β2 -Adrenoceptor agonist activity of higenamine

Determination of doping higenamine in Chinese herbal medicines and their concentrated preparations by LC-MS/MS

The World Anti-Doping Agency (WADA) has included higenamine in the β2 agonist (S3) category of the Prohibited List since 2017 due to its pharmacological effects on adrenergic receptors. Although higenamine contained in Chinese herbal medicines has been identified by previous studies, comprehensive investigation on the higenamine content of Chinese herbs and their concentrated preparations is still required. This study aimed to determine the levels of higenamine in Chinese medicinal materials and their concentrated preparations used in Chinese medicine prescriptions in Taiwan. The levels of higenamine in Chinese medicinal materials, including Cortex Phellodendri, Flos Caryophylli, Fructus Euodiae, Fructus Kochiae, Plumula Nelumbinis, Radix Aconiti Preparata, Radix Aconiti Lateralis Preparata, and Radix Asari, and their concentrated preparations were determined by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Our results showed that the amounts of higenamine were detected and quantified in studied Chinese medicinal materials and their concentrated preparations, except for Flos Caryophylli, Radix Aconiti Preparata, and Radix Aconiti Lateralis Preparata. Plumula Nelumbinis and Cortex Phellodendri have higher levels of higenamine when compared to other Chinese herbs tested in the present study. The highest level of higenamine was 2100 μg/g found in the Plumula Nelumbinis medicinal material. In contrast with Plumula Nelumbinis and Cortex Phellodendri, higenamine levels below 10 μg/g were found in other most of the studied Chinese medicinal materials and their concentrated preparations. This study confirmed that various Chinese herbs and their concentrated preparations contained higenamine, and it provided more coherent and comprehensive information for reducing the potential risk of higenamine misuse in sports.

Application of Surface-Enhanced Raman Spectroscopy Combined with Immunoassay for the Detection of Adrenoceptor Agonists

Rapid, sensitive, and accurate detection of adrenoceptor agonists is a significant research topic in the fields of food safety and public health. Immunoassays are among the most widely used methods for detecting adrenoceptor agonists. In recent years, surface-enhanced Raman spectroscopy combined with immunoassay (SERS-IA) has become an effective technique for improving detection sensitivity. This review focuses on the innovation of Raman reporter molecules and substrate materials for the SERS-IA of adrenoceptor agonists. In addition, it also investigates the challenges involved in potentially applying SERS-IA in the detection of adrenoceptor agonists. Overall, this review provides insight into the design and application of SERS-IA for the detection of adrenoceptor agonists, which is critical for animal-derived food safety and public health.

Comprehensive analysis of prohibited substances and methods in sports: Unveiling trends, pharmacokinetics, and WADA evolution

This review systematically compiles sports-related drugs, substances, and methodologies based on the most frequently detected findings from prohibited lists published annually by the World Anti-Doping Agency (WADA) between 2003 and 2021. Aligned with structure of the 2023 prohibited list, it covers all proscribed items and details the pharmacokinetics and pharmacodynamics of five representatives from each section. Notably, it explores significant metabolites and metabolic pathways associated with these substances. Adverse analytical findings are summarized in tables for clarity, and the prevalence is visually represented through charts. The review includes a concise historical overview of doping and WADA's role, examining modifications in the prohibited list for an understanding of evolving anti-doping measures.

In Vitro Activation of Human Adrenergic Receptors and Trace Amine-Associated Receptor 1 by Phenethylamine Analogues Present in Food Supplements

Pre-workout supplements are popular among sport athletes and overweight individuals. Phenethylamines (PEAs) and alkylamines (AA) are widely present in these supplements. Although the health effects of these analogues are not well understood yet, they are hypothesised to be agonists of adrenergic (ADR) and trace amine-associated receptors (TAARs). Therefore, we aimed to pharmacologically characterise these compounds by investigating their activating properties of ADRs and TAAR1 in vitro. The potency and efficacy of the selected PEAs and AAs was studied by using cell lines overexpressing human ADRα1A/α1B/α1D/α2a/α2B/β1/β2 or TAAR1. Concentration-response relationships are expressed as percentages of the maximal signal obtained by the full ADR agonist adrenaline or the full TAAR1 agonist phenethylamine. Multiple PEAs activated ADRs (EC50 = 34 nM-690 µM; Emax = 8-105%). Almost all PEAs activated TAAR1 (EC50 = 1.8-92 µM; Emax = 40-104%). Our results reveal the pharmacological profile of PEAs and AAs that are often used in food supplements. Several PEAs have strong agonistic properties on multiple receptors and resemble potencies of the endogenous ligands, indicating that they might further stimulate the already activated sympathetic nervous system in exercising athletes via multiple mechanisms. The use of supplements containing one, or a combination of, PEA(s) may pose a health risk for their consumers.

