Organisms Commons^™

Plasma Pharmacokinetics And Tissue Disposition Of Novel Dextran- Methylprednisolone Conjugates With Peptide Linkers In Rats, Suman Penugonda, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

The plasma and tissue disposition of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP-1) or five (DMP-5) amino acids as linkers were studied in rats. Single 5-mg/kg doses (MP equivalent) of each prodrug or MP were administered intravenously, and blood and tissue samples were collected. Prodrug and drug concentrations were quantitated using HPLC, and noncompartmental pharmacokinetic parameters were estimated. Whereas conjugation of MP with dextran in both prodrugs substantially decreased the clearance of the drug by ∼200-fold, the accumulations of the drug in the liver, spleen, and kidneys were significantly increased by conjugation. However, the extent of accumulation …

Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar

Pharmacy Faculty Articles and Research

A specific and sensitive liquid chromatography (LC)-tandem mass spectrometric method for quantitative determination of methylprednisolone (MP) in rat plasma and liver was developed and validated using triamcinolone acetonide as an internal standard. Liquid-liquid extraction using tert-butyl methyl ether was used to extract the drug and the internal standard from plasma and liver. The separation of MP was performed on a C(18) column with a mobile phase of acetonitrile:0.5% formic acid aqueous solution (85:15, v/v) over 4 min. The assay was based on the selected reaction monitoring transitions at m/z 375 -> 161 for MP in plasma, 375 -> 357 for …

Trichostatin A Inhibits Corneal Haze In Vitro And In Vivo, Ajay Sharma, Maneesh M. Mehan, Sunilima Sinha, John W. Cowden, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

PURPOSE. Trichostatin A (TSA), a histone deacetylase inhibitor, has been shown to suppress TGF- –induced fibrogenesis in many nonocular tissues. The authors evaluated TSA cytotoxicity and its antifibrogenic activity on TGF- –driven fibrosis in the cornea with the use of in vitro and in vivo models.

METHODS. Human corneal fibroblasts (HSFs) were used for in vitro studies, and New Zealand White rabbits were used for in vivo studies. Haze in the rabbit cornea was produced with photorefractive keratectomy (PRK) using excimer laser. Trypan blue exclusion and MTT assays evaluated TSA cytotoxicity to the cornea. Density of haze in the rabbit …

The First Total Synthesis Of (±)-4-Methoxydecanoic Acid: A Novel Antifungal Fatty Acid, Nestor Carballeira, Carlos Miranda, Keykavous Parang

Pharmacy Faculty Articles and Research

The hitherto unknown (±)-4-methoxydecanoic acid was synthesized in six steps and in 25% overall yield starting from commercially available 4-penten-1-ol. The title compound demonstrated 17-fold higher antifungal activity (MIC = 1.5 mM) against Candida albicans ATCC 60193 and Cryptococcus neoformans ATCC 66031 when compared to unsubstituted n-decanoic acid. Our results demonstrate that mid-chain methoxylation appears to be a viable strategy for increasing the fungitoxicity of fatty acids.

Helical Peptides Derived From Lactoferrin Bind Hepatitis C Virus Envelope Protein E2, Reem Beleid, Donna Douglas, Norman Kneteman, Kamaljit Kaur

Pharmacy Faculty Articles and Research

Hepatitis C virus is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma infecting more than 170 million people. Hepatitis C virus envelope 2 glycoprotein (E2) binds several cell‐surface molecules that act as receptor candidates mediating hepatitis C virus entry into hepatocytes. Peptides derived from human lactoferrin have been shown to bind hepatitis C virus‐E2 protein thereby preventing hepatitis C virus entry in cultured hepatocytes. In this study, starting from a 33‐residue human lactoferrin‐derived peptide, a number of biotin‐linked α‐peptides were synthesized and investigated for their E2 protein binding activity. E2 protein from hepatitis C virus genotype 1b …

Synthesis And In Vitro Characterization Of Novel Dextran- Methylprednisolone Conjugates With Peptide Linkers: Effects Of Linker Length On Hydrolytic And Enzymatic Release Of Methylprednisolone And Its Peptidyl Intermediates, Suman Penugonda, Anil Kumar, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

