Modulatory Effects of Eschscholzia californica Alkaloids on Recombinant GABAA Receptors

Herbgenomics meets Papaveraceae: a promising -omics perspective on medicinal plant research

Herbal medicines were widely used in ancient and modern societies as remedies for human ailments. Notably, the Papaveraceae family includes well-known species, such as Papaver somniferum and Chelidonium majus, which possess medicinal properties due to their latex content. Latex-bearing plants are a rich source of diverse bioactive compounds, with applications ranging from narcotics to analgesics and relaxants. With the advent of high-throughput technologies and advancements in sequencing tools, an opportunity exists to bridge the knowledge gap between the genetic information of herbs and the regulatory networks underlying their medicinal activities. This emerging discipline, known as herbgenomics, combines genomic information with other -omics studies to unravel the genetic foundations, including essential gene functions and secondary metabolite biosynthesis pathways. Furthermore, exploring the genomes of various medicinal plants enables the utilization of modern genetic manipulation techniques, such as Clustered Regularly-Interspaced Short Palindromic Repeats (CRISPR/Cas9) or RNA interference. This technological revolution has facilitated systematic studies of model herbs, targeted breeding of medicinal plants, the establishment of gene banks and the adoption of synthetic biology approaches. In this article, we provide a comprehensive overview of the recent advances in genomic, transcriptomic, proteomic and metabolomic research on species within the Papaveraceae family. Additionally, it briefly explores the potential applications and key opportunities offered by the -omics perspective in the pharmaceutical industry and the agrobiotechnology field.

California poppy (Eschscholzia californica), the Papaveraceae golden girl model organism for evodevo and specialized metabolism

California poppy or golden poppy (Eschscholzia californica) is the iconic state flower of California, with native ranges from Northern California to Southwestern Mexico. It grows well as an ornamental plant in Mediterranean climates, but it might be invasive in many parts of the world. California poppy was also highly prized by Native Americans for its medicinal value, mainly due to its various specialized metabolites, especially benzylisoquinoline alkaloids (BIAs). As a member of the Ranunculales, the sister lineage of core eudicots it occupies an interesting phylogenetic position. California poppy has a short-lived life cycle but can be maintained as a perennial. It has a comparatively simple floral and vegetative morphology. Several genetic resources, including options for genetic manipulation and a draft genome sequence have been established already with many more to come. Efficient cell and tissue culture protocols are established to study secondary metabolite biosynthesis and its regulation. Here, we review the use of California poppy as a model organism for plant genetics, with particular emphasis on the evolution of development and BIA biosynthesis. In the future, California poppy may serve as a model organism to combine two formerly separated lines of research: the regulation of morphogenesis and the regulation of secondary metabolism. This can provide insights into how these two integral aspects of plant biology interact with each other.

Placental Passage of Protopine in an Ex Vivo Human Perfusion System

The placental passage of protopine was investigated with a human ex vivo placental perfusion model. The model was first validated with diazepam and citalopram, 2 compounds known to cross the placental barrier, and antipyrine as a positive control. All compounds were quantified by partially validated U(H)PLC-MS/MS bioanalytical methods. Protopine was transferred from the maternal to the fetal circuit, with a steady-state reached after 90 min. The study compound did not affect placental viability or functionality, as glucose consumption, lactate production, and beta-human chorionic gonadotropin, and leptin release remained constant. Histopathological evaluation of all placental specimens showed unremarkable, age-appropriate parenchymal maturation with no pathologic findings.

Medicinal Plants for the Treatment of Mental Diseases in Pregnancy: An In Vitro Safety Assessment