Determination of higenamine in common natural spices by ultrahigh-performance liquid chromatography-tandem mass spectrometry

Higenamine (HG) is a β2 receptor agonist and was explicitly added to the Prohibited List of the World Anti-Doping Agency in 2017. This compound is prohibited in both in- and out-of-competition athletes and falls under the category of nonthreshold substances. Because of HG presence in numerous plants, as evidenced by a growing body of research data, an exception was made for HG in the TD2017MRPL document, in which adverse analytical findings (AAFs) were not reported if the urinary HG concentration was less than 10 ng/mL. In this study, a comprehensive and systematic analysis of the HG content in five batches of samples from each of the 48 natural spices selected for this investigation was conducted using UPLC-MS/MS technology. Method validation was carried out in accordance with the ICH Analytical Procedures and Methods Validation for Drugs and Biologics Guidance, and the experimental results demonstrated that the method provided appropriate sensitivity, precision, stability, linearity, and accuracy. HG was detected for the first time in Houttuynia cordata, Zingiber officinale, Cinnamomum cassia, Stevia rebaudiana, Piper nigrum, Siraitia grosuenorii, Platycodon grandiflorus, and Myristica fragrans. Furthermore, the content of HG was found to vary significantly among the different plant parts of Nelumbo nucifera, such as rhizomes, leaves, seeds, and plumules. This paper provides systematic and comprehensive data to support the safe use of spices in athletes' diets, thereby reducing the risk of food-sourced doping violations.

Testing anabolic activity, potency and mechanisms of action of the phyto-derived beta 2 agonist higenamine

Higenamine (Hige), a plant derived alkaloid is classified as β2 agonist by the World Anti-Doping Agency (WADA). However, pharmacologic mechanisms of its performance-enhancing activity have not been investigated so far. Therefore, we investigate the anabolic activity and associated molecular mechanisms of Hige in C2C12 myotubes. In differentiated C2C12 cells dose-dependent effects of Hige on myotube size were analyzed. The mRNA expression of genes involved in hypertrophy was measured. For mechanistic studies, β2-adrenoceptor (ADRB2), androgen receptor (AR), and estrogen receptor (ER) inhibitors and dexamethasone (Dexa) were co-incubated and myotube diameter was evaluated. The interaction of Hige with the AR and ER was investigated. Hige treatment significantly increased myotube diameters and stimulated the mRNA expression of hypertrophy-involved genes. In contrast to the ADRB2 inhibitor (ICI 118551), the ER inhibitor ZK 191703, the AR inhibitor Flutamide (Flu), and treatment with Dexa were able to antagonize the Hige-induced increase of myotube diameter. Hige has antagonistic activity in the AR and ER yeast transactivation assay. Our results demonstrate that Hige induces anabolic effects in C2C12 cells but not via the ADRB2. There are indications for a cross talk between Hige and the AR and ER. Future studies are necessary to investigate the involved molecular mechanisms.

