Antileukemic potential of Nile blue-mediated photodynamic therapy on HL60 human myeloid leukemia cells.

Background/aim: Photodynamic therapy (PDT) has received great attention over the past decade in the treatment of diseases such as leukemia which is a cancer of the blood and bone marrow cells that causes a significant number of deaths worldwide. In this study, it was aimed to investigate the effects of Nile blue-mediated PDT (NB-mediated PDT) on HL60 cells. Materials and methods: The effect of NB-mediated PDT on cell proliferation was evaluated with cell volume analysis using flow cytometry at 24 h. Cell apoptosis, ROS production, mitochondrial membrane potential, and cell cycle analysis were evaluated using annexin V-FITC, H2DCFDA, JC-1, and PI staining, respectively, by flow cytometry and fluorescence microscopy. The morphological and ultrastructural analyses were examined by Giemsa staining and SEM. CD11b staining is used to determine the differentiation of leukemia cells. Results: NB-mediated PDT induced an apoptotic response at 12.5 µM in HL60 cells. When Giemsa staining and SEM images were evaluated, apoptotic bodies, holes, and occasional folds were detected on the surfaces of cells in the NB-mediated PDT group. Conclusion: The NB-mediated PDT had no effect on the differentiation of leukemia cells, but this therapy affects the growth of HL60 cells in vitro, which may provide a new idea for removing leukemic cells from bone marrow intended for autologous transplant.

The Synergistic Effect of Theranekron and Cisplatin on the Neuroblastoma (SH-SY5Y) Cell Line.

AIM: To assess the combined antitumor potential of theranekron (Trn) and cisplatin in neuroblastoma (NB), a pediatric tumor characterized by high prevalence and mortality rates. The investigation involved examining the interaction between theranekron (10-100 ?M) and cisplatin (40 ?M) within this cell line. MATERIAL AND METHODS: The cytotoxicity of Trn was evaluated using MTT assays, cell volume analyses, apoptosis assessments, and measurements of mitochondrial membrane potential. These evaluations were conducted over a 24-hour incubation period. RESULTS: The coadministration of 100 µM Trn with cisplatin exhibited a cytotoxic effect of approximately 60%. Furthermore, it led to a reduction of up to 38% in cell volume. Notably, SH-SY5Y cells demonstrated an early apoptosis rate of 34.4%, accompanied by an eightfold decrease in mitochondrial membrane potential compared to the control group. CONCLUSION: Trn demonstrated synergism and significantly enhanced the efficacy of cisplatin (p < 0.001). Nevertheless, further in-depth investigations are necessary to elucidate the intricacies of these synergistic effects.

Orally disintegrating tablet containing carbamazepine and levetiracetam: formulation and in vitro and in vivo characterization.

This study aimed to prepare and characterize the orally disintegrating tablet (ODT) formulations containing the combination of levetiracetam (LEV) and carbamazepine (CBZ) (CBZ + LEV combination) for the treatment of epilepsy. The ODT formulations were prepared using the lyophilization (L) and direct compression (DC) methods. The flowability of the mixed powders used for DC formulation was evaluated. The quality control tests for the ODTs were performed. Also, the antiepileptic effects of pure drugs, their combination, and the suspension of CBZ + LEV-DC-ODT formulation were evaluated in the rats with pentylenetetrazole (PTZ)-induced epilepsy model. The obtained results for the mixed powders of the DC formulation (angle of repose: 26.18 ± 0.794°; compressibility index: 15.24 ± 0.764%) suggest that the flow properties of the powder blend were suitable for the preparation of CBZ + LEV-ODT using DC method. The mean values of diameter and hardness of L-ODTs and DC-ODTs were found to be 16.87 mm and 16.18 mm and 11.96 N and 30.11 N, respectively. The friability of both formulations was <1%. Both formulations were disintegrated in seconds. Drugs in L-ODT had faster dissolution than those in DC-ODT. Compared to the seizure scores obtained for the groups treated with LEV or CBZ, generally, there was a higher decrease in seizure scores in the groups treated with CBZ + LEV combination or the suspension of CBZ + LEV-DC-ODTs. Consequently, the ODT formulations containing the CBZ + LEV combination might be beneficial in the treatment of epilepsy.

Differential effects of inhibitors of PTZ-induced kindling on glutamate transporters and enzyme expression.

