The known, unknown, and the intriguing about members of a critically endangered traditional medicinal plant genus Aconitum

Humanity will always be indebted to plants. In the ongoing scientific era, the 'Herbal Revolution' has helped discover several valuable medicinal plants and associated novel secondary metabolites from the diverse unexplored ecosystems, treating several diseases via phytotherapy. The Aconitum genus comprises several economically-important poisonous mountainous medicinal plant species whose unique biodiversity is on the verge of extinction due to illegal human intervention triggered habitat loss, over-harvesting, and unrestricted trading. Owing to its vast diversity of diterpene alkaloids, most species are extensively used to treat several ailments in rural parts of the world. Irrespective of this, many unexplored and intriguing prospects exist to understand and utilize this critical plant for human benefit. This systematic review tries to fill this gap by compiling information from the sporadically available literature known for ~300 Aconitum spp. regarding its nomenclature and classification, endangerment, plant morphology, ploidy, secondary metabolites, drug pharmacokinetics, conservation, and omics-based computational studies. We also depicted the disparity in the studied model organisms for this diverse genus. The absence of genomic/metagenomic data is becoming a limiting factor in understanding its plant physiology, metabolic pathways, and plant-microbes interactions, and therefore must be promoted. Additionally, government support and public participation are crucial in establishing conservation protocols to save this plant from endangerment.

Compatibility of Fuzi and Ginseng Significantly Increase the Exposure of Aconitines

The herb-pair ginseng-Fuzi (the root of Aconitum carmichaelii) is the material basis of Shenfu prescriptions and is popular in traditional Chinese medicine for the treatment of heart failure, and even shock with severe-stage of COVID-19. A narrow therapeutic window of Fuzi may cause significant regional loss of property and life in clinics. Therefore, systemic elucidation of active components is crucial to improve the safety dose window of Shenfu oral prescriptions. A high performance liquid chromatography-mass spectrometry method was developed for quantification of 10 aconitines in SD rat plasma within 9 min. The limit of detection and the limit of quantification were below 0.032 ng/ml and 0.095 ng/ml, respectively. Furthermore, a systemic comparison with their pharmacokinetic characteristics after oral administration of a safe dosage of 2 g/kg of Fuzi and ginseng-Fuzi decoction for 24 h was conducted. Eight representative diester, monoester, and non-ester aconitines and two new active components (i.e., songorine and indaconitine) were all adopted to elucidating the differences of the pharmacokinetic parameters in vivo. The compatibility of Fuzi and ginseng could significantly increase the in vivo exposure of active components. The terminal elimination half-life and the area under the concentration-time curve of mesaconitine, benzoylaconitine, benzoylmesaconitine, benzoylhypaconitine, and songorine were all increased significantly. The hypaconitine, benzoylmesaconitine, and songorine were regarded as the main active components in vivo, which gave an effective clue for the development of new Shenfu oral prescriptions.

Over a century since ephedrine discovery: an updated revisit to its pharmacological aspects, functionality and toxicity in comparison to its herbal extracts

Ephedrine, a sympathomimetic amine that exhibits several adrenaline actions, is a plant alkaloid that is a common ingredient in several cold, asthma and narcolepsy treatment preparations, and in obesity management and sport medicine. Its principal action mechanism relies on its direct adrenergic actions as well as indirect role that involves the release of epinephrine and norepinephrine, thus increasing the activity of epinephrine and norepinephrine at the postsynaptic α and β receptors. Nevertheless, its serious side effects, including stroke, heart attack, drug abuse and interactions, have never been comprehensively reviewed. We conducted a systematic review of data on ephedrine, including its occurrence in functional foods, pharmacological aspects, metabolism, pharmaco/toxicokinetics and clinical features. Furthermore, a review of ephedrine natural structural analogues with regards to their differential adrenergic receptor binding affinities, food interaction, and their impact on the pharmacokinetics and effects relative to ephedrine are presented for the first time, and in comparison to its action when present in herbs.

The toxicology and detoxification of Aconitum: traditional and modern views

Aconitum carmichaeli Debx.-derived herbal medicine has been used for anti-inflammation and anti-arrhythmia purpose for more than two thousand years. It is processed into Chuanwu (Radix Aconiti praeparata) and Fuzi (Radix Aconiti lateralis praeparata) in Traditional Chinese Medicine, which are two useful drugs but with toxic properties. There have been patients poisoned by accidental ingestion of Aconitum plants or misuse of the herbal drug, and this is of great concern to study in-depth. In this review, we provided the traditional and contemporary practice of using Aconitum herbs as medicine, from functions, processing methods to toxicity in ethnomedicine aspects to discuss the underlying connections of traditional and modern understanding on the toxicity of Aconitum plants. We summarized the functions and toxicology of the herbal drugs are analyzed from chemical and clinical aspects, with the help of traditional and modern knowledge of medicine. The medicinal doses and lethal doses determined by researches are summarized, and the usage and processing methods are updated and reviewed in the modern view. In addition, clinical management of poisoned cases using western medicine is discussed. This review provides insights and awareness of safety when using Aconitum-derived herbal medicine, and the application of modern scientific knowledge to optimize the detoxification processes. We suggest the possibility to renew the current standard processing method from the official Pharmacopoeia all over the world.

