The enhanced atorvastatin hepatotoxicity in diabetic rats was partly attributed to the upregulated hepatic Cyp3a and SLCO1B1

Atorvastatin ameliorates α-KGDH and GDH functions in rats with diet-induced hypercholesterolemia

BACKGROUND

α-ketoglutarate dehydrogenase complex (α-KGDH) belongs to mitochondrial 2-oxoacid dehydrogenases family and is the key regulatory enzyme of cell metabolism. It is functionally interconnected with glutamate dehydrogenase (GDH) which is a source of α-KG, a substrate for α-KGDH. Our previous studies demonstrated that simvastatin had an influence on 2-oxoacid dehydrogenases, including α-KGDH. Hence, we hypothesised that atorvastatin, one of the most commonly prescribed lipid-lowering drugs, may modify liver α-KGDH and GDH.

OBJECTIVES

The purpose of the present study was to evaluate the effect of atorvastatin on liver α-KGDH and GDH in rats with diet-induced hypercholesterolemia.

METHODS

Atorvastatin at dose 20 mg/kg b.wt. (HC + A group, n = 10) or vehicle (HC group, hypercholesterolemic control, n = 10) were administered to rats with hypercholesterolemia for 21 days. The normal control group was fed a standard diet (ST group, normal control, n = 10). α-KGDH and GDH activities as well as their protein levels were determined. Moreover, serum parameters of lipid profile and liver function were measured.

RESULTS

Liver α-KGDH and GDH activities were lower in HC than in ST rats. Atorvastatin enhanced the inhibited activities of α-KGDH and GDH. Stimulation of α-KGDH and GDH by atorvastatin did not correspond with the increase in protein levels of these enzymes indicating that atorvastatin activated α-KGDH and GDH most likely via post-translational mechanism. Atorvastatin had a beneficial effect on serum lipid profile and did not change the parameters of liver function.

CONCLUSION

The present study demonstrated that atorvastatin ameliorated liver α-KGDH and GDH functions in rats with diet-induced hypercholesterolemia.

Improved Antidiabetic Potential of Quercetin-Loaded Chitosan-Lecithin Nanoparticles for Effective Glycemic Control

IntroductionDiabetes mellitus is a major global health challenge, causing significant morbidity and mortality. Quercetin, a natural flavonoid, has potential antidiabetic and insulin-sensitizing effects. However, its clinical use is limited by poor solubility and bioavailability. We developed the quercetin (QTN) loaded chitosan-lecithin nanoparticles (QTN/LCHS-NPs) to enhance its therapeutic profile.Materials and MethodsQTN/LCHS-NPs were synthesized using a 20:1 lecthin:chitosan ratio. Characterization included encapsulation efficiency, particle size, and zeta potential. In vitro, drug release studies were conducted to evaluate release kinetics. In vivo, pharmacokinetic and pharmacodynamic studies were performed in male Wistar rats to assess bioavailability, antidiabetic activity, and lipid-modulating effects.ResultsThe optimized QTN/LCHS-NP formulation exhibited 79.72% encapsulation efficiency, diameter of 130.1 nm, and a zeta potential of 23.46 mV. In vitro release studies showed a biphasic pattern, with an initial burst release followed by a sustained release of 86.10% over 24 h. Bioavailability (AUC: 167.22 h⋅µg/mL) exceeded free QTN (AUC: 26.2 h⋅µg/mL). Fasting blood glucose decreased from 292.9 to 107.7 mg/dL, along with improved lipid profiles.ConclusionQTN/LCHS-NPs significantly enhanced the oral bioavailability of quercetin and improved its antidiabetic and antihyperlipidemic effects, demonstrating their potential as an effective delivery system for addressing metabolic disorders.

Cytochrome P450 3A gene family in gastric cancer: Unveiling diagnostic biomarkers and therapeutic targets for personalized treatment

The cytochrome P450 3A (CYP3A) gene family's role in early progression of gastric cancer was comprehensively investigated. Its potential as a therapeutic target was evaluated. Upon literature review, aberrant expression of the CYP3A gene family has a strong correlation with gastric cancer onset, although the precise underlying mechanisms remain unclear. To assess its potential as a biomarker for early diagnosis and a therapeutic target, we have provided a comprehensive review of the regulatory mechanisms governing CYP3A gene family expression in gastric cancer, as well as its relation with early tumor progression and the tumor microenvironment. The CYP3A gene family is crucial in the proliferation, migration, and invasion of gastric cancer cells and promotes cancer progression by modulating inflammatory responses and oxidative stress within the tumor microenvironment. Furthermore, genetic polymorphisms in CYP3Aenzymes highlight its potential value in personalized medicine. Based on these findings, this paper explores the feasibility of developing inhibitors and activators targeting CYP3A enzymes and discusses potential applications in gene therapy. This research provides crucial theoretical support for the CYP3A gene family as an early diagnostic marker and therapeutic target for gastric cancer. In the future, multi-omics studies and large-scale clinical trials will be essential to advance clinical translation of these findings.