Higenamine Reduces Fine-Dust-Induced Matrix Metalloproteinase (MMP)-1 in Human Keratinocytes

Environmental pollutants such as fine dust are increasingly linked to premature skin aging. In this study, we investigated the protective effects of higenamine, a natural plant alkaloid, against fine-dust-induced skin aging in human keratinocytes (HaCaT cells). We found that higenamine significantly attenuated fine-dust-induced expression of matrix metalloproteinase-1 (MMP-1), a key enzyme involved in collagen degradation. Furthermore, higenamine was found to modulate fine-dust-induced AP-1 and NF-κB transactivation, which are crucial factors for MMP-1 transcription. Higenamine also impeded fine-dust-induced phosphorylation in specific pathways related to AP-1 and NF-κB activation, and effectively alleviated reactive oxygen species (ROS) production, a key factor in oxidative stress caused by fine dust exposure. These results suggest that higenamine exerts protective effects against fine-dust-induced skin aging, primarily through its MMP-1 inhibitory properties and ability to mitigate ROS-induced oxidative damage. Our data highlight the potential of higenamine as an effective ingredient in skincare products designed to combat environmental skin damage.

Dietary higenamine from Annonaceae family fruits as a possible source of unintentional doping

Members of the genus Aconitum have been used for millennia, both as poisons and medicines, in Eastern culture. Higenamine has non-selective beta-agonist effects, activating both β₁ and β₂ adrenoreceptors, and is present in a variety of plants. The World Anti-Doping Agency has banned Higenamine both in competition and out of competition. Due to the common uses of higenamine in Brazilian culture, both as medicine and food, we studied the urinary concentrations of higenamine after the consumption of fruits of the Annona genus. We evaluated whether the ingestion of these fruits has the potential to cause anti-doping code violations. We measured higenamine concentrations for a 72 h period in the urine of ten healthy, physically active males (age 20-30; weight 70-80 kg; not consuming supplements or medications) after eating a unique meal containing fruits. Fruit consumption ranges were: Carica papaya (control) 348 ± 98 g; A. muricata 450 ± 282 g; and A. squamosa 314 ± 60 g. (all mean± SD). Higenamine was measured using ultra-performance liquid chromatography coupled with electrospray-tandem mass spectrometry. The appearance of urinary higenamine occurred within the first 12 h after eating A. muricata (n = 3), and the maximum concentration found was 1.9 ng/mL. The ingestion of A. squamosa has also been shown to cause higenamine urinary excretion. The elimination kinetics of the subjects who ingested A. squamosa (n = 4) were different from each other. After ingestion of the control fruit, C. papaya, we detected no higenamine in the urine of any participants (n = 3). Although the kinetics varied by individuals and fruits, A. muricata ingestion produced higher higenamine excretion; however, the A. squamosa portion weighed ∼66 % of the A. muricata portion. We conclude that eating Annonaceae family fruits cause detectable higenamine excretion. Conversely, single ingestion did not reach the WADA's threshold to cause adverse analytical findings.

β2 -Adrenoceptor agonist profiling reveals biased signalling phenotypes for the β2 -adrenoceptor with possible implications for the treatment of asthma

BACKGROUND AND PURPOSE

β-Adrenoceptor agonists relieve airflow obstruction by activating β2 -adrenoceptors, which are G protein-coupled receptors (GPCRs) expressed on human airway smooth muscle (HASM) cells. The currently available β-adrenoceptor agonists are balanced agonists, however, and signal through both the stimulatory G protein (Gs )- and β-arrestin-mediated pathways. While Gs signalling is beneficial and promotes HASM relaxation, β-arrestin activation is associated with reduced Gs efficacy. In this context, biased ligands that selectively promote β2 -adrenoceptor coupling to Gs signalling represent a promising strategy to treat asthma. Here, we examined several β-adrenoceptor agonists to identify Gs -biased ligands devoid of β-arrestin-mediated effects.

EXPERIMENTAL APPROACH

Gs -biased ligands for the β2 -adrenoceptor were identified by high-throughput screening and then evaluated for Gs interaction, Gi interaction, cAMP production, β-arrestin interaction, GPCR kinase (GRK) phosphorylation of the receptor, receptor trafficking, ERK activation, and functional desensitization of the β2 -adrenoceptor.

KEY RESULTS

We identified ractopamine, dobutamine, and higenamine as Gs -biased agonists that activate the Gs /cAMP pathway upon β2 -adrenoceptor stimulation while showing minimal Gi or β-arrestin interaction. Furthermore, these compounds did not induce any receptor trafficking and had reduced GRK5-mediated phosphorylation of the β2 -adrenoceptor. Finally, we observed minimal physiological desensitization of the β2 -adrenoceptor in primary HASM cells upon treatment with biased agonists.

