In vitro pharmacodynamics and in vivo efficacy of fluconazole,amphotericin B and caspofungin in a murine infection by Candida lusitaniae

The in vitro activities of fluconazole (FLC), amphotericin B (AmB) and caspofungin (CSP) were evaluated against three isolates of Candida lusitaniae using time–kill curves. AmB showed in vitro fungicidal activity, whilst FLC and CSP exerted mainly strain-dependent fungistatic activity. The in vivo efficacies of the three drugs were evaluated in a murine model of disseminated infection. The doses administered were FLC 50 mg/kg/day, AmB 0.8 mg/kg/day and CSP 5 mg/kg/day. All three drugs were able to reduce the fungal burden in the kidneys of infected mice, with AmB showing the highest efficacy, followed by CSP. At least in this model, FLC, AmB and CSP are good candidates for treating invasive infections by C. lusitaniae.     

Inhibitory actions of mGlu4 receptor ligands on cocaine-, but not nicotine-, induced sensitizing and conditioning locomotor responses in rats

BackgroundMale Wistar rats were used to verify the hypothesis that metabotropic glutamate 4 (mGlu₄) receptor ligands may modulate the locomotor effects evoked by cocaine or nicotine.MethodsThe preferential mGlu₄ receptor orthosteric agonist (2S)-2-amino-4-[hydroxy[hydroxy(4-hydroxy-3-methoxy-5-nitrophenyl)methyl]phosphoryl]butanoic acid (LSP1-2111) and the mGlu₄ receptor positive allosteric modulator (+)-cis-N¹-(3,4-dichlorophenyl)cyclohexane-1,2-dicarboxamide (Lu AF21934) were used in the study. Rats were given repeated pairings of a test environment with cocaine (10 mg/kg), nicotine (0.4 mg/kg) or the respective vehicles for 5 days. On day 10, animals were challenged with cocaine (10 mg/kg, cocaine sensitization), nicotine (0.4 mg/kg, nicotine sensitization) or vehicle (conditioned hyperlocomotion) in experimental cages.ResultsGiven on day 10, LSP1-2111 (3 mg/kg) as well as Lu AF21934 (2.5–5 mg/kg) decreased the expression of cocaine sensitization. In another set of experiments, LSP1-2111 (3 mg/kg) and Lu AF21934 (5 mg/kg) administered on day 10 attenuated the conditioned hyperlocomotion in rats treated repeatedly with cocaine. Neither LSP1-2111 (1–3 mg/kg) nor Lu AF21934 (2.5–5 mg/kg) changed the expression of nicotine sensitization and conditioned hyperlocomotion in rats treated repeatedly with nicotine. None of the mGlu₄ receptor agonist/modulator altered the basal locomotor activity or acute hyperactivity to cocaine or nicotine.ConclusionsThe present data indicate that pharmacological stimulation of mGlu₄ receptors reduces the cocaine-induced expression of sensitization as well as conditioned hyperactivity. In contrast, mGlu₄ receptor activation seems to be devoid of any effect on the locomotor effects of nicotine.     

Antifungal and immunomodulatory activity of a novel cochleate for amphotericin B delivery against Sporothrix schenckii

Introduction: Sporotrichosis is an emergent subcutaneous mycoses caused by species of the Sporothrix schenckii complex. Amphotericin B (AmB) remains the main antifungal drug for the treatment of systemic infections, but its use is limited by toxicity reasons. AFCo3 is a novel cochleate containing detoxified LPS, which exhibits drug delivery and immunomodulating properties. Here, AFCo3 was used as the vehicle for AmB to evaluate the immunomodulatory and antifungal efficacy against S. schenckii in vitro and in vivo. Methods and results: The minimum inhibitory concentrations of AFCo3-AmB and AmB were 0.25 and 1 μg/mL respectively. The minimum fungicidal concentration was 0.5 μg/mL for AFCo3-AmB and 2 μg/mL for AmB. AFCo3-AmB was less cytotoxic than AmB for peritoneal macrophages, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and reduced the AmB-induced hemolysis in murine erythrocytes. AFCo3-AmB improved the intracellular killing of phagocytized yeast and it enhanced the in vitro production of IL-1β, TNF-α and NO in peritoneal macrophages. Moreover, AFCo3-AmB was more effective than AmB in reducing spleen and liver fungal burden after repeated (five days) intraperitoneal administration of 5 mg/kg of AmB, in a Balb/c model of systemic infection, associated to a significant induction of Th1/Th17 response. Finally, blood chemistry revealed that AFCo3-AmB did not cause changes suggestive of nephrotoxicity, such as increases in total proteins, albumin, creatinine and blood urea nitrogen that were caused by free AmB. Conclusions: AFCo3-AmB exhibited a significant immunomodulator action, reduced toxicity and improved antifungal action against S. schenckii, suggesting a potential use as AmB delivery for systemic sporotrichosis treatment.     

