Antitumor activities on HL-60 human leukemia cell line, molecular docking, and quantum-chemical calculations of some sulfonamide-benzoxazoles.

We previously synthesized some novel benzoxazole derivatives-containing sulfonamide. In this study, the compounds were investigated for their antitumor activities against the HL-60 human leukemia cells, using the MTT assay. Moreover, quantum chemical calculations using the DFT methods were applied for understanding the difference in antitumor activity. Additionally, molecular docking into active site of the DNA Topo II enzyme was performed on 3QX3. PDB file in order to find out possible mechanism of antitumor effect. According to all obtained results showed that compounds 1b, 1c, and 1d could be potential drug candidates as new antitumor agents, and are promising for cancer therapy.

Aberrant expressions of leptin and adiponectin receptor isoforms in chronic myeloid leukemia patients.

BACKGROUND: Leptin and adiponectin receptors mediate the role of leptin in stimulating the growth of leukemic cells and the protective function of adiponectin undertaken in several malignancies such as leukemia. In this study, we investigated the involvement of the expression of leptin and adiponectin receptors in chronic myeloid leukemia (CML) pathogenesis. METHODS: The expression of leptin receptor isoforms, OB-Rt, OB-Ra, and OB-Rb, and the expression of adiponectin receptors, AdipoR1 and AdipoR2, were measured as mRNA levels in two CML cell lines (K562 and Meg-01) and 20 CML patients and 24 healthy controls by using RT-PCR. RESULTS: OB-Rt and OB-Ra isoforms expression of the leptin receptors were found to be significantly lower in Meg-01 cell lines than K562 cells. All leptin receptors were downregulated in CML patients and more particularly OB-Rb level was found to be undetectably low in normal PBMC as well as in CML patients. AdipoR1 expression level was higher in Meg-01 than in K562, whereas AdipoR2 level was found to be unchanged in both cell lines. Interestingly, while AdipoR1 expression increased in CML patients, AdipoR2 decreased. Moreover, imatinib therapy did not affect both leptin and adiponectin isoform expressions. CONCLUSION: While the decrease in leptin receptor levels in CML patients was confirmed, the increase in AdipoR1 levels and relevant decrease in AdipoR2 levels depicted their possible involvement in CML pathogenesis. This suggests different functions of adiponectin receptors in CML development.

Ex vivo produced oral mucosa equivalent by using the direct explant cell culture technique.

OBJECTIVE: The aim of this study is the histological and immunohistochemical evaluation of ex vivo produced oral mucosal equivalents using keratinocytes cultured by direct explant technique. MATERIAL AND METHODS: Oral mucosa tissue samples were obtained from the keratinized gingival tissues of 14 healthy human subjects. Human oral mucosa keratinocytes from an oral mucosa biopsy specimen were dissociated by the explant technique. Once a sufficient population of keratinocytes was reached, they were seeded onto the type IV collagen coated "AlloDerm" and taken for histological and immunohistochemical examinations at 11 days postseeding of the keratinocytes on the cadaveric human dermal matrix. RESULTS: Histopathologically and immunohistochemically, 12 out of 14 successful ex vivo produced oral mucosa equivalents (EVPOME) that consisted of a stratified epidermis on a dermal matrix have been developed with keratinocytes cultured by the explant technique. CONCLUSION: The technical handling involved in the direct explant method at the beginning of the process has fewer steps than the enzymatic method and use of the direct explant technique protocol for culturing of human oral mucosa keratinocyte may be more adequate for EVPOME production.

Resveratrol shows vasoprotective effect reducing oxidative stress without affecting metabolic disturbances in insulin-dependent diabetes of rabbits.

PURPOSE: Resveratrol has been shown to have vasoprotective effects by upregulating oxidative defense mechanisms in a variety of pathophysiological conditions. However, the effect of resveratrol on diabetic oxidative stress and vascular and metabolic abnormalities is not completely understood. Therefore, this study was designed to evaluate whether long-term resveratrol supplementation has a protective effect on vascular function and integrity in association with metabolic parameters and oxidative stress in insulin-dependent diabetes. METHODS: Diabetes was induced in rabbits with alloxan and maintained for 8 weeks. We used a resveratrol dose of 5 mg/L (10 weeks, starting 14 days before alloxan injection) and 50 mg/L (8 or 10 weeks, starting concomitantly or 14 days before alloxan injection) in the drinking water of rabbits. RESULTS: Relaxation to acetylcholine was impaired (control 75.6 ± 3.59%, versus diabetic 42.23 ± 2.53%) and contractions to phenylephrine increased (control 136.89 ± 2.27%, versus diabetic 159.37 ± 6.27%) in aortas from diabetic animals. These changes were associated with increased basal or NAD(P)H-induced superoxide production, as well as lipid peroxide and superoxide dismutase (SOD) levels in the aortic samples. The maximal relaxation to acetylcholine improved by 75.74 ± 9.04% in diabetic rabbits treated with resveratrol. The increased contractions to phenylephrine were not restored to control values after resveratrol treatments, but sensitivity to the contractions tended to decrease. Resveratrol increased nitrite/nitrate levels and suppressed basal or NAD(P)H-induced superoxide production and lipid peroxide levels in the aortas. Importantly, resveratrol increased serum insulin levels without affecting blood glucose and the lipid profile in diabetic rabbits. Using electron microscopic examinations, resveratrol was found to markedly protect the endothelial integrity from diabetes. CONCLUSION: Overall, there was no noticeable difference between resveratrol treatment groups on the recovery from diabetes. Our results indicate that resveratrol alleviates type 1 diabetes-induced vasculopathy by decreasing vascular oxidative stress and thereby increasing the bioavailability of nitric oxide without changing metabolic abnormalities.