Pharmacokinetic interaction between regorafenib and atorvastatin in rats

BACKGROUND

Regorafenib is used in the treatment of colorectal cancer and hepatocellular carcinoma. Due to the co-morbidity of hyperlipidemia in these conditions, statins, including atorvastatin, are used as potential adjuvant therapy agents. Both regorafenib and atorvastatin are metabolized by CYP3A4. In addition, atorvastatin is a P-gp and BCRP substrate, whereas regorafenib and its active metabolites M-2 and M-5 are inhibitors of these transporters. Hence, the concomitant use of both drugs may increase the risk of a clinically significant drug-drug interaction. Therefore, the present study aimed to assess the pharmacokinetic interactions of atorvastatin and regorafenib and their active metabolites.

METHODS

Male Wistar rats were assigned to three groups (eight animals in each) and were orally administered: regorafenib and atorvastatin (IREG+ATO), a carrier with regorafenib (IIREG), and atorvastatin with a carrier (IIIATO). Blood samples were collected for 72 h. UPLC-MS/MS was the method of measurement of regorafenib and atorvastatin concentrations. The pharmacokinetic parameters were calculated with a non-compartmental model.

RESULTS

A single administration of atorvastatin increased the exposure to regorafenib and its active metabolites. In the IREG+ATO group, the Cmax, AUC0-t, and AUC0-∞ of regorafenib increased 2.7, 3.2, and 3.2-fold, respectively. Atorvastatin also significantly increased the Cmax, AUC0-t, and AUC0-∞ of both regorafenib metabolites. Regorafenib, in turn, decreased the AUC0-t and AUC0-∞ of 2-OH atorvastatin by 86.9% and 67.3%, and the same parameters of 4-OH atorvastatin by 45.0% and 46.8%, respectively.

CONCLUSIONS

This animal model study showed a significant pharmacokinetic interaction between regorafenib and atorvastatin. While this interaction may be clinically significant, this needs to be confirmed in clinical trials involving cancer patients.

Autonomous circadian rhythms in the human hepatocyte regulate hepatic drug metabolism and inflammatory responses

Critical aspects of physiology and cell function exhibit self-sustained ~24-hour variations termed circadian rhythms. In the liver, circadian rhythms play fundamental roles in maintaining organ homeostasis. Here, we established and characterized an in vitro liver experimental system in which primary human hepatocytes display self-sustained oscillations. By generating gene expression profiles of these hepatocytes over time, we demonstrated that their transcriptional state is dynamic across 24 hours and identified a set of cycling genes with functions related to inflammation, drug metabolism, and energy homeostasis. We designed and tested a treatment protocol to minimize atorvastatin- and acetaminophen-induced hepatotoxicity. Last, we documented circadian-dependent induction of pro-inflammatory cytokines when triggered by LPS, IFN-β, or Plasmodium infection in human hepatocytes. Collectively, our findings emphasize that the phase of the circadian cycle has a robust impact on the efficacy and toxicity of drugs, and we provide a test bed to study the timing and magnitude of inflammatory responses over the course of infection in human liver.

Sesamol combats diabetogenic effects of atorvastatin through GLUT-4 expression and improved pancreatic viability

Statin-associated diabetes (SAD) is an issue that has come to light after a series of recent clinical trials that has led to the issue of a black box warning for statins by the US FDA. However, the benefit of statin outweighs its risk. Nevertheless, experiments have been conducted to identify the mechanism by which statins aggravate the risk of diabetes only in a select population who bear the risk factors of obesity, sedentary lifestyle, hypertension, and other associated risk factors of lifestyle disorders. In this study, the possibility of utilization of a phyto-molecule, sesamol, for its ability to combat statin-associated diabetes using atorvastatin as the agent of choice has been explored. MMP assay and western blot was conducted to investigate the effects of atorvastatin on apoptotic cascade with sesamol as a protective agent was conducted in MIN-6 cells. Effect of the combination was tested in L6 cells with 2-NBDG uptake assay and as well as western blot for GLUT-4. A diet-induced hypercholesterolemia model was developed in an in vivo model animals and treated with atorvastatin and sesamol with histopathological analysis being carried out to evaluate the apoptotic markers and GLUT-4 presence. It was found that sesamol can combat pancreatic beta cell apoptosis via the internal apoptotic pathway activated by atorvastatin. With regards to muscle cells, sesamol could improve the GLUT-4 vesical production, but not improve glucose uptake which is inhibited by atorvastatin. These findings are further confirmed by animal studies. These findings indicate that sesamol can serve as a prototype molecule for further development and investigation of similar compounds to tackle SAD.

Acetylsalicylic Acid Suppresses Alcoholism-Induced Cognitive Impairment Associated with Atorvastatin Intake by Targeting Cerebral miRNA155 and NLRP3: In Vivo, and In Silico Study

