Naval Medical Research Institute Mice Research Articles

Epicatechin as a promising agent against arsenic-induced neurobehavioral toxicity in NMRI mice: behavioral and biochemical alterations.

Epicatechin (Epi) is one of the most abundant flavonoids present in different fruits and tea leaves. Emerging research illuminates the promising potential of catechins to serve as a shield against the damaging effects of arsenic (As) exposure in diverse organs.This study sought to discern whether Epi exhibits a therapeutic efficacy against arsenic-induced neurotoxicity in a murine model.The Naval Medical Research Institute (NMRI) mice were randomly partitioned into six distinct groups, which included a control group receiving normal saline, a group receiving a daily oral dose of arsenic (10mg/kg) for 5weeks, groups receiving As (10mg/kg/day) orally for 5weeks along with different doses of Epi (25-100mg/kg) orally for the last 2weeks, and a group receiving Epi (100mg/kg) orally for 2weeks. To assess the potential effects of Epi, neurobehavioral tests, various parameters of oxidative stress, and inflammation were evaluated.The findings of this investigation revealed that As-induced neurobehavioral toxicity was associated with a notable surge in lipid peroxidation and nitric oxide (NO) concentration, accompanied by a reduction in the levels of antioxidant markers. As heightened pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) levels were observed alongside amplified nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) expression. However, treatment with Epi reversed these effects.On the whole, these findings indicate that Epi may hold promise therapeutic efficacy on As-induced neurotoxicity by improving antioxidant status and mitigating oxidative stress and inflammation. Nevertheless, further research is imperative to comprehensively grasp the potential protective effects of Epi in this particular context.

Additive Anticonvulsive Effects of Sumatriptan and Morphine on Pentylenetetrazole-Induced Clonic Seizures in Mice.

Sumatriptan protects the brain from damage and enhance the anti-seizure effect of morphine. There is evidence that nitric oxide (NO) may mediate these effects of both drugs. In the present study, we investigated the effects of sumatriptan (0.1-20 mg/kg, intraperitoneal [i.p.]) and morphine (0.1-20 mg/kg, i.p.) alone or in combination on seizure thresholds in an in vivo model of seizure in mice. Using various NO synthase inhibitors as well as the NO precursor, we assessed possible involvement of NO signaling in these effects. Clonic seizures were induced in male Naval Medical Research Institute mice by intravenous administration of pentylenetetrazol (PTZ). Acute sumatriptan administration exerted anti-convulsive effects at 0.5 (p<0.01) and 1 mg/kg (p<0.05), but pro-convulsive effects at 20 mg/kg (p<0.05). Morphine had anti-convulsive effects at 0.5 (p<0.05) and 1 mg/kg (p<0.001), but exerted pro-convulsive effect at 20 mg/kg (p<0.05). Combination treatment with sub-effective doses of sumatriptan (0.1 mg/kg) and morphine (0.1 mg/kg) significantly (p<0.05) exerted an anti-convulsive effect. Co-administration of the NO precursor L-arginine (60 mg/kg) with sub-effective doses of sumatriptan and morphine significantly (p<0.05) increased seizure threshold compared with sumatriptan alone, but not sumatriptan+morphine group. While concomitant administration of either the non-selective NO synthase (NOS) inhibitor L-NG-nitroarginine methyl ester (5 mg/kg) or the selective inducible NOS inhibitor aminoguanidine (50 mg/kg) with combined sub-effective doses of morphine and sumatriptan produced significant anticonvulsive effects, concomitant administration with the selective neuronal NOS inhibitor 7-nitroindazole (30 mg/kg) inhibited this effect. Our data suggest a possible role for the NO signaling in the anticonvulsive effects of combined sumatriptan and morphine on the PTZ-induced clonic seizures in mice.