CONCLUSION AND IMPLICATIONS

Our work demonstrates that Gs -biased signalling through the β2 -adrenoceptor may prove to be an effective strategy to promote HASM relaxation in the treatment of asthma. Such biased compounds may also be useful in identifying the molecular mechanisms that determine biased signalling and in design of safer drugs.

Pharmacological effects of higenamine based on signalling pathways and mechanism of action

Higenamine (HG) is a chemical compound found in various plants, such as aconite. Recent pharmacological studies have demonstrated its effectiveness in the management of many diseases. Several mechanisms of action of HG have been proposed; however, they have not yet been classified. This review summarises the signalling pathways and pharmacological targets of HG, focusing on its potential as a naturally extracted drug. Articles related to the pharmacological effects, signalling pathways and pharmacological targets of HG were selected by searching the keyword “Higenamine” in the PubMed, Web of Science and Google Scholar databases without limiting the search by publication years. HG possesses anti-oxidant, anti-apoptotic, anti-inflammatory, electrophysiology regulatory, anti-fibrotic and lipid-lowering activities. It is a structural analogue of catecholamines and possesses characteristics similar to those of adrenergic receptor ligands. It can modulate multiple targets, including anti-inflammation- and anti-apoptosis-related targets and some transcription factors, which directly or indirectly influence the disease course. Other naturally occurring compounds, such as cucurbitacin B (Cu B) and 6-gingerol (6-GR), can be combined with HG to enhance its anti-apoptotic activity. Although significant research progress has been made, follow-up pharmacological studies are required to determine the exact mechanism of action, new signalling pathways and targets of HG and the effects of using it in combination with other drugs.

Suppressive effects of processed aconite root on dexamethasone-induced muscle ring finger protein-1 expression and its active ingredients

Processed aconite root (PA), the tuberous root of Aconitum carmichaelii prepared by autoclaving, is a crude drug used in Japanese traditional Kampo medicine and traditional Chinese medicine for the symptoms of kidney deficiency, that is related to the muscle atrophy in modern medicine. The objective of the present study is to evaluate the effectiveness of PA on muscle atrophy and to find its active ingredients using dexamethasone-induced muscle ring finger protein-1 (MuRF1) mRNA expression in murine myoblast C2C12 cells. Dexamethasone-induced MuRF1 expression was significantly suppressed by methanol-soluble part of boiling water extract of PA in a concentration-dependent manner with its IC₅₀ value of 1.5 mg/ml. By the activity-guided fractionations of PA extract using the partition between organic solvents and its aqueous solution, the activity of PA did not transfer into the fraction containing aconitine-type diterpenoid alkaloids but into BuOH layer. Then, we found higenamine and salsolinol as the active ingredients in PA. Higenamine and salsolinol significantly suppressed dexamethasone-induced MuRF1 expression, and their IC₅₀ values were 0.49 and 50 µM, respectively. The contents of higenamine and salsolinol in the decoctions of commercially available fourteen PA products are 0.12 and 14 µg/ml as the average values, and varied with the coefficient of variation (CV) values of 97 and 63%, respectively. Higenamine also significantly suppressed dexamethasone-induced mRNA expressions of muscle atrophy F-box protein (MAFbx)/atrogin1, casitas B-lineage lymphoma-b (Cbl-b), troponin, branched-chain amino acid aminotransferase 2 (BCAT2), and Bcl-2 binding and pro-apoptotic protein3 (Bnip3). Although the quality control of PA is regulated by the contents of diterpene alkaloids, salsolinol and higenamine can be used as the marker compounds to certificate the pharmacological activities of PA.