Serotonergic modulation of extrapyramidal motor disorders in mice and rats: Role of striatal 5-HT3 and 5-HT6 receptors

Previous studies showed that 5-HT_1A and 5-HT₂ receptors play an important role in controlling the extrapyramidal motor disorders. However, the functions of other 5-HT receptor subtypes remain elusive. To elucidate the role of 5-HT receptors, specifically of 5-HT₃～5-HT₇ subtypes, in modifying antipsychotic- induced extrapyramidal side effects (EPS), we studied the effects of the 5-HT stimulant 5-hydroxytryptophan (5-HTP) and various 5-HT receptor antagonists on haloperidol (HAL)-induced bradykinesia and catalepsy in mice and rats. Pretreatment of mice with 5-HTP (25–100 mg/kg, i.p.) dose-dependently enhanced HAL (0.3 mg/kg, i.p.)-induced bradykinesia and catalepsy. The potentiation of HAL-induced EPS by 5-HTP (50 mg/kg, i.p.) was significantly inhibited by ritanserin (5-HT₂ antagonist, 0.3-3 mg/kg, i.p.), ondansetron (5-HT₃ antagonist, 0.1–1 mg/kg, i.p.), or SB-258585 (5-HT₆ antagonist, 1–10 mg/kg, i.p.) in a dose-dependent manner. However, neither WAY-100135 (5-HT_1A antagonist, 1–10 mg/kg, i.p.), GR-125487 (5-HT₄ antagonist, 1–10 mg/kg, i.p.), SB-699551 (5-HT_5A antagonist, 1–10 mg/kg, i.p.) nor SB-269970 (5-HT₇ antagonist, 1–10 mg/kg, i.p.) reduced the 5-HTP and HAL-induced bradykinesia or catalepsy. In addition, both ondansetron (0.1–1 mg/kg, i.p.) and SB-258585 (3 and 10 mg/kg, i.p.) also alleviated bradykinesia and catalepsy induced by HAL (0.5 mg/kg, i.p.) alone in mice. Furthermore, bilateral microinjection of ondansetron (5 μg (13.7 nmol) per side) or SB-258585 (5 μg (8.92 nmol) per side) into the dorsolateral striatum (dlST) attenuated haloperidol-induced catalepsy in rats. These results suggest that serotonergic stimulation augments extrapyramidal motor disorders by activating the striatal 5-HT₃ and 5-HT₆ receptors and the antagonism of these receptors effectively alleviates antipsychotic-induced EPS.     

Further studies on anti-inflammatory activity of maprotiline in carrageenan-induced paw edema in rat

Antidepressant drugs are commonly used for treatment of different medical disorders besides of psychiatric diseases. Accumulating evidence suggests that antidepressants exhibit anti-inflammatory activity in vivo and in vitro conditions, but the mechanisms of this property are not clear very well. In our earlier work, we demonstrated that i.c.v. and i.p. injection of maprotiline, as an antidepressant, decreased paw edema at the fourth hour after subplantar injection of carrageenan. Therefore, this work was undertaken to investigate anti-inflammatory effects of maprotiline in more details. Our results verified that i.p. (25 and 50 mg/kg) and i.c.v. (100 μg/rat) application of maprotiline significantly reduced paw edema at 1, 2, 3 and 4 h intervals after carrageenan challenge. Pathological examinations and MPO activity also showed that both i.p. and i.c.v. maprotiline considerably inhibited infiltration of PMN leucocytes into the inflamed paws. Additionally, i.p. and i.c.v. maprotiline at all applied doses noticeably declined levels of IL-1β into the site of inflammation, while only i.p. maprotiline at a dose of 50 mg/kg significantly decreased TNF-α levels in the carrageenan-injected paws.These results confirmed anti-edematogenic activity of i.p. and i.c.v. maprotiline in the carrageenan induced paw edema model and showed that these properties of maprotiline might be mediated through inhibition of PMN infiltration and release of IL-1β and TNF-α.     

