Cytotoxicity of 34 FDA approved small-molecule kinase inhibitors in primary rat and human hepatocytes

Hepatic Bile Acid Transporters and Drug-induced Hepatotoxicity

Drug-induced liver injury (DILI) remains a major concern in drug development from a patient safety perspective because it is the leading cause of acute liver failure. One mechanism of DILI is altered bile acid homeostasis and involves several hepatic bile acid transporters. Functional impairment of some hepatic bile acid transporters by drugs, disease, or genetic mutations may lead to toxic accumulation of bile acids within hepatocytes and increase DILI susceptibility. This review focuses on the role of hepatic bile acid transporters in DILI. Model systems, primarily in vitro and modeling tools, such as DILIsym, used in assessing transporter-mediated DILI are discussed. Due to species differences in bile acid homeostasis and drug-transporter interactions, key aspects and challenges associated with the use of preclinical animal models for DILI assessment are emphasized. Learnings are highlighted from three case studies of hepatotoxic drugs: troglitazone, tolvaptan, and tyrosine kinase inhibitors (dasatinib, pazopanib, and sorafenib). The development of advanced in vitro models and novel biomarkers that can reliably predict DILI is critical and remains an important focus of ongoing investigations to minimize patient risk for liver-related adverse reactions associated with medication use.

The role of cytochrome P450 3A4-mediated metabolism in sorafenib and lapatinib hepatotoxicity

Tyrosine kinase inhibitors (TKIs) are increasingly popular drugs used to treat more than a dozen different diseases, including some forms of cancer. Despite having fewer adverse effects than traditional chemotherapies, they are not without risks. Liver injury is a particular concern. Of the FDA-approved TKIs, approximately 40% cause hepatotoxicity. However, little is known about the underlying pathophysiology. The leading hypothesis is that TKIs are converted by cytochrome P450 3A4 (CYP3A4) to reactive metabolites that damage proteins. Indeed, there is strong evidence for this bioactivation of TKIs in in vitro reactions. However, the actual toxic effects are underexplored. Here, we measured the cytotoxicity of several TKIs in primary mouse hepatocytes, HepaRG cells, and HepG2 cells with and without CYP3A4 modulation. To our surprise, the data indicate that CYP3A4 increases resistance to sorafenib and lapatinib hepatotoxicity. The results have implications for the mechanism of toxicity of these drugs in patients and underline the importance of selecting an appropriate experimental model.

Adverse Toxic Effects of Tyrosine Kinase Inhibitors on Non-Target Zebrafish Liver (ZFL) Cells

Over the past 20 years, numerous tyrosine kinase inhibitors (TKIs) have been introduced for targeted therapy of various types of malignancies. Due to frequent and increasing use, leading to eventual excretion with body fluids, their residues have been found in hospital and household wastewaters as well as surface water. However, the effects of TKI residues in the environment on aquatic organisms are poorly described. In the present study, we investigated the cytotoxic and genotoxic effects of five selected TKIs, namely erlotinib (ERL), dasatinib (DAS), nilotinib (NIL), regorafenib (REG), and sorafenib (SOR), using the in vitro zebrafish liver cell (ZFL) model. Cytotoxicity was determined using the MTS assay and propidium iodide (PI) live/dead staining by flow cytometry. DAS, SOR, and REG decreased ZFL cell viability dose- and time-dependently, with DAS being the most cytotoxic TKI studied. ERL and NIL did not affect viability at concentrations up to their maximum solubility; however, NIL was the only TKI that significantly decreased the proportion of PI negative cells as determined by the flow cytometry. Cell cycle progression analyses showed that DAS, ERL, REG, and SOR caused the cell cycle arrest of ZFL cells in the G0/G1 phase, with a concomitant decrease of cells in the S-phase fraction. No data could be obtained for NIL due to severe DNA fragmentation. The genotoxic activity of the investigated TKIs was evaluated using comet and cytokinesis block micronucleus (CBMN) assays. The dose-dependent induction of DNA single strand breaks was induced by NIL (≥2 μM), DAS (≥0.006 μM), and REG (≥0.8 μM), with DAS being the most potent. None of the TKIs studied induced micronuclei formation. These results suggest that normal non-target fish liver cells are sensitive to the TKIs studied in a concentration range similar to those previously reported for human cancer cell lines. Although the TKI concentrations that induced adverse effects in exposed ZFL cells are several orders of magnitude higher than those currently expected in the aquatic environment, the observed DNA damage and cell cycle effects suggest that residues of TKIs in the environment may pose a hazard to non-intentionally exposed organisms living in environments contaminated with TKIs.

