13 results on '"Z. Pala Kara"'
Search Results
2. Effects of atorvastatin on talinolol absorption: A potential drug-drug interaction
- Author
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Z Pala, Kara, D, Ozturk, N, Ozturk, M N, Orman, G, Baktir, and A, Okyar
- Subjects
Male ,Propanolamines ,Intestinal Absorption ,Adrenergic beta-Antagonists ,Atorvastatin ,Animals ,Biological Availability ,Drug Interactions ,Rats, Wistar ,Rats - Abstract
In this study, we aimed to determine the drug-drug interaction potential between atorvastatin (ATOR), and talinolol (TAL). Concentration-dependent effects of ATOR on the intestinal permeability of TAL were investigated by an
- Published
- 2020
3. Pharmacokinetics of talinolol is modified by barnidipine: implication of P-glycoprotein modulation
- Author
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N, Ozturk, D, Ozturk, Z, Pala-Kara, and A, Okyar
- Subjects
Propanolamines ,ATP Binding Cassette Transporter, Subfamily B ,Dose-Response Relationship, Drug ,Nifedipine ,Area Under Curve ,Adrenergic beta-Antagonists ,Animals ,Biological Availability ,Drug Interactions ,Calcium Channel Blockers ,Rats - Abstract
Concomitant administration of P-glycoprotein substrates and inhibitors may cause pharmacokinetic drug interactions leading to increased concentrations associated with serious side effects and toxicities. Barnidipine is a longacting calcium-channel blocker and potent inhibitor of P-glycoprotein in vitro, and talinolol is a beta-blocker and probe substrate of P-glycoprotein. This study was designed to investigate the effects of single and repeated oral doses of barnidipine on talinolol pharmacokinetics in rats. In the single-dose study, talinolol (20 mg/kg) alone and with barnidipine at low (1 mg/kg) and high doses (10 mg/kg) were orally administered to rats. In the repeated-dose study, rats were treated with barnidipine (1 mg/kg/day) or vehicle only for four days, then with talinolol (20 mg/kg, on day 5). Blood samples were collected at 0.5, 1, 2, 4, 6 h following last dose and plasma talinolol levels were determined by HPLC. Compared to the control, Cmax of talinolol elevated 10% (p=0.79) and 110% (p0.05); plasma AUC0-6h increased 33% (p=0.41) and 46% (p0.05) following low and high single doses of barnidipine co-administration, respectively. In the repeated-dose study, Cmax and AUC0-6h of talinolol increased 131% (p0.05) and 130% (p0.05) respectively, following co-administration of a low barnidipine dose. Double-peaks were observed when single or repeated low doses of barnidipine were co-administered. There may be coupling between occurrence of double-peak phenomenon and P-glycoprotein inhibition. Increment of talinolol bioavailability upon low and high doses of barnidipine co-administration may be due to P-glycoprotein inhibition. The higher increase of talinolol plasma AUC0-6h due to the repeated doses of barnidipine may be explained by downregulation of P-glycoprotein.
- Published
- 2018
4. The role of the circadian timing system on drug metabolism and detoxification: an update.
- Author
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Okyar A, Ozturk Civelek D, Akyel YK, Surme S, Pala Kara Z, and Kavakli IH
- Subjects
- Humans, Animals, Pharmaceutical Preparations metabolism, Pharmaceutical Preparations administration & dosage, Circadian Clocks physiology, Blood-Brain Barrier metabolism, Female, Cytochrome P-450 Enzyme System metabolism, Liver metabolism, Drug Chronotherapy, Male, Sex Factors, Circadian Rhythm physiology, Inactivation, Metabolic
- Abstract
Introduction: The 24-hour variations in drug absorption, distribution, metabolism, and elimination, collectively known as pharmacokinetics, are fundamentally influenced by rhythmic physiological processes regulated by the molecular clock. Recent advances have elucidated the intricacies of the circadian timing system and the molecular interplay between biological clocks, enzymes and transporters in preclinical level., Area Covered: Circadian rhythm of the drug metabolizing enzymes and carrier efflux functions possess a major role for drug metabolism and detoxification. The efflux and metabolism function of intestines and liver seems important. The investigations revealed that the ABC and SLC transporter families, along with cytochrome p -450 systems in the intestine, liver, and kidney, play a dominant role in the circadian detoxification of drugs. Additionally, the circadian control of efflux by the blood-brain barrier is also discussed., Expert Opinion: The influence of the circadian timing system on drug pharmacokinetics significantly impacts the efficacy, adverse effects, and toxicity profiles of various drugs. Moreover, the emergence of sex-related circadian changes in the metabolism and detoxification processes has underscored the importance of considering gender-specific differences in drug tolerability and pharmacology. A better understanding of coupling between central clock and circadian metabolism/transport contributes to the development of more rational drug utilization and the implementation of chronotherapy applications.