Acute atorvastatin treatment exerts antidepressant-like effect in mice via the l-arginine–nitric oxide–cyclic guanosine monophosphate pathway and increases BDNF levels

Atorvastatin is a synthetic and lipophilic statin that presents a good effect in decreasing cholesterol levels and is safe and well tolerated. Population-based studies have suggested a positive role of statins in reducing depression risk. This study aimed at investigating the atorvastatin effect in the tail suspension test (TST) and in the forced swimming test (FST). The participation of NMDA receptors and l–arginine–NO–cGMP in an atorvastatin antidepressant-like effect in the TST was evaluated. Acute atorvastatin administration (0.1–30 mg/kg) reduced the immobility time both in TST and FST. A similar effect was observed by using imipramine as a positive control in the TST and FST (1 and 0.1–1 mg/kg, p.o., respectively). An atorvastatin (0.1 mg/kg) antidepressant-like effect was prevented by the pretreatment of mice with NMDA (0.1 pmol/site, i.c.v.), l-arginine (750 mg/kg, i.p.) or sildenafil (5 mg/kg, i.p.). The administration of MK-801 (0.001 mg/kg, i.p.), ketamine (0.1 mg/kg, i.p.), 7-nitroindazole (50 mg/kg, i.p.), methylene blue (20 mg/kg, i.p.), or ODQ (30 pmol/site i.c.v.) in combination with a subeffective dose of atorvastatin (0.01 mg/kg, p.o.) reduced the immobility time in the TST compared to drugs alone, showing the participation of the pathway l-arginine–NO–cGMP. The administration of drugs did not produce any significant alteration in locomotor activity in the open-field test. Acute atorvastatin treatment (0.1–10.0 mg/kg, v.o.) increased the hippocampal BDNF levels, which is an effect that has not been observed in imipramine-treated mice. These results demonstrate that atorvastatin exerts an antidepressant-like effect and point to dependence on the inhibition of NMDA receptors and NO–cGMP synthesis, and on the increase of hippocampal BDNF levels.     

Protective effect of artemisinin on chronic alcohol induced-liver damage in mice

The liver disease related to chronic alcohol consumption is one of the leading causes of death for alcoholics. The efficient drug to ameliorate the alcoholic liver injury was needed urgently. The present study was performed to investigate whether artemisinin possessed the protective effect against chronic alcohol consumption. 50 male Kunming mice were divided into 5 groups: control group (C): 10 ml/kg saline + 10 ml/kg saline, alcohol group (A): 10 ml/kg 56%(v/v) alcohol + 10 ml/kg saline, low dose group of artemisinin (L): 10 ml/kg 56%(v/v) alcohol + 30 mg/kg/day artemisinin, medium dose group of artemisinin (M): 10 ml/kg 56%(v/v) alcohol + 60 mg/kg/day artemisinin, high dose group of artemisinin (H): 10 ml/kg 56%(v/v) alcohol + 120 mg/kg/day artemisinin. Drugs were given orally every day. The general state of mice was observed and the levels of serum activities of AST and ALT were detected after treatment with drugs for 30 days. Besides, the liver weight index was calculated and histopathological analysis was performed. We successfully demonstrated that treatment with high dose of artemisinin significantly decreased the elevated levels of AST (p < 0.05) and ALT (p < 0.01) in plasma, as well as the liver weight index (p < 0.01). The loss of body weight, tissue injury, oedema and inflammatory cell infiltration in the hepatocytes were found in the A group. These symptoms were remarkably alleviated in animals treated with artemisinin. Artemisinin can inhibit the activation of NF-кB and the expression of inflammatory cytokines inducible nitric oxide synthase. Besides, it can also enhance the stability of liver cell membrane, and reduce the damage of liver cell membrane and liver cell. Artemisinin showed a protective effect against chronic alcohol poisoning and it has a great potential for the clinical application to treat the liver injury induced by alcohol.     