Neuroimmune response and oxidative stress in the prefrontal cortex mediate seizure susceptibility in experimental colitis in male mice.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder. Oxidative stress and inflammatory responses have a vital role in the pathophysiology of IBD as well as seizure. IBD is associated with extraintestinal manifestations. This study aimed to explore the relationship between colitis and susceptibility to seizures, with a focus on the roles of neuroinflammation and oxidative stress in acetic acid-induced colitis in mice. Forty male Naval Medical Research Institute mice were divided into four groups: control, colitis, pentylenetetrazole (PTZ), and colitis + PTZ. Colitis was induced by intrarectal administration of acetic acid, and seizures were induced by intravenous injection of PTZ 7 days postcolitis induction. Following the measurement of latency to seizure, the mice were killed, and their colons and prefrontal cortex (PFC) were dissected. Gene expression of inflammatory markers including interleukin-1β, tumor necrosis factor-alpha, NOD-like receptor protein 3, and toll-like receptor 4, as well as total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels were measured in the colon and PFC. Histopathological evaluations were performed on the colon samples. Data were analyzed by t-test or one-way variance analysis. Colitis decreased latency to seizure, increased gene expression of inflammatory markers, and altered levels of MDA, nitrite, and TAC in both the colon and PFC. Simultaneous induction of colitis and seizure exacerbated the neuroimmune response and oxidative stress in the PFC and colon. Results concluded that neuroinflammation and oxidative stress in the PFC at least partially mediate the comorbid decrease in seizure latency in mice with colitis.

The effects of vitamin E supplementation on sperm parameters, chromatin integrity, and gene expression before and after freezing in aged mice.

Some age-related testicular changes, such as Sertoli cell vacuolization and blood-testis barrier breakdown, reduce total sperm production and male fertility. Therefore, this study investigated the effect of vitamin E on restoring testicular function in aged mice. Sperm cryo-resistance was also assessed. Twenty-eight 48-week-old male Naval Medical Research Institute mice were divided into four groups for a daily gavage of vitamin E: the control group received distilled water, while the three treatment groups were administered 100, 200, and 400 mg/kg, respectively, for 4 weeks. Subsequently, semen analyses, DNA fragmentation index (DFI), and protamine deficiency tests were conducted. Testicular histology, tissue antioxidant enzyme activity, and gene expression levels were also assessed. The two higher dosages of vitamin E were associated with a higher sperm count, greater progressive motility, and improved sperm morphology (p<0.05). These benefits were also evident after sperm freezing (p<0.05). Although chromatin abnormalities increased following vitrification, the treatment groups showed better outcomes (p<0.05). The tubular diameter, epithelium height, and luminal diameters remained unchanged with age. The tissue antioxidant capacity was greater in the groups receiving the high doses of vitamin E. Additionally, significant increases in inhibitor of DNA binding protein-4 (Id4) and GDNF family receptor alpha-1 (Gfra1) expression were observed in the higher vitamin E dosage groups, and promyelocytic leukemia zinc finger protein (Plzf) expression was notably present in the 400 mg/kg treatment group compared to the control group (p<0.05). Antioxidant supplementation might enhance reproductive outcomes in aging males. The observed effects included improved sperm cryo-resistance, which is advantageous for future applications such as sperm freezing or fertility preservation.

Antiseizure Activity of Mitragyna inermis in the Pentylenetetrazol-Induced Seizure Model in Mice: Involvement of Flavonoids and Alkaloids.

This study aimed to investigate whether Mitragyna inermis (Willd.) Otto Kuntze organic and aqueous extracts are able to control seizures induced by pentylenetetrazol (PTZ) in mice based on flavonoid fingerprints and alkaloidal contents. Ethanolic extract and decoction-derived fractions from roots, leaves, and stems were subjected to chromatographic fingerprinting using AlCl3 and screening for their antiseizure effects using PTZ-induced acute seizure model. From the fractions that showed potent bioactivities, plausible antiseizure alkaloids were isolated using thin layer chromatography, and their structures were elucidated using 1H NMR, 2D NMR, 13C NMR, and FAB-HR (+ve or -ve). All fractions, with the exception of the dichloromethane and hexane fractions, revealed remarkable flavonoid fingerprints. An acute PTZ-induced seizure test revealed that ethanolic extract of stem bark [500 mg/kg body weight (bw)], ethyl acetate extract of stem bark (500 mg/kg bw), and aqueous extract of leaves (300 mg/kg bw) significantly delayed the occurrence of hind limb tonic extension (HLTE); however, a non-significant delay was observed in the onset of first myoclonic jerk compared with control animals. Isolation yielded four main alkaloids: that are, pteropodine (1), isopteropodine (2), mitraphylline (3) and corynoxeine (4). Corynoxeine is a new compound derived from M. inermis. This study suggests that flavonoid fingerprints are tracers of M. inermis anticonvulsant ingredients. The stem bark ethanolic and ethyl acetate extracts and leaf aqueous extracts contain anticonvulsant bioactive principles that delay notifying the HLTE occurring in male naval medical research institute mice. Furthermore, alkaloidal contents also remain plausible bioactive anticonvulsant principles. All observations support the traditional use of M. inermis to manage epilepsy. However, further studies are needed to understand the effects of alkaloid fractions, flavonoids, and the isolated compounds as promising antiseizure agents derived from M. inermis in experimental animals.

