Current perspectives and trend of computer-aided drug design: a review and bibliometric analysis.

AIM: Computer-aided drug design (CADD) is a drug design technique for computing ligand-receptor interactions and is involved in various stages of drug development. To better grasp the frontiers and hotspots of CADD, we conducted a review analysis through bibliometrics. METHODS: A systematic review of studies published between 2000 and 20 July 2023 was conducted following the PRISMA guidelines. Literature on CADD was selected from the Web of Science Core Collection. General information, publications, output trends, countries/regions, institutions, journals, keywords, and influential authors were visually analyzed using software such as Excel, VOSviewer, RStudio, and CiteSpace. RESULTS: A total of 2031 publications were included. These publications primarily originated from 99 countries or regions led by the U.S. and China. Among the contributors, MacKerell AD had the highest number of articles and the greatest influence. The Journal of Medicinal Chemistry was the most cited journal, whereas the Journal of Chemical Information and Modeling had the highest number of publications. CONCLUSIONS: Influential authors in the field were identified. Current research shows active collaboration between countries, institutions, and companies. CADD technologies such as homology modeling, pharmacophore modeling, quantitative conformational relationships, molecular docking, molecular dynamics simulation, binding free energy prediction, and high-throughput virtual screening can effectively improve the efficiency of new drug discovery. Artificial intelligence-assisted drug design and screening based on CADD represent key topics that will influence future development. Furthermore, this paper will be helpful in better understanding the frontiers and hotspots of CADD.

Dissection of scientific compatibility of Chinese medicinal formula Realgar-Indigo naturalis as an effective treatment for promyelocytic leukemia from the perspective of toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Realgar-Indigo naturalis formula (RIF), a first-line drug for the treatment of acute promyelocytic leukemia (APL),is also a TCM formula entirely designed based on TCM theories. There have been studies that explain the scientific connotation of the compatibility of RIF from the perspective of pharmacodynamics. However, as one of the arsenic-containing preparations, the safety of realgar is widely concerned, and there has not been systematic studies to explain the scientific connotation of RIF from the perspective of toxicology. AIM OF THIS STUDY: Dissection of scientific compatibility of Chinese medicinal formula Realgar-Indigo naturalis as an effective treatment for promyelocytic leukemia from the perspective of toxicology. MATERIALS AND METHODS: We used normal mice and an APL model to explore (i) the effects of different components on intestinal permeability, (ii) the changes in intestinal flora, and (iii) toxic effects. At the same time, a bionic extraction method was used to study the effects of different components on the dissolution of soluble arsenic in realgar under the acidic environment in the stomach and the alkaline environment in the intestinal tract. RESULTS: Salvia miltiorrhiza Bunge can repair the intestinal mucosal barrier, maintain the homeostasis of intestinal flora, intervene in the dissolution process of realgar, reverse the increase in intestinal permeability and the disturbance of intestinal flora caused by realgar, and reduce toxicity. CONCLUSION: From the perspective of toxicology, we propose new insights into the definition of the roles of each component in the RIF formula, namely realgar is the monarch, Indigo naturalis is the minister, Salvia miltiorrhiza Bungeis the assistant.

From cis-Lobeline to trans-Lobeline: Study on the Pharmacodynamics and Isomerization Factors.

Lobeline is an alkaloid derived from the leaves of an Indian tobacco plant (Lobelia inflata), which has been prepared by chemical synthesis. It is classified as a partial nicotinic agonist and has a long history of therapeutic usage ranging from emetic and respiratory stimulant to tobacco smoking cessation agent. The presence of both cis and trans isomers in lobeline is well known, and many studies on the relationship between the structure and pharmacological activity of lobeline and its analogs have been reported. However, it is a remarkable fact that no studies have reported the differences in pharmacological activities between the two isomers. In this article, we found that different degrees of isomerization of lobeline injection have significant differences in respiratory excitatory effects in pentobarbital sodium anesthetized rats. Compared with cis-lobeline injections, the respiratory excitatory effect was significantly reduced by 50.2% after administration of injections which contained 36.9% trans-lobeline. The study on the influencing factors of isomerization between two isomers shown that this isomerization was a one-way isomerism and only converted from cis to trans, where temperature was the catalytic factor and pH was the key factor. This study reports a new discovery. Despite the widespread use of ventilators, first-aid medicines such as nikethamide and lobeline has retired to second line, but as a nonselective antagonist with high affinity for a4b2 and a3b2 nicotinic acetylcholine receptors (nAChRs). In recent years, lobeline has shown great promise as a therapeutic drug for mental addiction and nervous system disorders, such as depression, Alzheimer disease and Parkinson disease. Therefore, we suggest that the differences between two isomers should be concerned in subsequent research papers and applications.