Elucidation of protective efficacy of Pentahydroxy flavone isolated from Madhuca indica against arsenite-induced cardiomyopathy: Role of Nrf-2, PPAR-γ, c-fos and c-jun

BackgroundMadhuca indica J. F. Gmel. (Sapotaceae) is widely used ethnobotanically as anti-diabetic, antipyretic, hepatoprotective, anti-inflammatory and analgesic. It was shown to possess potent anti-apoptotic property.The aim of the studyTo evaluate the possible mechanism of action of isolated phytoconstituent from Madhuca indica Leaves methanolic extract (MI-ALC) on arsenic-induced cardiotoxicity in rats.Materials and methodsThe 3,5,7,3′,4′-Pentahydroxy flavone (QTN) was isolated and characterized by using HPTLC, ¹H NMR, and LC–MS from MI-ALC. QTN (5, 10 and 20 mg/kg, p.o.) was administered in arsenic intoxicated rats (5 mL/kg, p.o.) for 28 days and evaluated for various behavioral, biochemical, molecular and ultra-histological changes.ResultsTreatment with QTN (10 and 20 mg/kg, p.o.) significantly inhibited (p < 0.05) arsenic-induced electrocardiographic, hemodynamic and left ventricular function alterations. Elevated levels of cardiac markers (LDH, CK-MB, AST, ALT, and ALP), altered lipid metabolism (total cholesterol, triglyceride, LDL, HDL, and VLDL) was significantly restored (p < 0.05) by QTN. It also significantly inhibited (p < 0.05) altered cardiac oxido-nitrosative stress, Na-K-ATPase level and mitochondrial enzymes (I–IV) activity after arsenite administration. QTN significantly increased (p < 0.05) myocardial Nrf-2, PPAR-γ and significantly decreased (p < 0.05) myocardial c-fos and c-jun mRNA expressions. Flow cytometric analysis showed that treatment with QTN (10 and 20 mg/kg) significantly inhibited (p < 0.05) arsenite-induce ROS and apoptosis. It also reduced ultra-histological aberrations induced by sodium arsenite.ConclusionAdministration of 3,5,7,3′,4′- Pentahydroxy flavone (i.e. Quercetin (QTN)) isolated from MI-ALC showed significant protection against arsenic-induced oxido-nitrosative stress and myocardial injury via modulation of Nrf2, PPAR-γ, and apoptosis.     

Involvement of NMDA receptors and l-arginine-nitric oxide-cyclic guanosine monophosphate pathway in the antidepressant-like effects of escitalopram in the forced swimming test

Escitalopram is a serotonin reuptake inhibitor used in the treatment of depression and anxiety disorders. This study investigated the effect of escitalopram in forced swimming test (FST) and in the tail suspension test (TST) in mice, and tested the hypothesis that the inhibition of NMDA receptors and NO-cGMP synthesis is implicated in its mechanism of action in the FST. Escitalopram administered by i.p. route reduced the immobility time both in the FST (0.3–10 mg/kg) and in the TST (0.1–10 mg/kg). Administration of escitalopram by p.o route (0.3–10 mg/kg) also reduced the immobility time in the FST. The antidepressant-like effect of escitalopram (3 mg/kg, p.o.) in the FST was prevented by the pretreatment of mice with NMDA (0.1 pmol/site, i.c.v.), l-arginine (750 mg/kg, i.p., a substrate for nitric oxide synthase) or sildenafil (5 mg/kg, i.p., a phosphodiesterase 5 inhibitor). The administration of 7-nitroindazole (50 mg/kg, i.p., a neuronal nitric oxide synthase inhibitor), methylene blue (20 mg/kg, i.p., an inhibitor of both nitric oxide synthase and soluble guanylate cyclase) or ODQ (30 pmol/site i.c.v., a soluble guanylate cyclase inhibitor) in combination with a subeffective dose of escitalopram (0.1 mg/kg, p.o.) reduced the immobility time in the FST as compared with either drug alone. None of the drugs produced significant effects on the locomotor activity in the open-field test. Altogether, our data suggest that the antidepressant-like effect of escitalopram is dependent on inhibition of either NMDA receptors or NO-cGMP synthesis. The results contribute to the understanding of the mechanisms underlying the antidepressant-like effect of escitalopram and reinforce the role of NMDA receptors and l-arginine-NO-GMP pathway in the mechanism of action of antidepressant agents.     

