Okşak, Nilgün; Korkut, Işık Neslişah; Erol-Bozkurt, Ayşe; Danışman-Kalındemirtaş, Ferdane; Özerkan, Dilşad; Süleymanoğlu, Mediha; Erdem-Kuruca, Serap

It is believed that CSCs, which are resistant to chemotherapy and radiation, develop in certain situations, stay in the tissue niche after treatment, and cause disease recurrence. Targeting these cells, which are thought to be chemoresistant, may enable treatment to eliminate metastasis or recurrence. For this reason, we aimed to isolate CSCs from various breast cancer cell lines using a drug selection method in this study and then identify them via flow cytometry and fluorescent staining. MDA-123, MCF-7, and 4T1 were used as in vitro models, with HUVEC as controls. After isolation of stem cells from these cells by incubation with 5-fluorouracil (5-FU) and cisplatin (Cis), CSCs were identified by flow cytometry using CD24/CD44/CD133/EPCAM by assessing the rhodamine 123 (Rho 123). The results showed that 5-FU and Cis reduced the CD24 receptor in both cancer and normal cells, while the others showed varying expression levels. Administration of 5-FU and Cis significantly decreased Rho 123 fluorescence intensity in MDA-MB-231, MCF-7, 4T1, and HUVEC cells compared to the untreated group. A subpopulation of breast cancer cells with low CD24 and Rho123 expression was cancer stem cells. The 4T1 cells, which expressed low levels of CD24/CD133/EpCAM expression, had significantly lower Rho 123 levels than MDA-MB-231 and MCF-7 cells. This suggests that 4T1 cells may have greater chemoresistance and more aggressive properties. In conclusion, studying surface receptors and rhodamine uptake for the identification of CSCs is a powerful and valuable method for evaluating the efficacy of chemotherapy. The discovery of CSC markers that indicate therapeutic strategies could lead to clinical trials of medicines with potentially better therapeutic outcomes, particularly for recurring malignancies.

Ayar, Arif; Çolak, Deniz Altun; Uysal, Handan

Chloral hydrate (CH) is commonly used as a sedative and a hypnotic in pediatric medicine. In this study, the effects of CH on various developmental stages of Drosophila melanogaster were investigated. Different concentrations of CH (0.1; 0.3; 0.5 and 1 mg/mL) were used during development of the flies. Maternal toxicity due to increasing the concentration of CH was observed as a large number of adult flies died. When the F1 progeny of the control and application groups were compared, CH was found to extend the process of metamorphosis and to decrease the total number of offspring. The embryotoxic effects on the offspring and an increase in the number of malformed offspring was identified as depending on feeding. It was found that the difference between the groups was significantly important (p < 0.05).

Sunar, Serap; Anar, Mustafa; Sengul, Meryem; Agar, Guleray

In this research, the genotoxic and antigenotoxic effects of methanol extract of Sempervivum armenum (MSA) were studied using micronucleus (MN) test and sister chromatid exchange (SCE) test systems in cultured human peripheral blood cells. According to the SCE and MN tests results, MSA reduced the genotoxic effects of aflatoxin B1. In order to explain the reason for the antigenotoxic effects of MSA, antioxidants levels were determined. Cotreatments of 5, 10, 20 mg/mL concentrations of MSA with aflatoxin B1 decreased the frequencies of SCE, MN and the malondialdehyde level and increased the amount of superoxide dismutase, glutathione and glutathione peroxidase which were decreased by aflatoxin. The results of this experiment showed that MSA has strong antioxidative and antigenotoxic effects and this antigenotoxic activities of MSA can be due to the antioxidant activities.