Single-cell transcriptomics profiling the compatibility mechanism of As2O3-indigo naturalis formula based on bone marrow stroma cells.

Compound realgar natural indigo tablet is the only oral arsenic agent widely used in acute promyelocytic leukemia (APL) treatment. However, as a therapeutic drug for diseases of the blood system, the scientific knowledge of As2O3-indigo naturalis formula compatibility has not been studied in bone marrow stromal cells (BMSCs). We chose arsenic trioxide (As2O3: A), tanshinone IIA (T) and indirubin (I) as representative active compounds of realgar, indigo naturalis, and Salvia miltiorrhiza, respectively, to evaluated the pharmaceutical mechanism and the compatibility of ATI (drug combination) using single-cell RNA sequencing (scRNA-seq). The overlapped genes associated with both disease and drug were selected in BMSCs for in-depth analysis. Results show that joint applications of ATI had the strongest therapeutic efficacy in a murine APL model. Lepr-MSCs, OLCs and BMECs were the sensitive cell groups targeted by ATI in the murine APL model. ATI could regulate the related genes of osteogenic differentiation, adipogenic differentiation, and endothelial cell migration in bone marrow mesenchymal lineage cells in murine APL model and improve normal hematopoiesis-related gene expression and poor prognosis of Lepr-MSCs, OLCs and BMECs in mice with leukemia according to scRNA-seq data. The strongest regulatory effects were found in the joint applications of ATI. ATI combination had the potential mechanism to maintain the stability of the hematopoietic microenvironment and promote hematopoiesis to assist in the treatment of APL. This study illustrated the potential mechanism of ATI in regulating BMSCs from the overall perspective of the hematopoietic microenvironment, and broadened the scientific understanding of ATI compatibility in BMSCs.

Study on the mechanism of reducing biofilm toxicity and increasing antioxidant activity in vinegar processing phytomedicines containing pentacyclic triterpenoid saponins.

ETHNOPHARMACOLOGICAL RELEVANCE: Pentacyclic triterpenoid saponin (PTS) is a kind of particular chemicals with various pharmacological activities, as well as surface activity, mucosal irritation and hemolysis. PTS is closely related to the exertion of efficacy or adverse reactions in plant medicines rich in this component. For the better clinical application of natural resources, how to reduce toxicity and enhance curative efficacy is an important problem which needs to be solved at present. Till now, there has been few studies directly investigating the problem. AIM OF STUDY: Through comparison study of Radix Bupleuri (Chai hu) and Pulsatilla chinensis (Bai tou weng), which are typical traditional Chinese medicines containing PTS, explore the potential change rule of material basis and the mechanism of detoxification and synergistic effect of vinegar processing. MATERIALS AND METHODS: Composition change rule after vinegar processing was applied by UPLC-QTOF-MS/MS coupled with principal component analysis (PCA). Based on our previous research, this paper expounded the action mechanism from the perspective of reducing biofilm toxicity and increasing antioxidant activity. Direct toxicity reducing information was obtained at the cellular level including cellular morphology, MTT assays, western blots and RT-PCR in L02 cells with overload sphingomyelin (SM). The synergistic effect was investigated through histological examinations, mesenteric hemorheology, ELISA, flow cytometry and confocal microscopy. RESULTS: It was found that the structure of PTS take place a series of chemical reactions in the process of vinegar processing which enabled the more toxic components transformed into less toxic components and components with clear efficacy, so as to achieve the purpose of detoxification and synergistic effect. The results indicated that the mechanism of detoxification in vinegar processing was that vinegar processing could act on SM, cause less balance disturbance to sphingomyelin/ceramide (SM/Cer), inhibit apoptosis and then alleviate toxicity. In addition, the pharmacodynamic results showed that the vinegar processing could have an obvious synergistic effect through anti-oxidant stress. CONCLUSIONS: By changing the structures of the PTS, the SM/Cer disrupt was reduced and the antioxidant activity was enhanced, so as to decrease toxicity and increase efficiency in vinegar processing phytomedicines containing PTS.

