Sezen Canim Ates

Investigation of antileishmanial activities of Tio2@Ag nanoparticles on biological properties of L. tropica and L. infantum parasites, in vitro.

Leishmaniasis is a public health problem which is caused by protozoon parasites belonging to Leishmania species. The disease threatens approximately 350 million people in 98 countries all over the world. Cutaneous Leishmaniasis (CL) and Visceral Leishmaniasis (VL) are the mostly commonly seen forms of the disease. Treatment of the disease has remained insufficient since current antileishmanial drugs have several disadvantages such as toxicity, costliness and drug-resistance. Therefore, there is an immediate need to search for new antileishmanial compounds. TiO2@Ag nanoparticles (TiAg-Nps) have been demonstrated as promising antimicrobial agents since they provide inhibition of several types of bacteria. The basic antimicrobial mechanism of TiAg-Nps is the generation of reactive oxygen species (ROS). Even though Leishmania parasites are sensitive to ROS, there is no study in literature indicating antileishmanial activities of TiAg-Nps. Herein, in this study, TiAg-Nps are shown to possess antileishmanial effects on Leishmania tropica and Leishmania infantum parasites by inhibiting their biological properties such as viability, metabolic activity, and survival within host cells both in the dark and under visible light. The results indicate that TiAg-Nps decreased viability values of L. tropica, and L. infantum promastigotes 3- and 10-fold, respectively, in the dark, while these rates diminished approximately 20-fold for each species in the presence of visible light, in contrast to control. On the other hand, non-visible light-exposed TiAg-Nps inhibited survival of amastigotes nearly 2- and 2.5-fold; while visible light-exposed TiAg-Nps inhibited 4- and 4.5-fold for L. tropica and L. infantum parasites, respectively. Consequently, it was determined that non-visible light-exposed TiAg-Nps were more effective against L. infantum parasites while visible light-exposed TiAg-Nps exhibited nearly the same antileishmanial effect against both species. Therefore, we think that a combination of TiAg-Nps and visible light can be further used for treatment of CL, while application of TiAg-Nps alone can be a promising alternative in VL treatment.

Conjugation, characterization and toxicity of lipophosphoglycan-polyacrylic acid conjugate for vaccination against leishmaniasis

Research on the conjugates of synthetic polyelectrolytes with antigenic molecules, such as proteins, peptides, or carbohydrates, is an attractive area due to their highly immunogenic character in comparison to classical adjuvants. For example, polyacrylic acid (PAA) is a weak polyelectrolyte and has been used in several biomedical applications such as immunological studies, drug delivery, and enzyme immobilization. However, to our knowledge, there are no studies that document immune-stimulant properties of PAA in Leishmania infection. Therefore, we aimed to develop a potential vaccine candidate against leishmaniasis by covalently conjugating PAA with an immunologically vital molecule of lipophosphoglycan (LPG) found in Leishmania parasites. In the study, LPG and PAA were conjugated by a multi-step procedure, and final products were analyzed with GPC and MALDI-TOF MS techniques. In cytotoxicity experiments, LPG-PAA conjugates did not indicate toxic effects on L929 and J774 murine macrophage cells. We assume that LPG-PAA conjugate can be a potential vaccine candidate, and will be immunologically characterized in further studies to prove its potential.

The use of platensimycin and platencin to fight antibiotic resistance

Infectious diseases are known as one of the most life-threatening disabilities worldwide. Approximately 13 million deaths related to infectious diseases are reported each year. The only way to combat infectious diseases is by chemotherapy using antimicrobial agents and antibiotics. However, due to uncontrolled and unnecessary use of antibiotics in particular, surviving bacteria have evolved resistance against several antibiotics. Emergence of multidrug resistance in bacteria over the past several decades has resulted in one of the most important clinical health problems in modern medicine. For instance, approximately 440,000 new cases of multidrug-resistant tuberculosis are reported every year leading to the deaths of 150,000 people worldwide. Management of multidrug resistance requires understanding its molecular basis and the evolution and dissemination of resistance; development of new antibiotic compounds in place of traditional antibiotics; and innovative strategies for extending the life of antibiotic molecules. Researchers have begun to develop new antimicrobials for overcoming this important problem. Recently, platensimycin – isolated from extracts of Streptomyces platensis – and its analog platencin have been defined as promising agents for fighting multidrug resistance. In vitro and in vivo studies have shown that these new antimicrobials have great potential to inhibit methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae by targeting type II fatty acid synthesis in bacteria. Showing strong efficacy without any observed in vivo toxicity increases the significance of these antimicrobial agents for their use in humans. However, at the present time, clinical trials are insufficient and require more research. The strong antibacterial efficacies of platensimycin and platencin may be established in clinical trials and their use in humans for coping with multidrug resistance may be allowed in the foreseeable future.

Utility of the microculture method for Leishmania detection in non-invasive samples obtained from a blood bank.