Alcoholism is one of the most common diseases that can lead to the development of several chronic diseases including steatosis, and cognitive dysfunction. Statins are lipid-lowering drugs that are commonly prescribed for patients with fatty liver diseases; however, the exact effect of statins on cognitive function is still not fully understood. In the present study, we have investigated the molecular and microscopic basis of cognitive impairment induced by alcohol and/or Atorvastatin (ATOR) administration to male Wistar albino rats and explored the possible protective effect of acetylsalicylic acid (ASA). The biochemical analysis indicated that either alcohol or ATOR or together in combination produced a significant increase in the nucleotide-binding domain-like receptor 3 (NLRP3), interleukin-1β (IL-1β) miRNA155 expression levels in the frontal cortex of the brain tissue. The histological and morphometric analysis showed signs of degeneration in the neurons and the glial cells with aggregations of inflammatory cells and a decrease in the mean thickness of the frontal cortex. Immunohistochemical analysis showed a significant increase in the caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex. Interestingly, administration of ASA reversed the deleterious effect of the alcohol and ATOR intake and improved the cognitive function as indicated by biochemical and histological analysis. ASA significantly decreased the expression levels of miRNA155, NLRP3, and IL1B, and produced a significant decrease in caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex with a reduction in the process of neuroinflammation and neuronal damage. To further investigate these findings, we have performed an extensive molecular docking study to investigate the binding affinity of ASA to the binding pockets of the NLRP3 protein. Our results indicated that ASA has high binding scores toward the active sites of the NLRP3 NACHT domain with the ability to bind to the NLRP3 pockets by a set of hydrophilic and hydrophobic interactions. Taken together, the present study highlights the protective pharmacological effect of ASA to attenuate the deleterious effect of alcohol intake and long term ATOR therapy on the cognitive function via targeting miRNA155 and NLRP3 proteins.

Hepatic Ischemia-Reperfusion Impairs Blood-Brain Barrier Partly Due to Release of Arginase From Injured Liver

Aim: Hepatic ischemia-reperfusion (HIR) induces remote organs injury, including the brain. The homeostasis of the brain is maintained by the blood-brain barrier (BBB); thus, we aimed to investigate whether HIR impaired BBB and attempted to elucidate its underlying mechanism.

Methods: Cell viability of human cerebral microvascular endothelial cells (hCMEC/D3) was measured following 24 h incubation with a serum of HIR rat undergoing 1 h ischemia and 4 h reperfusion, liver homogenate, or lysate of primary hepatocytes of the rat. The liver homogenate was precipitated using (NH₄)₂SO₄ followed by separation on three columns and electrophoresis to identify the toxic molecule. Cell activity, apoptosis, proliferation, cell cycle, and expressions of proteins related to cell cycle were measured in hCMEC/D3 cells incubated with identified toxic molecules. HIR rats undergoing 1 h ischemia and 24 h reperfusion were developed to determine the release of an identified toxic molecule. BBB function was indexed as permeability to fluorescein and brain water. Endothelial cell proliferation and expressions of proteins related to the cell cycle in cerebral microvessels were measured by immunofluorescence and western blot.

Results: Toxic molecule to BBB in the liver was identified to be arginase. Arginase inhibitor nor-NOHA efficiently attenuated hCMEC/D3 damage caused by liver homogenate and serum of HIR rats. Both arginase and serum of HIR rats significantly lowered arginine (Arg) in the culture medium. Arg addition efficiently attenuated the impairment of hCMEC/D3 caused by arginase or Arg deficiency, demonstrating that arginase impaired hCMEC/D3 via depriving Arg. Both arginase and Arg deficiency damaged hCMEC/D3 cells by inhibiting cell proliferation, retarding the cell cycle to G1 phase, and downregulating expressions of cyclin A, cyclin D, CDK2, and CDK4. HIR notably increased plasma arginase activity and lowered Arg level, increased the BBB permeability accompanied with enhanced brain water, and decreased the proliferative cells (marked by Ki67) in cerebral microvessels (marked by CD31) and protein expressions of cyclin A, cyclin D, CDK2 and CDK4 in isolated brain microvessels. Oral supplement of Arg remarkably attenuated these HIR-induced alterations.

Conclusion: HIR leads to substantial release of arginase from the injured liver and then deprives systemic Arg. The Arg deficiency further impairs BBB via inhibiting the proliferation of brain microvascular endothelial cells by cell cycle arrest.

Machine Learning to Identify Interaction of Single-Nucleotide Polymorphisms as a Risk Factor for Chronic Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a major cause of drug development failure and drug withdrawal from the market after approval. The identification of human risk factors associated with susceptibility to DILI is of paramount importance. Increasing evidence suggests that genetic variants may lead to inter-individual differences in drug response; however, individual single-nucleotide polymorphisms (SNPs) usually have limited power to predict human phenotypes such as DILI. In this study, we aim to identify appropriate statistical methods to investigate gene-gene and/or gene-environment interactions that impact DILI susceptibility. Three machine learning approaches, including Multivariate Adaptive Regression Splines (MARS), Multifactor Dimensionality Reduction (MDR), and logistic regression, were used. The simulation study suggested that all three methods were robust and could identify the known SNP-SNP interaction when up to 4% of genotypes were randomly permutated. When applied to a real-life DILI chronicity dataset, both MARS and MDR, but not logistic regression, identified combined genetic variants having better associations with DILI chronicity in comparison to the use of individual SNPs. Furthermore, a simple decision tree model using the SNPs identified by MARS and MDR was developed to predict DILI chronicity, with fair performance. Our study suggests that machine learning approaches may help identify gene-gene interactions as potential risk factors for better assessing complicated diseases such as DILI chronicity.

