Establishment of one-step approach to detoxification of hypertoxic aconite based on the evaluation of alkaloids contents and quality.

Aconite is a valuable drug and also a toxic material, which can be used only after detoxification processing. Although traditional processing methods can achieve detoxification effect as desired, there are some obvious drawbacks, including a significant loss of alkaloids and poor quality consistency. It is thus necessary to develop a new detoxification approach. In the present study, we designed a novel one-step detoxification approach by quickly drying fresh-cut aconite particles. In order to evaluate the technical advantages, the contents of mesaconitine, aconitine, hypaconitine, benzoylmesaconine, benzoylaconine, benzoylhypaconine, neoline, fuziline, songorine, and talatisamine were determined using HPLC and UHPLC/Q-TOF-MS. Multivariate analysis methods, such as Clustering analysis and Principle component analysis, were applied to determine the quality differences between samples. Our results showed that traditional processes could reduce toxicity as desired, but also led to more than 85.2% alkaloids loss. However, our novel one-step method was capable of achieving virtually the same detoxification effect, with only an approximately 30% alkaloids loss. Cluster analysis and Principal component analysis analyses suggested that Shengfupian and the novel products were significantly different from various traditional products. Acute toxicity testing showed that the novel products achieved a good detoxification effect, with its maximum tolerated dose being equivalent to 20 times of adult dosage. And cardiac effect testing also showed that the activity of the novel products was stronger than that of traditional products. Moreover, particles specification greatly improved the quality consistency of the novel products, which was immensely superior to the traditional products. These results would help guide the rational optimization of aconite processing technologies, providing better drugs for clinical treatment.

Mechanistic understanding of the effect of Dengzhan Shengmai capsule on the pharmacokinetics of clopidogrel in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The Dengzhan Shengmai capsule (DZSM) is known in China for its remarkable curative effect as a treatment of cardiovascular diseases, such as coronary heart disease and ischemic stroke. DZSM is a Chinese herbal compound preparation that consists of four ingredients, including Erigeron breviscapus (Vaniot) Hand.-Mazz., Panax ginseng C.A. Mey, Ophiopogon japonicas (Thunb.) Ker-Gawl. and Schisandra chinensis (Turcz.) Baill., and was indexed in the Chinese Pharmacopoeia 2010. DZSM and clopidogrel are often co-prescribed in the clinic to prevent the recurrence of stroke or other cardiovascular and cerebrovascular diseases. However, the effect of DZSM on the pharmacokinetics of clopidogrel remains unclear. AIM OF THE STUDY: The purpose of the study is to explore the pharmacokinetics and potential interaction between DZSM and clopidogrel and the underlying mechanism. MATERIALS AND METHODS: Rats were used to investigate the effect of DZSM on the pharmacokinetics of clopidogrel and its active metabolite in vivo. The plasma concentrations were simultaneously determined using LC-MS/MS. The effects of DZSM on the P-gp-mediated efflux transport and CYP450-mediated metabolism of clopidogrel were investigated using MDCKII-MDR1 cells and rat liver microsomes, respectively. RESULTS: After pretreatment with DZSM, the Cmax and AUC0-∞ of clopidogrel increased from 0.4±0.1 to 1.7±0.6ng/mL and 0.9±0.4 to 2.0±0.2ng/mLh, respectively. The Cmax and AUC0-∞ of the derivatized active metabolite of clopidogrel decreased from 8.2±1.2 to 2.8±0.5ng/mL and 18.2±5.6 to 6.4±3.7ngh/mL, respectively. In MDCKII-MDR1 cells, the P-gp-mediated efflux transport of clopidogrel was significantly inhibited by the DZSM extract. In rat liver microsomes, DZSM inhibited clopidogrel metabolism with an IC50 of 0.02mg/mL. CONCLUSIONS: DZSM significantly affects the pharmacokinetics of clopidogrel and its active metabolite by inhibiting the P-gp-mediated efflux transport and CYP450-mediated metabolism of clopidogrel. Thus, caution is needed when DZSM is co-administered with clopidogrel in the clinic because the interaction of these drugs may result in altered plasma concentrations of clopidogrel and its active metabolite.