Insulin Ameliorates Neurodegeneration in an Experimental Animal Model of Brain Aging by a Decrease of GFAP Expression and Apoptosis Inhibition

Background: Aging is one of the factors that will cause gradual changes in brain tissue and its destruction. One of the protective factors against aging is insulin. Objectives: Our study investigated insulin's neuroprotective effect by preventing oxidative stress-mediated neuronal damage. Methods: A total of 48 adult male NMRI (the Naval Medical Research Institute) mice were divided into 2 groups: Control and insulin. Insulin was administered intraperitoneally (IP) for 8 weeks to the control group and for 12 weeks to the insulin group. In this study, animals were treated with insulin, and insulin's role in the aging process was evaluated. Then, brain tissue was extracted for evaluation of oxidative stress by assessment of glutathione disulfide (GSH) and reactive oxygen species (ROS) levels, the expression of the glial fibrillary acidic protein (GFAP) as a biomarker for astrogliosis, stereological study, and the real-time polymerase chain reaction (PCR) technique evaluated the level of apoptosis biomarker. Results: The results of stereological parameters show that the volumes of the brain cortex and the number of neurons improved in the insulin group by aging as compared to the control group. The results of real-time PCR showed that the expression level of apoptotic markers decreased in the insulin group compared to the control group. In the insulin group, GSH levels were higher than in the control group, and the control group produced more ROS than the insulin group. As compared with insulin, the control group expressed more GFAP protein and increased the number of glial cells by aging. Conclusions: The results showed that insulin could have neuroprotective effects against aging changes and reduce apoptosis and cell death.

Anethole via increase in the gene expression of PI3K/AKT/mTOR mitigates the autistic-like behaviors induced by maternal separation stress in mice

Autism spectrum disorder (ASD) is a neurodegenerative disease with increasing incidence in the world. The maternal separation (MS) stress at early life with its own neuroendocrine and neurostructural changes can provide the basis for development of ASD. Previously it has been reported neuroprotective characteristics for anethole. The PI3K/AKT/mTOR signaling pathway has pivotal role in the function of central nervous system (CNS). This study aimed to evaluate the possible effects of anethole on the autistic-like behaviors in the maternally separated (MS) mice focusing on the potential role of the PI3K/AKT/mTOR pathway. Forty male Naval Medical Research Institute (NMRI) mice were assigned to five groups (n = 8) comprising a control group (treated with normal saline) and four groups subjected to MS and treated with normal saline and or anethole at doses of 31.25, 62.5 and 125 mg/kg, respectively. All gents were administrated via intraperitoneal (i.p.) route for 14 constant days. Behavioral tests were conducted, including the three-chamber test, shuttle box and resident-intruder test. The gene expression of the PI3K, AKT and mTOR assessed in the hippocampus by qRT-PCR. Findings indicated that MS is associated with autistic-like behaviors. Anethole increased the sociability and social preference indexes in the three-chamber test, increased duration of secondary latency in the shuttle box test and decreased aggressive behaviors in the resident-intruder test. Also, anethole increased the gene expression of PI3K, AKT and mTOR in the hippocampus of MS mice. We concluded that anethole through increase in the gene expression of PI3K/ AKT/mTOR mitigated autistic-like behaviors induced by MS in mice.

