Determinação do período de estabilidade de soluções volumétricas rotineiramente utilizadas em laboratórios de análises químicas / Determination of the stability period of volumetric solutions routinely used in chemical analysis laboratories / Determinación del período de estabilidad de las soluciones volumétricas utilizadas habitualmente en los laboratorios de análisis químicos

As soluções volumétricas são rotineiramente utilizadas nos laboratórios, principalmente nos processos de síntese de produtos e nas análises quantitativas de matéria-prima e/ou produto acabado, entretanto poucos são os estudos que abordam a estabilidade destas soluções. Considerando que a qualidade das soluções volumétricas pode afetar os procedimentos de análises químicas e consequentemente induzir a erros, e ainda que, a Farmacopeia Brasileira (2010) não cita tempo máximo de utilização dessas soluções padronizadas, a avaliação da estabilidade das mesmas é importante. Sendo assim, o objetivo do trabalho foi avaliar a estabilidadede 10 soluções volumétricas, empregadas rotineiramente em laboratórios de análises químicas, com o intuito de estabelecer o período que essas soluções permanecem estáveis, isto é, sem sofrer alteração na concentração. As metodologias de preparo e padronização das soluções volumétricas seguiram os métodos descritos na Farmacopeia Brasileira (2010), sendo as mesmas padronizadas no momento do preparo e a cada 20 dias, por um período de 180 dias. As soluções contendo ácidos e bases, bem como as soluções de iodato de potássio e nitrato de prata, permaneceram constantes durante o período de análises. As soluções de EDTA, iodo, nitrito de sódio, permanganato de potássio e tiossulfato de sódio apresentaram estabilidade inferior a 180 dias, tornando necessária a realização de padronização periódica. As soluções volumétricas utilizadas nos laboratórios apresentam diferentes estabilidades, o que ressalta a importância da determinação do período que as mesmas se mantêmcom as concentrações estáveis, evitando possíveis alterações de resultados nas análises químicas.

Volumetric solutions are routinely used in laboratories, mainly in product synthesis processes and in quantitative analyzes of raw materials and/or finished products, however there are few studies that address the stability of these solutions. Considering that the quality of volumetric solutions can affect chemical analysis procedures and consequently induce errors, and even though the Brazilian Pharmacopoeia (2010) does not mention the maximum time for using these standardized solutions, the evaluation of their stability is important. Therefore, the aim of this work was to evaluate the stability of 10 volumetric solutions, routinely used in chemical analysis laboratories, in order to establish the period that these solutions remain stable without changing their concentrations. The methodologies for preparing and standardizing the volumetric solutions followed the methods described in the Brazilian Pharmacopoeia (2010), being standardized at the time of preparation and every 20 days, for a period of 180 days. Solutions containing acids and bases, as well as potassium iodate and silver nitrate solutions, were stable during the analysis period. The solutions of EDTA, iodine, sodium nitrite, potassium permanganate and sodium thiosulfate showed stability less than 180 days, making it necessary to carry out periodic standardization of these solutions. The volumetric solutions used in the laboratories have different stabilities, which highlights the importance of determining the period in which they remain stable, avoiding possible changes in results in chemical analyzes.

Las soluciones volumétricas se utilizan de forma rutinaria en los laboratorios, principalmente en los procesos de síntesis de productos y en el análisis cuantitativo de materias primas y/o productos acabados. Sin embargo, existen pocos estudios que aborden la estabilidad de estas soluciones. Considerando que la calidad de las soluciones volumétricas puede afectar los procedimientos de análisis químico y consecuentemente inducir a errores, y también que, la Farmacopea Brasileña (2010) no menciona el tiempo máximo de uso de estas soluciones estandarizadas, la evaluación de su estabilidad es importante. Así, el objetivo del trabajo fue evaluar la estabilidad de 10 soluciones volumétricas, utilizadas rutinariamente en los laboratorios de análisis químico, con el fin de establecer el período en que estas soluciones permanecen estables, es decir, sin sufrir alteraciones en la concentración. Las metodologías de preparación y estandarización de las soluciones volumétricas siguieron los métodos descritos en la Farmacopea Brasileña (2010), siendo las mismas estandarizadas en el momento de la preparación y cada 20 días, por un período de 180 días. Las soluciones que contienen ácidos y bases, así como las soluciones de yodato de potasio y nitrato de plata, permanecieron constantes durante el periodo de análisis. Las soluciones de EDTA, yodo, nitrito de sodio, permanganato de potasio y tiosulfato de sodio fueron estables durante menos de 180 días, por lo que fue necesario realizar estandarizaciones periódicas. Las soluciones volumétricas utilizadas en los laboratorios presentan diferentes estabilidades, lo que pone de manifiesto la importancia de determinar el periodo que permanecen con concentraciones estables, evitando posibles cambios en los resultados en los análisis químicos.