Cardiotoxicity screening: a review of rapid-throughput in vitro approaches.

Cardiac toxicity represents one of the leading causes of drug failure along different stages of drug development. Multiple very successful pharmaceuticals had to be pulled from the market or labeled with strict usage warnings due to adverse cardiac effects. In order to protect clinical trial participants and patients, the International Conference on Harmonization published guidelines to recommend that all new drugs to be tested preclinically for hERG (Kv11.1) channel sensitivity before submitting for regulatory reviews. However, extensive studies have demonstrated that measurement of hERG activity has limitations due to the multiple molecular targets of drug compound through which it may mitigate or abolish a potential arrhythmia, and therefore, a model measuring multiple ion channel effects is likely to be more predictive. Several phenotypic rapid-throughput methods have been developed to predict the potential cardiac toxic compounds in the early stages of drug development using embryonic stem cells- or human induced pluripotent stem cell-derived cardiomyocytes. These rapid-throughput methods include microelectrode array-based field potential assay, impedance-based or Ca(2+) dynamics-based cardiomyocytes contractility assays. This review aims to discuss advantages and limitations of these phenotypic assays for cardiac toxicity assessment.

The Safety Evaluation of Salvianolic Acid B and Ginsenoside Rg1 Combination on Mice.

Our previous study indicated that the combination of salvianolic acid B (SalB) and ginsenoside Rg1 (Rg1), the main components of Salvia miltiorrhizae and Panax notoginseng, improves myocardium structure and ventricular function in rats with ischemia/reperfusion injury. The present study aimed to determine the safety of the combined SalB and Rg1 (SalB-Rg1) in mice. The safety of SalB-Rg1 was evaluated through acute toxicity and repeated-dose toxicity. In the acute toxicity study, the up and down procedure was carried out firstly, and then, the Bliss method was applied. In the toxicity study for seven-day repeated treatment of SalB-Rg1, forty Kunming mice were randomly divided into four groups. The intravenous median lethal dose (LD50) of the SalB-Rg1 combination was 1747 mg/kg using the Bliss method. For both the acute toxicity study and the seven-day repeated toxicity study, SalB-Rg1 did not induce significant abnormality on brain, heart, kidney, liver and lung structure at any dose based on H&E stain. There were no significant changes related to the SalB-Rg1 toxicity detected on biochemical parameters for two kinds of toxicity studies. The LD50 in mice was 1747 mg/kg, which was more than one hundred times higher than the effective dose. Both studies of acute toxicity and seven-day repeated dose toxicity indicated the safety of the SalB-Rg1 combination.

Methylation and its role in the disposition of tanshinol, a cardiovascular carboxylic catechol from Salvia miltiorrhiza roots (Danshen).

AIM: Tanshinol is an important catechol in the antianginal herb Salvia miltiorrhiza roots (Danshen). This study aimed to characterize tanshinol methylation. METHODS: Metabolites of tanshinol were analyzed by liquid chromatography/mass spectrometry. Metabolism was assessed in vitro with rat and human enzymes. The major metabolites were synthesized for studying their interactions with drug metabolizing enzymes and transporters and their vasodilatory properties. Dose-related tanshinol methylation and its influences on tanshinol pharmacokinetics were also studied in rats. RESULTS: Methylation, preferentially in the 3-hydroxyl group, was the major metabolic pathway of tanshinol. In rats, tanshinol also underwent considerable 3-O-sulfation, which appeared to be poor in human liver. These metabolites were mainly eliminated via renal excretion, which involved tubular secretion mainly by organic anion transporter (OAT) 1. The methylated metabolites had no vasodilatory activity. Entacapone-impaired methylation did not considerably increase systemic exposure to tanshinol in rats. The saturation of tanshinol methylation in rat liver could be predicted from the Michaelis constant of tanshinol for catechol-O-methyltransferase (COMT). Tanshinol had low affinity for human COMT and OATs; its methylated metabolites also had low affinity for the transporters. Tanshinol and its major human metabolite (3-O-methyltanshinol) exhibited negligible inhibitory activities against human cytochrome P450 enzymes, organic anion transporting polypeptides 1B1/1B3, multidrug resistance protein 1, multidrug resistance-associated protein 2, and breast cancer resistance protein. CONCLUSION: Tanshinol is mainly metabolized via methylation. Tanshinol and its major human metabolite have low potential for pharmacokinetic interactions with synthetic antianginal agents. This study will help define the risk of hyperhomocysteinemia related to tanshinol methylation.