Metabolic activation of tyrosine kinase inhibitors: recent advance and further clinical practice

At present, receptor tyrosine kinase signaling-related pathways have been successfully mediated to inhibit tumor proliferation and promote anti-angiogenesis effects for cancer therapy. Tyrosine kinase inhibitors (TKIs), a group of novel chemotherapeutic agents, have been applied to treat diverse malignant tumors effectively. However, the latent toxic and side effects of TKIs, such as hepatotoxicity and cardiotoxicity, limit their use in clinical practice. Metabolic activation has the potential to lead to toxic effects. Numerous TKIs have been demonstrated to be transformed into chemically reactive/potentially toxic metabolites following cytochrome P450-catalyzed activation, which causes severe adverse reactions, including hepatotoxicity, cardiotoxicity, skin toxicity, immune injury, mitochondria injury, and cytochrome P450 inactivation. However, the precise mechanisms of how these chemically reactive/potentially toxic species induce toxicity remain poorly understood. In addition, we present our viewpoints that regulating the production of reactive metabolites may decrease the toxicity of TKIs. Exploring this topic will improve understanding of metabolic activation and its underlying mechanisms, promoting the rational use of TKIs. This review summarizes the updated evidence concerning the reactive metabolites of TKIs and the associated toxicities. This paper provides novel insight into the safe use of TKIs and the prevention and treatment of multiple TKIs adverse effects in clinical practice.

Sunitinib induced hepatotoxicity in L02 cells via ROS-MAPKs signaling pathway

Sunitinib is a multi-targeted tyrosine kinase inhibitor with remarkable anticancer activity, while hepatotoxicity is a potentially fatal adverse effect of its administration. The aim of this study was to elucidate the mechanism of hepatotoxicity induced by Sunitinib and the protective effect of glycyrrhetinic acid (GA). Sunitinib significantly reduced the survival of human normal hepatocytes (L02 cells), induced the increase of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH). Chloroquine (CQ) and Z-VAD-FMK were applied to clarify the cell death patterns induced by Sunitinib. Sunitinib significantly induced L02 cells death by triggering apoptosis and autophagy acted as a self-defense mechanism to promote survival. Sunitinib exposure caused excessive ROS generation which activated mitogen-activated protein kinases (MAPKs) signaling. Mechanistically, SP600125 (JNK inhibitor) and SB203580 (p38 inhibitor) respectively blocked apoptosis and autophagy induced by Sunitinib. And inhibition of ROS by NAC pretreatment ameliorated the effect of Sunitinib on MAPKs phosphorylation. GA alleviated Sunitinib-induced cell damage by inhibiting apoptosis and autophagy. These results suggested ROS/MAPKs signaling pathway was responsible for Sunitinib-induced hepatotoxicity and GA could be a preventive strategy to alleviate liver injury caused by Sunitinib.

Concept of Hybrid Drugs and Recent Advancements in Anticancer Hybrids

Cancer is a complex disease, and its treatment is a big challenge, with variable efficacy of conventional anticancer drugs. A two-drug cocktail hybrid approach is a potential strategy in recent drug discovery that involves the combination of two drug pharmacophores into a single molecule. The hybrid molecule acts through distinct modes of action on several targets at a given time with more efficacy and less susceptibility to resistance. Thus, there is a huge scope for using hybrid compounds to tackle the present difficulties in cancer medicine. Recent work has applied this technique to uncover some interesting molecules with substantial anticancer properties. In this study, we report data on numerous promising hybrid anti-proliferative/anti-tumor agents developed over the previous 10 years (2011–2021). It includes quinazoline, indole, carbazole, pyrimidine, quinoline, quinone, imidazole, selenium, platinum, hydroxamic acid, ferrocene, curcumin, triazole, benzimidazole, isatin, pyrrolo benzodiazepine (PBD), chalcone, coumarin, nitrogen mustard, pyrazole, and pyridine-based anticancer hybrids produced via molecular hybridization techniques. Overall, this review offers a clear indication of the potential benefits of merging pharmacophoric subunits from multiple different known chemical prototypes to produce more potent and precise hybrid compounds. This provides valuable knowledge for researchers working on complex diseases such as cancer.