Antimutagenic evaluation of vitamins B1, B6 and B12 in vitro and in vivo,with the Ames test

The aim of this work is to evaluate vitamins B antimutagenic effect against alkylatings methyl-N-nitro-N-nitrosoguanidine (MNNG), ethyl-N-nitro-N′- nitrosoguanidine (ENNG), frameshift mutagens 2-aminoanthracene (2AA) and 2-acetyl-amino-fluorene (2AF) and ROS-generating antibiotics norfloxacin (NOR) and nalidixic acid (NLX), using the in vitro Ames test. In vivo antimutagenesis studies were performed against urinary mutagens induced by NOR (70 mg/kg) or NLX (100 mg/kg) in CD1 mice.Vitamin B1 was antimutagenic against alkylatings MNNG (P < 0.05) or ENNG (P < 0.001). In fact as per the results observed during the current study, none of the vitamins reduced mutagenesis caused by frameshift mutagens. All of them reduced mutagenesis of NOR or NLX (P < 0.001). In vivo studies showed that vitamins B1 and B6 (10 or 100 mg/kg) reduced urinary mutagens from NOR (P < 0.001) or NLX (P < 0.02) either free or β-glucoronidase-conjugates. None of the studied samples were toxic for the employed antimutagenic system. Vitamin B12 (4 mg/kg) reduced urinary mutagens of NOR or NLX (P < 0.02).Vitamins B inhibited DNA mutations induced by ROS generated by NLX or NOR, both in vitro and in vivo. Vitamin B1is antimutagenic against mutations induced by the alkylating MNNG or ENNG. Based on the observations, employment of vitamins B in vivo can be a promising alternative to reduce genotoxic risk exposure to ROS.     

Research on choleretic effect of menthol,menthone, pluegone,isomenthone, and limonene in DanShu capsule

Danshu capsule (DSC) is a medicinal compound in traditional Chinese medicine (TCM). It is commonly used for the treatment of acute & chronic cholecystitis as well as choleithiasis. To study its choleretic effect, healthy rats were randomly divided into DSC high (DSCH, 900 mg/kg), medium (DSCM, 450 mg/kg), and low (DSCL, 225 mg/kg) group, Xiaoyan Lidan tablet (XYLDT, 750 mg/kg), and saline group. The bile was collected for 1 h after 20-minute stabilization as the base level, and at 1 h, 2 h, 3 h, and 4 h after drug administration, respectively. Bile volume, total cholesterol, and total bile acid were measured at each time point. The results revealed that DSC significantly stimulated bile secretion, decreased total cholesterol level and increased total bile acid level. Therefore, it had choleretic effects. To identify the active components contributing to its choleretic effects, five major constituents which are menthol (39.33 mg/kg), menthone (18.02 mg/kg), isomenthone (8.18 mg/kg), pluegone (3.31 mg/kg), and limonene (4.39 mg/kg) were tested on our rat model. The results showed that menthol and limonene could promote bile secretion when compared to DSC treatment (p > 0.05); Menthol, menthol and limonene could significantly decrease total cholesterol level (p < 0.05 or p < 0.01) as well as increase total bile acid level (p < 0.05 or p < 0.01); Isomenthone, as a isomer of menthone, existed slightly choleretic effects; Pluegone had no obvious role in bile acid efflux. These findings indicated that the choleretic effects of DSC may be attributed mainly to its three major constituents: menthol, menthone and limonene.     

Correlation between aflatoxin M1 content of breast milk,dietary exposure to aflatoxin B1 and socioeconomic status of lactating mothers in Ogun State,Nigeria

Aflatoxin M₁ (AF M₁), a hydroxylated metabolite of AF B₁, is an important toxin that can contaminate the milk of lactating mothers. A correlation study was conducted to determine the relationship between AF M₁ content of breast milk, dietary exposure to AF B₁ and socioeconomic status of lactating mothers in the three Senatorial districts of Ogun State, Nigeria. Equal amounts of breast milk (20 ml) and food rations (40 kg) obtained from 50 volunteer lactating mothers and eighty-two frequently consumed food commodities in the preceding month were used for the study. The level of contamination of the foods by AF B₁ was low (0.16–0.33 μg/kg) and differed significantly (p < 0.05) across the state but did not exceed the EU limit of 2 μg/kg. The occurrence level of AF B₁ was however high (93.75–94.45%) and was more pronounced in Ogun East Senatorial district (94.45%). Eighty-two percent of the breast milk was contaminated with AF M₁ (3.49–35 ng/l) and 16% exceeded the EU limit of 25 ng/l while a 100% occurrence risk was recorded in Ogun Central Senatorial district. The socioeconomic status of the mothers also significantly influenced their dietary exposure and exposure risk of the sucklings to AF M_1.     

