Effects of mancozeb, metalaxyl and tebuconazole on steroid production by bovine luteal cells in vitro.

Mancozeb, metalaxyl and tebucanazole are widely used pesticides in agriculture and industry to treat plant pathogenic fungi. Livestock may be exposed to such substances by consuming contaminated plants. The present study was designed to evaluate the effects of these three fungicides on bovine luteal cell steroidogenesis. Luteal slices from mid-cycle corpus luteum were dissociated into single cell suspension in aerated (O2) culture media (DMEM/F12) by enzymatic digestion. The cells were incubated in newborn calf serum (10%) for 18 h and then with serum-free media containing mancozeb (0.01 µM, 0.1 µM, 1 µM), tebuconazole (1 µM, 10 µM, 100 µM) or metalaxyl (100 µM, 500 µM, 2500 µM) for additional 96 h. The medium was replaced on day 1 and 3; and the retrieved medium was stored at -20 °C until progesterone assay. Treatment of cells with three different fungicides induced dose dependent variable decrease in steroid synthesis during incubation periods. Incubation of cells with 1 µM mancozeb exhibited a 33% decline in steroid synthesis on day 3 and 48% decline on day 5 compared with controls. Treatment of cells with 100 µM tebuconazole and 500 µM metalaxyl resulted in a 65% and 31% decrease, respectively, in progesterone accumulation on day 5 of incubation. Fungicide induced suppressive effects on luteal steroidogenesis were as metalaxyl < tebuconazole < mancozeb. Results of the present study suggest that designated concentrations of all three fungicides studied might have varying degrees of adverse effects on luteal steroidogenesis.

Protective effects of silymarin on fumonisin B1-induced hepatotoxicity in mice.

The present study was conducted to investigate the effect of silymarin on experimental liver toxication induced by Fumonisin B11 (FB1) in BALB/c mice. The mice were divided into six groups (n = 15). Group 1 served as the control. Group 2 was the silymarin control (100 mg/kg by gavage). Groups 3 and 4 were treated with FB1 (Group 3, 1.5 mg/kg FB1, intraperitoneally; and Group 4, 4.5 mg/kg FB1). Group 5 received FB1 (1.5 mg/kg) and silymarin (100 mg/kg), and Group 6 was given a higher dose of FB1 (4.5 mg/kg FB1) with silymarin (100 mg/kg). Silymarin treatment significantly decreased (p < 0.0001) the apoptotic rate. FB1 administration significantly increased (p < 0.0001) proliferating cell nuclear antigen and Ki-67 expression. Furthermore, FB1 elevated the levels of caspase-8 and tumor necrosis factor-alpha mediators while silymarin significantly reduced (p < 0.0001) the expression of these factors. Vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expressions were significantly elevated in Group 4 (p < 0.0001). Silymarin administration alleviated increased VEGF and FGF-2 expression levels (p < 0.0001). In conclusion, silymarin ameliorated toxic liver damage caused by FB1 in BALB/c mice.

New perspective for the treatment of Alzheimer diseases: liposomal rivastigmine formulations.

The aim of this study was to determine the transportations of rivastigmine containing from various liposome formulations through Madin Darby Canine Kidney (MDCK) cells monolayer and to compare the in vitro test results with in vivo. There is no other liposome formulation of rivastigmine and the transportations of rivastigmine through MDCK cell monolayers or related study available in the literature. Cytotoxicity (MTT) test was used to determine cell viabilities. The effect of sodium-taurocholate or dimethyl-beta-cyclodextrine as penetration enhancer was also investigated. Characterization and stability studies for liposome formulations were performed. Permeation experiments of rivastigmine were performed through MDCK cells and dialysis membrane. The kinetic of release from liposomes was also investigated. The highest apparent permeability coefficient (log. values) was obtained with sodium-taurocholate liposomes for -1.15 ± 0.16 for MDCK cell. Rivastigmine liposomes and solutions were also administered to mice orally and intraperitonally. Acetylcholinesterase (AChE) activity was determined by Ellman method. AChE% inhibition values were calculated for both blood and brain after administration of rivastigmine solution and liposomes. The highest AChE inhibition was observed for rivastigmine-sodium-taurocholate liposomes. Histological observations of the mice' brains were performed under transmission electron microscope (TEM). The histological results were also indicated and supported all these findings.

Prophylactic effect of N-acetylcysteine against sodium fluoride-induced blood oxidative stress in mice.