- Published
- 2024
- Full Text
- View/download PDF
5. Dosing-time, feeding, and sex-dependent variations of everolimus pharmacokinetics in mice.
- Author
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Ozturk Civelek D, Ozturk Seyhan N, Akyel YK, Gazioglu I, Pala Kara Z, Orman MN, and Okyar A
- Abstract
Background: Everolimus is an oral mammalian target of rapamycin (mTOR) inhibitor used as an immunosuppressant and anticancer. Its pharmacokinetics is highly variable, it has a narrow therapeutic window and shows chronotoxicity with the best time at ZT13 and worst time at ZT1 (ZT; Zeitgeber time, time after light onset) in the preclinical setting., Objectives: In the present study, we aimed to investigate whether the pharmacokinetics of everolimus vary according to dosing time and whether sex and feeding status interfere with the chronopharmacokinetics., Method: A single dosage of 5 mg/kg everolimus was administered orally to C57BL/6J male and female mice, in fed or fasted states at ZT1-rest and ZT13-activity times and blood and tissue samples were collected at 0.5, 1, 2, 4, 12, and 24 h following drug administration. Ileum, liver, plasma, and thymus concentrations of everolimus were determined., Results: Females had a greater ileum AUC
0-24h than males when fed (P = 0.043). Everolimus AUC0-24h in the liver was substantially greater at ZT1 than at ZT13 in a fasted state (P = 0.001). Plasma Cmax , AUC0-24h , and AUCtotal were not statistically significant between the groups (P = 0.098). In one of the target organs of everolimus, the thymus, males had considerably higher amounts at ZT1 than females (P = 0.029)., Conclusion: Our findings imply that the pharmacokinetics of everolimus in mice may differ according to dosing time, sex, and feeding. Greater tissue distribution of everolimus at ZT1 may be associated with the worst tolerated time of everolimus. Our research suggests that oral chronomodulated everolimus therapy may be more effective and safer for cancer patients., (© 2024 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.)- Published
- 2024
- Full Text
- View/download PDF
6. Diurnal Changes in Capecitabine Clock-Controlled Metabolism Enzymes Are Responsible for Its Pharmacokinetics in Male Mice.
- Author
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Akyel YK, Ozturk Civelek D, Ozturk Seyhan N, Gul S, Gazioglu I, Pala Kara Z, Lévi F, Kavakli IH, and Okyar A
- Subjects
- Male, Mice, Rats, Animals, Capecitabine pharmacokinetics, Mice, Inbred C57BL, Fluorouracil metabolism, Fluorouracil therapeutic use, Antimetabolites, Antineoplastic pharmacokinetics, Antimetabolites, Antineoplastic therapeutic use, Circadian Rhythm
- Abstract
The circadian timing system controls absorption, distribution, metabolism, and elimination processes of drug pharmacokinetics over a 24-h period. Exposure of target tissues to the active form of the drug and cytotoxicity display variations depending on the chronopharmacokinetics. For anticancer drugs with narrow therapeutic ranges and dose-limiting side effects, it is particularly important to know the temporal changes in pharmacokinetics. A previous study indicated that pharmacokinetic profile of capecitabine was different depending on dosing time in rat. However, it is not known how such difference is attributed with respect to diurnal rhythm. Therefore, in this study, we evaluated capecitabine-metabolizing enzymes in a diurnal rhythm-dependent manner. To this end, C57BL/6J male mice were orally treated with 500 mg/kg capecitabine at ZT1, ZT7, ZT13, or ZT19. We then determined pharmacokinetics of capecitabine and its metabolites, 5'-deoxy-5-fluorocytidine (5'DFCR), 5'-deoxy-5-fluorouridine (5'DFUR), 5-fluorouracil (5-FU), in plasma and liver. Results revealed that plasma C
max and AUC0-6h (area under the plasma concentration-time curve from 0 to 6 h) values of capecitabine, 5'DFUR, and 5-FU were higher during the rest phase (ZT1 and ZT7) than the activity phase (ZT13 and ZT19) ( p < 0.05). Similarly, Cmax and AUC0-6h values of 5'DFUR and 5-FU in liver were higher during the rest phase than activity phase ( p < 0.05), while there was no significant difference in liver concentrations of capecitabine and 5'DFCR. We determined the level of the enzymes responsible for the conversion of capecitabine and its metabolites at each ZT. Results indicated the levels of carboxylesterase 1 and 2, cytidine deaminase, uridine phosphorylase 2, and dihydropyrimidine dehydrogenase ( p < 0.05) are being rhythmically regulated and, in turn, attributed different pharmacokinetics profiles of capecitabine and its metabolism. This study highlights the importance of capecitabine administration time to increase the efficacy with minimum adverse effects.- Published