Aconitine attenuates mitochondrial dysfunction of cardiomyocytes via promoting deacetylation of cyclophilin-D mediated by sirtuin-3.

ETHNOPHARMACOLOGICAL RELEVANCE: Aconite is a processed product of seminal root of perennial herbaceous plant Aconitum Carmichaclii Debx. of Ranunculaceae. It has the effects of warming and tonifying heart yang and restoring yang to save from collapse. Aconitine is the main effective constituent of aconite and used to prevent and treat heart disease. However, how aconitine exerts myocardial protection is still poorly understood. AIM OF THE STUDY: The present study aimed to investigate the effects of aconitine on mitochondrial dysfunction and explore its mechanism of action. MATERIALS AND METHODS: The model of myocardial injury was induced by Angiotensin II (Ang II) (1 × 10-6 mol L-1), and H9c2 cells were incubated with different concentrations of aconitine. The effect of aconitine on mitochondrial was determined by flow cytometry, transmission electron microscopy, luciferase, Seahorse technique and Western blot. The effects of aconitine on sirtuin-3 (Sirt3) activity and Cyclophilin D (CypD) acetylation were detected by immunofluorescence, RT-PCR and co-immunoprecipitation. RESULTS: We demonstrate that aconitine alleviates the energy metabolic dysfunction of H9c2 cells by activating Sirt3 to deacetylate CypD and inhibiting mitochondrial permeability transition pore (mPTP) opening. In cardiomyocytes, aconitine significantly reduced mitochondrial fragmentation, inhibited acetylation of CypD, suppressed the mPTP opening, mitigated mitochondrial OXPHOS disorders, and improved the synthesis ability of ATP. In contrast, Sirt3 deficiency abolished the effects of aconitine on mPTP and OXPHOS, indicating that aconitine improves mitochondrial function by activating Sirt3. CONCLUSIONS: These results showed that aconitine attenuated the energy metabolism disorder by promoting Sirt3 expression and reducing CypD-mediated mPTP excess openness, rescuing mitochondrial function. Improve mitochondrial function may be a therapeutic approach for treating heart disease, which will generate fresh insight into the cardioprotective of aconitine.

Global metabolomic and lipidomic analysis reveals the potential mechanisms of hemolysis effect of Ophiopogonin D and Ophiopogonin D' in vivo.

BACKGROUND: OPD and OPD' are the two main active components of Ophiopogon japonicas in Shenmai injection (SMI). Being isomers of each other, they are supposed to have similar pharmacological activities, but the actual situation is complicated. The difference of hemolytic behavior between OPD and OPD' in vivo and in vitro was discovered and reported by our group for the first time. In vitro, only OPD' showed hemolysis reaction, while in vivo, both OPD and OPD' caused hemolysis. In vitro, the primary cause of hemolysis has been confirmed to be related to the difference between physical and chemical properties of OPD and OPD'. In vivo, although there is a possible explanation for this phenomenon, the one is that OPD is bio-transformed into OPD' or its analogues in vivo, the other one is that both OPD and OPD' were metabolized into more activated forms for hemolysis. However, the mechanism of hemolysis in vivo is still unclear, especially the existing literature are still difficult to explain why OPD shows the inconsistent hemolysis behavior in vivo and in vitro. Therefore, the study of hemolysis of OPD and OPD' in vivo is of great practical significance in response to the increase of adverse events of SMI. METHODS: Aiming at the hemolysis in vivo, this manuscript adopted untargeted metabolomics and lipidomics technology to preliminarily explore the changes of plasma metabolites and lipids of OPD- and OPD'-treated rats. Metabolomics and lipidomics analyses were performed on ultra-high performance liquid chromatography (UPLC) system tandem with different mass spectrometers (MS) and different columns respectively. Multivariate statistical approaches such as principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) were applied to screen the differential metabolites and lipids. RESULTS: Both OPD and OPD' groups experienced hemolysis, Changes in endogenous differential metabolites and differential lipids, enrichment of differential metabolic pathways, and correlation analysis of differential metabolites and lipids all indicated that the causes of hemolysis by OPD and OPD' were closely related to the interference of phospholipid metabolism. CONCLUSIONS: This study provided a comprehensive description of metabolomics and lipidomics changes between OPD- and OPD'-treated rats, it would add to the knowledge base of the field, which also provided scientific guidance for the subsequent mechanism research. However, the underlying mechanism require further research.

