3‐Aryl Coumarin Derivatives Bearing Aminoalkoxy Moiety as Multi‐Target‐Directed Ligands against Alzheimer's Disease

Two series of novel coumarin derivatives, substituted at 3 and 7 positions with aminoalkoxy groups, are synthesized, characterized, and screened. The effect of amine substituents and the length of cross‐linker are investigated in acetyl‐ and butyrylcholinesterase (AChE and BuChE) inhibition. Target compounds show moderate to potent inhibitory activities against AChE and BuChE. 3‐(3,4‐Dichlorophenyl)‐7‐[4‐(diethylamino)butoxy]‐2H‐chromen‐2‐one ( 4y ) is identified as the most potent compound against AChE (IC₅₀=0.27 μm ). Kinetic and molecular modeling studies affirmed that compound 4y works in a mixed‐type way and interacts simultaneously with the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. In addition, compound 4y blocks β‐amyloid (Aβ) self‐aggregation with a ratio of 44.11 % at 100 μm and significantly protects PC12 cells from H₂O₂‐damage in a dose‐dependent manner.     

Antileishmanial and Cytotoxic Effects of Essential Oil and Methanolic Extract of Myrtus communis L.

Plants used for traditional medicine contain a wide range of substances that can be used to treat various diseases such as infectious diseases. The present study was designed to evaluate the antileishmanial effects of the essential oil and methanolic extract of Myrtus communis against Leishmania tropica on an in vitro model. Antileishmanial effects of essential oil and methanolic extract of M. communis on promastigote forms and their cytotoxic activities against J774 cells were evaluated using MTT assay for 72 hr. In addition, their leishmanicidal activity against amastigote forms was determined in a macrophage model, for 72 hr. Findings showed that the main components of essential oil were α-pinene (24.7%), 1,8-cineole (19.6%), and linalool (12.6%). Findings demonstrated that M. communis, particularly its essential oil, significantly (P<0.05) inhibited the growth rate of promastigote and amastigote forms of L. tropica based on a dose-dependent response. The IC₅₀ values for essential oil and methanolic extract was 8.4 and 28.9 μg/ml against promastigotes, respectively. These values were 11.6 and 40.8 μg/ml against amastigote forms, respectively. Glucantime as control drug also revealed IC₅₀ values of 88.3 and 44.6 μg/ml for promastigotes and amastigotes of L. tropica, respectively. The in vitro assay demonstrated no significant cytotoxicity in J774 cells. However, essential oil indicated a more cytotoxic effect as compared with the methanolic extract of M. communis. The findings of the present study demonstrated that M. communis might be a natural source for production of a new leishmanicidal agent.     

Physio-morphological and structural changes in common bermudagrass and Kentucky bluegrass during salt stress

Environmental pollution has increased human attention toward developing green spaces every day. One of the most important goals in developing green spaces is to create beautiful and pleasant scenes and consequently creating mental relaxation; turfs are the most important plants for this purpose. One factor which affects the growth of plants in arid and semi-arid regions is the salinity of the water and soil; therefore, using some types of turfgrasses which are tolerant to salinity is a key factor for culturing them more in the city landscapes in such regions. The aim of this study was to investigate the physio-morphological and structural changes in common bermudagrass (Cynodon dactylon [L.] Pers., as more tolerant species) and Kentucky bluegrass (Poa pratensis L., as less tolerant species) under salt stress condition. The salt stress treatments were applied by seven concentrations of NaCl + CaCl₂ (1:1 proportion based on the final EC) including: 0.0, 2.5, 5.0, 7.5, 10.0, 12.5 and 15.0 dS m^?1. This study was conducted in a completely randomized design with factorial arrangements, each treatment with four replications. Data were analyzed and means were compared using LSD test at 5 % level. Results showed that with increasing salinity levels Kentucky bluegrass started to decrease in visual quality at 2.5 dS m^?1, but bermudagrass’ visual quality was still acceptable at 5.0 dS m^?1. Furthermore, increasing the salinity level caused a reduction in the following indices in both species: shoot height, shoot fresh and dry weight, root fresh and dry weight, leaf area, photosynthetic rate, total chlorophyll, and starch level. However, the reducing sugar levels and indices of proline, and catalase and superoxide dismutase enzymes had shown an increasing trend while salinity increased. However, reducing sugar levels, and catalase and superoxide dismutase activities decreased at salinity levels higher than 10 dS m^?1. Structural studies showed that bermudagrass, with help of bulliform cells, could prevent water loss and tolerate the higher salinity levels. Based on these results, it can be concluded that under the no salinity condition Kentucky bluegrass has more folded leaves than common bermudagrass, however, bermudagrass is more tolerant because of thicker epidermis. Under high salinity conditions, bermudagrass kept their leaves folded, whereas the leaf structure was drastically damaged in bluegrass and no folded leaf was seen at 15 dS m^?1. Further ultrastructural studies are needed to clarify more the changes occurring in leaves under salinity stress condition.     