- 2023
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- View/download PDF
7. Dosing-time dependent testicular toxicity of everolimus in mice.
- Author
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Ozturk N, Ozturk Civelek D, Sancar S, Kaptan E, Pala Kara Z, and Okyar A
- Subjects
- Animals, Circadian Rhythm, Male, Mice, Mice, Inbred C57BL, Testis, Antineoplastic Agents pharmacology, Everolimus toxicity
- Abstract
The circadian timing system controls many biological functions in mammals including drug metabolism and detoxification, cell cycle events, and thus may affect pharmacokinetics, target organ toxicity and efficacy of medicines. Selective mTOR (mammalian target of rapamycin) inhibitor everolimus is an immunosuppressant and anticancer drug that is effective against several cancers. The aim of this study was to investigate dosing-time dependent testicular toxicity of subacute everolimus administration in mice. C57BL/6 J male mice were synchronized with Light-Dark (12h:12 h) cycle, with Light-onset at Zeitgeber Time (ZT)-0. Everolimus (5 mg/kg/day) was administered orally to mice at ZT1
rest-span or ZT13activity-span for 4 weeks. Body weight loss, clinical signs, changes in testicular weights, testis histology, spermatogenesis and proliferative activity of germinal epithelium of seminiferous tubules were examined. Steady-state everolimus concentrations in testes were determined with validated HPLC method. Everolimus toxicity was less severe following dosing at ZT13 compared to ZT1, as shown with least body weight loss (p<0.001), least reductions in testes weights (p<0.001) and least histopathological findings. Everolimus-induced histological changes on testes included vacuolisation and atrophy of germinal epithelium, and loss of germinal cell attachment. The severity of everolimus-induced histological toxicity on testes was significantly more evident in mice treated at ZT1 than ZT13 (p<0.001). Spermatogenic cell population significantly decreased when everolimus administered at ZT1 compared to ZT13 (p<0.001). Proliferative activity of germinal epithelium was significantly decreased due to treatment at ZT1 compared to ZT13 (p<0.001). Everolimus concentrations in testes indicated a pronounced circadian variation, which was greater in mice treated at ZT1 compared to ZT13 (p<0.05). Our study revealed dosing-time dependent testicular toxicity of everolimus in mice, which was greater in severity when everolimus administered at early rest-span (daytime-ZT1) than early activity-span (nighttime-ZT13). These findings support the concept of everolimus chronotherapy for minimizing reproductive toxicity and increasing the tolerability of everolimus, as a clinical advantage., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
8. The effects of P-glycoprotein inhibitor zosuquidar on the sex and time-dependent pharmacokinetics of parenterally administered talinolol in mice.
- Author
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Pala Kara Z, Ozturk Civelek D, Ozturk N, and Okyar A
- Subjects
- ATP Binding Cassette Transporter, Subfamily B metabolism, Animals, Area Under Curve, Female, Male, Mice, Pharmaceutical Preparations, Propanolamines
- Abstract
P-glycoprotein (P-gp) is an efflux protein that forms a tissue barrier and plays a role in the pharmacokinetics of drugs, limiting the influx of them and other xenobiotics into the cells, as expressed in various tissues such as liver, brain, intestinal mucosa and kidneys. Circadian clock controls many biological functions in mammals including xenobiotic metabolism and detoxification. Circadian rhythms of biological functions may affect the pharmacokinetics, and thus efficacy and/or toxicity of drugs. Aim of this study is to determine how the intraperitoneally administered pharmacokinetics of talinolol, as the probe substrate of P-gp, will change depending on the circadian time and sex in the presence of P-gp inhibitor zosuquidar. 20 mg/kg talinolol with or without 30 mg/kg zosuquidar was administred intraperitoneally to male and female mice at day period (ZT3) and night period (ZT15). Plasma and tissue concentrations of talinolol were determined by using validated HPLC/UV method. The protein levels of P-gp in the liver and small intestine in male and female mice were determined by PCR and Western blot techniques. P-gp protein levels in liver and ileum tissues were not different in female mice but higher in ZT15 as compared to ZT3 in male mice (p<0.05). There was no statistically significant difference in talinolol concentration depending on time and sex in the plasma and liver. There was significant time-dependent difference between ZT3 and ZT15 groups in ileum AUC
0-5 h of talinolol (p<0.01). Talinolol plasma and liver AUC0-5 h were increased by zosuquidar administration regardless of dosing-time and sex (p<0.05). Our study findings are considerable in terms of revealing changes in pharmacokinetic profiles of P-gp substrates due to the time of administration in combination with P-gp inhibitors/modulators in managing polypharmacy., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