Study on the Characteristics of Small-Molecule Kinase Inhibitors-Related Drug-Induced Liver Injury

Background and Aim: More than half of the small-molecule kinase inhibitors (KIs) induced liver injury clinically. Meanwhile, studies have shown a close relationship between mitochondrial damage and drug-induced liver injury (DILI). We aimed to study KIs and the binding between drugs and mitochondrial proteins to find factors related to DILI occurrence.

Methods: A total of 1,223 oral FDA-approved drugs were collected and analyzed, including 44 KIs. Fisher’s exact test was used to analyze DILI potential and risk of different factors. A total of 187 human mitochondrial proteins were further collected, and high-throughput molecular docking was performed between human mitochondrial proteins and drugs in the data set. The molecular dynamics simulation was used to optimize and evaluate the dynamic binding behavior of the selected mitochondrial protein/KI complexes.

Results: The possibility of KIs to produce DILI is much higher than that of other types (OR = 46.89, p = 9.28E-13). A few DILI risk factors were identified, including molecular weight (MW) between 400 and 600, the defined daily dose (DDD) ≥ 100 mg/day, the octanol–water partition coefficient (LogP) ≥ 3, and the degree of liver metabolism (LM) more than 50%. Drugs that met this combination of rules were found to have a higher DILI risk than controls (OR = 8.28, p = 4.82E-05) and were more likely to cause severe DILI (OR = 8.26, p = 5.06E-04). The docking results showed that KIs had a significant higher affinity with human mitochondrial proteins (p = 4.19E-11) than other drug types. Furthermore, the five proteins with the lowest docking score were selected for molecular dynamics simulation, and the smallest fluctuation of the backbone RMSD curve was found in the protein 5FS8/KI complexes, which indicated the best stability of the protein 5FS8 bound to KIs.

Conclusions: KIs were found to have the highest odds ratio of causing DILI. MW was significantly related to the production of DILI, and the average docking scores of KI drugs were found to be significantly different from other classes. Further analysis identified the top binding mitochondrial proteins for KIs, and specific binding sites were analyzed. The optimization of molecular docking results by molecular dynamics simulation may contribute to further studying the mechanism of DILI.

A Risk Scoring System Utilizing Machine Learning Methods for Hepatotoxicity Prediction One Year After the Initiation of Tyrosine Kinase Inhibitors

Background

There is currently no method to predict tyrosine kinase inhibitor (TKI) -induced hepatotoxicity. The purpose of this study was to propose a risk scoring system for hepatotoxicity induced within one year of TKI administration using machine learning methods.

Methods

This retrospective, multi-center study analyzed individual data of patients administered different types of TKIs (crizotinib, erlotinib, gefitinib, imatinib, and lapatinib) selected in five previous studies. The odds ratio and adjusted odds ratio from univariate and multivariate analyses were calculated using a chi-squared test and logistic regression model. Machine learning methods, including five-fold cross-validated multivariate logistic regression, elastic net, and random forest were utilized to predict risk factors for the occurrence of hepatotoxicity. A risk scoring system was developed from the multivariate and machine learning analyses.

Results

Data from 703 patients with grade II or higher hepatotoxicity within one year of TKI administration were evaluated. In a multivariable analysis, male and liver metastasis increased the risk of hepatotoxicity by 1.4-fold and 2.1-fold, respectively. The use of anticancer drugs increased the risk of hepatotoxicity by 6.0-fold. Patients administered H2 blockers or PPIs had a 1.5-fold increased risk of hepatotoxicity. The area under the receiver-operating curve (AUROC) values of machine learning methods ranged between 0.73-0.75. Based on multivariate and machine learning analyses, male (1 point), use of H2 blocker or PPI (1 point), presence of liver metastasis (2 points), and use of anticancer drugs (4 points) were integrated into the risk scoring system. From a training set, patients with 0, 1, 2-3, 4-7 point showed approximately 9.8%, 16.6%, 29.0% and 61.5% of risk of hepatotoxicity, respectively. The AUROC of the scoring system was 0.755 (95% CI, 0.706-0.804).