Pregnancy is a critical period for medical care, during which the well-being of woman and fetus must be considered. This is particularly relevant in managing non-psychotic mental disorders since treatment with central nervous system-active drugs and untreated NMDs may have negative effects. Some well-known herbal preparations (phytopharmaceuticals), including St. John's wort, California poppy, valerian, lavender, and hops, possess antidepressant, sedative, anxiolytic, or antidepressant properties and could be used to treat mental diseases such as depression, restlessness, and anxiety in pregnancy. Our goal was to assess their safety in vitro, focusing on cytotoxicity, induction of apoptosis, genotoxicity, and effects on metabolic properties and differentiation in cells widely used as a placental cell model (BeWo b30 placenta choriocarcinoma cells). The lavender essential oil was inconspicuous in all experiments and showed no detrimental effects. At low-to-high concentrations, no extract markedly affected the chosen safety parameters. At an artificially high concentration of 100 µg/mL, extracts from St. John's wort, California poppy, valerian, and hops had minimal cytotoxic effects. None of the extracts resulted in genotoxic effects or altered glucose consumption or lactate production, nor did they induce or inhibit BeWo b30 cell differentiation. This study suggests that all tested preparations from St. John's wort, California poppy, valerian, lavender, and hops, in concentrations up to 30 µg/mL, do not possess any cytotoxic or genotoxic potential and do not compromise placental cell viability, metabolic activity, and differentiation. Empirical and clinical studies during pregnancy are needed to support these in vitro data.

Advanced in Vitro Safety Assessment of Herbal Medicines for the Treatment of Non-Psychotic Mental Disorders in Pregnancy

When confronted with non-psychotic mental disorders, pregnant women often refrain from using synthetic drugs and resort to herbal medicines such as St. John’s wort, California poppy, valerian, lavender, and hops. Nevertheless, these herbal medicines have not yet been officially approved in pregnancy due to lack of safety data. Using a variety of in vitro methods (determination of cytotoxicity, apoptosis induction, genotoxicity, effects on metabolic properties, and inhibition/induction of differentiation) in a commonly used placental cell line (BeWo b30), we were previously able to show that extracts from these plants are likely to be safe at the usual clinical doses. In the present work, we wanted to extend our safety assessment of these herbal medicines by 1) looking for possible effects on gene expression and 2) using the same in vitro methods to characterize effects of selected phytochemicals that might conceivably lead to safety issues. Proteomics results were promising, as none of the five extracts significantly affected protein expression by up- or down-regulation. Protopine (contained in California poppy), valerenic acid (in valerian), and linalool (in lavender) were inconspicuous in all experiments and showed no adverse effects. Hyperforin and hypericin (two constituents of St. John’s wort) and valtrate (typical for valerian) were the most obvious phytochemicals with respect to cytotoxic and apoptotic effects. A decrease in cell viability was evident with hypericin (≥1 µM) and valtrate (≥10 µM), whereas hyperforin (≥3 µM), hypericin (30 µM) and valtrate (≥10 µM) induced cell apoptosis. None of the tested phytochemicals resulted in genotoxic effects at concentrations of 0.1 and 1 µM and thus are not DNA damaging. No decrease in glucose consumption or lactate production was observed under the influence of the phytochemicals, except for valtrate (at all concentrations). No compound affected cell differentiation, except for hyperforin (≥1 µM), which had an inhibitory effect. This study suggests that extracts from St. John’s wort, California poppy, valerian, lavender, and hops are likely to be safe during pregnancy. High plasma concentrations of some relevant compounds—hyperforin and hypericin from St. John’s wort and valtrate from valerian—deserve special attention, however.

Placental Passage of Humulone and Protopine in an Ex Vivo Human Perfusion System

The placental passage of humulone and protopine was investigated with a human ex vivo placental perfusion model. The model was first validated with diazepam and citalopram, 2 compounds known to cross the placental barrier, and antipyrine as a positive control. All compounds were quantified by partially validated U(H)PLC-MS/MS bioanalytical methods. Only a small portion of humulone initially present in the maternal circuit reached the fetal circuit. The humulone concentration in the maternal circuit rapidly decreased, likely due to metabolization in the placenta. Protopine was transferred from the maternal to the fetal circuit, with a steady-state reached after 90 min. None of the study compounds affected placental viability or functionality, as glucose consumption, lactate production, beta-human chorionic gonadotropin, and leptin release remained constant. Histopathological evaluation of all placental specimens showed unremarkable, age-appropriate parenchymal maturation with no pathologic findings.

Neuroprotective effects of allocryptopine-rich alkaloid extracts against oxidative stress-induced neuronal damage

BACKGROUND

Oxidative stress is a significant feature in the pathomechanism of neurodegenerative diseases. Thus, the search for an effective and safe novel antioxidant agent with neuroprotective properties has increased the interest in medicinal plant products as a bioactive phytochemical source. However, little is known about the potential effects of the medically important Glaucium corniculatum as a natural antioxidant.