Ninety female Balb/c mice were used. The animals were allocated to evenly six groups. While the first group was maintained as control, Groups 3, 4, 5, and 6 were administered 750 ppm, 1500 ppm, 3000 ppm, and 6000 ppm of N-acetylcysteine, respectively, for a period of 15 days. After day 15, Groups 2-6 were administered sodium fluoride, containing 100 ppm fluoride in drinking water, for another 15 days. Plasma malondialdehyde (MDA) levels and erythrocyte superoksid dismutase (SOD) and catalase (CAT) activities were determined at the beginning of the trial and on days 15 and 30. According to the data obtained in the present study, N-acetylcysteine, when administered at the indicated doses, did not produce a significant alteration in any of the three parameters investigated. On the other hand, while the plasma MDA level was determined to have increased significantly, erythrocyte SOD and CAT activities were ascertained to have decreased significantly in the group, which was administered sodium fluoride alone on day 30. In the groups, which were administered N-acetylcysteine prior to sodium fluoride, however, it was observed that, after sodium fluoride administration, plasma MDA levels and erythrocyte SOD and CAT activities drew closer to the values of the control group.

Aflatoxin M1 levels in Surk samples, a traditional Turkish cheese from southern Turkey.

In this study, aflatoxin M(1) (AFM(1)) contamination was investigated in Surk cheese, a traditional Turkish cheese consumed particularly in southern Turkey. For this purpose, 120 Surk cheese samples were collected from different retail markets and analysed by enzyme-linked immunoassay. The level of AFM(1) varied from 16 to 1,043 ng/kg in 72 of the Surk samples (60%), 16 of which (13.3% of 120 samples) contained AFM(1) amounts exceeding the maximum tolerance limit (250 ng/kg) established in Turkey. The results indicated that the occurrence of AFM(1) in Surk cheese samples may be considered as a possible risk for consumer health.

The effects of experimental aflatoxicosis on the exocrine pancreas in quails (Coturnix coturnix japonica).

The present investigation was undertaken to assess the effects of aflatoxin (AF) on the exocrine pancreas in quails by means of light and electron microscopy. A total of 30 quails were divided into three groups, each composed of ten animals. Total AF was incorporated into the diet of these groups, at doses of 0, 2.5, and 5.0 mg of AF/kg feed, ppm, respectively. The quails were raised in cages with electrical heating and 24-h lighting for a period of 3 weeks. Ad libitum access was provided to feed and drinking water. Pancreas samples were taken for light and electron microscopic examination from animals that were killed by means of cervical dislocation at the end of the study. Light microscopic examination demonstrated mild mononuclear cell infiltration of exocrine tissue and vacuolisation of acinar cells in the group fed on AF at 2.5 ppm. On the other hand, electron microscopic examination demonstrated degranulation of the rough endoplasmic reticulum (rER) of acinar cells, decrease in the number of zymogen granules and free ribosomes and polisomes, and dilatation of capillaries in the group fed on AF at a dose of 2.5 ppm. Numerous degenerative acinar cells were determined in the group fed a diet containing 5.0 ppm AF, in addition to the findings common with the other group exposed to the toxin.

Studies on antioxidant enzymes in mice exposed to pulsed electromagnetic fields.

In this study, 56 female albino mice weighing 30-35 g were used. The animals were divided into a control and an experimental group. The animals in the experimental group were subjected to a pulsed electromagnetic field (PEMF) with a field magnitude of 50 Hz and 2 mT for 8h each day between 0900 and 1700 for 90 days. In both control and experimental groups, blood was sampled at 45, 60, and 90 days in heparinized tubes and erythrocyte malondialdehyde levels, and superoxide dismutase, glutathione peroxidase, catalase, and glucose-6-phosphate dehydrogenase activities were determined. The results revealed that the PEMF applied chronically within the given period and field magnitude does not cause oxidative damage.

Pharmacokinetic of sulfisoxazole in aqueous humor after topical and subconjunctival application in dogs.