Conclusion

Our scoring system may be helpful for patient assessment and clinical decisions when administering TKIs included in this study.

An Insight on the Pathways Involved in Crizotinib and Sunitinib Induced Hepatotoxicity in HepG2 Cells and Animal Model

Both crizotinib and sunitinib, novel orally-active multikinase inhibitors, exhibit antitumor activity and extend the survival of patients with a malignant tumor. However, some patients may suffer liver injury that can further limit the clinical use of these drugs, however the mechanisms underlying hepatotoxicity are still to be elucidated. Thus, our study was designed to use HepG2 cells in vitro and the ICR mice model in vivo to investigate the mechanisms of hepatotoxicity induced by crizotinib and sunitinib. Male ICR mice were treated orally with crizotinib (70 mg/kg/day) or sunitinib (7.5 mg/kg/day) for four weeks. The results demonstrated that crizotinib and sunitinib caused cytotoxicity in HepG2 cells and chronic liver injury in mice, which were associated with oxidative stress, apoptosis and/or necrosis. Crizotinib- and sunitinib-induced oxidative stress was accompanied by increasing reactive oxygen species and malondialdehyde levels and decreasing the activity of superoxide dismutase and glutathione peroxidase. Notably, the activation of the Kelch-like ECH-associated protein-1/Nuclear factor erythroid-2 related factor 2 signaling pathway was involved in the process of oxidative stress, and partially protected against oxidative stress. Crizotinib and sunitinib induced apoptosis via the mitochondrial pathway, which was characterized by decreasing Bcl2/Bax ratio to dissipate the mitochondrial membrane potential, and increasing apoptotic markers levels. Moreover, the pan-caspase inhibitor Z-VAD-FMK improved the cell viability and alleviated liver damage, which further indicated the presence of apoptosis. Taken together, this study demonstrated that crizotinib- and sunitinib-caused oxidative stress and apoptosis finally impaired hepatic function, which was strongly supported by the histopathological lesions and markedly increased levels of serum alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase.

FOXO3 mutation predicting gefitinib-induced hepatotoxicity in NSCLC patients through regulation of autophagy

Hepatotoxicity is a common side effect for patients treated with gefitinib, but the related pathogenesis is unclear and lacks effective predictor and management strategies. A multi-omics approach integrating pharmacometabolomics, pharmacokinetics and pharmacogenomics was employed in non-small cell lung cancer patients to identify the effective predictor for gefitinib-induced hepatotoxicity and explore optional therapy substitution. Here, we found that patients with rs4946935 AA, located in Forkhead Box O3 (FOXO3) which is a well-known autophagic regulator, had a higher risk of hepatotoxicity than those with the GA or GG variant (OR = 18.020, 95%CI = 2.473 to 459.1784, P = 0.018) in a gefitinib-concentration dependent pattern. Furthermore, functional experiments identified that rs4946935_A impaired the expression of FOXO3 by inhibiting the promotor activity, increasing the threshold of autophagy initiation and inhibiting the autophagic activity which contributed to gefitinib-induced liver injury. In contrast, erlotinib-induced liver injury was independent on the variant and expression levels of FOXO3. This study reveals that FOXO3 mutation, leading to autophagic imbalance, plays important role in gefitinib-induced hepatotoxicity, especially for patients with high concentration of gefitinib. In conclusion, FOXO3 mutation is an effective predictor and erlotinib might be an appropriately and well-tolerated treatment option for patients carrying rs4946935 AA.

Have molecular hybrids delivered effective anti-cancer treatments and what should future drug discovery focus on?

INTRODUCTION

Cancer continues to be a big threat and its treatment is a huge challenge among the medical fraternity. Conventional anti-cancer agents are losing their efficiency which highlights the need to introduce new anti-cancer entities for treating this complex disease. A hybrid molecule has a tendency to act through varied modes of action on multiple targets at a given time. Thus, there is the significant scope with hybrid compounds to tackle the existing limitations of cancer chemotherapy.

AREA COVERED

This perspective describes the most significant hybrids that spring hope in the field of cancer chemotherapy. Several hybrids with anti-proliferative/anti-tumor properties currently approved or in clinical development are outlined, along with a description of their mechanism of action and identified drug targets.