OBJECTIVE

In the present study, it was aimed to investigate the anti-oxidative, anti-apoptotic, and cell cycle regulatory mechanisms underlying the neuroprotective effects of alkaloid extracts (chloroform, methanol, and water) from G. corniculatum, which was profiled for major alkaloid/alkaloids, against H₂O₂-induced neuronal damage in differentiated PC12 cells.

MATERIALS AND METHODS

The profiles of the alkaloid extracts were analyzed by GC-MS. The effects of the alkaloid extracts on intracellular ROS production, level of apoptotic cells, and cell cycle dysregulation were analyzed by flow cytometry; the effects on mRNA expression of apoptosis-related genes were also analyzed by qRT-PCR.

RESULTS

The same alkaloid components, allocryptopine, tetrahydropalmatine, and tetrahydroberberine N-oxide were obtained in all three solvents, but the ratios of the components differed according to the solvents. Allocryptopine was determined to be the major alkaloid ingredient in the alkaloid extracts, with the highest amount of allocryptopine (497 μg/mg) being found in the chloroform alkaloid extract (CAE) (*p < 0.05). The best results were obtained from CAE, which has the highest amount of allocryptopine among alkaloid extracts in all studies. CAE suppressed intracellular ROS production (5.7-fold), percentage of apoptotic cells (3.0-fold), and cells in the sub G1 phase (6.8-fold); additionally, it increased cells in the G1 phase (1.5-fold) (**p < 0.01). CAE remarkably reduced the expressions of Bax, Caspase-9/-3 mRNA (2.4-3.5-fold) while increasing the expression of Bcl-2 mRNA (3.0-fold) (*p < 0.05).

CONCLUSIONS

Our results demonstrated that alkaloid extracts from G. corniculatum, which contain allocryptopine, tetrahydropalmatine, and tetrahydroberberine N-oxide suppressed oxidative stress-induced neuronal apoptosis, possibly by suppressing the mitochondrial apoptotic pathway and regulating the cell cycle. These results are the first report that related alkaloids have played a neuroprotective role by regulating multiple mechanisms. Thus, our study indicated that these alkaloids especially allocryptopine could offer an efficient and novel strategy to explore novel drugs for neuroprotection and cognitive improvement.

Herbal Remedies and Their Possible Effect on the GABAergic System and Sleep

Sleep is an essential component of physical and emotional well-being, and lack, or disruption, of sleep due to insomnia is a highly prevalent problem. The interest in complementary and alternative medicines for treating or preventing insomnia has increased recently. Centuries-old herbal treatments, popular for their safety and effectiveness, include valerian, passionflower, lemon balm, lavender, and Californian poppy. These herbal medicines have been shown to reduce sleep latency and increase subjective and objective measures of sleep quality. Research into their molecular components revealed that their sedative and sleep-promoting properties rely on interactions with various neurotransmitter systems in the brain. Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that plays a major role in controlling different vigilance states. GABA receptors are the targets of many pharmacological treatments for insomnia, such as benzodiazepines. Here, we perform a systematic analysis of studies assessing the mechanisms of action of various herbal medicines on different subtypes of GABA receptors in the context of sleep control. Currently available evidence suggests that herbal extracts may exert some of their hypnotic and anxiolytic activity through interacting with GABA receptors and modulating GABAergic signaling in the brain, but their mechanism of action in the treatment of insomnia is not completely understood.

