Riad Awad

Pharmacokinetics and pharmacodynamics profiles of enalapril maleate in healthy volunteers following determination of enalapril and enalaprilat by two specific enzyme immunoassays

Background and objectives:  Most of the pharmacokinetic (PK) parameters for enalapril and enalaprilat were established following determination of the drug and its metabolite, using angiotensin converting enzyme (ACE) inhibition assays. In these methods, enalapril has to be hydrolysed to enalaprilat first and then assayed. The purpose of this study was to re‐estimate the PK parameters of enalapril and enalaprilat in healthy volunteers using two specific enzyme immunoassays for enalapril and enalaprilat.

Two new proanthocyanidin trimers isolated from Cistus incanus L. demonstrate potent anti-inflammatory activity and selectivity to cyclooxygenase isoenzymes inhibition

Abstract Two new proanthocyanidin trimers have been isolated from Cistus incanus herb; gallocatechin-(4α→6)-gallocatechin-(4α→8)-gallocatechin (compound 1) and epigallocatechin-3-O-gallate-(4ß→8)-epigallocatechin-3-O-gallate-(4ß→8)-gallocatechin (compound 2). The structures were determined on the basis of 1D- and 2D-NMR (HSQC, HMBC) of their peracetylated derivatives, MALDI-TOF-MS and by acid-catalysed degradation with phloroglucinol. A more abundant proanthocyanidin oligomer was also isolated, purified and its chemical constitution studied by 13C-NMR and phloroglucinol degradation. The mean molecular weight of the polymer was estimated to be about 7 to 8 flavan-3-ol-units with a ratio of procyanidin : prodelphinidin units at 1:5, some of which are derivatised by gallic acid. Water extract and higher oligomeric proanthocyanidin fractions of C. incanus significantly inhibited TPA-induced oedema when applied topically at doses of 0.5 and 1 mg/ear in mice. Furthermore, the extracts and the pure compounds inhibited COX-1 and COX-2 activities. In addition, compound 2 exhibited an IC50 of 4.5 μM against COX-2 indicating its high selectivity towards COX-2. Graphical abstract

Nationality, Gender, Age, and Body Mass Index Influences on Vitamin D Concentration among Elderly Patients and Young Iraqi and Jordanian in Jordan

Vitamin D is necessary for maintaining and regulating calcium levels; thus, insufficiency of vitamin D increases the risk of many chronic diseases. This study aimed to examine vitamin D levels among Jordanian and Iraqi volunteers and find the relation between vitamin D level and lipid profile patients. Vitamin D levels were evaluated using enzyme-linked immunosorbent assay. For young healthy group subjects, vitamin D levels were 20.60 ± 5.94 ng/mL for Jordanian and 27.59 ± 7.74 ng/mL for Iraqi. Vitamin D concentrations for young males and females were 25.82 ± 8.33 ng/mL and 21.95 ± 6.39 ng/mL, respectively. Females wearing hijab were 20.87 ± 6.45 ng/mL, while uncovered females were 23.55 ± 6.04 ng/mL. For >40 years Iraqi subjects, vitamin D level for healthy was 29.78 ± 9.49 ng/mL and 23.88 ± 7.93 ng/mL for hyperlipidemic subjects. Vitamin D levels for overweight and obese healthy groups were significantly higher (P < 0.050) than those for the hyperlipidemic patients groups. Vitamin D levels for males were significantly higher than females and were significantly higher for healthy than those hyperlipidemic Iraqi patients. These findings showed that vitamin D levels are affected by age, nationality, gender, and health statues and highlight the importance of vitamin D supplementation for groups with low levels particularly old, hijab wearing females, and hyperlipidemic groups.

