Deciphering the Mechanism of the Anti-Hypertensive Effect of Isorhynchophylline by Targeting Neurotransmitters Metabolism of Hypothalamus in Spontaneously Hypertensive Rats

The circadian rhythm: A new target of natural products that can protect against diseases of the metabolic system, cardiovascular system, and nervous system

BACKGROUND

The treatment of metabolic system, cardiovascular system, and nervous system diseases remains to be explored. In the internal environment of organisms, the metabolism of substances such as carbohydrates, lipids and proteins (including biohormones and enzymes) exhibit a certain circadian rhythm to maintain the energy supply and material cycle needed for the normal activities of organisms. As a key factor for the health of organisms, the circadian rhythm can be disrupted by pathological conditions, and this disruption accelerates the progression of diseases and results in a vicious cycle. The current treatments targeting the circadian rhythm for the treatment of metabolic system, cardiovascular system, and nervous system diseases have certain limitations, and the identification of safer and more effective circadian rhythm regulators is needed.

AIM OF THE REVIEW

To systematically assess the possibility of using the biological clock as a natural product target for disease intervention, this work reviews a range of evidence on the potential effectiveness of natural products targeting the circadian rhythm to protect against diseases of the metabolic system, cardiovascular system, and nervous system. This manuscript focuses on how natural products restore normal function by affecting the amplitude of the expression of circadian factors, sleep/wake cycles and the structure of the gut microbiota.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

This work proposes that the circadian rhythm, which is regulated by the amplitude of the expression of circadian rhythm-related factors and the sleep/wake cycle, is crucial for diseases of the metabolic system, cardiovascular system and nervous system and is a new target for slowing the progression of diseases through the use of natural products. This manuscript provides a reference for the molecular modeling of natural products that target the circadian rhythm and provides a new perspective for the time-targeted action of drugs.

Unified Strategy Enables the Collective Syntheses of Structurally Diverse Indole Alkaloids

Natural products and their analogues are significant sources of therapeutic lead compounds. However, synthetic strategies for generating large collections of these molecules remain a significant challenge. The most difficult step in their synthesis is the design of a common intermediate that can be easily transformed into natural products belonging to different families. This study demonstrates the evolution of synthetic tactics designed to assemble the functionalized piperidines present in indole alkaloids from a common intermediate. More importantly, we also report a previously unknown Ir- and Er-catalyzed dehydrogenative spirocyclization reaction that enables direct access to spirocyclic oxindole alkaloids. As a practical application, the asymmetric total syntheses of 29 natural alkaloids belonging to different families were accomplished by following a uniform synthetic route. The proposed methodology extends the capability of the iridium-catalyzed dehydrogenative coupling reaction to the realm of indole-alkaloid synthesis and provides new opportunities for the efficient preparation of natural product-like molecules.

Study on material basis and anti-hypertensive metabolomics of different extraction methods of the Uncaria rhynchophylla Scrophularia Formula

Hypertension is one of the most challenging public health problems worldwide. Previous studies suggested that the Uncaria rhynchophylla Scrophularia Formula (URSF), a medical institution preparation of the affiliated Hospital of Shandong University of Traditional Chinese Medicine, is effective for essential hypertension. However, the efficacy of URSF for hypertension remains unclear. We aimed to clarify the anti-hypertensive mechanism of the URSF. The material basis of URSF was identified by the LC-MS. We also evaluated the antihypertensive efficacy of URSF on SHR rats by body weight, blood pressure and biochemical indicators. The LC-MS spectrometry-based serum non-targeted metabolomics was used to seek potential biomarkers and relevant pathways for URSF in the treatment of SHR rats. 56 biomarkers were metabolically disturbed in SHR rats in the model group compared with the control group. After URSF intervention, 13 biomarkers showed a recovery in the optimal method compared with the other three groups. We identified 3 metabolic pathways in which URSF is involved: the arachidonic acid metabolism pathway, the niacin and nicotinamide metabolism pathway, and the purine metabolism pathway. These discoveries offer a basis for the study of URSF for the treatment of hypertension.