9. The immune system as a chronotoxicity target of the anticancer mTOR inhibitor everolimus.
- Author
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Ozturk N, Ozturk D, Pala-Kara Z, Kaptan E, Sancar-Bas S, Ozsoy N, Cinar S, Deniz G, Li XM, Giacchetti S, Lévi F, and Okyar A
- Subjects
- Animals, Antineoplastic Agents toxicity, Everolimus toxicity, Female, Immune System immunology, Immune System pathology, Immunosuppressive Agents toxicity, Male, Mice, Inbred C57BL, Organ Size drug effects, Protein Kinase Inhibitors toxicity, Sex Factors, Spleen drug effects, Spleen immunology, Spleen pathology, TOR Serine-Threonine Kinases metabolism, Thymus Gland drug effects, Thymus Gland immunology, Thymus Gland pathology, Time Factors, Antineoplastic Agents administration & dosage, Drug Chronotherapy, Everolimus administration & dosage, Immune System drug effects, Immunosuppressive Agents administration & dosage, Protein Kinase Inhibitors administration & dosage, TOR Serine-Threonine Kinases antagonists & inhibitors
- Abstract
The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. C57BL/6J mice were synchronized with light-dark 12h:12h, with L onset at Zeitgeber Time (ZT) 0. Everolimus was administered orally to male (5 mg/kg/day) and female mice (15 mg/kg/day) at ZT1, during early rest span or at ZT13, during early activity span for 4 weeks. Body weight loss, as well as hematological, immunological and biochemical toxicities, were determined. Spleen and thymus were examined histologically. Everolimus toxicity was less severe following dosing at ZT13, as compared to ZT1, as shown with least body weight inhibition in both genders; least reductions in thymus weight both in males (p < 0.01) and females (p < 0.001), least reduction in female spleen weight (p < 0.05), and less severe thymic medullar atrophy both in males (p < 0.001) and females (p < 0.001). The mean circulating counts in total leukocytes, total lymphocytes, T-helper and B lymphocytes displayed minor and non-significant changes following dosing at ZT13, while they were decreased by 56.9% (p < 0.01), 45.5% (p < 0.01), 43.1% (p < 0.05) and 48.7% (p < 0.01) after everolimus at ZT1, respectively, in only male mice. Chronotherapy of everolimus is an effective way to increase the general tolerability and decrease toxicity on the immune system.