Effects of some food additives on some biochemical parameters in young male albino rats and the ameliorative role of royal jelly

Background: the use of food additives is one of the most important problems in the human health nutrition field. Food additives are widely used for various purposes; including preservation, coloring, and sweetening, however, the physiological and biochemical changes may be produced

Aim of the work: was to investigate the protective role of royal jelly [RJ] against abnormalities in metabolic biochemical parameters that induced by these food additives in male albino rats

Materials and Methods: thirty young male albino rats with an average body weight 120-140 g were divided into three groups [10/cage]; Group I: served as normal control group, Group II: rats orally administrated with the mixture which consists of sodium nitrite [NaNO2 0.1 mg/kg b.wt./ day], annatto [0.065 mg/kg b.wt./day] and monosodium glutamate [MSG 15 mg/kg b.wt./day] and Group III: rats orally administrated with the previous mixture and then orally administrated with royal jelly [14.28 mg/kg b.wt./day soluble in maize oil]. At the end of the experiment, blood samples were collected for biochemical estimations which including levels of serum glucose, creatinine, urea, testosterone, thyroid hormones [T3 and T4], activities of AST and ALT, total protein [TP], albumin, total cholesterol, triglycerides, high-density lipoprotein [HDL-c] and low-density lipoprotein [LDL-c]

Results: the present study showed marked elevation in levels of fasting blood glucose, activities of AST, ALT, levels of serum urea, creatinine, TC, TG, LDL-c, VLDLand ratios of TC/HDL-c and LDL-c/HDL-c [risk factors] as well as albumin /globulin ratio and serum thyroid hormones [T3andT4] accompanied with significant reduction in the body weight, serum total proteins, albumin, globulin, albumin/creatinine, testosterone and HDL-C concentrations in the group that administrated with the mixture which consists of [NaNO2, MSG and annatto] as compared to control rats. While administration with royal jelly significantly ameliorated the disturbed biochemical parameters and showed significant improvement in most of these parameters

Conclusion: it could be concluded that royal jelly offers a therapeutic advantage that minimizes the metabolic abnormalities and biochemical changes which induced by these food additives

Concentrações de nitrito e nitrato em salsichas / Nitrite and nitrate levels in sausages / Concentraciones de nitrito y nitrato en salchichas

OBJETIVO: Determinar as concentrações de nitrito e nitrato, potencial hidrogeniônico (pH) e atividade de água (Aa) em salsichas comercializadas em uma região do sul do Brasil, e comparar essas concentrações entre as diferentes marcas. MÉTODOS: Estudo experimental, transversal, quantitativo, realizado com 72 amostras de salsicha coletadas em dois municípios da Região do Vale do Taquari/RS, entre junho e agosto de 2015. Avaliaram-se três amostras de lotes diferentes, por meio das variáveis de nitrito, nitrato, pH e atividade de água, em triplicata, de cada uma das oito marcas de salsichas fiscalizadas pelo Serviço de Inspeção Federal. Dados submetidos aos testes ANOVA e Qui-quadrado, com p<0,05. RESULTADOS: A totalidade das amostras apresentou-se dentro dos padrões para pH e Aa (6,33 ± 0,32 e 0,91 ± 0,01, respectivamente), enquanto 40,3% (29) e 50,0% (36) apresentaram níveis de nitrito e nitrato, respectivamente, significativamente acima do estabelecido pela legislação (p<0,05). A média de nitrito das amostras restantes apresentou-se significativamente inferior (p=0,001), e a média de nitrato, significativamente superior (p=0,009) ao valor estabelecido pela legislação. CONCLUSÃO: A totalidade das amostras estava adequada em relação aos níveis de pH e Aa. Do total das oito marcas avaliadas, três se encontravam em condições satisfatórias referente à adição do nitrato e nitrito. A média de nitrito e Aa foi significativamente inferior, e as médias do nitrato e pH, significativamente superior, enquanto os níveis de nitrato e nitrito apresentaram médias superiores aos valores estabelecidos legislação, em cinco marcas analisadas