Co-administration of CSL112 (apolipoprotein A-I [human]) with atorvastatin and alirocumab is not associated with increased hepatotoxic or toxicokinetic effects in rats

CSL112 (apolipoprotein A-I, apo AI [human]) is an investigational drug in Phase 3 development for risk reduction of early recurrent cardiovascular events following an acute myocardial infarction (AMI). Although CSL112 is known to be well tolerated with a regimen of four weekly 6 g intravenous infusions after AMI, high doses of reconstituted apo AI preparations can transiently elevate liver enzymes in rats, raising the possibility of additive liver toxicity and toxicokinetic (TK) effects upon co-administration with cholesterol-lowering drugs, i.e., HMG-CoA reductase and proprotein convertase subtilisin/kexin type 9 inhibitors. We performed a toxicity and TK study in CD rats assigned to eleven treatment groups, including two dose levels of intravenous (IV) CSL112 (140 mg/kg, low-dose; 600 mg/kg, high-dose) administered as a single dose, alone or with intravenous alirocumab 50 mg/kg/week and/or oral atorvastatin 10 mg/kg/day. In addition, control groups of atorvastatin and alirocumab alone and in combination were investigated. Results showed some liver enzyme elevations (remaining <2-fold of baseline) related to administration of CSL112 alone. There was limited evidence of an additive effect of CSL112 on liver enzymes when combined, at either dose level, with alirocumab and/or atorvastatin, and histology revealed no evidence of an increased incidence or severity of hepatocyte vacuolation compared to the control treatments. Co-administration of the study drugs had minimal effect on their respective exposure levels, and on levels of total cholesterol and high-density lipoprotein cholesterol. These data support concomitant use of CSL112 with alirocumab and/or atorvastatin with no anticipated negative impact on liver safety and TK.

Potential Alteration of Statin-Related Pharmacological Features in Diabetes Mellitus

OBJECTIVE

Type 2 diabetes mellitus is a chronic metabolic disease caused by insulin resistance or insulin deficiency resulting in elevated blood glucose levels. Poorly controlled diabetes is associated with the development of cardiovascular disease and dyslipidemia. 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statin) are an important class of therapeutic agents used to control hyperlipidemia and prevent cardiovascular disease in diabetic and nondiabetic patients. Since the effect of diabetes on the pharmacokinetics and pharmacodynamics of drugs and toxins has been shown, the aim was to review previous studies on the efficacy of statins such as atorvastatin, simvastatin, pravastatin, pitavastatin, fluvastatin, and rosuvastatin in clinical and preclinical studies in both diabetic and nondiabetic groups.

METHOD

For this purpose, Web of Science, PubMed, Scopus, and Google Scholar databases were reviewed, and related English articles published until October 2020 were included in this review article.

RESULTS

The findings revealed that diabetes affected statin effectiveness through changes in pharmacokinetic parameters such as clearance and biotransformation biomarkers at mRNA and protein levels. Plasma and serum concentrations of statins were accompanied by alteration in cellular activities including oxidative stress, Akt inhibition, and endothelial nitric oxide synthase (eNOS) and phosphorylation that were reflected in changes in the adverse drug reaction profile of the differing statins.

CONCLUSION

Given that dyslipidemia frequently accompanies diabetes and statin therapy is common, more clinical studies are needed regarding the effects of diabetes on the effectiveness of these drugs.

Atorvastatin Induces FXR and CYP7A1 Activation as a Result of the Sequential Action of PPARγ/PGC-1α/HNF-4α in Hep3B Cells

Backgrounds/Aims

PPARγ, farnesoid X receptor (FXR) and CYP7A1 are associated with solubility of bile. This study was performed to understand a mechanism and interactions of statin-induced PPARγ, PGC-1α and HNF-4α related to the statin-induced activation of FXR and CYP7A1, and verify whether the mevalonate pathway is involved in the mechanism.

Methods

MTT assays were performed using cultured human Hep3B cells to determine the effect of atorvastatin on the cell proliferation. Expression levels of indicated proteins were measured using Western blotting assays by inhibiting the protein expression or not.

Results

Atorvastatin increased expression of PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. PPARγ ligand of troglitazone upregulated the expression of PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. Silencing of PPARγ, PGC1α, and HNF4α using respective siRNA demonstrated that atorvastatin-induced FXR and CYP7A1 activation required sequential action of PPARγ /PGC-1α/HNF-4α. The silencing of PPARγ completely inhibited atorvastatin-induced PGC-1α expression, and the PGC1α silencing partially inhibited atorvastatin-induced PPARγ expression. The inhibition of HNF4α did not affect atorvastatin-induced PPARγ expression, but partially inhibited atorvastatin-induced PGC-1α expression. Besides, mevalonate completely reversed the effect of atorvastatin on PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1.

Conclusions

Atorvastatin induces FXR and CYP7A1 activation as a result of sequential action of PPARγ/PGC-1α/HNF-4α in human hepatocytes. We propose that atorvastatin enhances solubility of cholesterol in bile by simultaneously activating of FXR and CYP7A1.