Biomimetic cardiac microsystems for pathophysiological studies and drug screens.

Microfabricated organs-on-chips consist of tissue-engineered 3D in vitro models, which rely on engineering design and provide the physiological context of human organs. Recently, significant effort has been devoted to the creation of a biomimetic cardiac system by using microfabrication techniques. By applying allometric scaling laws, microengineered cardiac systems simulating arterial flow, pulse properties, and architectural environments have been implemented, allowing high-throughput pathophysiological experiments and drug screens. In this review, we illustrate the recent trends in cardiac microsystems with emphasis on cardiac pumping and valving functions. We report problems and solutions brought to light by existing organs-on-chip models and discuss future directions of the field. We also describe the needs and desired design features that will enable the control of mechanical, electrical, and chemical environments to generate functional in vitro cardiac disease models.

Alkaloids from piper: a review of its phytochemistry and pharmacology.

OBJECTIVE: Piper has been used for long timelike condiment and food, but also in traditional medicine around of the world. This work resumes the available and up to date work done on members of the Piperaceae family and their uses for therapeutic purposes. METHODS: Information on Piper genus was gathered via internet using scientific databases such as Scirus, Google Scholar, CAB-abstracts, MedlinePlus, Pubmed, SciFinder, Scopus and Web of Science. RESULTS: The largeleafed perennial plant Piper is used for its spicy aromatic scent and flavor. It has an important presence in the cuisine of different cultures. Another quality of these plants is their known medicinal properties. It has been used as emollient, antirheumatic, diuretic, stimulant, abortifacient, anti-inflammatory, antibacterial, antifungal and antidermatophytic. A survey of the literature shows that the genus Piper is mainly known for its alkaloids with cytotoxic, chemopreventive, antimetastatic and antitumor properties in several types of cancer. Studies of its alkaloids highlight the existence of various potential leads to develop new anti-cancer agents. Modern pharmacology studies have demonstrated that its crude extracts and active compounds possess wide pharmacological activities, especially asantioxidant, anti-depressive, hepatoprotective, antimicrobial, anti-obesity, neuropharmacological, to treat cognitive disorders, anti-hyperlipidemic, anti-feedant, cardioactive, immuno-enhancing, and anti-inflamatory. All this evidence supporting its traditional uses. AIM OF THE REVIEW: This review summarizes the up-to-date and comprehensive information concerning the botany, traditional use, phytochemistry and pharmacology of Piper together with its toxicology, and discusses the possible trend and scope for further research on Piper in the future.

An in silico canine cardiac midmyocardial action potential duration model as a tool for early drug safety assessment.