EXPERT OPINION

The success of molecular hybridization in cancer chemotherapy is quite evident by the number of molecules entering into clinical trials and/or have entered the drug market over the past decade. Indeed, the recent advancements and co-ordinations in the interface between chemistry, biology, and pharmacology will help further the advancement of hybrid chemotherapeutics in the future.List of abbreviations: Deoxyribonucleic acid, DNA; national cancer institute, NCI; peripheral blood mononuclear cells, PBMC; food and drug administration, FDA; histone deacetylase, HDAC; epidermal growth factor receptor, EGFR; vascular endothelial growth factor receptor, VEGFR; suberoylanilide hydroxamic acid, SAHA; farnesyltransferase inhibitor, FTI; adenosine triphosphate, ATP; Tamoxifen, TAM; selective estrogen receptor modulator, SERM; structure activity relationship, SAR; estrogen receptor, ER; lethal dose, LD; half maximal growth inhibitory concentration, GI₅₀; half maximal inhibitory concentration, IC₅₀.

Hepatotoxicity of FDA-approved small molecule kinase inhibitors

Introduction: Given their importance in cellular processes and association with numerous diseases, protein kinases have emerged as promising targets for drugs. The FDA has approved greater than fifty small molecule kinase inhibitors (SMKIs) since 2001. Nevertheless, severe hepatotoxicity and related fatal cases have grown as a potential challenge in the advancement of these drugs, and the identification and diagnosis of drug-induced liver injury (DILI) are thorny problems for clinicians.Areas covered: This article summarizes the progression and analyzes the significant features in the study of SMKI hepatotoxicity, including clinical observations and investigations of the underlying mechanisms.Expert opinion: The understanding of SMKI-associated hepatotoxicity relies on the development of preclinical models and improvement of clinical assessment. With a full understanding of the role of inflammation in DILI and the mediating role of cytokines in inflammation, cytokines are promising candidates as sensitive and specific biomarkers for DILI. The emergence of three-dimensional spheroid models demonstrates potential use in providing clinically relevant data and predicting hepatotoxicity of SMKIs.

Hepatic Transcript Profiles of Cytochrome P450 Genes Predict Sex Differences in Drug Metabolism

Safety assessments of new drug candidates are an important part of the drug development and approval process. Often, possible sex-associated susceptibilities are not adequately addressed, and better assessment tools are needed. We hypothesized that hepatic transcript profiles of cytochrome P450 (P450) enzymes can be used to predict sex-associated differences in drug metabolism and possible adverse events. Comprehensive hepatic transcript profiles were generated for F344 rats of both sexes at nine ages, from 2 weeks (preweaning) to 104 weeks (elderly). Large differences in the transcript profiles of 29 drug metabolizing enzymes and transporters were found between adult males and females (8-52 weeks). Using the PharmaPendium data base, 41 drugs were found to be metabolized by one or two P450 enzymes encoded by sexually dimorphic mRNAs and thus were candidates for evaluation of possible sexually dimorphic metabolism and/or toxicities. Suspension cultures of primary hepatocytes from three male and three female adult rats (10-13 weeks old) were used to evaluate the metabolism of 11 drugs predicted to have sexually dimorphic metabolism. The pharmacokinetics of the drug or its metabolite was analyzed by liquid chromatography/tandem mass spectrometry using multiple reaction monitoring. Of those drugs with adequate metabolism, the predicted significant sex-different metabolism was found for six of seven drugs, with half-lives 37%-400% longer in female hepatocytes than in male hepatocytes. Thus, in this rat model, transcript profiles may allow identification of potential sex-related differences in drug metabolism. SIGNIFICANCE STATEMENT: The present study showed that sex-different expression of genes coding for drug metabolizing enzymes, specifically cytochrome P450s, could be used to predict sex-different drug metabolism and, thus, provide a new tool for protecting susceptible subpopulations from possible adverse drug events.

Dr. Daniel Acosta and In Vitro toxicology at the U.S. Food and Drug Administration's National Center for Toxicological Research

For the past five years, Dr. Daniel Acosta has served as the Deputy Director of Research at the National Center for Toxicological Research (NCTR), a principle research laboratory of the U.S. Food and Drug Administration (FDA). Over his career at NCTR, Dr. Acosta has had a major impact on developing and promoting the use of in vitro assays in regulatory toxicity and product safety assessments. As Dr. Acosta nears his retirement we have dedicated this paper to his many accomplishments at the NCTR. Described within this paper are some of the in vitro studies that have been conducted under Dr. Acosta's leadership. These studies include toxicological assessments involving developmental effects, and the development and application of in vitro reproductive, heart, liver, neurological and airway cell and tissue models.