Hydroxyethyl cellulose hydrogel for skin delivery of khellin loaded in ascosomes: Characterization, in vitro/in vivo performance and acute toxicity

Aim of this work was to prepare and characterize a hydroxyethyl cellulose hydrogel loaded with ascosomes, nanovesicles based on phosphatidylcholine plus ascorbyl octanoate (ASC8) or ascorbyl decanoate (ASC1), and khellin (2 mg/mL), for topical use. ASC10 vesicles were selected for the hydrogel formulation because of the best biopharmaceutical characteristics, namely size of 115 nm, PDI of 0.26, ζ-potential of -40.1 meV, EE% of 90.2%. After 24 h the in vitro release of khellin was more than 80%, while the ex-vivo skin permeation of khellin after application of the vesicles was 42% of the dose. The hydrogel formulations had a pH value of 5, viscosity properties were different according to the different temperatures and in addition, they presented characteristics of non-Newtonian fluids with a pseudoplastic shear thinning behaviour according to the Herschel-Bulkley equation. These hydrogels combine the advantages of a suitable viscosity for dermal use (hydrogel matrix) and an increased transdermal absorption (ascosome components). The best permeability of the ASC10 ascosomes, led to select the formulation for skin irritation and corrosion tests in rats. Liver and dermal histological and pathological analyses demonstrated that hydroxyethyl cellulose hydrogels based on khellin loaded in the ASC10 ascosomes have no toxic effects.

Pharmacokinetic Interaction between Sorafenib and Atorvastatin, and Sorafenib and Metformin in Rats

The tyrosine kinase inhibitor sorafenib is the first-line treatment for patients with hepatocellular carcinoma (HCC), in which hyperlipidemia and type 2 diabetes mellitus (T2DM) may often coexist. Protein transporters like organic cation (OCT) and multidrug and toxin extrusion (MATE) are involved in the response to sorafenib, as well as in that to the anti-diabetic drug metformin or atorvastatin, used in hyperlipidemia. Changes in the activity of these transporters may lead to pharmacokinetic interactions, which are of clinical significance. The study aimed to assess the sorafenib−metformin and sorafenib−atorvastatin interactions in rats. The rats were divided into five groups (eight animals in each) that received sorafenib and atorvastatin (I_SOR+AT), sorafenib and metformin (II_SOR+MET), sorafenib (III_SOR), atorvastatin (IV_AT), and metformin (V_MET). Atorvastatin significantly increased the maximum plasma concentration (C_max) and the area under the plasma concentration–time curve (AUC) of sorafenib by 134.4% (p < 0.0001) and 66.6% (p < 0.0001), respectively. Sorafenib, in turn, caused a significant increase in the AUC of atorvastatin by 94.0% (p = 0.0038) and its metabolites 2−hydroxy atorvastatin (p = 0.0239) and 4−hydroxy atorvastatin (p = 0.0002) by 55.3% and 209.4%, respectively. Metformin significantly decreased the AUC of sorafenib (p = 0.0065). The AUC ratio (II_SOR+MET group/III_SOR group) for sorafenib was equal to 0.6. Sorafenib did not statistically significantly influence the exposure to metformin. The pharmacokinetic interactions observed in this study may be of clinical relevance in HCC patients with coexistent hyperlipidemia or T2DM.

Effect of Rooibos (Aspalathus linearis) extract on atorvastatin-induced toxicity in C3A liver cells

Rooibos (Aspalathus linearis) has various health benefits. Two case studies have associated chronic Rooibos consumption with conventional prescription medications, including atorvastatin (ATV), with hepatotoxicity. Statins act by inhibiting hydroxymethylglutaryl‐coenzyme A reductase, a rate‐limiting enzyme in cholesterol synthesis. Although rare, statins are potentially hepatotoxic. The aim was to investigate interactions between aspalathin‐rich Rooibos extract GRT™ and ATV‐induced hepatotoxicity in C3A liver cells cultured with and without palmitate. Effects of co‐treatment of GRT + ATV on cell viability, oxidative stress, apoptosis, mitochondrial integrity, and cellular reactive oxygen species (ROS) production were assessed. Significantly increased ROS production was observed in cells exposed to ATV and palmitate. Combination therapy of GRT + ATV also showed significant increases in ROS production. Under palmitate‐treated conditions, ATV‐induced significant apoptosis which was not ameliorated by GRT + ATV co‐treatment. Despite studies purporting hepatoprotection from Rooibos, our study showed that GRT was unable to modulate ATV‐induced hepatotoxic effects in this model.

Imbalance of Drug Transporter-CYP450s Interplay by Diabetes and Its Clinical Significance

The pharmacokinetics of a drug is dependent upon the coordinate work of influx transporters, enzymes and efflux transporters (i.e., transporter-enzyme interplay). The transporter-enzyme interplay may occur in liver, kidney and intestine. The influx transporters involving drug transport are organic anion transporting polypeptides (OATPs), peptide transporters (PepTs), organic anion transporters (OATs), monocarboxylate transporters (MCTs) and organic cation transporters (OCTs). The efflux transporters are P-glycoprotein (P-gp), multidrug/toxin extrusions (MATEs), multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP). The enzymes related to drug metabolism are mainly cytochrome P450 enzymes (CYP450s) and UDP-glucuronosyltransferases (UGTs). Accumulating evidence has demonstrated that diabetes alters the expression and functions of CYP450s and transporters in a different manner, disordering the transporter-enzyme interplay, in turn affecting the pharmacokinetics of some drugs. We aimed to focus on (1) the imbalance of transporter-CYP450 interplay in the liver, intestine and kidney due to altered expressions of influx transporters (OATPs, OCTs, OATs, PepTs and MCT6), efflux transporters (P-gp, BCRP and MRP2) and CYP450s (CYP3As, CYP1A2, CYP2E1 and CYP2Cs) under diabetic status; (2) the net contributions of these alterations in the expression and functions of transporters and CYP450s to drug disposition, therapeutic efficacy and drug toxicity; (3) application of a physiologically-based pharmacokinetic model in transporter-enzyme interplay.

