REDUCING TOXICITY AND INCREASING EFFICIENCY: ACONITINE WITH LIQUIRITIN AND GLYCYRRHETINIC ACID REGULATE CALCIUM REGULATORY PROTEINS IN RAT MYOCARDIAL CELL

Effects of plant extracts and derivatives on cardiac K+, Nav, and Cav channels: a review

Natural products (NPs) are endless sources of compounds for fighting against several pathologies. Many dysfunctions, including cardiovascular disorders, such as cardiac arrhythmias have their modes of action regulation of the concentration of electrolytes inside and outside the cell targeting ion channels. Here, we highlight plant extracts and secondary metabolites' effects on the treatment of related cardiac pathologies on hERG, Nav, and Cav of cardiomyocytes. The natural product's pharmacology of expressed receptors like alpha-adrenergic receptors causes an influx of Ca2+ ions through receptor-operated Ca2+ ion channels. We also examine the NPs associated with cardiac contractions such as myocardial contractility by reducing the L-type calcium current and decreasing the intracellular calcium transient, inhibiting the K+ induced contractions, decreasing amplitude of myocyte shortening and showed negative ionotropic and chronotropic effects due to decreasing cytosolic Ca2+. We examine whether the NPs block potassium channels, particular the hERG channel and regulatory effects on Nav1.7.

An integrated approach for investigating pharmacodynamic material basis of Lingguizhugan Decoction in the treatment of heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

As a classical formula of traditional Chinese medicine (TCM), Lingguizhugan Decoction (LGZGD) has been used for treating heart failure (HF) because it has an efficiency of yang-warming and fluid-dispersing. However, the pharmacodynamic material basis of LGZGD responsible for the therapeutic benefits is not well understood.

AIM OF THE STUDY

The aim of this study was to elucidate the pharmacodynamic material basis of LGZGD by an integrated approach.

MATERIALS AND METHODS

Following oral administration of LGZGD in mice, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to identify prototype substances. A heart failure (HF) model was established, followed by an untargeted metabolomics study to determine potential targets of LGZGD. The network pharmacology method was performed to screen substances that interacted with potential targets of LGZGD treating HF. Molecular docking technology was applied to further screen substances based on binding energy. Cell viability assays were conducted to verify pharmacodynamic effects of selected substances.

RESULTS

In all, forty-two prototype substances were identified in the blood, urine, and fecal samples of mice. A total of fifty-five differential metabolites were identified using heart tissue untargeted metabolomics. Twenty-five substances of LGZGD were screened relating to thirty-three targets treating HF. Twenty-two substances were filtered according to their binding energy using molecular docking technology. Cell experiments revealed cinnamaldehyde, glycyrrhetinic acid, kaempferol, daidzein, caffeic acid, and catechin could significantly improve the survival rate of H9c2 cells, which might be the pharmacodynamic material basis of LGZGD.

CONCLUSIONS

A scientific approach that integrated in vivo substances identification, metabolomics, network pharmacology, molecular docking, and cell pharmacodynamic assay has been developed to study the pharmacodynamic material basis of LGZGD in the treatment of HF.

Glycyrrhiza uralensis promote the metabolism of toxic components of Aconitum carmichaeli by CYP3A and alleviate the development of chronic heart failure

Aconitum, as "the first drug of choice for invigorating Yang and saving lives", has been widely used for the treatment of heart failure. However, toxic components of Aconitum can easily lead to serious arrhythmia, even death (Y. CT., 2009; Zhang XM., 2018). In this study, a High Performance Liquid Chromatography (HPLC) method for the determination of aconitine (AC), mesaconitine (MA) and hypaconitine (HA) was established; The effect of Glycyrrhiza on CYP3A1 / 2 mRNA expression was detected by RT-PCR; SD rats were given Aconitum and compatibility of Glycyrrhizae and Aconitum by gavage respectively, the blood concentration of toxic components were determined by LC-MS / MS; The CHF rat model was established by intraperitoneal injection of adriamycin (2.5 mg / kg), and were randomly divided into model, Aconitum, the compatibility of Glycyrrhizae and Aconitum and Captopril group, 5 mice/group. After 4 weeks of gavage, the corresponding indexes were detected by ELISA and HPLC. The results showed that Ketoconazole significantly inhibited the metabolites of AC, MA and HA; Glycyrrhiza induced CYP3A gene expression; The level of ALD in the compatibility of Glycyrrhizae and Aconitum group was significantly lower than that in Aconitum group. After intervention with the compatibility of Glycyrrhizae and Aconitum, ATP increased, ADP decreased significantly. In conclusion, we found Glycyrrhiza promoted the metabolism of toxic components of Aconitum by up regulating the expression of CYP3A, and reduced the content of BNP, Ang II and ALD, improved the energy metabolism disorder of myocardium, alleviated the development of CHF.