Possible role of NO/NMDA pathway in the autistic-like behaviors induced by maternal separation stress in mice.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Maternal separation (MS) stress is an established model of early-life stress associated with autistic-like behaviors. Altered glutamatergic and nitrergic neurotransmissions may contribute to the pathophysiology of ASD. However, the specific mechanisms underlying these alterations and their relationship to MS-induced autistic-like behaviors remain unclear. Addressing this knowledge gap, this study aims to elucidate the involvement of the nitric oxide (NO)/ N-methyl-D-aspartate (NMDA) pathway in MS-induced autistic-like behaviors in mice. This knowledge has the potential to guide future research, potentially leading to the development of targeted interventions or treatments aimed at modulating the NO/NMDA pathway to ameliorate ASD symptoms. Ninety male Naval Medical Research Institute (NMRI) mice were assigned to six groups (n = 15) comprising a control group (treated with saline) and five groups subjected to MS and treated with saline, ketamine, NMDA, L-NAME, and L-arginine. Behavioral tests were conducted, including the three-chamber test, shuttle box, elevated plus-maze, and marble burying test. Gene expression of iNOS, nNOS, and NMDA-R subunits (NR2A and NR2B), along with nitrite levels, was evaluated in the hippocampus. The findings demonstrated that MS induced autistic-like behaviors, accompanied by increased gene expression of iNOS, nNOS, NR2B, NR2A, and elevated nitrite levels in the hippocampus. Modulation of the NO/NMDA pathway with activators and inhibitors altered the effects of MS. These results suggest that the NO/NMDA pathway plays a role in mediating the negative effects of MS and potentially contributes to the development of autistic-like behaviors in maternally separated mice.

Comparison of the effects of mycophenolate mofetil alone and with testosterone on sperm, sex hormones and antioxidant enzymes in male rats

Background: Mycophenolate mofetil (MMF) is an immunosuppressant drug which is used to inhibit organ transplant rejection and to treat autoimmune diseases. Theoretically, such medications have spermatotoxic and genotoxic effects. However, evidence on the effects of MMF on fertility is limited and controversial.This study evaluated the effects of MMF and testosterone on sperm, sex hormones and antioxidant enzymes in male rats. Materials and Methods: In this experimental study 24 adult male Naval Medical Research Institute (NMRI) mice randomly divided into 3 groups: 1- saline serum (control), 2- MMF and 3- MMF along with testosterone by subcutaneous injection, for 65 days. Change in body weight, sperm quality (concentration, motility and morphology), serum level of gonadotropin hormones, and testosterone, superoxide dismutase (SOD), glutathione (GSH), catalase, total antioxidant capacity (TAC) in serum and epididymis were evaluated. Findings: Both MMF treatment groups compared to control showed a decrease in body weight, number and motility of sperm, level of testosterone, antioxidant enzymes (SOD, GSH, and catalase) and TAC (P&lt;0.05), and increase of gonadotropin hormones and sperm morphology abnormality (P&lt;0.05). The adverse effects on sperm count and epididymis testosterone levels in the Mycophenolatemofetil +testosterone group was less than the Mycophenolate mofetil group (P&lt;0.05). Conclusion: This study showed that Mycophenolatemofetil has adverse effects on sperm count, gonadotropins , testosterone and antioxidant pathway enzymes, and the use of testosterone cannot reduce the adverse effects of MMF. The adverse effects of Mycophenolate mofetil may be due to a decrease in the level of antioxidants.

A novel experimental model to investigate fungal involvement shows expression of Dectin-1 in periapical lesion pathogenesis.

