exhibits a higher acute toxic potential than morphine. Therefore, exposure to thebaine by consumption of poppy seed-containing food could pose a health risk. Here, we discuss the recent knowledge regarding thebaine's toxicological profile available for the assessment of potential health risks associated with its consumption via food.

Concentrations of the Opium Alkaloids Morphine, Codeine, and Thebaine in Poppy Seeds are Reduced after Thermal and Washing Treatments but are Not Affected when Incorporated in a Model Baked Product.

Limited information exists on the effectiveness of potential treatments to reduce levels of opium alkaloids that may be present in seeds from poppy (Papaver somniferum L.). Poppy seeds containing morphine at relatively lower (14.7 mg kg-1) and higher (210.0 mg kg-1) concentrations were subjected to dry heat and steam treatments, water washing, and baking. Sample extracts were then analyzed using liquid chromatography-tandem mass spectrometry for the opium alkaloids morphine, codeine, and thebaine. The results indicated that thermal treatment promoted opium alkaloid degradation in poppy seed samples, with a 50% loss of morphine observed after 30-40 min at 200 °C. Water washing reduced concentrations of opium alkaloids in poppy seeds by approximately 50-80%, while steam treatment resulted in reduction of morphine in only one sample type. Importantly, baking had no significant effect on concentrations of opium alkaloids. Overall, these results indicate that opium alkaloids may not be significantly affected by baking or steam application and that poppy seeds may require water washing or extended thermal treatment to promote reduction of these compounds.

It takes two to tango - The case of thebaine 6-O-demethylase.

Thebaine 6-O-demethylase (T6ODM) is an Fe(II)/2-oxoglutarate-dependent dioxygenase catalysing two oxidative O-demethylation reactions in morphine biosynthesis. Its crystal structure revealed a large active site pocket which is at least two times larger than necessary to accommodate a substrate (thebaine or oripavine) molecule. Since so far no crystal structures have been obtained for enzyme-substrate complex, which is necessary to explain the enzyme regiospecificity towards the C6-bound methoxy group, in this work we used computational methods and multi-parametric surface plasmon resonance measurements to elucidate the most likely structure of this complex and the reaction mechanism starting therefrom. Results of simulations and experiments unanimously indicate that the enzyme-substrate complex of T6ODM has a 1:2 stoichiometry. The key residues responsible for substrate binding are: Val-128, Glu-133, Met-150 and Agr-219 for the substrate in the distal position, and Asp-144, Leu-235 and Leu-353 for the proximal substrate molecule. QM/MM and DFT calculations show that the oxo ligand is bound trans to His-295 and the enzyme catalyzes hydroxylation of the C6-bound methoxy group according to the established rebound mechanism. The final stage of the demethylation reaction, which includes deformylation and enol-keton tautomerization steps, is most likely catalysed by water molecules and takes place in the solvent.

Opium Alkaloids in Harvested and Thermally Processed Poppy Seeds.

The opium alkaloids (morphine, codeine, thebaine, noscapine, and papaverine) have been detected on poppy seeds; they are widely used by the food industry for decoration and flavor but can introduce opium alkaloids into the food chain. Of the opium alkaloids found on poppy seeds, morphine, and codeine are the most pharmacologically active and have been detected in biological matrices collected in workplace and roadside drug testing resulting in positive opiate results. The European Food Safety Authority introduced an acute reference dose of 10 µg morphine/kg of body weight as a safe level for morphine in food products. In this work, it was found that in harvested poppy seeds, and thermally processed poppy seeds (with and without a food matrix), if used in normal levels would not exceed the recommended acute reference dose. It was also shown that the levels of all alkaloids reduce when thermally processed, in comparison with harvested, untreated seeds.

Morphine Concentrations in Human Urine Following Poppy Seed Paste Consumption.

Papaver somniferum (opium poppy) is one of the world's oldest medicinal plants which are widely used for medicinal, nutritive and scientific purposes. Turkey is one of the major legal opium poppy producer countries in the world and the seed paste of the poppies is consumed in great deal, even more than 100g per meal. The main objective of this study is to investigate the influence of poppy seed paste ingestion on urine tests for opiates whether or not could lead to opiate positive urine test results. For this purpose, a variety of poppies were used and the morphine content of white, yellow and blue-black poppies were determined as 1.9, 4.0 and 2.6mg/kg, respectively. 100g of these seed pastes were consumed in the breakfast by ten healthy adults enrolled in the study over three days and urine samples were collected before and after the breakfast. Opiate screening analysis was carried out by enzyme immunoassay method and the results were evaluated by two different cut-off values (300 and 2000ng/mL). Morphine confirmation analysis was made by GC-MS system and the chromatographic method was validated in terms of selectivity, extraction efficiency, linearity (25-2000ng/ml), intra-assay precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ) (3 and 10ng/ml), carryover, matrix effect, dilution integrity and stability. According to cut-off value 300ng/ml, opiate concentrations were found positive up to 48h. For cut-off value 2000ng/mL; this time was up to 12h in collected urine samples after consumption of three different colored poppy seed pastes. In all urine samples, thebaine was detected while the heroin abuse metabolite 6-acetyl morphine (6-AM) was not. Urine drug testing legislation was revised on 2016 in Turkey and opiate screening cut-off values increased from 300 to 2000ng/mL. Overall results have shown that poppy seed paste as food consumption could lead to opiate positive urine test result even if increased cut off levels are used. It can also be deduced that thebaine can be taken as supportive biomarker for poppy seed paste consumption. Awareness of interpretation of urine test results and defining the procedures especially for forensic drug testing must be done in legal aspect to ensure justice for each individual (workplace, traffic, court etc.).