Mechanism of Action of Zhi Gan Cao Decoction for Atrial Fibrillation and Myocardial Fibrosis in a Mouse Model of Atrial Fibrillation: A Network Pharmacology-Based Study

Atrial fibrillation (AF), a commonly seen cardiac disease without optimal curative treatment option, is usually treated by traditional Chinese medicine in China. The Zhi-Gan-Cao decoction (ZGCD) is an alternative medicine for clinical use and has definitive effects. It remains to be defined regarding the specific components and related mechanisms of ZGCD for the treatment of AF. We determined the primary constituents and major targets of the herbs in ZGCD using the TCMSP, HERB, and BATMAN-TCM databases. The UniProt databank database amended and combined the prospective names to supply objective data and records. Every target connected to AF was generated using the GeneCards databank, Drugbank database, TTD, Disgenet database, and OMIM. After identifying possible common targets between ZGCD and AF, the interface network illustration “ZGCD component-AF-target” was created using Cytoscape. We obtained 175 constituents and 839 targets for seven herbal drug categories in the ZGCD and identified 1008 targets of AF. After merging and removing repetitions, 136 collective targets between the ZGCD and AF were removed using the Cytoscape system. These renowned targets were generated from 38 suitable components from among the 157 components. GO enhancement examination and KEGG enrichment analysis by Metascape identified the close connection between the critical target genes and 20 signaling pathways. Then, we injected isoproterenol subcutaneously into the mouse and gave gavage with roasted licorice soup. Two weeks later, mouse were processed and sampled for testing. The results of HE and Masson staining showed that ZGCD effectively alleviated the degree of myocardial fibrosis. As indicated by qRT-PCR and Western blotting, ZGCD significantly reduced COL1A1, COL1A2, COL3A1, and TGF-β1 in myocardial fibrotic tissue to reduce myocardial fibrosis and treat AF by interfering with the expression of COL1A1, COL1A2, COL3A1, and TGF-β1 in myocardial tissue. ZGCD may treat AF by lowering the degree of myocardial fibrosis.

Ginsenoside Rg1 Reduces Cardiotoxicity While Increases Cardiotonic Effect of Aconitine in vitro

OBJECTIVE

To explore the synergic mechanism of ginsenoside Rg₁ (Rg₁) and aconitine (AC) by acting on normal neonatal rat cardiomyocytes (NRCMs) and pentobarbital sodium (PS)-induced damaged NRCMs.

METHODS

The toxic, non-toxic, and effective doses of AC and the most suitable compatibility concentration of Rg₁ for both normal and damaged NRCMs exposed for 1 h were filtered out by 3- (4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide, respectively. Then, normal NRCMs or impaired NRCMs were treated with chosen concentrations of AC alone or in combination with Rg₁ for 1 h, and the cellular activity, cellular ultrastructure, apoptosis, leakage of acid phosphatase (ACP) and lactate dehydrogenase (LDH), intracellular sodium ions [Na⁺], potassium ions [K⁺] and calcium ions [Ca²⁺] levels, and Nav1.5, Kv4.2, and RyR₂ genes expressions in each group were examined.

RESULTS

For normal NRCMs, 3000 µ mol/L AC significantly inhibited cell viability (P<0.01), promoted cell apoptosis, and damaged cell structures (P<0.05), while other doses of AC lower than 3000 µ mol/L and the combinations of AC and Rg₁ had little toxicity on NRCMs. Compared with AC acting on NRCMs alone, the co-treatment of 3000 and 10 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ (P<0.01 or P<0.05), and the co-treatment of 3000 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ via regulating Nav1.5, RyR₂ expression (P<0.01). For damaged NRCMs, 1500 µ mol/L AC aggravated cell damage (P<0.01), and 0.1 and 0.001 µ mol/L AC showed moderate protective effect. Compared with AC used alone, the co-treatment of Rg₁ with AC reduced the cell damage, 0.1 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular Na⁺ (P<0.05), 1500 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular K⁺ (P<0.01) via regulating Nav1.5, Kv4.2, RyR₂ expressions in impaired NRCMs.