Sharing and Helping: Regularity and Characteristics of Pathogenesis of a Widely Used Transgene Initiated Murine Acute Promyelocytic Leukemia Model.

A transgenic acute promyelocytic leukemia (APL) murine model established by Michael Bishop by cloning a human PML-RARα cDNA into the hMRP8 expression cassette has been widely used in the all-trans retinoid acid and arsenic preparations for the research of APL. However, in the existing literature, the data of regularity and characteristics of the pathogenesis of this model were still missing, which hinder the development of many studies, especially application of new technologies such as single-cell sequencing. Therefore, in this article, we have made up this part of the missing data using an improved APL murine model. We clarified the effects of different inoculation doses on the onset time, latency, morbidity, life span, and proportion of APL cells in peripheral blood (PB), spleen, bone marrow, and so on. The relationship between the proportion of APL cells in the bone marrow, spleen, and PB and organ histological changes was also revealed. These results were a supplement and refinement of this APL model. It would add to the knowledge base of the field and aid in ensuring that accurate models are used for directed interventions. It also provides a great convenience for the researchers who will carry out similar research.

Differences in the Hemolytic Behavior of Two Isomers in Ophiopogon japonicus In Vitro and In Vivo and Their Risk Warnings.

Ophiopogonin D (OPD) and Ophiopogonin D' (OPD') are two bioactive ingredients in Ophiopogon japonicus. Previously published studies have often focused on the therapeutic effects related to OPD's antioxidant capacity but underestimated the cytotoxicity-related side effects of OPD', which may result in unpredictable risks. In this study, we reported another side effect of OPD', hemolysis, and what was unexpected was that this side effect also appeared with OPD. Although hemolysis effects for saponins are familiar to researchers, the hemolytic behavior of OPD or OPD' and the interactions between these two isomers are unique. Therefore, we investigated the effects of OPD and OPD' alone or in combination on the hemolytic behavior in vitro and in vivo and adopted chemical compatibility and proteomics methods to explain the potential mechanism. Meanwhile, to explain the drug-drug interactions (DDIs), molecular modeling was applied to explore the possible common targets. In this study, we reported that OPD' caused hemolysis both in vitro and in vivo, while OPD only caused hemolysis in vivo. We clarified the differences and DDIs in the hemolytic behavior of the two isomers. An analysis of the underlying mechanism governing this phenomenon showed that hemolysis caused by OPD or OPD' was related to the destruction of the redox balance of erythrocytes. In vivo, in addition to the redox imbalance, the proteomics data demonstrated that lipid metabolic disorders and mitochondrial energy metabolism are extensively involved by hemolysis. We provided a comprehensive description of the hemolysis of two isomers in Ophiopogon japonicus, and risk warnings related to hemolysis were presented. Our research also provided a positive reference for the development and further research of such bioactive components.

[Preliminary study of Realgar and arsenic trioxide on gut microbiota of mice].