Endometrial damage and apoptosis in rats induced by dichlorvos and ameliorating effect of antioxidant Vitamins E and C

We aimed to investigate the effect of subchronic administration of dichlorvos (DDVP) on endometrium and to evaluate ameliorating effects of a combination of Vitamins E and C against DDVP toxicity in the rat. Three groups of rats were used in the experiment. The first group was treated with 4 mg/kg DDVP; the second group was treated with 4 mg/kg body weight DDVP plus Vitamins E and C (DDVP + Vit); the third group was given only corn oil (control). DDVP and DDVP + Vit groups were given DDVP by gavage 5 days a week for 4 weeks at a dose level of 4 mg/kg day by using corn oil as the vechicle. Vitamins E and C were injected at doses of 50 mg/kg i.m. and 20 mg/kg body weight i.p. Histopathological and immunohistochemical examinations for caspase-3 and caspase-9 were accomplished in the endometrium. The level of malondialdehyde (MDA) increased significantly in the DDVP group compared with the control group (p < 0.05). MDA significantly decreased in the DDVP + Vit group compared with the DDVP group (p < 0.05). Administration of Vitamins E and C along with DDVP significantly reduced the histopathological changes and the extent of apoptosis. In conclusion, subchronic DDVP administration caused endometrial damage and that treatment with a combination of Vitamins E and C reduced endometrial damage caused by DDVP.     

Protective effects of naringin against paraquat-induced acute lung injury and pulmonary fibrosis in mice

The present study evaluates protective effects of naringin against paraquat (PQ)-induced acute lung injury (ALI) and pulmonary fibrosis in mice. Survival probability against PQ intoxication was tested by a single intraperitoneal injection of PQ. Results showed that survival rates of mice exposed to PQ only (50 mg/kg within 7 days) were much lower than that in mice daily treatment with NAC or naringin. Moreover, protection against PQ-induced ALI was tested by daily pretreatment mice with saline, NAC or naringin for 3 days before PQ (30 mg/kg, i.p.). Results showed that increase in leukocytes infiltration and overexpressions of TNF-α and TGF-β1 caused by 8 h of PQ exposure were dose-dependently ameliorated by naringin. Furthermore, protection against PQ-induced pulmonary fibrosis was tested by pretreatment mice with PQ (20 mg/kg, i.p.), and then daily administration with saline, NAC or naringin for prolonged 21 days. Results showed that naringin of 60 and 120 mg/kg significantly reduced PQ-induced upregulations of TNF-α, TGF-β1, MMP-9 and TIMP-1, levels of pulmonary malonaldehyde and hydroxyproline, as well as pulmonary fibrosis deposition, while increased activities of SOD, GSH-Px and HO-1. These results indicated that naringin had effective protection against PQ-induced ALI and pulmonary fibrosis.     

Development of an alternative non-obese non-genetic rat model of type 2 diabetes using caffeine and streptozotocin

BackgroundThe aim of the present study was to develop an alternative non-obese non-genetic rat model of type 2 diabetes (T2D).MethodsSix-week-old male SD rats were randomly divided into six groups, namely: Normal Control (NC), Diabetic Control (DBC), Caffeine 5 mg/kg BW + STZ (CAF5), Caffeine 10 mg/kg BW + STZ (CAF10), Caffeine 20 mg/kg BW + STZ (CAF20) and Caffeine 40 mg/kg BW + STZ (CAF40) and were fed a normal rat pellet diet and drinking water ad libitum throughout the experimental period. After a one week acclimatization period, diabetes was induced in the animals in DBC and all CAF groups with an injection (i.p.) of the respective dosages of caffeine (mg/kg BW) 15 min before the injection of STZ (65 mg/kg BW) when normal saline was injected to the DBC group instead of caffeine. The NC group received normal saline and buffer instead of caffeine and STZ, respectively. One week after the STZ injection, animals with non-fasting blood glucose > 300 mg/dl were considered as diabetic. Three weeks after the STZ injection, the animals in the CAF5 and CAF10 groups were eliminated from the study due to the severity of diabetes and the experiment was continued with the remainder groups for a 13 weeks period.Results and conclusionThe data of food and fluid intake, body weight, blood glucose, glucose tolerance test, HOMA-IR, HOMA-beta, serum insulin, fructosamine, lipid profile and organ specific enzymes, anti-diabetic drug response tests, and pancreatic histopathology suggest that CAF20 group can be a better alternative non-genetic model of non-obese T2D.     