Anti-fungal resistance in candida isolated from oral and diaper rash candidiasis in neonates

The purpose of the present study is to evaluate the sensitivity of Candida species isolated from oral candidiasis and diaper dermatitis infections in children. The children referring to private and public clinics in Ilam, Iran were exmined for oral candidiasis and diaper dermatitis. In this study, 248 oral candidiasis and diaper dermatitis samples were collected and cultured.Candida species were identified by using standard methods. Resistance and sensitivity to amphotericin B, nystatin, ketoconazole, fluconazole, itraconazole, clotrimazole, and posaconazole were determined using the CLSI M44-A standard disk diffusion method. From the 248 studied samples, 149 were positive for Candida, among which the Candida albicans was the most prevalent (64.4%). The resistance of different Candida species to nystatin, itraconazole, fluconazole, ketoconazole, clotrimazole, voriconazole, and posaconazole were 4, 43, 34.2, 34.9, 21.5, 6, and 6.7%, respectively. No resistance to amphotericin B was observed. Considering rather low resistance to nystatin, this drug is the best choice for oral candidiasis and diaper dermatitis.     

Age-related macular degeneration and genetic polymorphisms of glutathione <Emphasis Type="Italic">S</Emphasis>-transferases M1 (<Emphasis Type="Italic">GSTM1</Emphasis>) and T1 (<Emphasis Type="Italic">GSTT1</Emphasis>)

The aim of this study is to understand the multifactorial causes of age-related macular degeneration (ARMD), and, therefore, it is reasonable to investigate whether genetic polymorphisms of antioxidant enzymes (GSTM1 and GSTT1) contribute to the development of ARMD. This study consisted of 112 subjects (44 females, 68 males) with exudative ARMD, who were recruited from Khalili Hospital ophthalmic clinic in Shiraz (southern Iran), referred by vitreoretinal surgeon. Also 112 sex-matched controls (44 females, 68 males) were randomly selected from unrelated volunteers in the same clinic. We excluded patients and controls with cataract or past history of cataract surgery, asthma, past history of malignancy, cardiovascular disease that on medication and known cases of glaucoma, because these traits were associated with GSTM1 and/or GSTT1 polymorphisms. There was no association between polymorphisms of neither GSTM1 nor GSTT1 and risk of ARMD. The combination genotypes of GSTM1 and GSTT1 were not associated with the risk of ARMD. We considered the time of deterioration of vision as the time of onset of exudative ARMD. The Kaplan–Meier analysis revealed that there was significant difference between genotypes of GSTM1 (log rank statistic = 7.03, df = 1, P = 0.008). The age at onset among GSTM1 null genotype was lower than the active genotype of GSTM1. Our results support the hypothesis that the protein encoded by the GSTM1 gene might have a protective function against oxidative stress in retina. Since the age at onset is influenced by the GSTM1 polymorphism, this implies that GSTM1 is a modifier gene.     

Thermal stability and enzymatic activity of RNase A in the presence of cationic gemini surfactants

The thermal stability and enzymatic activity of bovine pancreatic ribonuclease A (RNase A) have been investigated in the presence of a homologous series of cationic gemini surfactants (alkanediyl-α,ω-bis(hydroxyethyl methyl hexadecyl ammonium bromide)). UV, circular dichorism and fluorescence spectroscopies have been used for this study. The denaturation curves at various surfactant concentrations were analyzed on basis of a two-transition model to obtain values of T(m) (temperature at the midpoint of denaturation) and ΔH(m) (enthalpy change at T(m)) of each transition. The main conclusion of this study is that these cationic gemini surfactants slightly activate and stabilize RNase A below their critical micelle concentrations at pH 5.0. The cationic gemini surfactant with the shorter spacer interacts more efficiently with RNase A than those with longer spacers.     

Retraction: Effect of controlled and uncontrolled cooling rate on motility parameters of cryopreserved ram spermatozoa

ABSTRACT: Retraction This article [1] has been retracted at the request of the Editor. Although the authors withdrew their submission in order to publish elsewhere, the article was subsequently transmitted to the journal's production department which resulted in it being published in error.