Type 2 diabetes mellitus decreases systemic exposure of clopidogrel active metabolite through upregulation of P-glycoprotein in rats

Pharmacokinetic assessment of cefpodoxime proxetil in diabetic rats

Purpose

In diabetes, multi-organ level dysfunction arising from metabolic complications is reported to influence the pharmacokinetics (PK) profile of many drugs. Hence, the present study was planned in rats to evaluate the effect of diabetes on the PK profile of cefpodoxime, a widely prescribed oral antibiotic.

Method

PK profile of cefpodoxime was assessed after oral administration of cefpodoxime proxetil (10 and 20 mg/kg) and intravenous (i.v) administration of cefpodoxime sodium (10 mg/kg) in normal and streptozotocin induced diabetic rats. To evaluate the impact of diabetes on oral absorption and serum protein binding, in situ intestinal permeability and in vitro serum protein binding studies were performed for cefpodoxime using Single Pass Intestinal Perfusion model (SPIP) and ultracentrifugation technique, respectively.

Result

In diabetic rats, there was significant (p < 0.01) decrease in maximum concentration (Cmax) and area under the curve (AUC) of cefpodoxime by both oral and intravenous route, which was attributed to augmented clearance of cefpodoxime. There was no change in the time to achieve Cmax (Tmax) suggesting no alteration in oral absorption which was further confirmed through unaltered intestinal permeability in diabetic rats. The protein binding in diabetic rats also remained unchanged, indicating no influence of protein binding on elevated clearance.

Conclusion

The plasma exposure of cefpodoxime, a renally eliminated drug was significantly lowered in diabetic rats due to enhanced glomerular filtration. However, this observation needs to be confirmed through well controlled clinical trials.

Enhanced metabolic activation of and platelet response to clopidogrel in T cell-deficient mice through induction of Cyp2c and Cyp3a and inhibition of Ces1

BACKGROUND

T cells and platelets reciprocally coordinate mutual functions through crosstalk or interaction. However, it is not known whether metabolic activation of and platelet response to clopidogrel could be changed if T cells were deficient or impaired in some cases and, if any, how it would work.

OBJECTIVES

The objective of this study was to dissect the potential changes in platelet responses to and metabolic activation of clopidogrel in the case of T cell deficiency and to elucidate their mechanisms involved.

METHODS

BALB/c athymic nude mice or euthymic mice (controls) pretreated with cyclosporine A (CsA), thymosin α1 (Tα1), or their combination were used to investigate the changes in ADP-induced platelet activation and aggregation, systemic exposure of clopidogrel and its metabolites, and mRNA/protein expression and activity levels of clopidogrel-metabolizing enzymes in the liver, respectively.

RESULTS

Nude mice exhibited significantly enhanced antiplatelet effects of clopidogrel due to increased formation of clopidogrel active metabolite in the liver, where the enzyme activity levels of Cyp2c and Cyp3a were significantly elevated compared with control mice. Furthermore, the effects of CsA pretreatment on the metabolism of clopidogrel in euthymic mice were identical to those seen in athymic mice. As expected, concomitant use of Tα1 reversed all the observed effects of CsA on clopidogrel metabolism and relevant metabolic enzymes.

CONCLUSIONS

T cell deficiency or suppression enhances the antiplatelet effects of clopidogrel due to the boosted metabolic activation of clopidogrel in the liver through a dramatic induction of Cyp2c and Cyp3a in mice, suggesting that the metabolism of substrate drugs of Cyp2c and Cyp3a may be enhanced by T cell impairment.

Precision medicine in interventional cardiology: implications for antiplatelet therapy in patients undergoing percutaneous coronary intervention

Precision medicine is a medical model that proposes the customization of medical treatments to the individual patient, as opposed to a one-drug-fits-all model. Such a "personalized medicine" approach has been widely adopted in several medical fields, such as cancer medicine, but the implementation of precision medicine in cardiovascular medicine has not been similarly straightforward. Because pharmacogenomics plays an important role in the safety and efficacy of cardiovascular drug therapy, there has been a great interest in the use of tools aiming at personalizing antiplatelet therapy. Moreover, antiplatelet therapy is essential for the treatment of cardiovascular patients to reduce the risk of thrombotic complications, particularly those undergoing percutaneous coronary intervention, but it is inevitably associated with increased bleeding risk. In this review, the authors discuss the rationale, summarize the evidence and discuss the current and future directions for the personalization of antiplatelet treatment regimens in patients undergoing percutaneous coronary intervention.