Involvement of Pazopanib and Sunitinib Aldehyde Reactive Metabolites in Toxicity and Drug-Drug Interactions in Vitro and in Patient Samples

Tyrosine kinase inhibitors (TKI) are targeted anticancer drugs that have been successfully developed over the past 2 decades. To date, many of them (around 70%) require warnings for liver injury and five of them, including pazopanib and sunitinib, have Black Box Warning (BBW) labels. Although TKI-induced hepatotoxicity is the first cause of drug failures in clinical trials, BBW labels, and market withdrawals, the underlying mechanisms remain unclear. However, the recent discovery of new reactive metabolites (RM) with aldehyde structures during pazopanib and sunitinib metabolism offers new perspectives for investigating their involvement in the toxicity of these two TKI. These hard electrophiles have a high reactivity potential toward proteins and are thought to be responsible for cytochrome P450 inactivation, drug-drug interactions (DDI), and liver toxicity. We report here, for the first time, the presence of these aldehyde RM in human plasma samples obtained during drug monitoring. Docking experiments in the CYP3A4 active site were performed and showed that pazopanib and sunitinib fitting in the catalytic site are in accordance with their regioselective oxidation to aldehydes. They also suggested that aldehyde RM may react with lysine and arginine residues. Based on these results, we studied the reactivity of the aldehyde RM toward lysine and arginine residues as potential targets on the protein framework to better understand how these RM could be involved in liver toxicity and drug-drug interactions. Adduct formation with different hepatic and plasma proteins was investigated by LC-MS/MS, and adducts between pazopanib or sunitinib aldehyde derivatives and lysine residues on both CYP3A4 and plasma proteins were indeed shown for the first time.

Sirt3 promotes sensitivity to sunitinib-induced cardiotoxicity via inhibition of GTSP1/JNK/autophagy pathway in vivo and in vitro

Sunitinib malate is a multi-targeted tyrosine kinase inhibitor used extensively for treatment of human tumors. However, cardiovascular adverse effects of sunitinib limit its clinical use. It is pivotal to elucidate molecular targets that mediate sunitinib-induced cardiotoxicity. Sirtuin 3 (Sirt3) is an effective mitochondrial deacetylase that has been reported to regulate sensitivity of different types of cells to chemotherapies, but roles of Sirt3 in sunitinib-induced cardiotoxicity have not been investigated. In the present study, we established wild type, Sirt3-knockout, and Sirt3-overexpressing mouse models of sunitinib (40 mg kg^-1 day^-1 for 28 days)-induced cardiotoxicity and examined cardiovascular functions and pathological changes. We further cultured wild type, Sirt3-knockout, and Sirt3-overexpressing primary mouse cardiac pericytes and analyzed sunitinib (10 μMol for 48 h)-induced alterations in cellular viability, cell death processes, and molecular pathways. Our results show that sunitinib predominantly induced hypertension, left ventricular systolic dysfunction, and cardiac pericyte death accompanied with upregulation of Sirt3 in cardiac pericytes, and these cardiotoxicities were significantly attenuated in Sirt3-knockout mice, but aggravated in Sirt3-overexpressing mice. Mechanistically, sunitinib induced cardiac pericyte death through inhibition of GSTP1/JNK/autophagy pathway and Sirt3 interacted with and inhibited GSTP1, further inhibiting the pathway and aggravating sunitinib-induced pericyte death. Conclusively, we demonstrate that Sirt3 promotes sensitivity to sunitinib-induced cardiotoxicity via GSTP1/JNK/autophagy pathway. Our results suggest Sirt3 might be a potential target for developing cardioprotective therapies for sunitinib-receiving patients.