- Published
- 2018
- Full Text
- View/download PDF
10. Pharmacokinetics of talinolol is modified by barnidipine: implication of P-glycoprotein modulation.
- Author
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Ozturk N, Ozturk D, Pala-Kara Z, and Okyar A
- Subjects
- ATP Binding Cassette Transporter, Subfamily B metabolism, Animals, Area Under Curve, Biological Availability, Dose-Response Relationship, Drug, Drug Interactions, Nifedipine pharmacology, Rats, ATP Binding Cassette Transporter, Subfamily B genetics, Adrenergic beta-Antagonists pharmacokinetics, Calcium Channel Blockers pharmacology, Nifedipine analogs & derivatives, Propanolamines pharmacokinetics
- Abstract
Concomitant administration of P-glycoprotein substrates and inhibitors may cause pharmacokinetic drug interactions leading to increased concentrations associated with serious side effects and toxicities. Barnidipine is a longacting calcium-channel blocker and potent inhibitor of P-glycoprotein in vitro, and talinolol is a beta-blocker and probe substrate of P-glycoprotein. This study was designed to investigate the effects of single and repeated oral doses of barnidipine on talinolol pharmacokinetics in rats. In the single-dose study, talinolol (20 mg/kg) alone and with barnidipine at low (1 mg/kg) and high doses (10 mg/kg) were orally administered to rats. In the repeated-dose study, rats were treated with barnidipine (1 mg/kg/day) or vehicle only for four days, then with talinolol (20 mg/kg, on day 5). Blood samples were collected at 0.5, 1, 2, 4, 6 h following last dose and plasma talinolol levels were determined by HPLC. Compared to the control, Cmax of talinolol elevated 10% (p=0.79) and 110% (p<0.05); plasma AUC0-6h increased 33% (p=0.41) and 46% (p<0.05) following low and high single doses of barnidipine co-administration, respectively. In the repeated-dose study, Cmax and AUC0-6h of talinolol increased 131% (p<0.05) and 130% (p<0.05) respectively, following co-administration of a low barnidipine dose. Double-peaks were observed when single or repeated low doses of barnidipine were co-administered. There may be coupling between occurrence of double-peak phenomenon and P-glycoprotein inhibition. Increment of talinolol bioavailability upon low and high doses of barnidipine co-administration may be due to P-glycoprotein inhibition. The higher increase of talinolol plasma AUC0-6h due to the repeated doses of barnidipine may be explained by downregulation of P-glycoprotein.
- Published
- 2017
- Full Text
- View/download PDF
11. Chronomodulated oxaliplatin plus Capecitabine (XELOX) as a first line chemotherapy in metastatic colorectal cancer: A Phase II Brunch regimen study.
- Author
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Pilancı KN, Saglam S, Okyar A, Yucel S, Pala-Kara Z, Ordu C, Namal E, Ciftci R, Iner-Koksal U, and Kaytan-Saglam E
- Subjects
- Adult, Aged, Antineoplastic Combined Chemotherapy Protocols adverse effects, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Capecitabine, Colorectal Neoplasms pathology, Deoxycytidine administration & dosage, Deoxycytidine adverse effects, Deoxycytidine therapeutic use, Disease-Free Survival, Drug Administration Schedule, Female, Fluorouracil administration & dosage, Fluorouracil adverse effects, Fluorouracil therapeutic use, Humans, Male, Middle Aged, Neoplasm Metastasis, Oxaloacetates, Prospective Studies, Time Factors, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Colorectal Neoplasms drug therapy, Deoxycytidine analogs & derivatives, Fluorouracil analogs & derivatives
- Abstract
Purpose: The aim of this study was to evaluate safety and toxicity of chronomodulated capecitabine administered in the morning and at noon according to a specific time schedule (Brunch Regimen: Breakfast and Lunch) as a part of first-line XELOX chemotherapy in patients with metastatic colorectal cancer., Methods: A total of 30 treatment-naïve colorectal cancer patients with metastatic disease were included. Oxaliplatin 130 mg/m(2) on day 1 plus chronomodulated oral capecitabine 2000 mg/m(2) per day were administered (50 % dose at 8:00 a.m. and 50 % dose at 12:00 noon on days 1-14, every 21 days). All adverse events, treatment responses and survival were evaluated. In addition, pharmacokinetic profile of capecitabine was examined in a subset of 5 patients., Results: Median age was 57.1 years (range 32-77 years). Median follow-up was 19 months (range 3-36 months). Three patients (10 %) had complete response, 13 patients (43.3 %) had partial response and 4 patients (13.3 %) had stabile disease. Ten patients had progressive disease at their first evaluation (33.3 %). The median progression-free survival (PFS) was 10 months (range 2-36 months). There were no grade 4 toxicities. One patient (3.3 %) had grade 3 neutropenia. Hand-foot syndrome developed in three patients (10 %): 6.6 %, grade 1 and 3.3 %, grade 2., Conclusions: Chronomodulated XELOX seems to represent a promising therapeutic option in the first-line treatment of metastatic colorectal carcinoma due to good tumor control and favorable toxicity profile. Phase III randomized trials are required to assess the actual clinical efficacy and side effect profile of this regimen.