Reused palm oil from frying pork or potato induced expression of cytochrome P450s and the SLCO1B1 transporter in HepG2 cells

Deep frying degrades the oil and generates harmful products. This study evaluated effects of reused palm oil (from frying pork or potato) on expression of cytochrome P450s (CYPs), the transporter (SLCO1B1), and lipid metabolism regulators; proliferator-activated receptors (PPAR) and sterol regulatory element binding protein (SREBP). Human hepatic carcinoma cell line (HepG2) cells were incubated with oleic acid (OA), new palm oil, or reused palm oils for 24 hr. Fatty acid accumulation was examined by Nile red staining. Total RNA was extracted, followed by RT/qPCR of the target genes. Fatty acid accumulation was significantly different between the new and the reused oils. Expression of CYP1A2, CYP2C19, CYP2E1, CYP3A4, CYP4A11, and SLCO1B1 was induced by reused oils. Expression of PPAR-α was strongly increased in all treatments while SREBP-1a and SREBP-1c were suppressed. Modification of CYPs, PPAR-α, and SLCO1B1 by palm oil might increase the risk of fatty acid accumulation with associated oxidative stress. Therefore, consumption of palm oil or reused oil should be limited. PRACTICAL APPLICATIONS: Deep frying degrades the oil and generates harmful products. This study evaluated effects of reused palm oil (from frying pork or potato) on expression of cytochrome P450s (CYPs), the transporter (SLCO1B1), and lipid metabolism regulators; PPAR and SREBP in HepG2 cells. Both of the reused oils-induced profiles of all CYP and SLCO1B1, but the new oil upregulated CYP2E1, CYP3A4, and CYP4A11. PPAR-α was induced while SREBP-1a and SREBP-1c were suppressed by all treatments. Inductions of CYPs with suppression of SREBP-1a and SREBP-1c might contribute to an increased risk of fatty acid accumulation. These findings revealed the impacts of reused palm oil on metabolism via CYPs which related to oxidative stress for further study. Hence, consumption of palm oil or reused cooking oil should be of concern.

Effects of Ginkgo leaf tablets on the pharmacokinetics of atovastatin in rats

Context: Ginkgo leaf tablets (GLT), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in clinic. Objective: This study investigated the effects of GLT on the pharmacokinetics of AC and the potential mechanism. Materials and methods: The pharmacokinetics of AC (oral administered at a dose of 1 mg/kg) with or without pre-treatment of GLT (oral administered at a dose of 80 mg/kg/day for 10 days) were investigated in male Sprague-Dawley rats. The effects of GLT on the metabolic stability of AC were also investigated using rat liver microsome incubation systems. Results: The results indicated that the C_max increased from 36.84 ± 4.21 to 48.68 ± 6.35 ng/mL, and the AUC_(0-t) increased from 135.82 ± 21.05 to 77.28 ± 12.92 ng h/mL, and t_1/2 also increased from 2.62 ± 0.31 to 3.32 ± 0.57 h when GLT and AC were co-administered. The metabolic stability of AC was also increased (48.2 ± 6.7 vs. 36.7 ± 5.3 min) with the pre-treatment of GLT. Discussion: This study indicated that the main components in GLT could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviours of AC. So these results showed that the herb-drug interaction between GLT and AC might occur, and the clinical efficacy could increase when they were co-administered. Therefore, the clinical dose of AC should be decreased when GLT and AC are co-administered.

Current trends in drug metabolism and pharmacokinetics

Pharmacokinetics (PK) is the study of the absorption, distribution, metabolism, and excretion (ADME) processes of a drug. Understanding PK properties is essential for drug development and precision medication. In this review we provided an overview of recent research on PK with focus on the following aspects: (1) an update on drug-metabolizing enzymes and transporters in the determination of PK, as well as advances in xenobiotic receptors and noncoding RNAs (ncRNAs) in the modulation of PK, providing new understanding of the transcriptional and posttranscriptional regulatory mechanisms that result in inter-individual variations in pharmacotherapy; (2) current status and trends in assessing drug-drug interactions, especially interactions between drugs and herbs, between drugs and therapeutic biologics, and microbiota-mediated interactions; (3) advances in understanding the effects of diseases on PK, particularly changes in metabolizing enzymes and transporters with disease progression; (4) trends in mathematical modeling including physiologically-based PK modeling and novel animal models such as CRISPR/Cas9-based animal models for DMPK studies; (5) emerging non-classical xenobiotic metabolic pathways and the involvement of novel metabolic enzymes, especially non-P450s. Existing challenges and perspectives on future directions are discussed, and may stimulate the development of new research models, technologies, and strategies towards the development of better drugs and improved clinical practice.