A Systematic Review of Recently Reported Marine Derived Natural Product Kinase Inhibitors

Protein kinases are validated drug targets for a number of therapeutic areas, as kinase deregulation is known to play an essential role in many disease states. Many investigated protein kinase inhibitors are natural product small molecules or their derivatives. Many marine-derived natural products from various marine sources, such as bacteria and cyanobacteria, fungi, animals, algae, soft corals, sponges, etc. have been found to have potent kinase inhibitory activity, or desirable pharmacophores for further development. This review covers the new compounds reported from the beginning of 2014 through the middle of 2019 as having been isolated from marine organisms and having potential therapeutic applications due to kinase inhibitory and associated bioactivities. Moreover, some existing clinical drugs based on marine-derived natural product scaffolds are also discussed.

An inter-laboratory in vitro assessment of cigarettes and next generation nicotine delivery products

In vitro testing can facilitate the rapid assessment of next generation nicotine delivery products (NGPs) with comparisons to combustible tobacco products. In vitro assays for cytotoxicity and oxidative stress were employed at BAT (UK) and JT (Japan) to test total particulate matter (TPM) of a scientific reference cigarette and aerosol collected mass (ACM) of a commercially available E-cigarette and two tobacco heating products (THP). 3R4F TPMs were generated using the Health Canada intense (HCI) regimen, a modified regime (mHCI) for the THP ACMs and the CORESTA recommended method no. 81 for the E-cigarette ACM. Human lung cells were exposed to the test product TPM/ACMs at concentrations between 0-200 μg/ml followed by the employment of commercially available assays for endpoint analysis that included reactive oxygen species (ROS) generation, the glutathione ratio (GSH:GSSG), activation of the antioxidant response elements (ARE) and cellular viability. TPM/ACM nicotine concentrations were quantified using a UPLC-PDA technique. At both laboratories the 3R4F TPM induced significant and dose-dependent responses in all in vitro assays, whereas no significant responses could be measured for the NGP ACMs. In conclusion, both laboratories obtained comparable results across all endpoints therefore demonstrating the utility of the in vitro techniques combined with standardised test products to support the assessment of NGPs.

Selection and evaluation of quality markers from Yinlan capsule and its LXRα-mediated therapy for hyperlipidemia

BACKGROUND

The selection of active compounds for the quality evaluation of traditional Chinese medicine (TCM), specifically complex formulas, remains a challenge for researchers, as components selected as indexes usually have no clear relation with the therapeutic effects of interest. As a suggested resolution, quality control markers (Q-markers) showed good perspective for discriminating numerous compounds found for specific efficacies. In the presented study, the components of the Yinlan (YL) capsule, a TCM patent formula comprising four ingredients, were evaluated and selected for their lipid regulatory effects using principles for Q-marker selection.

PURPOSE

The mechanism of TCM therapeutic effects involves several pathways and targets that combine to become an integrated action in the body. Therefore, it is assumed that specific compounds in YL should have good affinity for related targets and obvious effects (both up- and downregulating). Thus, a series of experiments, including cytobiology, animal-based pharmacodynamics, computer-assisted drug design, conventional content determination and pharmacokinetics, would be helpful for the selection and final confirmation of Q-markers.

METHODS

The capsule was first administered to Wistar mice fed a high-fat diet and tested for their triglycerides (TG) and total cholesterol (TC) values to evaluate the effectiveness of YL. Then, liver tissue was extracted for gene expression. According to the results, the compounds in YL with good affiliation were selected and determined using UHPLC-MS-MS, and those with adequate results in the capsule were chosen as Q-marker candidates. Finally, pharmacokinetics research was performed; the candidates with desirable metabolite and bioavailability parameters were confirmed as Q-markers of YL.

RESULTS

YL capsule was capable of lowering TG and TC levels. For target selection, the expression of LXR mRNA increased significantly at all three tested dosages. Downstream genes, such as LCAT, CYP7A1, and ABCA1, and intestinal FXR mRNA also showed significant increases in expression. For screening of the Q-marker candidates, 5 compounds were selected according to abovementioned results. The pharmacokinetics research demonstrated that the rats exploited lupeol and ginsenoside Rb3 in a desirable pattern with adequate bioavailability, which confirmed their roles as lipid regulatory Q-markers.

CONCLUSION

The YL capsule was demonstrated to have obvious lipid regulatory effects, which are mainly exerted by targeting LXR and its related pathway. Lupeol and ginsenoside Rb3 were validated as Q-markers that represent the anti-hyperlipidemia activity of the capsule.