To control the rate of release of methylprednisolone (MP) in lysosomes, new dextran-MP conjugates with peptide linkers were synthesized and characterized. Methylprednisolone succinate (MPS) was attached to dextran 25 kDa using linkers with 1-5 Gly residues. The release characteristics of the conjugates in pH 4.0 and 7.4 buffers, blood, liver lysosomes, and various lysosomal proteinases were determined using a size-exclusion and/or a newly developed reversed-phase HPLC method capable of simultaneous quantitation of MP, MPS, and all five possible MPS-peptidyl intermediates. We synthesized conjugates with >= 90% purity and 6.9-9.5% (w/w) degree of MP substitution. The conjugates were stable at pH …

Effects Of Methylprednisolone And Its Liver-Targeted Dextran Prodrug On Ischemia–Reperfusion Injury In A Rat Liver Transplantation Model, Anjaneya Chimalakonda, Reza Mehvar

Pharmacy Faculty Articles and Research

Purpose. To evaluate the effectiveness of a liver-targeted dextran prodrug (DMP) of methylprednisolone ( MP) in cold preservation-warm reperfusion injury associated with liver transplantation.

Methods. The effects of donor pretreatment with single 5 mg/kg doses of MP or DMP on ischemia reperfusion damage to the liver were studied after 8 or 24 h of cold preservation in both isolated perfused rat liver (IPRL) and syngeneic orthotopic rat liver transplantation (OLT) models.

Results. In IPRL studies, donor pretreatment with DMP, and to a lesser degree MP, significantly improved the uptake of hyaluronic acid (HA), a marker of endothelial …

Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang

Pharmacy Faculty Articles and Research

4-Thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 6603 1), and Aspergillus niger (ATCC 16404) (MIC = 4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks P-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by a-substitution. The unprecedented (+/-)-2-tiydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic …

Rapid Determination Of Reduced And Oxidized Glutathione Levels Using A New Thiol-Masking Reagent And The Enzymatic Recycling Method: Application To The Rat Liver And Bile Samples, Imam H. Shaik, Reza Mehvar

Pharmacy Faculty Articles and Research

A microtiter plate assay for quantitation of reduced (GSH) and oxidized (GSSG) glutathione in the rat liver tissue and bile is described. The assay is based on the established enzymatic recycling method and a new thiol-masking reagent, 1-methyl-4-vinyl-pyridinium trifluoromethane sulfonate (M4VP). Samples were first processed by homogenization with (liver) or addition of (bile) sulfosalicylic acid. The total glutathione and GSSG were then determined before and after rapid (>= 2 min) and efficient (100%) masking of the GSH content of the samples with M4VP followed by the enzymatic recycling assay. The percentages of error and coefficient of variation of the …

Attenuation Of Acute Rejection In A Rat Liver Transplantation Model By A Liver-Targeted Dextran Prodrug Of Methylprednisolone, Anjaneya Chimalakonda, Donald L. Montgomery, Jon A. Weidanz, Imam H. Shaik, Justin H. Nguyen, John J. Lemasters, Eiji Kobayashi, Reza Mehvar

Pharmacy Faculty Articles and Research

Background. The use of methylprednisolone (MP) and other corticosteroids for the treatment of acute liver allograft rejection is associated with severe toxicities in nontarget tissues. Therefore, selective delivery of NIP to the liver may improve its efficacy and alleviate its side effects. We investigated the effects of a novel liver-targeted dextran prodrug of MP (DMP) in an orthotopic rat liver transplantation (OLT) model.

Methods. The model consisted of a high responder rejection strain combination (Dark Agouti donors and Lewis recipients). Liver recipients were intravenously administered saline or a single subtherapeutic dose of MP (5 mg/kg) as the parent …

Stromal Haze, Myofibroblasts, And Surface Irregularity After Prk, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, William Dupps, Steven E. Wilson

Pharmacy Faculty Articles and Research

The aim of this study was to investigate the relationship between the level of stromal surface irregularity after photorefractive keratectomy (PRK) and myofibroblast generation along with the development of corneal haze.