In vivo potentiation of reboxetine and citalopram effect on extracellular noradrenaline in rat brain by α2-adrenoceptor antagonism

The therapeutic activity of noradrenaline reuptake inhibitors (NaRIs) and serotonin reuptake inhibitors (SSRIs) as antidepressant is based on their ability to increase monoamine concentrations in the synaptic cleft. α₂-Adrenoceptors inhibit noradrenaline (NA) release, which modulates antidepressant neurochemical activity. The present study assesses the influence of the addition of the selective α₂-adrenoceptor antagonist RS79948 to the NaRI reboxetine and the SSRI citalopram on brain extracellular NA. Dual-probe microdialysis technique in the locus coeruleus (LC) and prefrontal cortex (PFC) was performed in freely moving rats. Acute reboxetine (3 and 5 mg/kg i.p.) promoted a dose-dependent increase of NA in LC (164 ± 15%; 243 ± 24%) and PFC (140 ± 7%; 181 ± 30%). Acute citalopram (5 mg/kg i.p.) did not change NA in LC or PFC, but at 10 mg/kg i.p. increased NA in LC (144 ± 14%) and decreased it in PFC (− 42 ± 7%). An inactive dose of RS79948 (0.1 mg/kg i.p.) in rats pretreated with reboxetine (3 mg/kg i.p.) or citalopram (5 mg/kg i.p.) induced a significant enhancement of NA in LC (reboxetine: 462 ± 137%; citalopram: 142 ± 11%) and PFC (reboxetine: 281 ± 56%; citalopram: 130 ± 16%). The results indicate that co-administration of selective α₂-adrenoceptor antagonist drugs might improve the effects of NaRI or SSRI antidepressants by enhancing extracellular NA concentrations in the brain.     

Na+–H+ exchange inhibition attenuates ischemic injury in rat random pattern skin flap: The role of mitochondrial ATP-sensitive potassium channels

Necrosis of distal portion of skin flaps due to ischemia still remains a problem in plastic surgery. Following ischemia, a cascade of deleterious events including over-activity of Na⁺–H⁺ Exchanger (NHE) takes place. In present study we evaluated the effect of the potent NHE inhibitor, 5-(N-ethyl-N-isopropyl) amiloride (EIPA) on ischemic tissue injury in a skin flap model, and investigated the role of mitochondrial ATP-sensitive K⁺ channels (K_ATP) in this phenomenon. Seventy-eight rats were randomly divided into thirteen treatment groups (6 rats each). Four groups received different doses of EIPA in the flap. EIPA/GLY group received an effective dose of a K_ATP channel blocker, glibenclamide (GLY, 0.3 mg/kg) intraperitoneally (i.p.) 30 min before raising the flap, and a local effective dose of EIPA (0.1 mM) immediately after raising the flap. EIPA/diazoxide group (EIPA/DIA) received a sub-effective dose of diazoxide (7.5 mg/kg i.p.) 30 min before raising the flap and a local sub-effective dose of EIPA (0.075 mM). EIPA 0.1 and 0.2 mM significantly increased flap survival area compared to control group (56.01±6.1%, P<0.001). The protective effect of EIPA (0.1 mM) was abolished by administration of glibenclamide (0.3 mg/kg i.p.). Co-administration of a sub-effective dose of EIPA (0.075 mM), with a sub-effective dose of diazoxide (7.5 mg/kg i.p.) significantly improved flap survival (P<0.05). We demonstrated that the NHE inhibitor, EIPA can increase random pattern skin flap survival. Administration of diazoxide potentiates this effect, while glibenclamide abolishes that, implicating that the protective effect of EIPA is mediated through mitochondrial-K_ATP channels.     