- Published
- 2016
- Full Text
- View/download PDF
12. Carbon tetrachloride-induced kidney damage and protective effect of Amaranthus lividus L. in rats.
- Author
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Yilmaz-Ozden T, Can A, Karatug A, Pala-Kara Z, Okyar A, and Bolkent S
- Subjects
- Animals, Antioxidants pharmacology, Catalase metabolism, Disease Models, Animal, Glutathione metabolism, Glutathione Peroxidase metabolism, Glutathione Reductase metabolism, Glutathione Transferase metabolism, Kidney pathology, Kidney Diseases chemically induced, Lipid Peroxidation drug effects, Male, Oxidative Stress drug effects, Peroxidase metabolism, Protective Agents pharmacology, Rats, Rats, Wistar, Superoxide Dismutase metabolism, Amaranthus chemistry, Carbon Tetrachloride toxicity, Kidney drug effects, Kidney Diseases drug therapy, Plant Extracts pharmacology
- Abstract
This study was designed to evaluate the protective effect of water extract of Amaranthus lividus L. (A. lividus) (Amaranthaceae) on carbon tetrachloride (CCl4)-induced toxicity in kidneys of rats. For this purpose, male albino Wistar rats were pretreated with A. lividus (250 and 500 mg/kg body weight (b.w.)) daily for 9 days and a single dose of CCl4 was applied intraperitoneally (50% in olive oil; 1.5 mL/kg b.w.) on the 10th day. All rats were killed 24 h after CCl4 administration, and kidneys were excised and used for determination of histopathological and biochemical parameters. CCl4 administration caused a remarkable increase in lipid peroxidation (LPO) and glutathione levels and glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, myeloperoxidase (MPO) activities and a decrease in catalase (CAT) activity when compared to the control group. Pretreatment with A. lividus (250 and 500 mg/kg b.w.) significantly prevented the elevation in LPO level and MPO activity as well as protected the decrease in CAT activity but did not alter other biochemical parameters. The protective effect of A. lividus was further evident through the decreased histological alterations in kidneys. In conclusion, this study has indicated that A. lividus possesses protective and antioxidant effects against CCl4-induced oxidative kidney damage., (© The Author(s) 2014.)
- Published
- 2016
- Full Text
- View/download PDF
13. The effect of terpenes on percutaneous absorption of tiaprofenic acid gel.
- Author
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Okyar A, Nuriyev M, Yildiz A, Pala-Kara Z, Ozturk N, and Kaptan E
- Subjects
- Administration, Cutaneous, Animals, Anti-Inflammatory Agents, Non-Steroidal adverse effects, Anti-Inflammatory Agents, Non-Steroidal blood, Area Under Curve, Cyclohexenes pharmacology, Dosage Forms, Drug Delivery Systems, Gels metabolism, Gels pharmacology, Limonene, Male, Menthol pharmacology, Permeability drug effects, Propionates adverse effects, Propionates blood, Rats, Rats, Wistar, Sesquiterpenes pharmacology, Skin drug effects, Skin metabolism, Skin Absorption, Solubility drug effects, Anti-Inflammatory Agents, Non-Steroidal administration & dosage, Anti-Inflammatory Agents, Non-Steroidal pharmacokinetics, Propionates administration & dosage, Propionates pharmacokinetics, Terpenes pharmacology
- Abstract
Tiaprofenic acid is a potent analgesic and nonsteroidal anti-inflammatory drug (NSAID) and like any other nonsteroidal anti-inflammatory drug, oral administration of the conventional dosage forms of tiaprofenic acid invariably causes gastrointestinal side effects. In an effort to eliminate these side effects while enhancing the drug concentration at the target tissue, an epidermal application of tiaprofenic acid seems to be an effective alternative drug delivery modality. This study attempts to demonstrate the influence of different terpenes (d-limonene, menthol and nerolidol) in various combinations of preparations on the percutaneous penetration of tiaprofenic acid from Carbopol(®) 940 based gel formulations (1%) in an ex vivo experiment using Franz-type diffusion cells. The enhancement effect of terpenes on skin absorption of tiaprofenic acid was further evaluated by an in vivo method in rats. Amongst the terpenes used, d-limonene was the most outstanding penetration enhancer that was reference to penetration of tiaprofenic acid through rat skin ex vivo. In vivo penetration study shows that the AUC₀(-)₄₈(h) was increased by about 10 fold by the addition of 5% d-limonene to the formulation. Histological studies show that d-limonene causes disruption on the skin surface and is responsible for enhanced penetration of tiaprofenic acid. Since tiaprofenic acid is known to cause gastrointestinal disturbances following systemic administration, topical formulations of tiaprofenic acid in gel form including 5% d-limonene could be suggested as an alternative.
- Published
- 2010
- Full Text
- View/download PDF
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