This study was undertaken to evaluate the ocular pharmacokinetic of sulfisoxazole. Male, 2-3 years old 10 mix breed dogs weighing 12-15 kg were used. A 2 mg dose/eye of sulfisoxazole was administrated to the animals by either subconjunctivally or by topically. Samples of aqueous humor were collected after 0.083, 0.25, 0.5, 1, 2, 4, 6, 24 and 72 h and level of sulfisoxazole was determined. Pharmacokinetic parameters including absorption rate constant (k(a)), slope factor (beta), absorption half-life (t1/2a), half-life of elimination in aqueous humor (t1/2beta), maximal concentration in aqueous humor (C(max)), time to reach C(max) (t(max)), mean residence time in aqueous humor (MRT) and area under the concentration time curve from zero up to infinity (AUC(0-infinity)) were calculated. Compared to topical application, value of k(a) in subconjunctival application increased while values of t1/2a and t(max) decreased and the value of t1/2beta prolonged (p < 0.05). There was no significant difference between groups regarding other parameters (p > 0.05). These results indicate that sulfisoxazole may not be potent enough to treat intraocular infections caused by bacteria when applied either subconjunctivally or topically at a dose of 2 mg/eye. Furthermore, subconjunctival application of sulfisoxazole could be more efficient for treatment of intraocular infections due to higher absorption of drug and longer remaining time in the eye compared to topical application.

Caco-2 cell culture as a model for famotidine absorption.

The aim of the study was to determine penetration properties of Famotidine fro the formulations through colon adenocarcinoma (Caco)-2 cell monolayers and to compare in vitro with in vivo test results. It also aimed to determine the effect of particle size on the penetration properties of Famotidine when microsphere formulations were used. Famotidine was chosen as a model drug and Caco-2 cell culture model was used. Biodegradable Famotidine microspheres of poly(lactide-co-glycolide)(PLGA) polymer (50:50) were prepared by using multiple emulsion technique. Microspheres were coded according to their particle size and polymer[LHIV:60 microm Famotidine-PLGA(high viscosity), SHIV:6 microm Famotidine PLGA(high viscosity), LLIV:60 microm Famotidine-PLGA (low viscosity), SLIV:6 microm Famotidine-PLGA (low viscosity)]. Famotidine solution(5 mg/ml) and microsphere formulations were administered orally to mice and blood drug levels were determined and compared with the Caco-2 cell experiments. Permeability values of Famotidine through Caco-2 cells from various formulations were determined (log k(solution) = 7,274 +/- 0,010,log kSHIV = -3,884 +/- 0,033,log kLHIV = -2,300 +/- 0,009,log kSLIV = -4,076 +/- 0,208,log kLLIV = 3,525 +/- 0,045). Our results showed that H2 receptor antagonists alter the barrier properties of the Caco-2 cell monolayer by causing an increment in the tightness of the tight junctions. Therefore, amount of the H2 receptor antagonist-like drug at the site of action was found to be important as well as polymer type and particle size of microspheres for drug permeation. Permeation of the drug was lower when higher amounts of Famotidine were present at the diffusion site. A controlled release dosage form of H2 receptor antagonist-like drugs may be beneficial for long-term treatments.

The effect of various liposome formulations on insulin penetration across Caco-2 cell monolayer.

The aim of the study was to determine the penetration properties of various insulin containing liposome formulations through Caco-2 cell monolayer and to compare the in vitro test results with in vivo tests. The effect of sodium taurocholate as a penetration enhancer when it was added to the liposome formulation was also investigated. In vitro permeation experiments were performed in diffusion cells with the Caco-2 cell monolayer used as the membrane. Permeability values of various insulin containing liposome formulations through Caco-2 cells were determined (log k(insulin-solution) = -2.217 +/- 0.0723 cm.h(-1), log k(insulin-liposome) = -2.141 +/- 0.0625 cm.h(-1), log k(insulin-sodium tauroholate liposome)= -1.952 +/- 0.0623 cm.h(-1)). In vivo tests were performed in mice. Formulations were administered orally and blood glucose levels were determined and penetrations were compared with the Caco-2 cell experiment results. In conclusion, the permeability of insulin was increased across Caco-2 cell monolayer when the liposome sodium taurocholate (NaTC) formulation was used. The oral administration of insulin and NaTC incorporated liposomes significantly decreased blood glucose levels. Furthermore, it was shown that a high in vitro/in vivo correlation was observed using the Caco-2 cell monolayer model.

Effects of short-term exposure to pulsed electromagnetic field on some biochemical parameters in mice.

Five-months-old male albino mice were subjected to an electromagnetic field (EMF) of 5 mT of magnitude with a frequency of 60 Hz for 8hr of single application. Analysis of blood sampled on hourly basis (up to 8 hr) for levels/activities of total protein, albumin, globulin, uric acid, creatinine, cholesterol, and alkaline phosphatase indicated no significant differences (p > 0.05) from that of the control group.