Candida albicans is linked to persistent endodontic lesions. However, the recognition receptor that identifies it is not explored previously. The aim of this study was to (1) establish a zymosan-induced model of apical periodontitis in mouse, (2) observe the expression of Dectin-1 and its possible relationship with toll-like receptor (TLR) 2 and (3) observe relationship between Osteopontin (OPN) and inflammatory cytokines. A total of 138 Naval Medical Research Institute (NMRI) mice were randomly divided into; Experimental Group n = 69 and Zymosan Group n = 69. Periapical periodontitis was developed in right maxillary molar. The animals were sacrificed at 7, 21 and 42 days. Bone blocks containing the mesial root (n = 15 for qRT-PCR, n = 45 for enzyme-linked immune sorbent assay (ELISA)) were collected for mRNA expression and ELISA. While whole maxilla (n = 3 from each time interval) were used for histology and immunohistochemical analysis. One way analysis of variance (ANOVA) and Tuckey's posthoc was used for statistical analysis at p ≤ .05. TLR-2, Dectin-1 and TLR4-positive cells was detected at all time intervals in both groups. A strong positive correlation was observed between TLR-2 and Dectin-1 in both lesions (regular r = .680, p = .015, zymosan (r = .861, p < .001)). A significant correlation was found between OPN and tumour necrosis factor-alpha (TNF-α) in zymosan lesion (r = .827, p = .001). Immune cells of inflamed periapical tissue expressed Dectin-1 receptor in response to the microbial challenge from infected root canals and showed positive correlation with TLR-2 and OPN suggesting a possible receptor collaboration mediated by OPN. The expression of OPN and TNF-α showed positive correlation in response to fungal antigen, indicating a possible relationship.

The Effect of Vitamin D3 Supplemented with PhytoSolve on Genes Involved in Implantation in an NMRI Mice Model of Polycystic Ovary Syndrome: An Experimental Study.

Vitamin D3 has been shown to be effective in the treatment of PCOS. However, due to its poor solvability and bioavailability, effective time is delayed and dosage requirements are increased. In our previous study, we demonstrated that PhytoSolve containing VD3 is more effective than vitamin D3 alone in the treatment of PCOS. In this study, we aimed to investigate the effect of this vitamin D3 formulation on gene expression involved in implantation in patients with PCOS. To create PhytoSolve, Lipid S75, glycerol, and MCT oil were combined using a sonicator probe. Six groups, each consisting of 36 female Naval Medical Research Institute (NMRI) mice, were included in the following groups: control; sham; PCOS; PhytoSolve; PhytoSolve containing VD3; and vitamin D3. The mice were given DHEA injections to induce PCOS. After administering PhytoSolve containing VD3 and vitamin D3 by gavage for one week from the 13th day of model creation, the female mice were mated and endometrial tissue was collected for analysis of LIF, β-integrin, and HOXA10 proteins and genes. Compared to the group receiving vitamin D3 alone, the group receiving PhytoSolve containing vitamin D3 showed a significant increase in the expression of LIF, β-integrin, and HOXA10 genes (p<0.05). Although there was an increase in the expression of β-integrin and HOXA10 proteins in the group given PhytoSolve containing vitamin D3 compared to the group given vitamin D3, this increase was not significant. However, the increase in LIF protein expression in the group given PhytoSolve containing vitamin D3 was significant when compared to the group given vitamin D3 (p<0.05). The use of PhytoSolve containing vitamin D3 was more effective than vitamin D3 alone. The PhytoSolve formulation might be a useful solution for medications with limited solubility and bioavailability.

Experimental Cardiac Toxicity Induced by the Injection of Uracoan Rattlesnake (Crotalus vegrandis) and the Black Rattlesnake (Crotalus pifanorum) Venoms

Background Snakebite is a collective health problem that afflicts areas with poor healthcare coverage. Venezuela has an important population of snakes, including the endemic species Crotalus vegrandis and Crotalus pifanorum, whose venom has not been fully characterized, especially of those aspects related to cardiac electrophysiology. Aims In this sense, this work aims to characterize the electrocardiographic and histopathological effect of crude venom of C. vegrandis and C. pifanorum on albino Naval Medical Research Institute (NMRI) mice. Results For this, mice were gathered in C. pifanorum and C. vegrandis experimental groups, including normal controls and envenomed mice injected with commercial antivenom. C. vegrandis venom showed a significant T and S wave flattening and pulmonic (pulmonary) regurgitation (PR) enlargement, in addition to atrial ectopic activity, notched R wave, triggered activity, and T wave inversion. C. pifanorum was the only group that registered triggered activity. Antivenom was able to revert conduction disorders showing a statistical increase in arrhythmogenic compared by χ2 . The multidimensional comparison confirmed the statistical differences between C. vegrandis and C. pifanorum venoms and between antivenom vs non-antivenom groups, detecting variables associated with cardiac conduction, as the most important variables. Conclusion In conclusion, this work demonstrated, as far as we know, for the first time the cardiotoxic effects associated with C. vegrandis and C. pifanorum venom injection, subsequently suggesting the duty of including an electrocardiogram in the consultation of any accident caused by these species.