OBJECTIVE: To determine nitrite and nitrate levels, hydrogen potential (pH), and water activity (aw) in sausages marketed in Southern Brazil, and compare the levels among different brands. METHODS: Quantitative experimental cross-sectional study conducted with 72 sausage samples collected in two municipalities in the Região do Vale do Taquari, Rio Grande do Sul,,between June and August 2015. Three samples from different batches of each eight distinct sausage brands which were supervised by the Federal Inspection Service were analyzed in triplicate according to their nitrite and nitrate levels, pH and water activity. Data underwent ANOVA and Chi-squared tests with p<0.05. RESULTS: Samples met the recommended standards for pH and water activity (6.33 ± 0.32 and 0.91 ± 0.01, respectively), while 40.3% (29) and 50.0% (36) of the samples presented nitrite and nitrate levels, respectively, significantly above what is recommended by the legislation (p<0.05). The mean nitrite levels of the remaining samples were significantly lower (p=0.001), and mean nitrate levels were significantly higher (p=0.009) than the value established by legislation. CONCLUSION: The samples met the recommended levels of pH and water activity. Of eight brands assessed, three presented satisfactory levels of nitrate and nitrite. The mean levels of nitrite and water activity were significantly lower and the mean levels of nitrate and pH were significantly higher than the recommendations. Additionally, mean nitrate and nitrite levels of five brands were significantly higher than what is recommended by the legislation

OBJETIVO: Determinar las concentraciones de nitrito y nitrato, del potencial de hidrógeno (pH) y de la actividad del agua (Aa) de salchichas del comercio de una región del sur de Brasil y compararlas entre las distintas marcas comerciales. MÉTODOS: Estudio experimental, transversal y cuantitativo realizado con 72 muestras de salchichas recogidas en dos municipios de la Región del Vale del Taquari/RS entre junio y agosto de 2015. Se evaluaron tres veces tres muestras de lotes distintos a través de las variables de nitrito, nitrato, pH y actividad del agua de cada una de las ocho marcas de salchichas fiscalizadas por el Servicio de Inspección Federal. Los datos fueron sometidos a las pruebas ANOVA y Chicuadrado para p<0,05. RESULTADOS: La totalidad de las muestras se presentó dentro de los patrones para el pH y la Aa (6,33 ± 0,32 e 0,91 ± 0,01, respectivamente) mientras el 40,3% (29) y el 50,0% (36) presentaron niveles de nitrito y nitrato, respectivamente, significativamente por encima de la legislación (p<0,05). La media de nitrito de las muestras restantes se presentó significativamente inferior (p=0,001) y la media de nitrato, significativamente superior (p=0,009) de la legislación. CONCLUSIÓN: La totalidad de las muestras estaba adecuada respecto a los niveles de pH y Aa. Del total de las ocho marcas evaluadas, tres se encontraban en condiciones satisfactorias de adicción del nitrato y nitrito. La media de nitrito y Aa fue significativamente inferior y las medias de nitrato y pH significativamente superior mientras los niveles de nitrato y nitrito presentaron medias superiores de la legislación em cinco marcas analizadas

Sodium nitrite enhanced the potentials of migration and invasion of human hepatocellular carcinoma SMMC-7721 cells through induction of mitophagy / 药学学报

