Enantioselective Kinetic Disposition of Fenoprofen in Rats with Experimental Diabetes or Adjuvant-Induced Arthritis

The Anticonvulsant Effect of Nonsteroidal Anti-Inflammatory Drug, Fenoprofen, in Pentylenetetrazole-Induced Epileptic Rats: Behavioral, Histological, and Biochemical Evidence

This study aimed to evaluate the anticonvulsant properties of fenoprofen on the experimental model of pentylenetetrazole (PTZ)-induced epilepsy. Male Wistar rats were randomly grouped into five, and the kindling model was induced by intraperitoneal injection of PTZ 35 (mg/kg) every other day for 1 month. Aside from the control and PTZ groups, three groups received intraperitoneal injections of fenoprofen at doses of 10, 20, and 40 (mg/kg) before each PTZ injection. Rats were challenged with PTZ 70 (mg/kg) 1 week after kindling development. Then rats were subjected to deep anesthesia, and serum and brain samples were prepared. Oxidative stress (OS) markers (malondialdehyde, superoxide dismutase, and glutathione peroxidase) were measured in serum samples. Hippocampal tissue was used to investigate the relative expression of OS-related genes (nuclear factor [erythroid-derived 2]-like 2 (Nrf2)/heme oxygenase 1 (Hmox1)) and histological studies. Seizure behavior was assessed based on Lüttjohann's score. In treated groups, the number of myoclonic jerks and generalized tonic-clonic seizure (GTCS) duration decreased significantly, while myoclonic jerks and GTCS latency increased compared with the PTZ group. The biochemical evaluation revealed the antioxidative effects of fenoprofen. The decreased expression of Nrf2/HO-1 genes in the PTZ group was reversed after fenoprofen administration. The results of the histological study obtained from Nissl staining in the hippocampal tissue also confirmed the protective effect of fenoprofen. The anticonvulsant effects of fenoprofen seem to be through inhibition of OS-related markers, induction of protective effect in hippocampal tissue, and activation of the Nrf2/HO-1 signaling pathway.

Pharmacodynamics, Chiral Pharmacokinetics, and Pharmacokinetic-Pharmacodynamic Modeling of Fenoprofen in Patients With Diabetes Mellitus

The objective of the present study was to assess the influence of type 1 and type 2 diabetes mellitus on the enantioselective pharmacodynamics and pharmacokinetics of fenoprofen. Patients with diabetes mellitus type 1 (n = 7) or type 2 (n = 7) and healthy volunteers (n = 13) received orally a single 600-mg dose of racemic fenoprofen. Monocompartmental analysis of (+)-(S)-fenoprofen showed a significant difference (P < .05, Kruskal-Wallis test) in area under the curve (AUC) values (153.68 vs 243.50 microg x h/mL) and oral clearance (1.95 vs 1.23 L/h) only between patients with diabetes mellitus type 2 and healthy volunteers. The inhibitory activity of cyclooxygenases was evaluated indirectly by the determination of prostaglandin E2 (COX-2) and thromboxane B2 (COX-1) using the sigmoidal inhibitory Emax model. The patients with type 2 diabetes mellitus presented lower IC50 (3.29 vs 6.0 microg/mL) and g (0.73 vs 2.01) values for COX-1 activity compared to healthy volunteers (P < .05, Kruskal-Wallis test). These results show that diabetes mellitus type 2, but not type 1, influences the pharmacokinetics and pharmacodynamics of (+)-(S)-fenoprofen.

Pharmacokinetics of drugs in rats with diabetes mellitus induced by alloxan or streptozocin: comparison with those in patients with type I diabetes mellitus

Objectives

In rats with diabetes mellitus induced by alloxan (DMIA) or streptozocin (DMIS), changes in the cytochrome P450 (CYP) isozymes in the liver, lung, kidney, intestine, brain, and testis have been reported based on Western blot analysis, Northern blot analysis, and various enzyme activities. Changes in phase II enzyme activities have been reported also. Hence, in this review, changes in the pharmacokinetics of drugs that were mainly conjugated and metabolized via CYPs or phase II isozymes in rats with DMIA or DMIS, as reported in various literature, have been explained. The changes in the pharmacokinetics of drugs that were mainly conjugated and mainly metabolized in the kidney, and that were excreted mainly via the kidney or bile in DMIA or DMIS rats were reviewed also. For drugs mainly metabolized via hepatic CYP isozymes, the changes in the total area under the plasma concentration–time curve from time zero to time infinity (AUC) of metabolites, AUCmetabolite/AUCparent drug ratios, or the time-averaged nonrenal and total body clearances (CLNR and CL, respectively) of parent drugs as reported in the literature have been compared.

Key findings

After intravenous administration of drugs that were mainly metabolized via hepatic CYP isozymes, their hepatic clearances were found to be dependent on the in-vitro hepatic intrinsic clearance (CLint) for the disappearance of the parent drug (or in the formation of the metabolite), the free fractions of the drugs in the plasma, or the hepatic blood flow rate depending on their hepatic extraction ratios. The changes in the pharmacokinetics of drugs that were mainly conjugated and mainly metabolized via the kidney in DMIA or DMIS rats were dependent on the drugs. However, the biliary or renal CL values of drugs that were mainly excreted via the kidney or bile in DMIA or DMIS rats were faster.

Summary

Pharmacokinetic studies of drugs in patients with type I diabetes mellitus were scarce. Moreover, similar and different results for drug pharmacokinetics were obtained between diabetic rats and patients with type I diabetes mellitus. Thus, present experimental rat data should be extrapolated carefully in humans.