Pharmacological mechanism of natural drugs and their active ingredients in the treatment of arrhythmia via calcium channel regulation

Arrhythmia is characterized by abnormal heartbeat rhythms and frequencies caused by heart pacing and conduction dysfunction. Arrhythmia is the leading cause of death in patients with cardiovascular disease, with high morbidity and mortality rates, posing a serious risk to human health. Natural drugs and their active ingredients, such as matrine(MAT), tetrandrine(TET), dehydroevodiamine, tanshinone IIA, and ginsenosides, have been widely used for the treatment of atrial fibrillation, ventricular ectopic beats, sick sinus syndrome, and other arrhythmia-like diseases owing to their unique advantages. This review summarizes the mechanism of action of natural drugs and their active ingredients in the treatment of arrhythmia via the regulation of Ca²⁺, such as alkaloids, quinones, saponins, terpenoids, flavonoids, polyphenols, and lignan compounds, to provide ideas for the innovative development of natural drugs with potential antiarrhythmic efficacy.

Isorhynchophylline inhibits inflammatory responses in endothelial cells and macrophages through the NF-κB/NLRP3 signaling pathway

BACKGROUND

Atherosclerosis is a chronic inflammatory disease of arterial wall, which is closely related to inflammatory reaction. In this study, the anti-inflammatory effect of isorhynchophylline was studied by NF- κB / NLRP3 pathway.

METHODS

(1) ApoE^-/- mice were fed with high-fat diet to establish atherosclerotic model, while C57 with the same genetic background was fed with common diet as control group. Body weight was recorded and blood lipids were detected. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and plaque formation was detected by HE and oil red O staining. (2) Lipopolysaccharide interfered with Human Umbilical Vein Endothelial Cells (HUVECs) and RAW264.7 to form inflammatory model, and was treated with isorhynchophylline. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and the ability of cell migration was detected by Transwell and scratch test.

RESULTS

(1) the expression of NLRP3, NF- κB, IL-18 and Caspase-1 in aorta of model group was higher than that of control group, and plaque formation was obvious. (2) the expressions of NLRP3, NF- κB, IL-18 and Caspase-1 in HUVECs and RAW264.7 model groups were higher than those in control group, while isorhynchophylline decreased their expression and enhanced cell migration ability.

CONCLUSION

Isorhynchophylline can reduce the inflammatory reaction induced by lipopolysaccharide and promote the ability of cell migration.

Dissecting the potential mechanism of antihypertensive effects of RVPSL on spontaneously hypertensive rats via widely targeted kidney metabolomics

BACKGROUND

Our previous study has demonstrated that the egg-white-derived peptide RVPSL can lower blood pressure in spontaneously hypertensive rats (SHRs), but its potential action mechanism remains unclear. In this work, the underlying mechanism of the antihypertensive effects of RVPSL in SHRs was elucidated using the widely targeted kidney metabolomics approach.

RESULTS

Ten SHRs were divided into two groups: SHR-Untreated group (0.9% saline) and SHR-RVPSL group (50 mg kg^-1 body weight RVPSL) for 4 weeks. After 4 weeks, kidney samples were collected and widely targeted (liquid chromatography-electrospray ionization-tandem mass spectrometry) metabolomics was used to detect metabolites. Fifty-six biomarkers were identified that may be associated with hypertension. Among them, 17 biomarkers were upregulated and 39 biomarkers were downregulated. The results suggested that eight potential biomarkers were identified in kidney samples: O-phospho-l-serine, tyramine, citric acid, 3-hydroxybutyrate, O-acetyl-l-serine, 15-oxo-5Z,8Z,11Z,13E-eicosatetraenoic acid (15-oxoETE), dopaquinone and 3,3',5-triiodo-l-thyronine. These potential biomarkers mainly involved carbon metabolism, thyroid hormone signaling pathway, tyrosine metabolism and arachidonic acid metabolism.

CONCLUSION

The study suggested that RVPSL may exert antihypertensive effects through upregulation of O-phospho-l-serine, 3-hydroxybutyrate and 15-oxoETE, and downregulation of tyramine, citric acid, O-acetyl-l-serine, 3,3',5-triiodo-l-thyronine and dopaquinone. The antihypertensive effects of RVPSL may be related to carbon metabolism, thyroid hormone signaling pathway, tyrosine metabolism and arachidonic acid metabolism. RVPSL exhibited a potent antihypertensive effect, and the antihypertensive effects were associated with inhibition of vascular smooth muscle cell proliferation, vascular remodeling, vascular endothelium dysfunction, restoring reactive oxygen species, oxidative stress, inflammation and immune reaction. © 2022 Society of Chemical Industry.

Identification of biomarkers for essential hypertension based on metabolomics

AIM

Essential hypertension (EH) is one of the most important public health problems worldwide. However, the pathogenesis of EH is unclear and early diagnostic methods are lacking. Metabolomics demonstrates great potential for biomarker discovery and the mechanistic exploration of metabolic diseases.