In recent years, the role of donor blood has taken an important place in epidemiology of Leishmaniasis. According to the WHO, the numbers of patients considered as symptomatic are only 5-20% of individuals with asymptomatic leishmaniasis. In this study for detection of Leishmania infection in donor blood samples, 343 samples from the Capa Red Crescent Blood Center were obtained and primarily analyzed by microscopic and serological methods. Subsequently, the traditional culture (NNN), Immuno-chromatographic test (ICT) and Polymerase Chain Reaction (PCR) methods were applied to 21 samples which of them were found positive with at least one method. Buffy coat (BC) samples from 343 blood donors were analyzed: 15 (4.3%) were positive by a microculture method (MCM); and 4 (1.1%) by smear. The sera of these 343 samples included 9 (2.6%) determined positive by ELISA and 7 (2%) positive by IFAT. Thus, 21 of (6.1%) the 343 subjects studied by smear, MCM, IFAT and ELISA techniques were identified as positive for leishmaniasis at least one of the techniques and the sensitivity assessed. According to our data, the sensitivity of the methods are identified as MCM (71%), smear (19%), IFAT (33%), ELISA (42%), NNN (4%), PCR (14%) and ICT (4%). Thus, with this study for the first time, the sensitivity of a MCM was examined in blood donors by comparing MCM with the methods used in the diagnosis of leishmaniasis. As a result, MCM was found the most sensitive method for detection of Leishmania parasites in samples obtained from a blood bank. In addition, the presence of Leishmania parasites was detected in donor bloods in Istanbul, a non-endemic region of Turkey, and these results is a vital importance for the health of blood recipients.

Aldehyde Dehydrogenase: Cancer and Stem Cells

Aldehyde dehydrogenases (ALDH) belong to the oxidoreductase family, which catalyze the conversion of aldehydes to their corresponding acids. As a group of NAD(P)+-dependent enzymes, aldehyde dehydrogenases (ALDHs) are involved in oxidation of a large number of aldehydes into their weak carboxylic acids (Moreb, et al., 2012). ALDH is found in every subcellular region such as cytosol, endoplasmic reticulum, mitochondria, and the nucleus, with some even found in more than one location (Marchitti, et al., 2008).

Detection of antileishmanial antibodies in blood sampled from blood bank donors in Istanbul.

AIMS According to the WHO, only 5-20% of the total cases of leishmaniasis are symptomatic leishmaniasis; the other cases are identified as asymptomatic leishmaniasis. In recent studies, it has been demonstrated that donor blood plays an important role in the epidemiology of asymptomatic leishmaniasis. However, the number of the studies on this subject is still insufficient. Additionally, donor blood samples obtained from Istanbul, which is the biggest metropolitan area in Turkey, have not been investigated with regard to Leishmania. Moreover, there is no information about the sensitivity of noninvasive serological methods that are used in the detection of leishmaniasis donor blood samples. Accordingly, this study aimed to investigate the presence of antileishmanial antibodies in blood samples obtained from blood bank donors in Istanbul, by using different serologic methods, and to determine the most sensitive detection method. MATERIALS & METHODS Blood samples were taken from 188 healthy blood bank donors to the Capa Turkish Red Crescent Blood Bank (Istanbul, Turkey), and the presence of antileishmanial antibodies was measured by indirect immunofluorescent antibody test (IFAT), ELISA, immunochromatographic dipstick rapid test, and western blot (WB). RESULTS Antileishmanial antibodies were determined in 12 out of 188 samples by IFAT (6.4%), and six out of these 12 donors were found to be positive at diagnostic titer 1:128 (3.2%). One hundred and eighty eight samples were investigated by ELISA and one (0.5%) of them gave a positive result. None of 188 samples provided a positive result by immunochromatographic test. WB applied to the 12 seroreactive donors showed that three out of 12 donors were positive. CONCLUSION In this study, the presence of antileishmanial antibodies in blood samples of blood bank donors from Istanbul has been demonstrated by using feasible and low-cost serological methods. Additionally, in comparison with other simple and low-cost detection methods, WB was used for confirmation. IFAT has a higher sensitivity and therefore may be preferred as a prescreening method in endemic or nonendemic areas.

Glucose-6-Phosphate Dehydrogenase Deficiency and Malaria: A Method to Detect Primaquine-Induced Hemolysis in vitro

© 2012 Allahverdiyev et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Glucose-6-Phosphate Dehydrogenase Deficiency and Malaria: A Method to Detect Primaquine-Induced Hemolysis in vitro

Development of New Antiherpetic Drugs Based on Plant Compounds

Herpes simplex virus (HSV) infections comprise one of the most important health problems worldwide. HSV-1 and HSV-2 that are the types most frequently seen in disease, manifested by sores and blisters on the mouth, tongue, skin, and genitals of infected individuals. Moreover, herpetic infections can reach life-threatening levels; for instance, HSV-2 prevalence has increased greatly in human immunodeficiency virus-positive patients. This indicates that the herpetic infection could be a major cause of morbidity in immunosuppressed patients. Unfortunately, resistance against antiherpetic drugs has recently been reported. Therefore there is an immediate need to search for new antiviral agents in order to cope with HSV infections. Recently, it has been demonstrated that traditional medicinal plants have strong antiviral activity and some are already being used in the treatment of viral infections, including herpes simplex infections. Accordingly, this chapter aims to present published information on various herbal compounds, investigate the antiherpetic effectiveness of these compounds, and determine the potential of plants as herpetic treatments in the future.