Antibiotics-induced disruption of gut microbiota increases systemic exposure of clopidogrel active metabolite in type 2 diabetic rats

Gut microbiota play an important role in the pathophysiology of type 2 diabetic mellitus (T2DM) and biodisposition of drugs. Our previous study demonstrated that T2DM rats had the decreased plasma exposure of clopidogrel active metabolite (Clop-AM) due to upregulation of P-glycoprotein (P-gp). However, whether the change to clopidogrel (Clop) disposition under T2DM condition is associated with gut microbiota needs to be elucidated. In the study, we used an antibiotic cocktail consisting of ampicillin, vancomycin, metronidazole, and neomycin to disrupt gut microbiota and observed their influence on pharmacokinetic profiles of Clop-AM. Antibiotic administration markedly alleviated T2DM rats' phenotype including hyperglycemia, insulin resistance, oxidative stress, inflammation, hyperlipidemia, and liver dysfunction. Meanwhile, treatment with antibiotics significantly reversed the reduced systemic exposure of Clop-AM in T2DM rats relative to control rats, which was associated with the decreased intestinal P-gp level that might promote Clop absorption, resulting in more Clop transformation to Clop-AM. Fecal microbiome analysis exhibited a serious disruption of gut microbiota after antibiotic treatment with the sharply reduced microbial load and the altered microbial composition. Interestingly, an in vitro study showed that antibiotics had no influence on P-gp mRNA leve in SW480 cells, suggesting the microbiome disruption, not the direct role of antibiotics on P-gp expression, contributes to the altered P-gp level and Clop disposition in T2DM rats. The findings add new insights into the potential impact of gut microbiota on Clop biodisposition. Significance Statement 1.Antibiotics increase systemic exposure of Clop-AM in T2DM rats, which is associated with the downregulation of P-gp level.2.Antibiotics-induced disruption of gut microbiota, not direct effect of antibiotics on P-gp and CYPs expression, contributes to the altered Clop disposition.3.Antibiotics also alleviate T2DM phenotype including hyperglycemia, hyperlipidemia, insulin resistance, liver dysfunction and inflammation.

Protective effects of calorie restriction on insulin resistance and islet function in STZ-induced type 2 diabetes rats

Background

Caloric restriction (CR) has become increasingly attractive in the treatment of type 2 diabetes mellitus (T2DM) because of the increasingly common high-calorie diet and sedentary lifestyle. This study aimed to evaluate the role of CR in T2DM treatment and further explore its potential molecular mechanisms.

Methods

Sixty male Sprague–Dawley rats were used in this study. The diabetes model was induced by 8 weeks of high-fat diet (HFD) followed by a single dose of streptozotocin injection (30 mg/kg). Subsequently, the diabetic rats were fed HFD at 28 g/day (diabetic control) or 20 g/day (30% CR regimen) for 20 weeks. Meanwhile, normal rats fed a free standard chow diet served as the vehicle control. Body mass, plasma glucose levels, and lipid profiles were monitored. After diabetes-related functional tests were performed, the rats were sacrificed at 10 and 20 weeks, and glucose uptake in fresh muscle was determined. In addition, western blotting and immunofluorescence were used to detect alterations in AKT/AS160/GLUT4 signaling.

Results

We found that 30% CR significantly attenuated hyperglycemia and dyslipidemia, leading to alleviation of glucolipotoxicity and thus protection of islet function. Insulin resistance was also markedly ameliorated, as indicated by notably improved insulin tolerance and homeostatic model assessment for insulin resistance (HOMA-IR). However, the improvement in glucose uptake in skeletal muscle was not significant. The upregulation of AKT/AS160/GLUT4 signaling in muscle induced by 30% CR also attenuated gradually over time. Interestingly, the consecutive decrease in AKT/AS160/GLUT4 signaling in white adipose tissue was significantly reversed by 30% CR.

Conclusion

CR (30%) could protect islet function from hyperglycemia and dyslipidemia, and improve insulin resistance. The mechanism by which these effects occurred is likely related to the upregulation of AKT/AS160/GLUT4 signaling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00575-y.

Regulation of CAR and PXR Expression in Health and Disease

Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.