Age-related paraoxonase activity changes in Turkish population.

Paraoxonase1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme capable of hydrolyzing diverse substrates from organophosphate (OP) toxins to oxidized phospholipids. As such, it has been linked with both the prevention of OP poisoning and inhibition of atherosclerosis initiated by oxidatively modified low-density lipoprotein (LDL). The aim of this study was to investigate, with aging, the activity of PON1 associated with HDL and partially responsible for its antiatherogenic activity. The study involved 187 individuals (67 males and 120 females) divided into three groups according to their ages, young (n = 49; 20-44 years, mean age = 30.12 +/- 6.6 years), middle aged (n = 25; 45-64 years, mean age = 52 +/- 5.6 years), and elderly subjects (n = 113; 65-95 years, mean age = 78.94 +/- 6.2 years). Interestingly, serum total cholesterol and LDL-cholesterol levels significantly decreased with age (P < 0.05). The elderly aged group had also significantly lower body mass index than the middle aged group (P < 0.05). Serum paraoxonase activity and HDL cholesterol levels remained unchanged with age. The prevalence of phenotype AA, AB, and BB in our subjects' group was 40.6%, 45.9%, and 13.5%, respectively.

Mitochondrial DNA alterations in aging.

During the aging process, the increase of mitochondrial DNA (mtDNA) alterations has been reported. In this study, we investigated deletions/insertions in the approximately 2.4-kb region (from 14680 to 578 bp) of mtDNA covering D-loop region. A total of 96 individuals (ages between 20 and 94 years) were screened in this study. Genomic DNA was purified from whole blood samples. The 2.4-kb region of mtDNA was amplified with PCR and visualized by agarose gel electrophoresis. The sequence of the amplicon was confirmed in one sample by sequencing. We detected mtDNA deletions in only two cases (ages 26 and 30 years) at this resolution. As a result, there is no increase in the major deletions/insertions in the analyzed mtDNA region with aging. Complete sequencing of this region is needed to detect any age-dependent changes.

Deuteronation and aging.

Deuterium has one proton and one neutron in its atomic nucleus, but hydrogen has only proton. The natural abundance of deuterium is 1 per approximately 6600 hydrogen atoms. Therefore deuterated water (both HOD + D(2)O [heavy water]) abundance is 1 per approximately 3300 water molecules. One dissociation product of deuterated and heavy water is deuteron (proton + neutron, D(+), H(2)OD(+)/D(3)O(+)). Because heavy water has a lower ionization constant than water, the D(+)/H(+) ratio is approximately 1/15,000 in biological fluids. O-D bond length is shorter than O-H, and D-O-D angle is lesser than H-O-H. Once a deuteron exchanges with proton on the water-exposed surface of a macromolecule, it can lead to a conformational change and the reverse exchange will be less likely. Deuteron bonds are stronger than proton bonds. Therefore an increase of deuteronated macromolecules can be expected in due course of time. In order to test this hypothesis, we conducted a pilot study and measured the D/H ratio in the tails of three Sprague-Dawley rats at different ages (4 weeks, 5 weeks, and >1-year old) by elemental analysis coupled with isotope ratio mass spectrometry (EA-IRMS) technique. To prevent the effect of daily water consumption, the homogenized tails were lyophilized before analysis. The results, as mean of several measurements, of 4 weeks, 5 weeks, and >1-year-old rats were per thousand-94 +/- 9.56, per thousand-101.71 +/- 6.89, per thousand-83.68 +/- 3.46 delta((2)H) relative to VSMOW, respectively. Although there is a slight increase in >1-year-old rat, the difference among the animals was not significant. We propose that, before reaching to a final conclusion about the accumulation of deuterium with aging, the measurements should be done not in whole tissue samples but in purified macromolecules from a larger set of animals.

Assessment of the relationship between the antimutagenic action of riboflavin and glutathione and the levels of antioxidant enzymes.

In this study the role of antioxidant enzymes on the antimutagenic actions of riboflavin and reduced glutathione against mutagenic potentials of 4-nitroquinoline 1-oxide and mitomycin C have been investigated. For this purpose the activities of catalase and superoxide dismutase enzymes have been determined in Salmonella typhimurium TA102 and TA100 strains preincubated with different combinations of 4-nitroquinoline 1-oxide, mitomycin C, riboflavin and reduced glutathione for thirty minutes. Also in part of the same samples, the mutagenicity has been determined for each combination of chemicals by using Salmonella preincubation test. The correlation between the levels of antioxidant enzymes and mutagenicity and antimutagenicity has been investigated.While riboflavin displayed a weakly antimutagenic effect on 4-nitroquinoline 1-oxide mutagenicity in TA102 and TA100 (0.25, 0.35 inhibition respectively), it did not have any effect on the strong mutagenicity of mitomycin C in both strains. Reduced glutathione, a well known antioxidant, had no antimutagenic effect against the mutagenicity of both compounds in TA102 and TA100 strains. The antioxidant enzymes, catalase and superoxide dismutase, seemed to have no direct effect on the antimutagenic action of riboflavin and mutagenic action of 4-nitroquinoline 1-oxide and mitomycin C because no change in the activities of catalase and superoxide dismutase was detected in relation to antimutagenicity of riboflavin and mutagenicity of 4-nitroquinoline 1-oxide and mitomycin C in both strains. It should be noted that many antimutagens have more than one mechanism of action and their effect depends on the mutagens being tested.