Determination of loperamide in human plasma and saliva by liquid chromatography–tandem mass spectrometry

A simple and sensitive liquid chromatography-tandem mass spectrometric method for quantification of loperamide in human plasma and saliva was developed and validated, and then successfully applied in pharmacokinetic clinical study to investigate and correlate bioavailability of Imodium(®) 2mg quartet tablet dose in both human plasma and saliva. Loperamide with labeled internal standard was extracted from its biological matrix by methanol as protein direct precipitant in single extraction step. Adequate chromatographic separation for analytes from plasma and saliva matrices was achieved using ACE C18 (50mm×2.1mm, 5μm) column, eluted by water/methanol/formic acid (30:70:0.1%, v/v), delivered isocratically at constant flow rate of 0.75ml/min. The method validation intends to investigate specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to European guideline, and partial validation was applied on saliva, specificity, matrix effect, recovery, sensitivity, within and between day precision and accuracy. The calibration curve was linear through the range of 20-3000pg/ml in both plasma and saliva using a 50μl sample volume. The partial validation sections outcome in saliva was so close to those in plasma. The within- and between-day precisions were all below 8.7% for plasma and below 11.4% for saliva. Accuracies ranged from 94 to 105% for both matrices. In this study, 26 healthy volunteers participated in the clinical study, and 6 of gave their saliva samples in addition to plasma at the same time schedule. The pharmacokinetic parameters of Cmax, AUC0-t and AUC0-∞, Tmax and T1/2 in both plasma and saliva were calculated and correlated.

Enhancing Doxorubicin-Induced MCA-Fibrosarcoma Cytotoxicity by an Eriobotrya japonica Hydrophilic Butanol-Treated Extract through Natural Killer Cells Activation

The combination of cytotoxic drugs with immunotherapy should be more effective than monotherapy alone since both therapeutic modalities may target different mechanisms. In addition, combination therapy may reduce adverse events associated with cytotoxic drugs. Eriobotrya japonica hydrophilic butanol-treated extract (EJWR) was found to modulate cytokines by enhancing IL-12, IFN-γ and TNF-α in vitro and in vivo and within tumor microenvironment. This was associated with enhancing survival time of mice bearing intra-peritoneal MCA fibrosarcoma (MCA FS). In the present work, we evaluated the combination of EJWR with doxorubicin (Dox) on MCA FS cytotoxicity using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay in the absence and presence of spleen cells or Natural Killer (NK) lymphocytes from tumor bearing mice. The results showed that Dox exhibited mild cytotoxicity to healthy spleen cells and EJWR reversed such cytotoxicity. In addition, increasing concentrations of Dox induced 40% (p<0.01) MCA FS cytotoxicity. This percent increased significantly to 60% at Dox 5 μM when co-cultured with NK cells from tumor bearing mice and increased further to 80% (p<0.01) when Dox was combined with EJWR. The latter increase in cytotoxicity was significantly (p<0.01) higher than each agent alone. This enhancement was associated with significant production of TNF-α and retaining IFN-γ levels from NK cells lysates. This concluded that the immunomodulator, EJWR, mediates NK activation and enhances Dox- induced MCA FS cytotoxicity.

Bis(methyl­sulfon­yl)methane

In the title compound, C3H8O4S2, the two central S—C(H2) bond lengths are almost identical [1.781 (2) and 1.789 (2) Å]. In the crystal, each molecule utilizes CH2 and CH3 bonds to form weak C—H⋯O hydrogen bonds to six other molecules, thus linking molecules into a three-dimensional network.

Investigation of possible pharmacokinetic interaction of metformin with sugar replacement sweeteners in rats.

Metformin is widely used for type II diabetes. Sugar replacement sweeteners such as Aspartame and Stevia, are usually consumed concomitantly with other antidiabetics by patients The aim of this work is to investigate possible effects of two types of sweeteners; stevia and aspartame on the pharmacokinetic parameters of metformin in rats. A simple, validated bio-analytical HPLC method was developed to measure metformin in rat plasma. Three groups of rats, each of eight were subjected to this study. The first group was given metformin solution 20mg/kg alone , the second group was given 20 mg/kg metformin with 4mg/kg stevia and the third group was given 20 mg/kg metformin with 10 mg/kg aspartame on fasting state. Blood samples were taken on scheduled time interval up to 6 hours and analyzed for metformin concentration. Pharmacokinetic parameters were calculated by Non-Compartmental Model and data were interpreted. The results showed that administration of these two sweeteners did not have high effect on pharmacokinetics of metformin.