Evaluation of cytochrome P450 3A4‑mediated drug‑drug interaction potential between P2Y12 inhibitors and statins

Ticagrelor and prasugrel are widely used in the treatment of acute coronary syndrome. The co‑administration of ticagrelor or prasugrel with statins in the clinic has already drawn a great deal of attention. The aims of the present study were to evaluate the safety and effectiveness, and guide the rational clinical use of, co‑administration of ticagrelor or prasugrel with statins by exploring potential drug interactions. The activity of cytochrome P450 family 3 subfamily A member 4 (CYP3A4) was detected, and its protein and mRNA expression levels were measured in a rat model and liver microsomes to evaluate the effect of the drug combinations on CYP3A4. High performance liquid chromatography, western blotting and reverse transcription‑quantitative PCR were used to perform these investigations. The in vitro experiments suggested that ticagrelor inhibited CYP3A4 activity, with IC50 and inhibitor constant (Ki) values of 68.74 and 26.47 µM, respectively; prasugrel also inhibited CYP3A4, activity with IC50 and Ki values of 16.24 and 10.84 µM, respectively. When different dosages of the antagonists were combined with simvastatin or atorvastatin, the metabolic rate was reduced more effectively at higher dosages when compared with lower dosages. An in vivo pharmacokinetic study demonstrated that the co‑administration of ticagrelor or prasugrel with simvastatin caused an increase in the principal pharmacokinetic parameters of the probe drug dapsone [area under the concentration/time curve (AUC)0‑t, AUC0‑∞ and t1/2] and a decrease in clearance compared with ticagrelor, prasugrel or simvastatin alone. Additional studies confirmed that the two investigated P2Y12 inhibitors were able to decrease the protein level of CYP3A4 by promoting protein degradation through the proteasomal pathway, and combination with statins such as simvastatin had a synergistic inhibitory effect on CYP3A4 activity. These results demonstrated that the co‑administration of P2Y12 inhibitors with simvastatin could markedly inhibit the activity of CYP3A4, and these findings will further influence the assessment of the clinical effectiveness (reduced or enhanced efficacy) and safety (bleeding and rhabdomyolysis) in the clinic.

Atorvastatin induces mitochondrial dysfunction and cell apoptosis in HepG2 cells via inhibition of the Nrf2 pathway

Atorvastatin (ATO) is a 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor widely used to treat hypercholesterolemia. However, clinical application is limited by potential hepatotoxicity. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a master regulator of cellular antioxidants, and oxidative stress is implicated in statin-induced liver injury. This study investigated mechanisms of ATO-induced hepatotoxicity and potential mitigation by Nrf2 signaling. ATO reduced Nrf2 and antioxidant enzyme superoxide dismutase-2 (SOD2) expression in human hepatocarcinoma HepG2 cells. ATO also induced concentration-dependent HepG2 cell toxicity, reactive oxygen species (ROS) accumulation, and mitochondrial dysfunction as evidenced by decreased mitochondrial membrane potential (MMP) and cellular adenosine triphosphate (ATP). Further, ATO induced mitochondria-dependent apoptosis as indicated by increased Bax/Bcl-2 ratio, cleaved caspase-3, mitochondrial cytochrome c release and Annexin V-fluorescein isothiocyanate/propidium iodide staining. Tert-butylhydroquinone enhanced Nrf2 and SOD2 expression, and partially reversed ATO-induced cytotoxicity, ROS accumulation, MMP reduction, ATP depletion and mitochondria-dependent apoptosis. In conclusion, the present study demonstrates that ATO induces mitochondrial dysfunction and cell apoptosis in HepG2 cells, at least in part, via inhibition of the Nrf2 pathway. Nrf2 pathway activation is a potential prevention for ATO-induced liver injury.

Impairment of Intestinal Monocarboxylate Transporter 6 Function and Expression in Diabetic Rats Induced by Combination of High-Fat Diet and Low Dose of Streptozocin: Involvement of Butyrate-Peroxisome Proliferator-Activated Receptor-γ Activation

Generally, diabetes remarkably alters the expression and function of intestinal drug transporters. Nateglinide and bumetanide are substrates of monocarboxylate transporter 6 (MCT6). We investigated whether diabetes down-regulated the function and expression of intestinal MCT6 and the possible mechanism in diabetic rats induced by a combination of high-fat diet and low-dose streptozocin. Our results indicated that diabetes significantly decreased the oral plasma exposure of nateglinide. The plasma peak concentration and area under curve in diabetic rats were 16.9% and 28.2% of control rats, respectively. Diabetes significantly decreased the protein and mRNA expressions of intestinal MCT6 and oligopeptide transporter 1 (PEPT1) but up-regulated peroxisome proliferator-activated receptor γ (PPARγ) protein level. Single-pass intestinal perfusion demonstrated that diabetes prominently decreased the absorption of nateglinide and bumetanide. The MCT6 inhibitor bumetanide, but not PEPT1 inhibitor glycylsarcosine, significantly inhibited intestinal absorption of nateglinide in rats. Coadministration with bumetanide remarkably decreased the oral plasma exposure of nateglinide in rats. High concentrations of butyrate were detected in the intestine of diabetic rats. In Caco-2 cells (a human colorectal adenocarcinoma cell line), bumetanide and MCT6 knockdown remarkably inhibited the uptake of nateglinide. Butyrate down-regulated the function and expression of MCT6 in a concentration-dependent manner but increased PPARγ expression. The decreased expressions of MCT6 by PPARγ agonist troglitazone or butyrate were reversed by both PPARγ knockdown and PPARγ antagonist 2-chloro-5-nitro-N-phenylbenzamide (GW9662). Four weeks of butyrate treatment significantly decreased the oral plasma concentrations of nateglinide in rats, accompanied by significantly higher intestinal PPARγ and lower MCT6 protein levels. In conclusion, diabetes impaired the expression and function of intestinal MCT6 partly via butyrate-mediated PPARγ activation, decreasing the oral plasma exposure of nateglinide.