Cell lines expressing ion channels (IC) and the advent of plate-based electrophysiology device have enabled a molecular understanding of the action potential (AP) as a means of early QT assessment. We sought to develop an in silico AP (isAP) model that provides an assessment of the effect of a compound on the myocyte AP duration (APD) using concentration-effect curve data from a panel of five ICs (hNav1.5, hCav1.2, hKv4.3/hKChIP2.2, hKv7.1/hminK, hKv11.1). A test set of 53 compounds was selected to cover a range of selective and mixed IC modulators that were tested for their effects on optically measured APD. A threshold of >10% change in APD at 90% repolarization (APD(90)) was used to signify an effect at the top test concentration. To capture the variations observed in left ventricular midmyocardial myocyte APD data from 19 different dogs, the isAP model was calibrated to produce an ensemble of 19 model variants that could capture the shape and form of the APs and also quantitatively replicate dofetilide- and diltiazem-induced APD(90) changes. Provided with IC panel data only, the isAP model was then used, blinded, to predict APD(90) changes greater than 10%. At a simulated concentration of 30 µM and based on a criterion that six of the variants had to agree, isAP prediction was scored as showing greater than 80% predictivity of compound activity. Thus, early in drug discovery, the isAP model allows integrating separate IC data and is amenable to the throughput required for use as a virtual screen.

Preparation, characterization and evaluation of breviscapine lipid emulsions coated with monooleate-PEG-COOH.

Series of monooleate-modified PEG with active carboxylic terminus on the other end (MO-PEG-COOH) were used to modify the lipid emulsions surface to prepare a sterically stabilized lipid emulsions for carrying Traditional Chinese Medicine - breviscapine. Based on the research of relationship between polymer structure and prolonged circulation activity, we developed an optimized formulation and a technological method to prepare the sterile and stable MO-PEG(10,000)-COOH (Bre-LE-PEG(10,000)) coated breviscapine lipid emulsions (Bre-LE) for intravenous administration. Follow the optimum preparation, the average particle size, polydispersity index, zeta potential, Ke value and content of final product were determined to be (207.1±8.5)nm, 0.197±0.005, (-33.6±2.0)mV, (21.1±2.3)% and (95.0±1.8)% respectively (n=3). The characteristics, stability and safety of Bre-LE-PEG(10,000) were also studied with Bre-LE as a control. Increased plasma concentration by surface modification of the lipid emulsions may enhance the pharmacological activity of breviscapine to promote blood circulation.

Paclitaxel-induced arterial wall toxicity and inflammation: tissue uptake in various dose densities in a minipig model.

PURPOSE: Paclitaxel is an antiproliferative agent in drug-eluting stents with largely unknown tissue interaction. Toxicity might result from overdosage and/or accumulation. Part 1 of this two-step study investigated how paclitaxel uptake depends on dose density, coronary drug transfer kinetics, and elution efficacy. MATERIALS AND METHODS: With cobalt chromium stents and Polyzene-F nanoscale coating, low, intermediate, and high paclitaxel dose densities (25 microg, 50 microg, and 150 microg per stent) were investigated in porcine right coronary arteries (RCAs). Coronary and myocardial tissue concentration measurements and determination of on-stent paclitaxel and plasma concentrations were performed at 2, 8, 24, and 72 hours. RESULTS: For all stents, uptake was similar at all time intervals (paclitaxel RCA concentration range, 1,610-33,300 ng). Low- and intermediate-dose stents showed similar RCA concentrations, but those for high-dose stents were three times greater. Residual on-stent paclitaxel concentration was not time-dependent, at 33.3% on low-, 30.6% on intermediate-, and 17.4% on high-dose stents. Paclitaxel was measurable in only the plasma immediately after stent placement, with a linear dose relationship and a timely regression: measurements in high-dose stents were 0.0454-0.656 ng/mL at 1 minute and 0.0329-0.0879 ng/mL at 5 minutes. Untreated control samples of the left coronary artery showed a linear dose-dependent concentration (12.6 ng/g, 21.2 ng/g, and 85.2 ng/g). CONCLUSIONS: Overall coronary paclitaxel uptake is fairly independent from the baseline overall dose density and, hence, depends on immediate binding mechanisms of the arterial wall. This is supported by the fact that, regardless of the applied dose density, the kinetics of paclitaxel uptake did not follow an exposure time pattern.

Effects of long-term mildronate treatment on cardiac and liver functions in rats.