Benzylisoquinoline alkaloid analysis using high-resolution Orbitrap LC-MSn

Benzylisoquinoline alkaloids (BIAs) have profound implications on human health owing to their potent pharmacological properties. Notable naturally occurring BIAs are the narcotic analgesics morphine, the cough suppressant codeine, the potential anticancer drug noscapine, the muscle relaxant papaverine, and the antimicrobial sanguinarine, all of which are produced in opium poppy (Papaver somniferum). Thebaine, an intermediate in the biosynthesis of codeine and morphine, is used in the manufacture of semisynthetic opiates, including oxycodone and naloxone. As the only commercial source of pharmaceutical opiates, opium poppy has been the focus of considerable research to understand BIA metabolism in the plant. The elucidation of several BIA biosynthetic pathways has enabled the development of synthetic biology platforms aimed at the alternative commercial production of valuable phytochemicals in microorganisms. The detection and identification of BIA pathway products and intermediates in complex extracts is essential for the continuing advancement of research in plant specialized metabolism and microbial synthetic biology. Herein, we report the use of liquid chromatography coupled with linear trap quadrupole and high-resolution Orbitrap multistage mass spectrometry to characterize 44 authentic BIAs using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and pulsed Q collision-induced dissociation (PQD) MS² fragmentation, with MS² CID followed by MS³ and MS⁴ fragmentation. Our deep library of diagnostic spectral data constitutes a valuable resource for BIAs identification. In addition, we identified 22 BIAs in opium poppy latex and roots extracts.

Assessment of Insecticidal Activity of Benzylisoquinoline Alkaloids from Chilean Rhamnaceae Plants against Fruit-Fly Drosophila melanogaster and the Lepidopteran Crop Pest Cydia pomonella

The Chilean plants Discaria chacaye, Talguenea quinquenervia (Rhamnaceae), Peumus boldus (Monimiaceae), and Cryptocarya alba (Lauraceae) were evaluated against Codling moth: Cydia pomonella L. (Lepidoptera: Tortricidae) and fruit fly Drosophila melanogaster (Diptera: Drosophilidae), which is one of the most widespread and destructive primary pests of Prunus (plums, cherries, peaches, nectarines, apricots, almonds), pear, walnuts, and chestnuts, among other. Four benzylisoquinoline alkaloids (coclaurine, laurolitsine, boldine, and pukateine) were isolated from the above mentioned plant species and evaluated regarding their insecticidal activity against the codling moth and fruit fly. The results showed that these alkaloids possess acute and chronic insecticidal effects. The most relevant effect was observed at 10 µg/mL against D. melanogaster and at 50 µg/mL against C. pomonella, being the alteration of the feeding, deformations, failure in the displacement of the larvae in the feeding medium of D. melanogaster, and mortality visible effects. In addition, the docking results show that these type of alkaloids present a good interaction with octopamine and ecdysone receptor showing a possible action mechanism.

An examination of naturopathic treatment of non-specific gastrointestinal complaints: comparative analysis of two cases

BACKGROUND

Functional gastrointestinal disorders (FGID) affect more than one-third of the general population and contribute a considerable burden on the health and wellbeing of the community and the economy. This study aims to examine the treatment approaches and outcomes of naturopathic management of individuals presenting with a non-specific FGID.

METHODS

We report a comparison of two clinical case studies of patients being treated by a naturopath for a functional gastrointestinal disorder. The care was provided by two different student practitioners under the supervision of an industry qualified mentor within a multidisciplinary academic clinic at the Endeavour College of Natural Health. A student practitioner and student observer conduct consultations under the supervision of an industry qualified mentor. The outcomes of care were measured by the Gastrointestinal Symptom Rating Scale.

RESULTS

Clinical notations partially correlate to Jane's outcomes measured by gastrointestinal rating scale scores, which remain stable. Significant changes in Rona's gastrointestinal rating scale scores equate to only generalizable minimal clinical notations.

CONCLUSIONS

The holistic and individualised approach core to naturopathic medicine practice is also informed by traditional methods, research evidence and the pragmatic needs of the patient. The emphasis within naturopathic treatment approaches on dietary changes and lifestyle prescription alongside other ingestive therapies such as herbal and nutritional medicine underscores the need for clinical research designs which support evaluation of complex interventions in real-world settings.