The aim of this paper was to observe the effect of Realgar and arsenic trioxide on gut microbiota. The mice were divided into low-dose Realgar group(RL), medium-dose Realgar group(RM), high-dose Realgar group(RH), and arsenic trioxide group(ATO), in which ATO and RL groups had the same trivalent arsenic content. Realgar and arsenic trioxide toxicity models were established after intragastric administration for 1 week, and mice feces were collected 1 h after intragastric administration on day 8. The effects of Realgar on gut microbiota of mice were observed through bacterial 16 S rRNA gene sequences. The results showed that Lactobacillus was decreased in all groups, while Ruminococcus and Adlercreutzia were increased. The RL group and ATO group were consistent in the genera of Prevotella, Ruminococcus, and Adlercreutzia but different in the genera of Lactobacillus and Bacteroides. Therefore, the effects of Realgar and arsenic trioxide with the same amount of trivalent arsenic on gut microbiota were similar, but differences were still present. Protective bacteria such as Lactobacillus were reduced after Realgar administration, causing inflammation. At low doses, the number of anti-inflammatory bacteria, such as Ruminococcus, Adlercreutzia and Parabacteroides increased, which can offset the slight inflammation caused by the imbalance of bacterial flora. At high doses, the flora was disturbed and the number of Proteobacteria was increased, with aggravated intestinal inflammation, causing edema and other inflammatory reactions. Based on this, authors believe that the gastrointestinal reactions after clinical use of Realgar may be related to flora disorder. Realgar should be used at a small dose in combination with other drugs to reduce intestinal inflammation.

Panax ginseng Inhibits Metabolism of Diester Alkaloids by Downregulating CYP3A4 Enzyme Activity via the Pregnane X Receptor.

To investigate the effects of P. ginseng C.A. Mey (P. ginseng) on the metabolism of diester alkaloids and explore the potential mechanism. P. ginseng was administered orally to rats for 7 days, after which liver microsome samples were prepared and then incubated with diester alkaloids. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to determinate the concentration of diester alkaloids to calculate the clearance rate. The cocktail method was used to evaluate the effects of oral administration of P. ginseng extracts on the activities of cytochrome P450 (CYP) isoforms in rats through the changes in the pharmacokinetic parameters of the probe drugs. The protein and gene expression of CYP3A2 and pregnane X receptor (PXR) in rats were evaluated by western blotting and quantitative PCR. The specific enzyme inhibitor method and human recombinant enzyme method were used to identify the involvement of sub-CYPs in the metabolism of diester alkaloids in human liver microsomes (HLMs). The clearances of aconitine, mesaconitine, and hypaconitine in the P. ginseng groups were lower than those of the control group. The areas under the curve of midazolam were 2.37 ± 1.05, 4.96 ± 0.51, and 6.23 ± 1.30 mg·L-1·h for the low-, medium-, and high-dose P. ginseng groups, respectively, which were higher than that of the control (2.23 ± 0.64 mg·L-1·h). The clearances of midazolam for the medium- (1.87 ± 0.16 L·h-1·kg-1) and high-dose (1.60 ± 0.34 L·h-1·kg-1) P. ginseng groups were lower than that of the control group (4.66 ± 1.43 L·h-1·kg-1). After exposure to P. ginseng extracts, the gene and protein expression levels of CYP3A4 and PXR were decreased. The hepatic metabolism rates of aconitine, mesaconitine, and hypaconitine in HLMs were decreased to 60.37%, 21.67%, and 10.11%, respectively, when incubated with ketoconazole, a specific inhibitor for CYP3A. The kinetic plots indicated that the KM and V max values of CYP3A4 were 10.08 ± 3.26 µM and 0.12 ± 0.01nmol·mg protein-1·min-1 for aconitine, 131.3 ± 99.75 µM and 0.73 ± 0.44 nmol·mg protein-1·min-1 for mesaconitine, and 17.05 ± 9.70 µM and 0.16 ± 0.04 nmol·mg protein-1·min-1 for hypaconitine, respectively. The in vitro mean intrinsic clearance rates by CYP3A4 were 0.0119, 0.0056, and 0.0091 mL·nmol CYP-1·min-1 for aconitine, mesaconitine, and hypaconitine, respectively. Therefore we implied that P. ginseng inhibited the metabolism of diester alkaloids in vitro and decreased the CYP3A4 enzyme activity as well as the gene and protein expression of CYP3A4 and PXR in vivo. CYP3A4 had a larger effect on diester alkaloid metabolism than the other human CYP isoforms, CYP1A2, CYP2C9, and CYP2E1.