Mildronate is a cardioprotective drug that improves cardiac function during ischaemia and functions by lowering l-carnitine concentration in body tissues and modulating myocardial energy metabolism. The aim of the present study was to characterise cardiovascular function and liver condition after long-term mildronate treatment in rats. In addition, changes in the plasma lipid profile, along with changes in the concentration of mildronate, l-carnitine and gamma-butyrobetaine were monitored in the rat tissues. Wistar rats were perorally treated daily with a mildronate dose of either 100, 200 or 400 mg/kg for 4, 8 or 12 weeks. The l-carnitine-lowering effect of mildronate was dose-dependent. However, the carnitine levels reached a plateau after about four weeks of treatment. During the additional weeks of treatment, the carnitine levels were not considerably changed. The obtained results provide evidence that even a high dose of mildronate does not alter cardiovascular parameters and the function of isolated rat hearts. Furthermore, the histological evaluation of liver tissue cryosections and measurement of biochemical markers of hepatic toxicity showed that all the measured values were within the normal reference range. Our results provide evidence that long-term mildronate administration induces significant changes in carnitine homeostasis, but it is not associated with cardiac impairment or disturbances in liver function.

High-throughput assay for small molecules that modulate zebrafish embryonic heart rate.

To increase the facility and throughput of scoring phenotypic traits in embryonic zebrafish, we developed an automated micro-well assay for heart rate using automated fluorescence microscopy of transgenic embryos expressing green fluorescent protein in myocardium. The assay measures heart rates efficiently and accurately over a large linear dynamic range, and it rapidly characterizes dose dependence and kinetics of small molecule-induced changes in heart rate. This is the first high-throughput micro-well assay for organ function in an intact vertebrate.

Cardiovascular effects of the South American medicinal plant Cecropia pachystachya (ambay) on rats.

Cecropia pachystachya is used in South America for relieving cough and asthma. In Argentina it is known as "ambay" and grows in the neotropical forests (Ntr C.p.) and in temperate hilly regions (Tp C.p.). To evaluate their cardiovascular profile, the effect of extracts obtained from plants growing in the neotropical region as well as in temperate areas were compared by i.v. administration in normotensive rats. The following parameters were measured: blood pressure (BP) and heart rate (HR). The hypotensive effect was stronger for Ntr C.p., which aqueous extract decreased BP at doses between 90 and 300 mg lyophilised/kg until 46.2 +/- 12% of basal. The extract of Tp C.p. reduced BP to 86.1 +/- 11% of basal (p < 0.05 respect to Ntr C.p.) at 180 mg/kg, but increased HR at 90 and 180 mg/kg (until 133.6 +/- 10.8% of basal, p < 0.05) and produced death by respiratory paralysis at 320 mg/kg (about 3g dry leaves/kg). The hypotensive effects, but not the chronotropic ones, were attenuated by pretreatment with reserpine (5 mg/kg). The plant extracts had not diuretic activity by oral administration in conscious rats, nor produced vasodilation of perfused hindquarters arterial bed precontracted with high-[K] or 100 microM phenylephrine. The results suggest that neotropical ambay is more hypotensive than the one from the temperate hilly region. When it reaches plasma, it could produce hypotension (by central blockade of sympathic innervation of vessels) and tachycardia (by central cholinergic inhibition of heart), although it happens at doses higher than the oral ethnotherapeutic (about 340 mg dried leaves/kg).

[The neurotropic and cardiotropic properties of new amino acid derivatives of isonicotinic acid]. / Neirotropnye i kardiotropnye svoistva nekotorykh novykh aminokislotnykh proizvodnykh izonikotinovoi kisloty.

Different derivatives of isonicotinic acid are used widely enough as antimicrobial and antituberculous agents. However, their neurotropic and cardiotropic effects have been studied little. The paper is concerned with investigations of these types of the activity of the new derivatives of isonicotinic acid: beta-phenyl-beta-alanine, l-proline, DL-valine, beta-alanine and DL-threonine synthesized for the first time at the Institute of Fine Organic Chemistry, Academy of Sciences of Armenia.