Chronic stress but not acute stress decreases the seizure threshold in PTZ-induced seizure in mice: role of inflammatory response and oxidative stress.

Seizure is paroxysmal abnormal electrical discharges in the cerebral cortex. Inflammatory pathways and oxidative stress are involved in the pathophysiology of seizures. Stress can induce an oxidative stress state and increase the production of inflammatory mediators in the brain. We investigated the effects of acute and chronic stresses on the seizure threshold in pentylenetetrazol (PTZ)-induced seizures in mice, considering oxidative stress and inflammatory mediators in the prefrontal cortex. In this study, 30 male Naval Medical Research Institute (NMRI) mice were divided into 3 groups, including acute stress, chronic stress, and control groups. PTZ was used for the induction of seizures. The gene expression of inflammatory markers (IL-1β, TNF-α, NLRP3, and iNOS), malondialdehyde (MDA) level, nitrite level, and total antioxidant capacity (TAC) were assessed in the prefrontal cortex and serum. Our results showed that stress could increase the expression of inflammatory cytokines genes and oxidative stress in the prefrontal cortex of the brain and serum following PTZ-induced seizures, which is associated with increased seizure sensitivity and decreased the seizure threshold. The effects of chronic stress were much more significant than acute stress. We concluded that the effects of chronic stress on seizure sensitivity and enhancement of neuroinflammation and oxidative stress are much greater than acute stress.

Differences in lipid metabolism in acquired versus preexisting glucose intolerance during gestation: role of free fatty acids and sphingosine-1-phosphate

BackgroundThe prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. There is increasing evidence that GDM is a heterogeneous disease with different subtypes. An important question in this context is whether impaired glucose tolerance (IGT), which is a typical feature of the disease, may already be present before pregnancy and manifestation of the disease. The latter type resembles in its clinical manifestation prediabetes that has not yet manifested as type 2 diabetes (T2DM). Altered lipid metabolism plays a crucial role in the disorder's pathophysiology. The aim was to investigate the role of lipids which are relevant in diabetes-like phenotypes in these both models with different time of initial onset of IGT.MethodsTwo rodent models reflecting different characteristics of human GDM were used to characterize changes in lipid metabolism occurring during gestation. Since the New Zealand obese (NZO)-mice already exhibit IGT before and during gestation, they served as a subtype model for GDM with preexisting IGT (preIGT) and were compared with C57BL/6 N mice with transient IGT acquired during gestation (aqIGT). While the latter model does not develop manifest diabetes even under metabolic stress conditions, the NZO mouse is prone to severe disease progression later in life. Metabolically healthy Naval Medical Research Institute (NMRI) mice served as controls.ResultsIn contrast to the aqIGT model, preIGT mice showed hyperlipidemia during gestation with elevated free fatty acids (FFA), triglycerides (TG), and increased atherogenic index. Interestingly, sphingomyelin (SM) concentrations in the liver decreased during gestation concomitantly with an increase in the sphingosine-1-phosphate (S1P) concentration in plasma. Further, preIGT mice showed impaired hepatic weight adjustment and alterations in hepatic FFA metabolism during gestation. This was accompanied by decreased expression of peroxisome proliferator-activated receptor alpha (PPARα) and lack of translocation of fatty acid translocase (FAT/CD36) to the hepatocellular plasma membrane.ConclusionThe preIGT model showed impaired lipid metabolism both in plasma and liver, as well as features of insulin resistance consistent with increased S1P concentrations, and in these characteristics, the preIGT model differs from the common GDM subtype with aqIGT. Thus, concomitantly elevated plasma FFA and S1P concentrations, in addition to general shifts in sphingolipid fractions, could be an interesting signal that the metabolic disorder existed before gestation and that future pregnancies require more intensive monitoring to avoid complications.Graphical This graphical abstract was created with BioRender.com.

Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis.

This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß. A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with ¼ round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis. Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6h, while TLR-2 was expressed at 24h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9h. NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern. Innate immunity of dental pulp is capable of detecting fungal pathogens.

Development of a murine model of oral carcinogenesis: an accelerated tool for biomarker and anti-tumour drug discovery.

Oral squamous cell carcinoma (OSCC) is the most common cancer in Pakistani men and the second most common cancer in women. The objective of our study was to devise a novel accelerated murine model of oral carcinogenesis that can be exploited as a tool to investigate the cancer circuitry involved in OSCC and to identify molecules of diagnostic, therapeutic and prognostic significance. A total of 40 healthy male, 6–8 weeks old, 22 ± 2 gram, Naval Medical Research Institute (NMRI) outbred strain mice were recruited in the experiment. NMRI mice are commonly used for animal experiments in various fields of biology and for drug toxicity. Of these, 25 mice underwent the oral carcinogenesis regimen via topical application of 0.5% 9,10-dimethyl-1,2-benzanthracene (DMBA) on the lower left lip for a maximum of 20 weeks and 15 mice were used as controls (without the carcinogenic regimen). Exophytic tissue masses were harvested, fixed in 10% formalin and stained with haematoxylin and eosin (H&E) for microscopic diagnosis. Additionally, the expression levels of CK 5/6, p53 and Ki-67 were investigated using immunohistochemistry. Of the 25 mice which underwent the carcinogenic regimen, 21 developed moderately differentiated squamous cell carcinoma and 1 showed dysplastic features with foci of invasion. Three mice were found dead with lesion(s). CK 5/6 showed strong positivity (100%) and p53 and Ki-67 showed patchy (<30%) strong positivity in OSCC, suggesting the similarity of our model to human OSCC. We present an accelerated, close-to-human carcinogenesis, model of oral carcinogenesis using DMBA in NMRI mice that can be exploited to study the pathogenesis of oral squamous cell carcinoma and subsequently devise immunotherapy or targeted therapy.

Pharmacological evidence for the possible involvement of the NMDA receptor pathway in the anticonvulsant effect of tramadol in mice.

Previous studies have shown controversial results regarding the pro- or anticonvulsant effects of tramadol. Additionally, the underlying mechanism of seizure induction or alleviation by tramadol has not been fully understood. In the current study, the effects of tramadol on pentylenetetrazole (PTZ)-induced seizure and the possible involvement of the N-methyl-D-aspartate (NMDA) pathway were assessed in mice. Male Naval Medical Research Institute (NMRI) mice were treated with intravenous infusion of PTZ in order to induce clonic seizures and determine seizure threshold. Tramadol was injected intraperitoneally (0.1-150 mg/kg) 30 minutes prior to elicitation of seizures. The possible effects of intraperitoneal injections of NMDA receptor antagonists, ketamine (0.5 mg/kg) and MK-801 (0.5 mg/kg) on the anticonvulsant property of tramadol were investigated subsequently. Tramadol (1-100 mg/kg) increased PTZ-induced seizure threshold in a dose-dependent, time-independent manner, with optimal anticonvulsant effect at a dose of 100 mg/kg. Acute administration of either ketamine (0.5 mg/kg) or MK-801 (0.5 mg/kg) potentiated the anticonvulsant effect of a subeffective dose of tramadol (0.3 mg/kg). These results suggest a possible role of the NMDA pathway in the anticonvulsant effect of tramadol.

The effect of curcumin on embryonic in vitro development in experimental polycystic ovary syndrome: An experimental study.