CONCLUSION

Rg₁ inhibited the cardiotoxicity and enhanced the cardiotonic effect of AC via regulating the ion channels pathway of [Na⁺], [K⁺], and [Ca²⁺].

Liquiritin from Radix Glycyrrhizae Protects Cardiac Mitochondria from Hypoxia/Reoxygenation Damage

AIMS

The purpose of this study was to evaluate the protective effect of liquiritin (LIQ) from Radix Glycyrrhizae on cardiac mitochondria against hypoxia/reoxygenation (HR) injury.

METHODS

H9C2 cells were subject to the HR model. LIQ purified from Radix Glycyrrhizae (purity > 95%) was administrated to reoxygenation period. Cell viability, mitochondrial mass, mitochondrial membrane potential, reactive oxygen species, and mitochondrial Ca2⁺ level were then assessed by using Cell Counting kit-8 and suitable fluorescence probe kits.

RESULTS

LIQ administration remarkably reduced the rate of HR damage via increasing H9C2 cell viability level and preserving mitochondria after HR. Particularly, 60 μM of LIQ posthypoxic treatment markedly reduced cell death in HR-subjected H9C2 cell groups (p < 0.05). Interestingly, posthypoxic treatment of LIQ significantly prevented the loss of mitochondrial membrane potential, the decrease in mitochondrial mass, the increase in reactive oxygen species production, and the elevation of mitochondrial Ca2⁺ level in HR-treated H9C2 cells.

CONCLUSION

The present study provides for the first time the cardioprotective of LIQ posthypoxic treatment via reducing H9C2 cell death and protecting cardiac mitochondria against HR damage.

Cardiac efficacy and toxicity of aconitine: A new frontier for the ancient poison

Aconitine (AC) is well-known as the main toxic ingredient and active compound of Aconitum species, of which several aconites are essential herbal medicines of Traditional Chinese Medicine (TCM) and widely applied to treat diverse diseases for their excellent anti-inflammatory, analgesic, and cardiotonic effects. However, the cardiotoxicity and neurotoxicity of AC attracted a lot of attention and made it a favorite botanic poison in history. Nowadays, the narrow therapeutic window of AC limits the clinical application of AC-containing herbal medicines; overdosing on AC always induces ventricular tachyarrhythmia and heart arrest, both of which are potentially lethal. But the underlying cardiotoxic mechanisms remained chaos. Recently, beyond its cardiotoxic effects, emerging evidence shows that low doses of AC or its metabolites could generate cardioprotective effects and are necessary to aconite's clinical efficacy. Consistent with TCM's theory that even toxic substances are powerful medicines, AC thus could not be simply identified as a toxicant or a drug. To prevent cardiotoxicity while digging the unique value of AC in cardiac pharmacology, there exists a huge urge to better know the characteristic of AC being a cardiotoxic agent or a potential heart drug. Here, this article reviews the advances of AC metabolism and focuses on the latest mechanistic findings of cardiac efficacy and toxicity of this aconite alkaloid or its metabolites. We also discuss how to prevent AC-related cardiotoxicity, as well as the issues before the development of AC-based medicines that should be solved, to provide new insight into the paradoxical nature of this ancient poison.

The Toxicity and Attenuation Methods of Toxic Chinese Materia Medica for its Reasonable Application: A Review

Over a millennia, traditional Chinese medicine (TCM) has been used to treat various diseases in China. In recent years, more and more Chinese materia medica (CMM) have been studied in scientific research projects, applied in clinical practice, and their extracts have even appeared in some health products. However, the toxicity of some CMM is often overlooked, including hepatotoxicity, nephrotoxicity, neurotoxicity, cardiotoxicity, etc. In this review, the toxic components and their toxicological mechanisms of some toxic CMM were listed according to the chemical structure classification of toxic components. Afterwards, the traditional methods (processing and compatibility) and modern methods (structural modification, biotransformation, etc.) of attenuation of CMM were discussed. Since ancient times, it has been said that "fight fire with fire, fight poison with poison," and toxic CMM are of great significance in the treatment of difficult and severe diseases. The rational application of toxic CMM and their components in clinical practice was also exemplified in this review. While the pharmacological effects of TCMs have been emphasized, the scientific attenuation and rational application of toxic components should be concerned. We hope this review can provide a reference for future related research.