Gürbüzel, Mehmet; Karaca, Ugur; Karayilan, Nermin

Bupivacaine and levobupivacaine are amino amide local anesthetics commonly used in medical practice. Although bupivacaine consists of a racemic mixture of S (–)-bupivacaine and R (+)-bupivacaine enantiomers, levobupivacaine is comprised of pure S (–)-bupivacaine. It has been known that levobupivacaine is preferable to bupivacaine since it may cause cardiovascular and nervous system toxicity. For determining genotoxicity of these anesthetics, we used the wing somatic mutation and recombination test in Drosophilamelanogaster. Three-day-old trans-heterozygous larvae were treated with bupivacaine and levobupivacaine. Analysis of the standard crosses indicated that bupivacaine and levobupivacaine did not exhibit mutagenic or recombinogenic activity until toxic doses have been reached at the larval stage. When we examined bupivacaine and levobupivacaine in the HB cross, bupivacaine did not exhibit any genotoxicity at high concentrations (500 µg/mL), but levobupivacaine did exert genotoxicity at high concentrations (1000 µg/mL)—depending on the substantial recombinogenic effect.

Kılıç, Yeliz; Geyikoglu, Fatime; Çolak, Suat; Turkez, Hasan; Bakır, Murat; Hsseinigouzdagani, Mirkhalil

Acute pancreatitis (AP) is considered as major problem around the world and the incidence of AP is increasing. Carvacrol (CAR), a monoterpenic phenol, has good antioxidant activity. This in vivo study was designed to evaluate whether CAR provide protection against AP that developed by pancreas injury. The rats were randomised into groups to receive (I) no therapy; (II) 50 µg/kg cerulein at 1 h intervals by four intraperitonally (i.p.) injections; (III) 50, 100 and 200 mg/kg CAR by one i.p. injection; and (IV) cerulein plus CAR after 2 h of cerulein administration. 12 h later, serum samples were obtained to assess pancreatic function, the lipase and amylase values. The oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde (MDA) and changes in main tissue antioxidant enzyme levels including SOD, CAT and GSH-PX. Histopathological examination was performed using scoring systems. Additionally, oxidative DNA damage was determined by measuring the increases of 8-hydroxy-deoxyguanosine (8-OH-dG) formations. We found that the increasing doses of CAR decreased AP-induced MDA and 8-OH-dG levels. Moreover, the pancreas antioxidant enzyme activities were higher than that of the rats in the AP group when compared to the AP plus CAR group. In the treatment groups, the lipase and amylase were reduced. Besides, histopathological findings in the pancreatic tissue were alleviated (p < 0.05). We suggest that CAR could be a safe and potent new drug candidate for treating AP through its antioxidative mechanism of action for the treatment of a wide range of disorders related to pancreas.

Hacimuftuoglu, Ahmet; Tatar, Abdulgani; Cetin, Damla; Taspinar, Numan; Saruhan, Fatih; Okkay, Ufuk; Turkez, Hasan; Unal, Deniz; Stephens, Robert Louis; Suleyman, Halis

The purpose of this study was to clarify the relationship between neuron cells and astrocyte cells in regulating glutamate toxicity on the 10th and 20th day in vitro. A mixed primary culture system from newborn rats that contain cerebral cortex neurons cells was employed to investigate the glutamate toxicity. All cultures were incubated with various glutamate concentrations, then viability tests and histological analyses were performed. The activities of glutamate transporters were determined by using in vitro voltammetry technique. Viable cell number was decreased significantly on the 10th day at 10−7 M and at 10−6 M glutamate applications, however, viable cell number was not decreased at 20th day. Astrocyte number was increased nearly six times on the 20th day as compared to the 10th day. The peak point of glutamate reuptake capacity was about 2 × 10−4 M on the 10th day and 10−3 M on the 20th day. According to our results, we suggested that astrocyte age was important to maintain neuronal survival against glutamate toxicity. Thus, we revealed activation or a trigger point of glutamate transporters on astrocytes due to time since more glutamate was taken up by astrocytes when glutamate transporters on the astrocyte were triggered with high exogenous glutamate concentrations. In conclusion, the present investigation is the first voltammetric study on the reuptake parameters of glutamate in vitro.