Association of Genetic polymorphisms of EDN1 gene and Endothelin-1 level in patients with type 2 diabetes mellitus in the Jordanian population

Endothelin-1 (ET-1) is one of the most potent vasoconstrictors, encoded by the endothelin-1 (EDN1) gene. It has been shown to play an important role in different diseases including Diabetes Mellitus (DM). Various single nucleotide polymorphisms (SNPs) in the EDN1 gene are related to microvascular complications of type 2 diabetes mellitus (T2DM) such as retinopathy, neuropathy and nephropathy. This study aims to determine the association between two selected EDN1 gene polymorphisms (rs2071942 G > A, rs5370 G > T) and T2DM in the Jordanian population, also to measure the level of ET-1 in T2DM. The samples were collected from the National Center of Diabetes, Endocrinology, and Genetics- Amman, Jordan, including 97 patients with T2DM and 80 healthy individuals. PCR-RFLP was used for SNPs genotyping. ET-1 level was determined using IQELISA kits. The univariate analysis for both SNPs didn't show statistically significant differences in the genotype or allele frequencies among T2DM cases as well as in controls. The same results were obtained regarding ET-1 concentration. The subgroup analysis by sex showed that the genotype and allelic frequencies of rs5370, rs2071942 G/A polymorphisms were not significantly different in males and females. Multivariate Analysis adjusted for various confounders didn't express statistical significance difference for occurrences of both SNPs. However, height and gender showed to be significant risk factors for occurrences of heterozygote alleles in both SNPs. On the other hand, the duration of diabetes has appeared to be related to the recessive allele in rs5370.

Association of KDR rs1870377 genotype with clopidogrel resistance in patients with post percutaneous coronary intervention

Background

Clopidogrel is an antiplatelet therapy that is widely used in pre and post percutaneous (PCI) coronary intervention procedures to prevent platelet aggregation and stent restenosis. However, there is a wide inter-individual variation in clopidogrel response and some patients showed resistance against the activity of Clopidogrel. Kinase insert domain receptor (KDR) gene is responsible for the transcription of vascular endothelial growth factor receptor 2 (VEGFR2) that plays a major role in the cardiovascular diseases (CVDs) and platelet aggregation. The aim of this study was to find out the association of KDR rs1870377 genotype with clopidogrel resistance (CR) in CVD patients, of Iraqi Arabic origin, hospitalized for elective PCI.

Materials and methods

This study was a case-control study with a total of 324 PCI patients. Those patients were classified into 213 patients with non-clopidogrel resistant and 111 patients with CR, depending on the analysis of platelet activity phenotype after clopidogrel administration. KDR rs1870377 was genotyped for all patients using polymerase chain reaction-restriction fragment length polymorphism technique and confirmed by DNA Sänger sequencing through applying Biosystems Model (ABI3730x1).

Results

KDR rs1870377 SNP is strongly associated (Chi-sqaure, p vale <0.05) with CR under dominant, co-dominant and recessive models. Additionally, A allele in the rs1870377 SNP may have an impact on the serum levels of VEGFR2 and low density lipoprotein.

Conclusions

KDR rs1870377 SNP is a potential genetic biomarker of CR among CVD patients of Iraqi Arabic origin. Further clinical studies, with larger sample, are required to confirm the findings of this study.

Antimutagenic activities of two suspected anticarcinogenic bifunctional organoiron seleno-terephthalate derivatives

Two newly bifunctional organoiron seleno-terephthalate derivatives (S1 and S2) were synthesized as potential anticarcinogenic compounds. In a previous study, they were found to have antibacterial and/or antifungal activity, while they did not show any mutagenic action. Such compounds were investigated in the present study for their antimutagenic activity. Sodium azide, hydrogen peroxide, and 4-nitro-o-phenylenediamine, as known mutagens for strains TA100, TA102, and TA98 of Salmonella typhimurium, respectively, were used. Both (S1 and S2) compounds showed a strong antimutagenic action of >98% against sodium azide, >70% against hydrogen peroxide, and >65% activity against 4-nitro-o-phenylenediamine. Bearing in mind the strong correlation between mutagenicity and carcinogenicity, the above compounds can be considered as potentially promising anticarcinogens. Therefore, the present results are very encouraging to investigate the above compounds for other biological activities, including their evaluation as anticarcinogens. A suggested mechanism for the antimutagenicity of the tested compounds is presented.