Epilepsy is a neurological disorder resulting from abnormal neuronal firing in the brain. Glutamate transporters and the glutamate-glutamine cycle play crucial roles in the development of seizures. In the present study, the correlation of epilepsy with glutamate transporters and enzymes was investigated. Herein, male Wistar rats were randomly allocated into four groups (six animals/group); 35 mg/kg pentylenetetrazole (PTZ) was used to induce a kindling model of epilepsy. Once the kindling model was established, animals were treated for 15 days with either valproic acid (VPA, 350 mg/kg) or ceftriaxone (CEF, 200 mg/kg) in addition to the control group receiving saline. After treatment, electrocorticography (ECoG) was performed to record the electrical activity of the cerebral cortex. The glutamate reuptake time (T80 ) was also determined in situ using an in vivo voltammetry. The expression levels of glutamate transporters and enzymes in the M1 and CA3 areas of the brain were determined using a real-time polymerase chain reaction (RT-PCR). ECoG measurements showed that the mean spike number of the PTZ + VPA and PTZ + CEF groups was significantly lower (p < 0.05) than that of the PTZ group. Compared with the PTZ group, VPA or CEF treatment decreased the glutamate reuptake time (T80 ). The expression levels of EAAC1, GLT-1, GLAST, glutamine synthetase (GS), and glutaminase were increased in the PTZ group. Treatment with VPA or CEF enhanced the expression levels of GLT-1, GLAST, EAAC1, and GS, whereas the glutaminase expression level was reduced. The current results suggest that VPA or CEF decreases seizure activity by increasing glutamate reuptake by upregulating GLT-1 and GLAST expression, implying a possible mechanism for treating epilepsy. Also, we have suggested a novel mechanism for the antiepileptic activity of VPA via decreasing glutaminase expression levels. To our knowledge, this is the first study to measure the glutamate reuptake time in situ during the seizure (i.e., real-time measurement).

The analgesic effect of metformin on paclitaxel-induced neuropathic pain model in rats: By considering pathological results.

BACKGROUND AND OBJECTIVE: Metformin (MET) has been used as an antidiabetic agent for type II diabetes. At the same time, recent researches have shown that the clinical improvement of MET is useful for nerve damage. In this study, we investigated the analgesic effect of MET in paclitaxel (PAC)-induced neuropathic pain. MATERIALS AND METHODS: Forty-two adult, female rats, Wistar strain weighing 220 ± 10 g were randomly divided into 5 experimental groups. PAC was intraperitoneally (IP) administered (2.0 mg/kg) for 4 groups every other day (0, 2, 4, and 6 days). By the 30th day, MET (100, 200, and 400 mg/kg) was administered to 4 groups. Before and after treatment, basal pain threshold values were measured with Randall-Selitto analgesiometer test. At the end of experiment, pathological values were measured in selected regions including brain (motor cortex, M1), spinal cord (L4-L5), sciatic nerve, and muscle. RESULTS: According to our results, PAC-induced neuropathic pain reached to highest level at 14th day. Four hundred milligram/kilogram concentration of MET remarkably decreased PAC-induced neuropathic pain. On the other hand, pathologic features have shown that PAC had significant pathological change in the brain and spinal cord while in the peripheral nerves and muscles had not shown any pathological change. CONCLUSION: The pathological results of the current study for the first time demonstrated that MET beside of its antidiabetic effects reversed neuropathic pain induced by PAC. Consequently, this research can be promising for cancer patients that suffering from neuropathic pain induced by anticancer drugs.

Carbamazepine and levetiracetam-loaded PLGA nanoparticles prepared by nanoprecipitation method: in vitro and in vivo studies.

Objective: The aim of this study was to develop the PLGA nanoparticles (NPs) containing carbamazepine (CBZ) and levetiracetam (LEV) combination (CBZ + LEV) for the treatment of epilepsy and to in vitro characterize the prepared NPs.Significance: LEV and CBZ, which are antiepileptic drugs, are used in the treatment of epilepsy. Nano-sized formulations are prepared to use for different purposes such as to improve the solubility/the physicochemical properties and bioavailability of drugs, to decrease their doses and frequency of administration, and to reduce side effects of drugs.Methods: CBZ + LEV-PLGA-NPs were prepared by a modified nanoprecipitation method and in vitro and in vivo characterized. Also, the antiepileptic effect of the NPs was evaluated in vivo in a rat epilepsy model.Results: The mean particle size and zeta potential of CBZ + LEV-PLGA-NPs were 180.62 ± 6.260 nm and -27.08 ± 3.110 mV, respectively. The values of encapsulation efficiency (EE%) of CBZ and LEV were 51.00 ± 5.944% and 2.05 ± 0.367%, respectively. CBZ showed a biphasic release profile with initial burst release followed by a sustained release. Ninety percent of CBZ was released from NPs within two days; however, % LEV release from NPs reached about 80% within 30 min.Conclusion: Our results showed that a decrease in seizure scores in the group treated with CBZ + LEV was observed and also, CBZ + LEV and CBZ + LEV-PLGA-NPs had similar antiepileptic activity. The NPs containing CBZ + LEV might be beneficial in the treatment of epilepsy.

Effect of metformin/irinotecan-loaded poly-lactic-co-glycolic acid nanoparticles on glioblastoma: in vitro and in vivo studies.

AIM: The present study was designed to evaluate the effects of irinotecan hydrochloride (IRI)- or metformin hydrochloride (MET)-loaded poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) for the treatment of glioblastoma multiforme using in vitro neuron and U-87 MG glioblastoma cell cultures and in vivo animal model. METHODS: The cytotoxic and neurotoxic effects of pure drugs, blank NPs and MET- and IRI-loaded PLGA NPs were investigated in vitro (using methylthiazolyldiphenyl-tetrazolium bromide assay) and in vivo (using Cavalieri's principle for estimation of cancer volume). RESULTS: 1 and 2 mM doses of MET and MET-loaded PLGA NPs, respectively, significantly reduced the volume of extracted cancer. CONCLUSION: Consequently, MET- and IRI-loaded PLGA NPs may be a promising approach for the treatment of glioblastoma multiforme.