Variation of Secondary Metabolites in the Aerial Biomass of Cryptocarya alba

Cryptocarya alba is an important tree species in the Chilean sclerophyllous forest. Its leaves and bark are used in traditional medicine to treat liver diseases and rheumatism. Analyses of the essential oil (EO) show serious discrepancies, and information on other constituents is limited. The aerial biomass of individual trees from 3 wild populations, some old trees, and farmed saplings were analyzed ( n = 132). The EO profiles were studied by gas chromatography/mass spectrometry (GC/MS). The alkaloidal and polyphenol compositions were determined by ultra-high-performance liquid chromatography (UHPLC)/MS-MS. The total polyphenol content, the total flavonoid content, and the antioxidant capacity (diphenylpicrylhydrazyl, azinobisethylbenzothiazolinesulfonic acid, and ferric reducing antioxidant power: DPPH, ABTS, and FRAP respectively) were determined by standard methods. Significant differences were found at the individual and population levels in the contents of polyphenols, total flavonoids, antioxidant capacity, and specific alkaloids for leaves, bark, and wood. Farmed saplings grown under less light showed higher concentrations of higenamine, N-methylcoclaurine, N-methyllaurotetanine, and isocorydine, while those receiving more light were richer in laurolitsine, boldine, coclaurine, catechin, quercetin, epicatechin, quercitrin, and procyanidins. Important variations were found according to the season, age of the tree and of the leaves. The EO composition also varied considerably. These results support the idea that the natural variability of medicinal species is an important subject for study.

Structural changes at the myrtenol backbone reverse its positive allosteric potential into inhibitory GABAA receptor modulation

GABAA receptors are ligand-gated anion channels that form pentameric arrangements of various subunits. Positive allosteric modulators of GABAA receptors have been reported as being isolated either from plants or synthesized analogs of known GABAA receptor targeting drugs. Recently, we identified monoterpenes, e.g. myrtenol as a positive allosteric modulator at α1β2 GABAA receptors. Here, along with pharmacophore-based virtual screening studies, we demonstrate that scaffold modifications of myrtenol resulted in the loss of modulatory activity. Two independent approaches, fluorescence-based compound analysis and electrophysiological recordings in whole-cell configurations were used for analysis of transfected cells. C-atoms 1 and 2 of the myrtenol backbone were identified as crucial to preserve positive allosteric potential. A modification at C-atom 2 and lack of the hydroxyl group at C-atom 1 exhibited significantly reduced GABAergic currents at α1β2, α1β2γ, α2β3, α2β3γ and α4β3δ receptors. This effect was independent of the γ2 subunit. A sub-screen with side chain length and volume differences at the C-atom 1 identified two compounds that inhibited GABAergic responses but without receptor subtype specificity. Our combined approach of pharmacophore-based virtual screening and functional readouts reveals that side chain modifications of the bridged six-membered ring structure of myrtenol are crucial for its modulatory potential at GABAA receptors.

The ethnobotany of psychoactive plant use: a phylogenetic perspective

Psychoactive plants contain chemicals that presumably evolved as allelochemicals but target certain neuronal receptors when consumed by humans, altering perception, emotion and cognition. These plants have been used since ancient times as medicines and in the context of religious rituals for their various psychoactive effects (e.g., as hallucinogens, stimulants, sedatives). The ubiquity of psychoactive plants in various cultures motivates investigation of the commonalities among these plants, in which a phylogenetic framework may be insightful. A phylogeny of culturally diverse psychoactive plant taxa was constructed with their psychotropic effects and affected neurotransmitter systems mapped on the phylogeny. The phylogenetic distribution shows multiple evolutionary origins of psychoactive families. The plant families Myristicaceae (e.g., nutmeg), Papaveraceae (opium poppy), Cactaceae (peyote), Convolvulaceae (morning glory), Solanaceae (tobacco), Lamiaceae (mints), Apocynaceae (dogbane) have a disproportionate number of psychoactive genera with various indigenous groups using geographically disparate members of these plant families for the same psychoactive effect, an example of cultural convergence. Pharmacological traits related to hallucinogenic and sedative potential are phylogenetically conserved within families. Unrelated families that exert similar psychoactive effects also modulate similar neurotransmitter systems (i.e., mechanistic convergence). However, pharmacological mechanisms for stimulant effects were varied even within families suggesting that stimulant chemicals may be more evolutionarily labile than those associated with hallucinogenic and sedative effects. Chemically similar psychoactive chemicals may also exist in phylogenetically unrelated lineages, suggesting convergent evolution or differential gene regulation of a common metabolic pathway. Our study has shown that phylogenetic analysis of traditionally used psychoactive plants suggests multiple ethnobotanical origins and widespread human dependence on these plants, motivating pharmacological investigation into their potential as modern therapeutics for various neurological disorders.