Involvement of PKA,PKC, CAMK-II and MEK1/2 in the acute antidepressant-like effect of creatine in mice

BackgroundThe aim of this study was to investigate the involvement of signaling pathways on the creatine antidepressant-like effect in the tail suspension test (TST) in mice.MethodsThe TST was used to assess the antidepressant-like properties of creatine.ResultsThe anti-immobility effect of creatine (1 mg/kg, p.o.) in the TST was blocked by i.c.v. pretreatment with H-89 (1 μg/site, PKA inhibitor), KN-62 (1 μg/site, CAMK-II inhibitor), chelerythrine (1 μg/site, PKC inhibitor), U0126 (5 μg/site, MEK1/2 inhibitor) or PD09058 (5 μg/site, MEK1/2 inhibitor).ConclusionThese results suggest that the antidepressant-like effect of creatine is dependent on PKA, CaMK-II, PKC and MEK 1/2 activation.     

Assessment of propofol,midazolam and ziprasidone,or the combinations for the prevention of acute cocaine toxicity in a mouse model

Study objectiveTo evaluate the effects of pretreatment, midazolam (M), propofol (P), ziprasidone (Z), and two combinations of [(midazolam plus propofol (MP); midazolam plus ziprasidone (MZ)] in mice models in the prevention of seizures, and death due to acute cocaine toxicity.Methods180 male CF-1 mice were randomized to 6 groups (30/group) in this experimental study. The animals were administered intraperitoneal injections of M (2 mg/kg), P (25 mg/kg), Z (4 mg/kg), MP (2 mg/kg and 25 mg/kg) and MZ (2 mg/kg and 4 mg/kg) or saline (S) as a pretreatment. 10 min later, the mice were administered intraperitoneal injections of 105 mg/kg cocaine. The groups were observed for cocaine-induced seizure and lethality.ResultsThe MP and MZ combinations showed the highest protective effect in terms of seizure and lethality relative to P and S (p < 0.001). M and Z were found effective compared to P and S (p < 0.001). There were no significant differences among MP and MZ, however there were significant differences between MP and Z in terms of lethality (p = 0.05). There were no significant differences among MP, MZ, M and Z groups in terms of seizure (p > 0.05). No death was observed in the MP combination group. Seizure rate was observed o be least in the MZ group with respect to the other groups.ConclusionAccording to our particular mouse model, this study suggests that MP and MZ combinations may be more effective than M or Z only for the prevention of cocaine-induced seizure and lethality. However, P alone does not prevent cocaine-induced seizure and lethality.     

Behavioural and neurochemical comparison of chronic intermittent cathinone,mephedrone and MDMA administration to the rat

The synthetic cathinone derivative, mephedrone, is a controlled substance across Europe. Its effects have been compared by users to 3,4-methylenedioxymethamphetamine (MDMA), but little data exist on its pharmacological properties. This study compared the behavioural and neurochemical effects of mephedrone with cathinone and MDMA in rats. Young-adult male Lister hooded rats received i.p. cathinone (1 or 4 mg/kg), mephedrone (1, 4 or 10 mg/kg) or MDMA (10 mg/kg) on two consecutive days weekly for 3 weeks or as a single acute injection (for neurochemical analysis). Locomotor activity (LMA), novel object discrimination (NOD), conditioned emotional response (CER) and prepulse inhibition of the acoustic startle response (PPI) were measured following intermittent drug administration. Dopamine, 5-hydroxytryptamine (5-HT) and their major metabolites were measured in striatum, frontal cortex and hippocampus by high performance liquid chromatography 7 days after intermittent dosing and 2 h after acute injection. Cathinone (1, 4 mg/kg), mephedrone (10 mg/kg) and MDMA (10 mg/kg) induced hyperactivity following the first and sixth injections and sensitization to cathinone and mephedrone occurred with chronic dosing. All drugs impaired NOD and mephedrone (10 mg/kg) reduced freezing in response to contextual re-exposure during the CER retention trial. Acute MDMA reduced hippocampal 5-HT and 5-HIAA but the only significant effect on dopamine, 5-HT and their metabolites following chronic dosing was altered hippocampal 3,4-dihydroxyphenylacetic acid (DOPAC), following mephedrone (4, 10 mg/kg) and MDMA. At the doses examined, mephedrone, cathinone, and MDMA induced similar effects on behaviour and failed to induce neurotoxic damage when administered intermittently over 3 weeks.