Comparative Pharmacokinetics and Bioavailability of Three Ephedrines in Rat after Oral Administration of Unprocessed and Honey-Fried Ephedra Extract by Response Surface Experimental Design

Ephedra have been used as a common traditional Chinese medicine for thousands of years. However, the perspiration effect of the unprocessed ephedra was too strong. Clinical trials have shown that processing methods play a critical role in moderating the perspiration property of ephedra according to the needs. A LC-MS/MS method was developed and validated to compare the pharmacokinetic properties of the three ephedrines after oral administration of unprocessed and honey-fried ephedra extract. The contents of honey, frying temperature, and frying time were set at 20%, 116°C, and 7 min by the Box-Behnken response surface method, respectively. In the pharmacokinetics study, the biosamples were pretreated and extracted by protein precipitation method with acetonitrile and separated on an Agilent TC-C₁₈ column (250 mm × 4.6 mm, 5 μm) using a mobile phase consisting of 0.1% formic acid methanol and 5 mM ammonium acetate aqueous solution (5 : 95, v/v). All calibration curves were linear (r > 0.9932) with lower limits of quantitation (LLOQs) < 12 ng/mL. The mean recoveries of the three analytes were higher than 75%. The pharmacokinetics study indicated that the reduced absorption of ephedrine hydrochloride (EH) and pseudoephedrine hydrochloride (PEH) in honey-fried ephedra group might be the main reason for the moderation of the diaphoretic property.

Recent advances in pharmacokinetics approach for herbal medicine

Traditional Chinese Medicine (TCM), an indispensable part of herbal medicine, has been used for treating many diseases and/or symptoms for thousands of years.

Comparative tissue distribution and excretion study of alkaloids from Herba Ephedrae-Radix Aconiti Lateralis extracts in rats

Herba Ephedrae-Radix Aconiti Lateralis, composed of Ephedrae (Mahuang in Chinese) and Radix Aconiti Lateralis (Fuzi in Chinese), is a classical herbal combination proven to be effective in treating common cold, asthma, and rheumatoid arthritis. Alkaloids, bioactive components of the herbal extract, have been associated with many side effects. Nine alkaloids, including norephedrine, norpseudoephedrine, ephedrine, pseudoephedrine, methylephedrine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypaconine, were simultaneously quantified within 14.5min, by a validated ultra-performance liquid chromatography-tandem mass spectrometry method in various rat tissues, urine, and feces after oral administration of Mahuang-Fuzi and single-herb extracts. The results indicated that the alkaloids were widely distributed in the heart, liver, spleen, lung, kidney, and brain. Lower bioavailability and higher clearance of some alkaloids were observed for the herbal combination, but hypaconitine showed a longer residence time and lower clearance. Elimination kinetics demonstrated that ephedra and aconitum alkaloids were mainly excreted in urine and feces, respectively. The tissue distribution and excretion of ephedra and aconitum alkaloids are comprehensively reported for the first time for the Mahuang-Fuzi combination. Compared with single-herb extracts, lower extraction efficiencies of alkaloids in vitro were observed which may result in their lower intake. However, the combination showed a prolonged residence time and delayed elimination of aconitum alkaloids, which increases the risk of drug accumulation. The study demonstrated potential risks of intoxication with aconitum alkaloids, associated with the use of Fuzi in combination with Mahuang. Mahuang-Fuzi is a classical combination used in clinics, further investigation is needed.

Concurrent quantification and comparative pharmacokinetic analysis of bioactive compounds in the Herba Ephedrae-Semen Armeniacae Amarum herb pair

The Mahuang-Xingren herb-pair (MX), the combination of Herba Ephedrae (Mahuang in Chinese) and Semen Armeniacae Amarum (Xingren in Chinese), is a classical combination used in traditional Chinese Medicine to treat asthma and bronchitis. A simple and reliable ultra-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously quantify and compare the pharmacokinetics of 5 ephedra alkaloids and epimers of amygdalin and prunasin in rat plasma after oral administration of Mahuang, Xingren, and MX aqueous extracts. Samples were pretreated by a single-step protein precipitation with acetonitrile, and diphenhydramine hydrochloride and puerarin were used as internal standards. Pharmacokinetic parameters were investigated using DAS 3.2.2 (Mathematical Pharmacology Professional Committee of China, Shanghai, China). The validated method demonstrated adequate sensitivity, selectivity, and process efficiency for the bioanalysis of 8 compounds, including 3 pairs of epimers. MX administration improved the bioavailability of amygdalin and prunasin. Furthermore, MX facilitated intake of lower doses of ephedra alkaloids and increased elimination rates in comparison with Mahuang alone. These results illustrate the rationale behind the preferred use of the combination of Mahuang and Xingren. To our knowledge, this is the first report of stereo-selective metabolism of amygdalin. Further, the metabolic mechanism underlying this phenomenon merits future research attention.