The Effect of Ultrasound, Oxygen and Sunlight on the Stability of (-)-Epigallocatechin Gallate.

(-)-Epigallocatechin gallate (EGCG), is the main catechin found in green tea, and has several beneficial effects. This study investigated the stability of EGCG aqueous solution under different stored and ultrasonic conditions to determine whether it can be used with an ultrasonic dental scaler to treat periodontal infection. Four concentrations (0.05, 0.1, 0.15, 2 mg/mL) of EGCG aqueous solution were prepared and stored under four different conditions (A: Exposed to neither sunlight nor air, B: Exposed to sunlight, but not air, C: Not exposed to sunlight, but air, D: Exposed to sunlight and air) for two days. The degradation rate of EGCG was measured by high performance liquid chromatography (HPLC). On the other hand, an ultrasonic dental scaler was used to atomize the EGCG solution under four different conditions (a: Exposed to neither air nor sunlight, b: Not exposed to air, but sunlight, c: Not exposed to sunlight, but air, d: Exposed to air and sunlight), the degradation of EGCG was measured by HPLC. We found that the stability of EGCG was concentration-dependent in water at room temperature. Both sunlight and oxygen influenced the stability of EGCG, and oxygen had a more pronounced effect on stability of EGCG than sunlight. The most important conclusion was that the ultrasound may accelerate the degradation of EGCG due to the presence of oxygen and sunlight, but not because of the ultrasonic vibration. Thus, EGCG aqueous solution has the potential to be used through an ultrasonic dental scaler to treat periodontal infection in the future.

Aptamer-drug conjugate: targeted delivery of doxorubicin in a HER3 aptamer-functionalized liposomal delivery system reduces cardiotoxicity.

INTRODUCTION: The toxic side effects of doxorubicin (DOX) have limited its use in chemotherapy. Neither liposomal DOX nor pegylated liposomal DOX are able to completely resolve this issue. This is a proof-of-concept study testing aptamer-drug conjugate (ApDC) targeted delivery systems for chemotherapeutic drugs. METHODS: Aptamer library targeting human epidermal growth factor receptor 3 (HER3) was screened and affinity was determined by enzyme-linked immunosorbent assay. Specificity was tested in MCF-7HER3-high, BT474HER3-high, and 293THER3-negative cells using flow cytometry and confocal microscopy. We further developed a HER3 aptamer-functionalized liposome encapsulating DOX and the efficiency of this ApDC was detected by cellular uptake analysis and cell viability assay. In MCF-7 tumor-bearing mice, tumor targeting evaluation, efficacy, toxicity and preliminary pharmocokinetic study was performed. RESULTS: The candidate #13 aptamer had highest affinity (Kd =98±9.7 nM) and specificity. ApDC effectively reduces the half maximal inhibitory concentration of DOX compared with lipsome-DOX and free DOX. In vivo imaging and preliminary distribution studies showed that actively targeted nanoparticles, such as Apt-Lip-DOX molecules, could facilitate the delivery of DOX into tumors in MCF-7-bearing mice. This targeted chemotherapy caused greater tumor suppression than other groups and alleviated side effects such as weight loss, low survival rate, and organ (heart and liver) injury demonstrated by H&E staining. CONCLUSION: The results indicate that targeted chemotherapy using the aptamer-drug conjugate format could provide better tolerability and efficacy compared with non-targeted delivery in relatively low-dose toxic drugs.

[Effect of clinical doses of Realgar-Indigo Naturalis formula and large-dose of realgar on CYP450s of rat liver].