BackgroundPolycystic ovary syndrome (PCOS) is a common disease in women. Some plant compounds which have antioxidant properties, such as curcumin, may be useful for these patients when delivered orally or in vitro.Objective The aim of this study was to evaluate the impact of PCOS on oocyte quality and the effect of curcumin on in vitro fertilization of oocytes.Materials and Methods In this experimental study, Naval Medical Research Institute mice aged six to eight wk were used. Mice were divided into five experimental groups (control, experimental PCOS, curcumin 6, 12 and 24 μM). To induce experimental PCOS, estradiol valerate (100 mg/kg, IP) was injected. The total antioxidant capacity and production of malondialdehyde in ovarian tissue and blood serum were evaluated in all groups. Finally, 6, 12 and 24 μM of curcumin were added to the culture medium of the PCOS group oocytes and development in the different groups was evaluated.ResultsA high percentage of oocytes for fertilization were not in good condition in terms of number and quality in the group of PCOS. The addition of curcumin to the embryo culture medium was associated with a higher percentage of fertilized oocytes, two-cells and blastocysts. This increase was significant at a concentration of 24 μM (p 0.01).ConclusionGiven that adding curcumin seemed to improve fetal growth and prevent the harmful effects of oxygen free radicals on the culture medium, it is recommended to add a certain concentration of curcumin under normal conditions without oxidative stress.

Epicatechin ameliorative effects on methotrexate-induced hepatotoxicity in mice.

Due to the fact that methotrexate is widely used both as an immunosuppressive drug and as a chemotherapy agent, many studies are needed to reduce the side effects of this drug on non-target organs. This study was designed to investigate the effects of epicatechin (Epi) on MTX (methotrexate)-induced hepatotoxicity in mice. After 1 week for adaptation, we randomly divided 42 male Naval Medical Research Institute mice into six groups: (I) control; (II) Epi (100 mg/kg, po); (III) MTX (20 mg/kg, i.p.) on the fifth day; and (IV, V, and VI) Epi (25, 50, and 100 mg/kg, po) + MTX (20 mg/kg, i.p.) on the fifth day. At day 10, the mice were sacrificed and serum factors, oxidative stress markers, and inflammatory cytokines were measured. MTX increased activity level of serum enzymes (alanine aminotransferase and aspartate aminotransferase), lipid peroxidation marker (malondialdehyde), and inflammatory factors including interleukin-1 beta, tumor necrosis factor-alpha, and nitric oxide. Furthermore, MTX decreased glutathione level and activity level of catalase, superoxide dismutase, and glutathione peroxidase. Epi was able to reduce the destructive effects of oxidative/antioxidant system imbalance and inflammatory reactions and also histopathological damage in MTX intoxicated mice. Epi pretreatment reduced liver dysfunction by improving the antioxidant defense system, anti-inflammatory effects, and alleviation of histopathological damage in MTX hepatotoxicity. Accordingly, Epi can be used as a therapeutic agent in hepatotoxicity associated with MTX chemotherapy.

Implication of nitrergic system in the anticonvulsant effects of ferulic acid in pentylenetetrazole-induced seizures in male mice.

Seizures are abnormal discharge of neurons in the brain. Ferulic acid (FA) is a phenolic compound with antioxidant and neuroprotective effects. The present study aimed to investigate the role of the nitrergic system in the anticonvulsant effect of FA in pentylenetetrazol (PTZ)-induced seizures in male mice. 64 male Naval Medical Research Institute (NMRI) mice weighing 25-29g were randomly divided into eight experimental groups (n=8). FA at doses 5, 10, and 40mg/kg alone and in combination with L-nitro-arginine methyl ester (L-NAME) (nitric oxide synthase inhibitor) or L-arginine (L-arg) (nitric oxide [NO] precursor) was administrated (intraperitoneal). PTZ was injected (i.v. route) 30min after drugs administration (1mL/min). Seizure onset time was recorded and the nitrite levels of prefrontal cortex and serum were determined by the Griess method. FA at doses of 10 and 40mg/kg significantly increased the seizure threshold as well as reduced the serum and brain NO levels in comparison to the saline-received group. Co-administration of the effective dose of FA (10mg/kg) plus L-arg significantly decreased the seizure threshold in comparison to the effective dose of FA alone. Co-injection of the sub-effective dose of FA (5mg/kg) with L-NAME significantly increased the seizure threshold as well as significantly decreased the brain NO level in comparison to the sub-effective dose of FA alone. We showed that the nitrergic system, partially at least, mediated the anticonvulsant effect of FA in PTZ-induced seizures in mice. We concluded that L-NAME potentiated while L-arg attenuated the anticonvulsant effect of FA.