DATA SYNTHESIS

This review included human and animal metabolomics studies related to EH in the PubMed and Web of Science databases between February 1996 and May 2020. The study designs, EH standards, and reported metabolic biomarkers were systematically examined and compared. The pathway analysis was conducted through the online software MetaboAnalyst 4.0. Twenty-two human studies and fifteen animal studies were included in this systematic review. There were many frequently reported biomarkers with consistent trends (e.g., pyruvate, lactic acid, valine, and tryptophan) in human and animal studies, and thus had potential as biomarkers of EH. In addition, several shared metabolic pathways, including alanine, aspartate, and glutamate metabolism, aminoacyl-tRNA biosynthesis, and arginine biosynthesis, were identified in human and animal metabolomics studies. These biomarkers and pathways, closely related to insulin resistance, the inflammatory state, and impaired nitric oxide production, were demonstrated to contribute to EH development.

CONCLUSIONS

This study summarized valuable metabolic biomarkers and pathways that could offer opportunities for the early diagnosis or prediction of EH and the discovery of the metabolic mechanisms of EH.

Therapeutic value of the metabolomic active neurotransmitter isorhynchophylline in the treatment of spontaneously hypertensive rats by regulating neurotransmitters

Hypertension is one of the most reported cardiovascular and cerebrovascular diseases with significantly high morbidity and mortality rates. This condition threatens the very existence of human beings. Numerous studies conducted earlier revealed the good therapeutic effect of isorhynchophylline on hypertension since the former regulates the metabolic disorders in neurotransmitters. However, the mechanism behind this action is yet to be deciphered. The current study followed the targeted metabolomics method to investigate the changes in the neurotransmitter level in the hippocampus of spontaneously hypertensive rats (SHRs) after the rats were treated with isorhynchophylline. The authors predicted the metabolic pathways involved in extensively modified neurotransmitters. Further, the expressions of metabolism-key enzymes in mRNA and protein levels were also determined. When treated with isorhynchophylline, it induced notably varying metabolomic profiles of the hippocampus in SHRs. Isorhynchophylline perturbed a total of seven extensively modified neurotransmitters as well as the primarily related pathways such as tyrosine and glutamate metabolism. An increase in the key metabolic enzymes such as DDC, MAO, COMT, TH, and DβH was observed in the SHR group, whereas their levels decreased after treatment with isorhynchophylline. The expression of GAD67 established cross-current validity. So, isorhynchophylline has been proved to have potential therapeutic value to treat hypertension via tyrosine and glutamate metabolism in the hippocampus. Further, the current study also opened new ventures to further investigate the working mechanism of isorhynchophylline in hypertension.

The genus Uncaria: A review on phytochemical metabolites and biological aspects

The genus Uncaira (Rubiaceae) comprises of 34 species, many of which are usually used as traditional Chinese medicines (TCMs) to treat hypertension, fever, headache, gastrointestinal illness, and fungal infection. Over the past twenty years, Uncaira species have been paid the considerable attentions in phytochemical and biological aspects, and about 100 new secondary metabolites, including alkaloids, triterpenes, and flavonoids, have been elucidated. This review aims to present a comprehensive and up-to date overview of the biological source, structures and their biosynthetic pathways, as well as the pharmacological of the compounds reported in the genus Uncaria for the past two decades. It would provide an insight into the emerging pharmacological applications of the genus Uncaria.

Recent research progress of Uncaria spp. based on alkaloids: phytochemistry, pharmacology and structural chemistry

Medicinal plants are well-known in affording clinically useful agents, with rich medicinal values by combining with disease targets through various mechanisms. Plant secondary metabolites as lead compounds lay the foundation for the discovery and development of new drugs in disease treatment. Genus Uncaria from Rubiaceae family is a significant plant source of active alkaloids, with anti-hypertensive, sedative, anti-Alzheimer's disease, anti-drug addiction and anti-inflammatory effects. This review summarizes and discuss the research progress of Uncaria based on alkaloids in the past 15 years, mainly in the past 5 years, including biosynthesis, phytochemistry, pharmacology and structural chemistry. Among, focusing on representative compounds rhynchophylline and isorhynchophylline, the pharmacological activities surrounding the central nervous system and cardiovascular system are described in detail. On the basis of case studies, this article provides a brief overview of the synthesis and analogues of representative compounds types. In summary, this review provides an early basis for further searching for new targets and activities, discussing the mechanisms of pharmacological activity and studying the structure-activity relationships of active molecules.