Study of the Effects on DNA of Two Novel Nucleoside Derivatives Synthesized as Potential Anti-HIV Agents

The pursuit of antiviral active compounds against different classes of viruses, in particular HIV, HBV, and HTLV is an area of important and intense research. In the current study, two novel nucleoside derivatives belonging to a new class of isoxazolidine were successfully synthesized as potential anti-HIV agents by replacement of the furanose ring by a N,O-heterocyclic ring Both compounds were investigated for biological activity, namely, mutagenic and antimutagenic properties. Using Salmonella typhimurium strains TA97, TA100, and TA102, both compounds proved to be nonmutagenic, which may be considered an encouraging result to further elucidate other biological activities. Antimutagenic testing of the synthesized compounds revealed that they are active against the base-pair substitution mutagen sodium azide. However, they did not show any indication as antimutagenic agents against hydrogen peroxide and mitomycin C (oxidative mutagens) or against nitrophenylenediamine (a base-pair substitution and frameshift mutagen). Structure-activity relationship is also discussed. Testing these compounds as antiviral agents is highly recommended.

In vitro cytogenetic testing of an organoselenium compound and its sulfur analogue in cultured rat bone marrow cells

Background

Selenium (Se) is a non-metal element, occurring in varying degrees in the environment and it has been found to be a component of several enzymes. Different selenium compounds have been associated with carcinogenicity, toxicity, modification of metal toxicity and prevention of cancer. Organoselenium compounds had substantially greater bioavailability and less toxicity than that of inorganic selenium. From a chemical point of view, Se resembles sulfur (S) in many of its properties, thus, Se and S may be considered to be isosteric. The ability of a synthetic organoselenium compound; cyclopenta-dienyldicarbonyl ironselenoterephthalic acid (CSe) and its sulfur analogue (CS) in the range of 10^-8 to 10^-5 M, to induce sister-chormatid exchanges (SCE) and alter cell division expressed as mitotic index (MI) as well as cell survival has been investigated.

Methods

Rat bone marrow cells were cultured in the presence of CSe and CS in the range of 10^-8 to 10^-5 M with a total exposure time of 4, 16 or 28 h at 37°C. Fluorescence-plus-Giemsa (FPG) technique was used to visualize chromosomes for SCE analysis and MI determination. Trypan blue exclusion technique was used to determine cell viability.

Results

At the three exposure times, cell survival progressively decreased with increasing concentration, but the effect of either chemical was not significant (ANOVA; P < 0.05) as compared to the negative control. Significant reductions in MI were calculated at the highest concentration (10^-5 M) when either chemical was applied for 16 or 28 h. Furthermore, the mean SCE increased with longer exposure times and, in general, CSe had slightly greater effect on cell survival and caused higher frequencies of SCE than CS. The exception was the 10^-8 M treatment. However, both CSe and CS failed to induce 2-fold SCE as that of the negative control and therefore they are not considered as mutagens.

Conclusion

Both CSe and CS in the range of 10^-8 to 10^-5 M could not double the SCE rate of the negative control and therefore not considered as mutagens at these experimental conditions.