Use of UPLC-MS/MS for determination of higenamine in urine following oral administration of traditional Chinese medicine

Since higenamine (HG) was first included in the World Anti-doping Agency (WADA) 2017 Prohibited List, an increasing number of plants have been found to contain this ingredient. As a result, doctors are hesitant to prescribe traditional Chinese medicine (TCM) to athletes. Thus, it is very important to assess the risks of doping violations due to HG following the oral administration of TCM. We determined the drug concentration-time curves for HG in urine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after single or multiple administrations of lotus seed powder on volunteers, the single dose was equivalent to 750 μg of HG, the multiple doses were equivalent to 90 μg of HG each, 3 times daily for 5 consecutive days. For the single-dose group, the HG could be detected in urine 0.5 hours after administration and reached a maximum concentration of 16.5 ng/ml 1 hour after administration. For the multiple-dose group, the HG concentrations in urine showed two peaks at 29 and 77 hours post-administration with 22.6 and 23.1 ng/mL, respectively. At the dosage used in this study, the maximum concentration of HG in some urine samples exceeded the WADA limit of 10.0 ng/mL; the risk was still very high, so athletes must avoid this amount of HG when using TCM. In addition, our study provided further data supporting the presence of sulfonated metabolites of HG in urine samples.

Role of Higenamine in Heart Diseases: A Mini-Review

Higenamine, a natural product with multiple targets in heart diseases, is originally derived from Aconitum, which has been traditionally used in China for the treatment of heart disease, including heart failure, arrhythmia, bradycardia, cardiac ischemia/reperfusion injury, cardiac fibrosis, etc. This study is aimed to clarify the role of higenamine in heart diseases. Higenamine has effects on improving energy metabolism of cardiomyocytes, anti-cardiac fibroblast activation, anti-oxidative stress and anti-apoptosis. Accumulating evidence from various studies has shown that higenamine exerts a wide range of cardiovascular pharmacological effects in vivo and in vitro, including alleviating heart failure, reducing cardiac ischemia/reperfusion injury, attenuating pathological cardiac fibrosis and dysfunction. In addition, several clinical studies have reported that higenamine could continuously increase the heart rate levels of healthy volunteers as well as patients with heart disease, but there are variable effects on systolic blood pressure and diastolic blood pressure. Moreover, the heart protection and therapeutic effects of higenamine on heart disease are related to regulating LKB1/AMPKα/Sirt1, mediating the β2-AR/PI3K/AKT cascade, induction of heme oxygenase-1, suppressing TGF-β1/Smad signaling, and targeting ASK1/MAPK (ERK, P38)/NF-kB signaling pathway. However, the interventional effects of higenamine on heart disease and its underlying mechanisms based on experimental studies have not yet been systematically reviewed. This paper reviewed the potential pharmacological mechanisms of higenamine on the prevention, treatment, and diagnosis of heart disease and clarified its clinical applications. The literature shows that higenamine may have a potent effect on complex heart diseases, and proves the profound medicinal value of higenamine in heart disease.

Sports drug testing and the athletes' exposome

Similar to the general population, elite athletes are exposed to a complex set of environmental factors including chemicals and radiation and also biological and physical stressors, which constitute an exposome that is, unlike for the general population, subjected to specific scrutiny for athletes due to applicable antidoping regulations and associated (frequent) routine doping controls. Hence, investigations into the athlete's exposome and how to distinguish between deliberate drug use and different contamination scenarios has become a central topic of antidoping research, as a delicate balance is to be managed between the vital and continually evolving developments of sensitive analytical techniques on the one hand, and the risk of the athletes' exposome potentially causing adverse analytical findings on the other.

β2 -Adrenoceptor agonist activity of higenamine

Higenamine was included in the World Anti-Doping Agency (WADA) Prohibited Substances and Methods List as a β2 -adrenoceptor agonist in 2017, thereby resulting in its prohibition both in and out of competition. The present mini review describes the physiology and pharmacology of adrenoceptors, summarizes the literature addressing the mechanism of action of higenamine and extends these findings with previously unpublished in silico and in vitro work. Studies conducted in isolated in vitro systems, whole-animal preparations and a small number of clinical studies suggest that higenamine acts in part as a β2 -adrenoceptor agonist. In silico predictive tools indicated that higenamine and possibly a metabolite have a high probability of interacting with the β2 -receptor as an agonist. Stable expression of human β2 -receptors in Chinese hamster ovary (CHO) cells to measure agonist activity not only confirmed the activity of higenamine at β2 but also closely agreed with the in silico prediction of potency for this compound. These data confirm and extend literature findings supporting the inclusion of higenamine in the Prohibited List.