18β-Glycyrrhetinic Acid Improves Cardiac Diastolic Function by Attenuating Intracellular Calcium Overload

Ranolazine, a late sodium current inhibitor, has been demonstrated to be effective on heart failure. 18β-glycyrrhetinic acid (18β-GA) has the similar inhibitory effect on late sodium currents. However, its effect on diastolic function is still unknown. This study aimed to determine whether 18β-GA can improve the diastolic function and to explore the underlying mechanisms. Eighty male Sprague Dawley (SD) rats of Langendorff model were randomly divided into the following groups: group A, normal cardiac perfusion group; group B, ischemia-reperfusion group; group C, ischemia-reperfusion with anemoniasulcata toxin II (ATX-II); group D, ranolazine group; and group E, 18β-GA group with four different concentrations. Furthermore, a pressure-overloaded rat model induced by trans-aortic constriction (TAC) was established. Echocardiography and hemodynamics were used to evaluate diastolic function at 14th day after TAC. Changes of free intracellular calcium (Ca²⁺) concentration was indirectly detected by laser scanning confocal microscope to confirm the inhibition of late sodium currents. With the intervention of ATX-II on ischemia reperfusion injury group, 5 µmol/L ranolazine, and 5, 10, 20, 40 µmol/L 18β-GA could improve ATX-II-induced cardiac diastolic dysfunction. 630 mg/kg glycyrrhizin tablets could improve cardiac diastolic function in the pressure-overloaded rats. 18β-GA and ranolazine had similar effects on reducing the free calcium in cardiomyocytes. The study demonstrates that 18β-GA and glycyrrhizin could improve diastolic dysfunction induced by ischemia-reperfusion injury in Langendorff-perfused rat hearts and pressure-overloaded rats. The mechanism may be attributed to the inhibition of enhanced late sodium currents.

Rethinking and new perspectives on cardiotoxicity of traditional Chinese medicine

Traditional Chinese Medicine (TCM) has been commonly used in clinical practice for thousands of years and has made enormous contributions to public health in China. However, the adverse effects on the cardiac system or TCM-induced cardiovascular diseases have emerged frequently in recent years, resulting in growing attention to the safety of TCM. Generally, TCM with adverse cardiac effects has typical therapeutic or toxic effects, which are based on specific material basis for efficacy/toxicity, specific clinical symptoms and toxic mechanisms. However, improper strategies adopted for research on the cardiotoxicity of TCM simply follow the basic principles of conventional toxicology and cause exaggerative or incorrect interpretations in the toxicity of TCM. In this review, we aim to present the classification and possible toxic mechanisms for TCM with cardiotoxicity based on the material basis for toxicity to rethink the existing problems in toxicity studies for TCM and provide new perspectives for research on the potential cardiotoxicity of TCM. We hope that this study can offer important theoretical support and scientific advice for the toxicity study and clinical rational use of TCM having cardiotoxicity.

Research progress of aconitine toxicity and forensic analysis of aconitine poisoning

Chinese herbal medicines have been extensively used in China and other countries for centuries. Aconitine, a diterpenoid alkaloid extracted from Aconitum plants, has anti-inflammatory and analgesic activities, but can also induce severe arrhythmia and neurotoxicity. Aconitine poisoning accidents caused by misuse, suicide, or homicide have been reported in recent years. In China, fatal aconitine poisoning can occasionally happen on account of accidental ingestion of some wild plants or consumption of herbal decoction made from the roots of Aconitum plants. However, it is rather difficult for forensic experts to find the specific results in present forensic autopsy of aconitine-induced death. To further clarify its potential risk following the widespread application of aconitine, toxicological characteristics and pharmacokinetics of aconitine are reviewed. Moreover, gastrointestinal, neurological, and cardiovascular symptoms were observed frequently in aconitine poisoning cases. In addition, the review also aims at providing some convincing evidences for forensic experts to identify unexplained death with postmortem examination.