The Effect of Polymerization and Preparation Techniques on the Microleakage of Composite Laminate Veneers.

BACKGROUND: Marginal leakage is the important factor influencing the maintenance of dental esthetic. AIM: The purpose of this study was to evaluate the relationship between the preparation techniques and type of polymerization techniques on microleakage of composite laminate veneers. MATERIALS AND METHODS: Ninety-one same sized, caries-free human maxillary central incisors were randomly assigned to 13 groups (n = 7) and were designed with four different preparation techniques (window type, feather type, bevel type, and incisal overlap type). One group determined as control group and any preparation was applied. Nanohybrid resin composite was used for restoration. Composite laminate veneers polymerized with three different techniques (direct light curing, indirect polymerization with a combination of pressure, light and heat using a light cup and heat cup, direct polymerization, and additionally heat cured in an oven). The specimens were thermocycled, and then immersed in 5% basic fuchsine solution. Following 24 h, all specimens were immersed in 65% nitric acid solutions for volumetric dye extraction test. Samples diluted with distilled water and centrifuged and microleakage determined by a spectrophotometer. STATISTICAL ANALYSIS USED: Data were analyzed with two-way ANOVA and Tukey honest significant difference post hoc multiple comparisons test (P < 0.05). RESULTS: For comparing the microleakage value of preparation and polymerization techniques, Window type preparation showed a significant difference in direct polymerization + additional cured group (P < 0.05). Control group was statistically different from the other groups (P < 0.05). CONCLUSIONS: Window type laminate preparation can be preferred in indirect polymerization technique because it caused less leakage in this present study.

Once the Light Touch to the Brain: Cytotoxic Effects of Low-Dose Gamma-Ray, Laser Light, and Visible Light on Rat Neuronal Cell Culture.

OBJECTIVE: We aimed to evaluate the effects of gamma-ray, laser light, and visible light, which neurons are commonly exposed to during treatment of various cranial diseases, on the viability of neurons. MATERIALS AND METHODS: Neuronal cell culture was prepared from the frontal cortex of 9 newborn rats. Cultured cells were irradiated with gamma-ray for 1-10 min by (152)Eu, (241)Am, and (132)Ba isotopes, visible light for 1-160 min, and laser light for 0.2-2 seconds. The MTT tetrazolium reduction assay was used to assess the number of viable cells in the neuronal cell cultures. Wavelength dispersive X-ray fluorescence spectrometer was used to determine Na, K, and Ca levels in cellular fluid obtained from neuronal cell culture plaques. RESULTS: Under low-dose radiation with (152)Eu, (241)Am, and (132)Ba isotopes, cell viability insignificantly decreased with time (p>0.05). On the other hand, exposure to visible light produced statistically significant decrease in cell viability at both short- (1-10 min) and long-term (20-160 min). Cell viability did not change with 2 seconds of laser exposure. Na, K, and Ca levels significantly decreased with gamma-ray and visible light. The level of oxidative stress markers significantly changed with gamma-ray. CONCLUSION: In conclusion, while low dose gamma-ray has slight to moderate apoptotic effect in neuronal cell cultures by oxidative stress, long-term visible light induces remarkable apoptosis and cell death. Laser light has no significant effect on neurons. Further genetic studies are needed to clarify the chronic effect of visible light on neuronal development and functions.

Astrocyte/neuron ratio and its importance on glutamate toxicity: an in vitro voltammetric study.

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.

Protective effects of cyclosativene on H2O 2-induced injury in cultured rat primary cerebral cortex cells.

Sesquiterpenes have attracted much interest with respect to their protective effect against oxidative damage that may be the cause of many diseases including several neurodegenerative disorders and cancer. Our previous unpublished work suggested that cyclosativene (CSV), a tetracyclic sesquiterpene, has antioxidant and anticarcinogenic features. However, little is known about the effects of CSV on oxidative stress induced neurotoxicity. We used hydrogen peroxide (H2O2) exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of CSV in H2O2-induced toxicity in new-born rat cerebral cortex cell cultures for the first time. For this aim, MTT and lactate dehydrogenase release assays were carried out to evaluate cytotoxicity. Total antioxidant capacity (TAC) and total oxidative stress (TOS) parameters were used to evaluate oxidative changes. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG) levels, the single cell gel electrophoresis (or Comet assay) was also performed for measuring the resistance of neuronal DNA to H2O2-induced challenge. Our results showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage (Comet assay) increased in the H2O2 alone treated cultures. But pre-treatment of CSV suppressed the cytotoxicity, genotoxicity and oxidative stress which were increased by H2O2. On the basis of these observations, it is suggested that CSV as a natural product with an antioxidant capacity in mitigating oxidative injuries in the field of neurodegenerative disorders.