Variable levels of stromal surface irregularity were generated in rabbit corneas by positioning a fine mesh screen in the path of excimer laser during ablation for a variable percentage of the terminal pulses of the treatment for myopia that does not otherwise generate significant opacity. Ninety-six rabbits were divided into eight groups[.]

Slit lamp analysis and haze grading were performed in all groups. Rabbits were sacrificed at 4 hr …

Effect Of Prophylactic And Therapeutic Mitomycin C On Corneal Apoptosis, Cellular Proliferation, Haze, And Long-Term Keratocyte Density In Rabbits, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, Pankaj C. Gupta, Steven E. Wilson

Pharmacy Faculty Articles and Research

PURPOSE—To determine the mechanism through which topical mitomycin C prevents and treats corneal haze after photorefractive keratectomy (PRK) and to examine the effects of dosage and duration of exposure.

METHODS—In 224 New Zealand rabbits, −9.0 diopter PRK with mitomycin C or balanced salt solution was performed. Haze level was graded at the slit-lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks, or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67 and α-SMA.

RESULTS—TUNEL-positive apoptotic cells marginally increased in all mitomycin C groups whereas Ki67-positive mitotic cells decreased significantly following mitomycin C application. A greater …

2,6-Hexadecadiynoic Acid And 2,6-Nonadecadiynoic Acid - Novel Synthesized Acetylenic Fatty Acids As Potent Antifungal Agents, Nestor Carballeira, David Sanabria, Clarisa Cruz, Keykavous Parang, Baojie Wan, Scott Franzblau

Pharmacy Faculty Articles and Research

The hitherto unknown 2,6-hexadecadiynoic acid, 2,6-nonadecadiynoic acid, and 2,9-hexadecadiynoic acid were synthesized in two steps and in 11–18% overall yields starting from either 1,5-hexadiyne or 1,8-nonadiyne. Among all the compounds 2,6-hexadecadiynoic acid displayed the best overall antifungal activity against both the fluconazole resistant Candida albicans strains ATCC 14053 and ATCC 60193 (MIC = 11 μM) and against Cryptococcus neoformans ATCC 66031 (MIC < 5.7 μM). The 2,9-hexadecadiynoic acid did not display any significant cytotoxicity against the fluconazole resistant C. albicans strains, but it showed fungitoxicity against C. neoformans ATCC 66031 with a MIC value of <5.8 μM. Other fatty acids, such as 2-hexadecynoic acid, 5-hexadecynoic acid, 9-hexadecynoic acid, and 6-nonadecynoic acid were also synthesized and their antifungal activities compared. The 2-hexadecynoic acid, a known antifungal fatty acid, exhibited the best antifungal activity (MIC = 9.4 μM) against the fluconazole resistant C. albicans ATCC 14053 strain, but it showed a MIC value of only 100 μM against C. albicans ATCC 60193. The fatty acids 2,6-hexadecadiynoic acid and 2-hexadecynoic acid also displayed a MIC of 140–145 μM towards Mycobacterium tuberculosis H37Rv in Middlebrook 7H12 medium. In conclusion, 2,6-hexadecadiynoic acid exhibited the best fungitoxicity profile compared to other analogues. This diynoic fatty acid has the potential to be further evaluated for use in topical antifungal formulations.

Hepatic Disposition Of Cyclosporine A In Isolated Perfused Rat Livers, Reza Mehvar, Anjaneya Chimalakonda

Pharmacy Faculty Articles and Research

PURPOSE. To develop an isolated perfused rat liver model to study the hepatic disposition of cyclosporine A (CyA) in both sexes.

METHODS. Livers were isolated from male (n = 6) and female (n = 7) rats and perfused with a physiological buffer in a single-pass manner. A bolus 1-mg dose of CyA was injected into the inlet catheter and periodical samples (0-15 min) were collected from the outlet perfusate. The concentrations of CyA in the outlet perfusate, collected bile (0-15 min), and liver tissue (at the end of perfusion) were quantitated by HPLC and subjected to statistical moment analysis. …

Dextran-Methylprednisolone Succinate As A Prodrug Of Methylprednisolone: Plasma And Tissue Disposition, Xiaoping Zhang, Reza Mehvar