To investigate the effect of clinical dose of Realgar-Indigo Naturais formula (RIF) and large-dose of Realgar on main drug-metabolizing enzymes CYP450s of rat liver, as well as its regulatory effect on mRNA expression. Wistar rats were administrated orally with tested drugs for 14 days. A Cocktail method combined with HPLC-MS/MS was used in the determination of 4 cytochrome P450 isozymes (CYP1A2, CYP2B, CYP3A and CYP2C) in liver of the rats, and the mRNA expression levels of the above subtypes were detected by real-time fluorescent quantitative PCR. The results showed that RIF can significantly induce CYP1A2 and CYP2B enzyme activity, and inhibit CYP3A enzyme activity. This result was consistent with the mRNA expression. However, its single compound showed weaker or even contrary phenomenon. Different doses of Realgar also showed significant inconsistencies on CYP450 enzymes activity and mRNA expression. These phenomena may be relevant with RIF compatibility synergies or toxicity reduction. The results can also prompt drug interactions when RIF is combined with other medicines in application.

Influences of Realgar-Indigo naturalis, A Traditional Chinese Medicine Formula, on the Main CYP450 Activities in Rats Using a Cocktail Method.

The purpose of this work was to study the influences of Realgar-Indigo naturalis (RIF) and its principal element realgar on 4 main cytochrome P450 enzymes activities in rats. A simple and efficient cocktail method was developed to detect the four probe drugs simultaneously. In this study, Wistar rats were administered intragastric RIF and realgar for 14 days; mixed probe drugs were injected into rats by caudal vein. Through analyzing the pharmacokinetic parameter of mixed probe drugs in rats, we can calculate the CYPs activities. The results showed that RIF could inhibit CYP1A2 enzyme activity and induce CYP2C11 enzyme activity significantly. Interestingly, in realgar high dosage group, CYP3A1/2 enzyme activity was inhibited significantly, and different dosage of realgar manifested a good dose-dependent manner. The RIF results indicated that drug coadministrated with RIF may need to be paid attention in relation to drug-drug interactions (DDIs). Realgar, a toxic traditional Chinese medicine (TCM), does have curative effect on acute promyelocytic leukemia (APL). Its toxicity studies should be focused on. We found that, in realgar high dosage group, CYP3A1/2 enzymes activity was inhibited. This phenomenon may explain its potential toxicity mechanism.

[Quality of realgar and its influencing factors based on toxicity].

The results of a toxicity analysis showed differences from those of the existing experimental data. Therefore, HPLC-ICP-MS was used to analyze the soluble arsenic content at different valences in realgar prepared with water grind processing, which were collected from 3 companies. The results showed that the free arsenic of the 3 companies did not exceed the limit of Chinese Pharmacopoeia. However, if the free arsenic was calculated based on the total value of As(Ⅲ) + As(Ⅴ), free arsenic of 1 company exceeded the limit of Chinese Pharmacopoeia. The method of determining free arsenic in Chinese Pharmacopoeia. was ancient Cai's arsenic detection method, which had a certain limitation and failed to effectively avoid the toxicity of remaining arsenics except for trivalent arsenic. Then, we examined the effects of water and temperature on the content and form of soluble arsenic in realgar. The results showed that the content of soluble arsenic increased with the rise of water content, and the form of soluble arsenic did not change, there were only As (Ⅲ) and As (Ⅴ); With the simple temperature factor, there was an increasing trend in the content of soluble arsenic in the samples, the maximum increment was As (Ⅲ) 2.489 mg•g⁻¹ and As (Ⅴ) 0.546 mg•g⁻¹; When water and temperature played an synergistic effect, the increase of soluble arsenic in the samples significantly changed, the maximum increment was As (Ⅲ) 23.690 mg•g⁻¹, As (Ⅴ) 0.468 mg•g⁻¹, respectively. Through comprehensive analysis, we believed that the quality of realgar was susceptible to water content and temperature. Both of the single effect of water content and the synergistic effect of water and temperature can significantly change the content of soluble arsenic in realgar, and the water content was a high-risk factor. In the current Chinese Pharmacopoeia 2015 version, the free arsenic detection method had limitations, hence new techniques shall be introduced; At the same time, realgar does not have a water content inspection item in the current pharmacopoeia, which shall be added. However, due to the limit of water content, more in-depth studies are required.