Improving Drug Discovery by Nucleic Acid Delivery in Engineered Human Microlivers

The liver plays a central role in metabolism; however, xenobiotic metabolism variations between human hepatocytes and those in model organisms create challenges in establishing functional test beds to detect the potential drug toxicity and efficacy of candidate small molecules. In the emerging areas of RNA interference, viral gene therapy, and genome editing, more robust, long-lasting, and predictive human liver models may accelerate progress. Here, we apply a new modality to a previously established, functionally stable, multi-well bioengineered microliver-fabricated from primary human hepatocytes and supportive stromal cells-in order to advance both small molecule and nucleic acid therapeutic pipelines. Specifically, we achieve robust and durable gene silencing in vitro to tune the human metabolism of small molecules, and demonstrate its capacity to query the potential efficacy and/or toxicity of candidate therapeutics. Additionally, we apply this engineered platform to test siRNAs designed to target hepatocytes and impact human liver genetic and infectious diseases.

Overview: Role of Drug Transporters in Drug Disposition and Its Clinical Significance

Absorption, distribution, and excretion of drugs are involved in drug transport across plasma membrane, most of which are mediated by drug transporters. These drug transporters are generally divided into solute carrier (SLC) family and ATP-binding cassette (ABC) family. These transporters not only mediate transport of therapeutic drugs across membrane but also transport various kinds of endogenous compounds. Thus besides being participated in disposal of drug and its clinical efficacy/toxicity, these transporters also play vital roles in maintaining cell homeostasis via regulating transport of endogenous compounds. This chapter will outline classification of drug transporters, their roles in drug disposal/drug response, and remote communication between tissues/organs.

Effects of Danshen tablets on pharmacokinetics of atorvastatin calcium in rats and its potential mechanism

CONTEXT

Danshen tablets (DST), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in the clinic.

OBJECTIVE

This study investigated the effects of DST on the pharmacokinetics of AC and the potential mechanism.

MATERIALS AND METHODS

The pharmacokinetics of AC (1 mg/kg) with or without pretreatment of DST (100 mg/kg) were investigated using LC-MS/MS. The effects of DST (50 μg/mL) on the metabolic stability of AC were also investigated using rat liver microsome incubation systems.

RESULTS

The results indicated that C_max (23.87 ± 4.27 vs. 38.94 ± 5.32 ng/mL), AUC_(0-t) (41.01 ± 11.32 vs. 77.28 ± 12.92 ng h/mL), and t_1/2 (1.91 ± 0.18 vs. 2.74 ± 0.23 h) decreased significantly (p < 0.05) when DST and AC were co-administered, which suggested that DST might influence the pharmacokinetic behavior of AC when they are co-administered. The metabolic stability (t_1/2) of AC was also decreased (25.7 ± 5.2 vs. 42.5 ± 6.1) with the pretreatment of DST.

DISCUSSION AND CONCLUSIONS

This study indicated that the main components in DST could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviors of AC. So these results showed that the herb-drug interaction between DST and AC might occur when they were co-administered. Therefore, the clinical dose of AC should be adjusted when DST and AC are co-administered.

Effects of Baoyuan decoction, a traditional Chinese medicine formula, on the activities and mRNA expression of seven CYP isozymes in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Baoyuan decoction (BYD), a traditional Chinese medicine (TCM) formula, is composed of four herbs and widely used with western drugs to treat coronary heart disease, aplastic anemia and chronic renal failure in clinic. However, no study of the effect of BYD on the cytochrome P450 (CYP) activities has been reported.

AIM OF THE STUDY

The purpose of the present study was to evaluate the potential influences of BYD on the activities of seven CYP isozymes (CYP1A2, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4) in rats.

MATERIALS AND METHODS

A sensitive and selective UPLC-MS/MS method for simultaneous determination of seven probe drugs and internal standard (IS) in rat plasma was developed and validated. The influence of BYD on the activities of CYP isozymes and mRNA expression levels were carried out by comparing plasma pharmacokinetics and real-time reverse transcription-polymerase chain reaction (RT-PCR) of probe drugs between control and BYD treatment groups respectively.

RESULTS

The calibration curve were linear, with correlation coefficient (r) > 0.99 for seven probe drugs. The intra and inter-assay accuracy and precision of the method were within ± 14.9% and the recoveries ranged from 83.2% to 106.1%. Compared with control group, BYD at low (1.46 g/kg) and high (7.30 g/kg) dosages could significantly increase C_max and AUC_0-t of chlorzoxazone and testosterone, while decrease AUC_0-t of phenacetin at high dosage and increase AUC_0-t of tolbu_tamide and metoprolol. Additionally, BYD had increased AUC_0-t of bupropion at low dosage and decreased it at high dosage. The mRNA expression results were in accordance with those of pharmacokinetic.

CONCLUSION

BYD exhibited inhibitory effects on CYP2C9, CYP2E1, and CYP3A4. Moreover, BYD had induction effects on CYP1A2, and CYP2D6 activities. However, no significant change in CYP2C19 activity was observed. It would be useful for the safe and effective usage of BYD in clinic.