Element analysis and biological studies on ten oriental spices using XRF and Ames test

Ten oriental spices were analyzed for their element composition using X-ray fluorescence (XRF): nutmeg (Myristica fragrans), coriander (Coriandrum sativum), safflower (Carthamus tinctorius), caraway (Carum carvi), Sicilian sumac (Rhus coriaria), aniseed (Anisum vulgare), black pepper (Piper nigrum), cardamom (Elettaria cardamomum), cumin (Cuminum cyminum) and nigella (Nigella sativum). The spices were found to contain the following elements: Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu and Zn, with varying concentrations. Mutagenic studies using Salmonella typhimurium strains TA97a, TA98, TA100, and TA102 showed that the above spices have no base pair substitution mutagenic activity. However, a weak frameshift mutagenicity has been shown by nutmeg and a very weak oxidative mutagenic action has been revealed by cumin.

Synthesis, antibacterial, antifungal and genotoxic activity of bis-1,3,4-oxadiazole derivatives

In the present investigation, four 1,3,4-bis-oxadiazole derivatives were synthesized as potential antimicrobial agents. The compounds are: 5,5'-dimercapto-bis-[1,3,4-oxadiazol-2-yl]propane (2a), 5,5'-dimercapto-bis-[1,3,4-oxadiazol-2-yl]butane (2b), 5,5'-dimercapto-bis-[1,3,4-oxadiazol-2-yl]octane (2c) and 5,5'-dibenzylthio-bis-[1,3,4-oxadiazol-2-yl]butane (3). The above newly synthesized compounds were investigated for their antibacterial, antifungal and mutagenic activities. The results of the biological activities revealed that the compounds 2a-c exhibited both antibacterial and antifungal activities against S. aureuss and B. subtilis. Compound 2a also showed activity against P. aeureoginosa. All the above compounds and compound 3 exhibited activity against C. albicans. Genotoxic studies showed that compound 2a had a weak base pair substitution mutagenicity but none of them exhibited a frameshift mutagenic action using Ames test.

Synthesis of 2,5-disubstituted-1,4-benzoquinone derivatives as potential antimicrobial and cytotoxic agents

A number of 2,5-disubstituted-1,4-benzoquinone derivatives were prepared and characterized by elemental analysis, infrared (IR), nuclear magnetic resonance (1H-NMR), and mass spectra (MS). These compounds and their synthetic precursors were evaluated for their in vitro antimicrobial and cytotoxic activity. The most potent antimicrobial compound was the thiadiazolyl derivative 4b, which was 2- to 4 times more active than the antimicrobial drug sulfathiazole. All the tested compounds were active in the Brine Shrimp Lethality (BS) Test. Compound 4e which was the most active in the BS test was also found to possess a significant cytotoxicity against two tumor cell lines. Some of the compounds were found to be mutagenic at relatively high concentration.

Chromosome aberrations, sister-chromatid exchanges and cell-cycle kinetics in human peripheral blood lymphocytes exposed to organoselenium in vitro

The ability of 2 synthetic organoselenium compounds, a dimer of p-methoxybenzeneselenol (DPMBS) and benzylselenocyanate (BSC), to induce sister-chromatid exchanges (SCE) and chromosome aberrations (CA) as well as to alter the progression of the cell through mitosis has been investigated in cultured human lymphocytes. Cultures treated with the highest concentration (2.27 x 10(-5) M) of the 2 compounds exhibited about a 3-fold increase in the level of SCE and about 2-3-fold increase in the incidence of CA. In addition, the 2 selenium compounds led to an inhibition of cell proliferation as was evidenced by the depression of the proliferation rate index (PRI).

Reformation of reduced disulfide bonds of pepsinogen and pepsin: role of the phosphate group

Reduction of the disulfide bonds in pepsinogen and pepsin with 2-mercaptoethanol eliminated the proteolytic activity of the enzyme and the potential proteolytic activity of the zymogen. Removal of the reducing agent followed by airation resulted in reformation of the disulfide bonds in the phospho-forms of pepsinogen and pepsin, but not in the dephospho-forms. To account for the role of the phosphate group in the stabilization of the native conformation even at reduced states of the zymogen and the enzyme, it is suggested that the group which is linked to the seryl residue is also linked to another amino acid residue in the form of anhydride, hydrogen bond(s), or/and ionic interaction.