Pharmacy Faculty Articles and Research

Plasma and tissue disposition of a macromolecular prodrug of methylprednisolone (MP), dextran (70 kDa)–methylprednisolone succinate (DMP), was studied in rats. Single 5‐mg/kg doses of DMP or unconjugated MP were administered into the tail veins of different groups of rats (n  = 4/group/time point). Blood (cardiac puncture) and tissues (liver, spleen, kidney, heart, lung, thymus, and brain) were collected at various times after DMP (0–96 h) or MP (0–2 h) injections. Concentrations of DMP and MP in samples were analyzed by size‐exclusion chromatography (SEC) and reversed‐phase high‐performance liquid chromatography (HPLC), respectively. Conjugation of MP with 70‐kDa dextran resulted in 22‐, …

Effect Of Actinomycin D And Cycloheximide On Ischemic Preconditioning-Induced Delayed Cardioprotective Effect In Rats, Devinder Singh, Ajay Sharma, Manjeet Singh

Pharmacy Faculty Articles and Research

The present study was designed to investigate the effect of actinomycin D, a transcription inhibitor, and cycloheximide, a translation inhibitor, on the delayed cardioprotective effect of ischemic preconditioning. Left thoracotomy was performed in anaesthetized rats at 4th/5th intercostal space and polypropylene suture (5-0) was employed to occlude left common coronary artery. Ischemic preconditioning was produced by four episodes of 5 min of coronary artery occlusion followed by 5 min of reperfusion and thoracic cavity was sutured. Left thoracotomy was performed again after 24 hr of ischemic preconditioning and left coronary artery was occluded for 30 min followed by reperfusion for …

Role Of KAtp Channels In Reduced Antinociceptive Effect Of Morphine In Streptozotocin-Induced Diabetic Mice, Vivek Sood, Ajay Sharma, Manjeet Singh

Pharmacy Faculty Articles and Research

The nociceptive effect was measured using withdrawal latency in tail flick test in mice rendered diabetic by administering streptozotocin (200 mg/kg, i.p.). The antinociceptive effect of morphine (4 and 8 mg/kg, s.c.) and cromakalim, a KATP channel opener, (0.3, 1 and 2 micrograms, i.c.v.) was significantly reduced in diabetic mice. Moreover, co-administration of cromakalim(0.3 microgram) did not alter the reduced antinociceptive effect of morphine(4 mg/kg) in diabetic mice. Spleenectomy in diabetic mice restored the decrease in antinociceptive effect of morphine and cromakalim. Multiple dose treatment with insulin to maintain euglycaemia for 3 days in diabetic mice prevented the decrease in …

The Amino Acid Sequence Of The Adult Sumatran Tiger (Panthera Tigris, Carnivora) Hemoglobins, Meeno Jahan, Aftab Ahmed, Gerhard Braunitzer, Reinhard Göltenboth

Pharmacy Faculty Articles and Research

The complete amino-acid sequences of the hemoglobins from the adult Sumatran tiger (Panthera tigris sumatrae) have been determined on automatic liquid- and gas-phase sequenators. The globin chains were isolated by reverse phase HPLC on a column of Nucleosil-C4.7V-Acetylserine was detected by FAB-mass spectroscopy as TV-terminal amino acid residue of the βI chain. Comparing the sequences of the globin chains of the tiger with that of human Hb-A, 23 substitutions were recognized in the a, 29 in βI and 28 in the βII chain.

The Primary Structure Of Hemoglobins Of The Adult Jaguar (Panthera Onco, Carnivora), Aftab Ahmed, Meeno Jahan, Zafar H. Zaidi, Gerhard Braunitzer, Reinhard Göltenboth

Pharmacy Faculty Articles and Research

The primary structure of the hemoglobins from Jaguar (Panthera onco) are presented. Electrophoretic separations without and with a dissociating agent revealed the presence of two hemoglobin components, OL2ß\ and a2 02. The separation of the hemoglobin components was achieved by ion-exchange chromatography. The globin chains were separated by ion-exchange chromatography and also by reversed phase HPLC. The amino-acid sequences of the native chains and peptides were determined by liquid-phase and gas-phase sequencing. N-Acetylserine was detected by FAB-mass spectroscopy as N-terminal group of the ßl chain. The sequences are compared with that of human hemoglobin (Hb A).