Nitrites play multiple characteristic functions in invasion and metastasis of hepatic cancer cells, but the exact mechanism is not yet known. Cancer cells can maintain the malignant characteristics via clearance of excess mitochondria by mitophagy. The purpose of this article was to determine the roles of nitrite, reactive oxygen species (ROS) and hypoxia inducing factor 1 alpha (HIF-1 α) in mitophagy of hepatic cancer cells. After exposure of human hepatocellular carcinoma SMMC-7721 cells to a serial concentrations of sodium nitrite for 24 h under normal oxygen, the maximal cell vitality was increased by 16 mg x (-1) sodium nitrite. In addition, the potentials of migration and invasion for SMMC-7721 cells were increased significantly at the same time. Furthermore, sodium nitrite exposure displayed an increase of stress fibers, lamellipodum and perinuclear mitochondrial distribution by cell staining with Actin-Tracker Green and Mito-Tracker Red, which was reversed by N-acetylcysteine (NAC, a reactive oxygen scavenger). DCFH-DA staining with fluorescent microscopy showed that the intracellular level of ROS concentration was increased by the sodium nitrite treatment. LC3 immunostaining and Western blot results showed that sodium nitrite enhanced cell autophagy flux. Under the transmission electron microscopy (TEM), more autolysosomes formed after sodium nitrite treatment and NAC could prevent autophagosome degradation. RT-PCR results indicated that the expression levels of COX I and COXIV mRNA were decreased significantly after sodium nitrite treatment. Meanwhile, laser scanning confocal microscopy showed that sodium nitrite significantly reduced mitochondrial mass detected by Mito-Tracker Green staining. The expression levels of HIF-1α, Beclin-1 and Bnip3 (mitophagy marker molecular) increased remarkably after sodium nitrite treatment, which were reversed by NAC. Our results demonstrated that sodium nitrite (16 mg x L(-1)) increased the potentials of invasion and migration of hepatic cancer SMMC-7721 cells through induction of ROS and HIF-1α mediated mitophagy.

Effect of sodium nitrite on phosphorylation of cytoskeletal proteins and spatial learning and memory in rats / 生理学报

The present study was aimed to explore the effect of sodium nitrite on cytoskeletal protein phosphorylation and spatial learning and memory in rats. Rats were served with drinking water containing sodium nitrite (100 mg/kg) for 60 days, then, the ability of spatial learning and memory of the rats was measured by Morris water maze. Phosphorylation level of tau and neurofilament, and the expression of protein phosphatase 2A (PP2A) catalytic subunit in the hippocampus were detected by immunohistochemistry and Western blot. In comparison with the rats served with normal tap water, the rats served with sodium nitrite water showed significantly longer latency to find the hidden platform in Morris water maze (P < 0.05), elevated phosphorylation level of tau and neurofilament, and decreased expression of PP2A catalytic subunit (P < 0.05). These results indicated that administration of sodium nitrite could impair the spatial learning and memory of the rats, and the hyperphosphorylation of cytoskeletal proteins and the down-regulation of PP2A might be underlying mechanisms for the impairment.

Sodium nitrite reduces lipid accumulation in steatotic cells by enhancing autophagy / 药学学报

Recent data have revealed that inhibiting autophagy exacerbates lipid accumulation in hepatocytes and nitrite treatment reduces total triglyceride levels in the high-fat diet mice. Therefore, the present study aimed to determine the effects of nitrite on simple hepatic steatosis and the possible role of autophagy. Firstly, steatotic L-02 cells were induced by incubating L-02 cells with 1.2 mmol · L(-1) oleic acid (OA) for 24 h. Secondly, steatotic L-02 cells were treated with 0.2 mmol · L(-1) sodium nitrite (SN) plus 3-methyladenine (3-MA), or chloroquine (CQ) for 24 h, and then lipid accumulation was measured with oil red O staining and triglyceride quantification. The notable steatosis could be observed in L-02 cells following exposure to 1.2 mmol · L(-1) OA for 24 h. Treatment with 0.2 mmol · L(-1) sodium nitrite reduced lipid accumulation in steatotic L-02 cells. 3-MA weakened the ability of sodium nitrite to ameliorate hepatic steatosis. Additionally, the sodium nitrite increased number of LC3-II immunostaining puncta and LC3-II protein expression was confirmed by immunofluorescence or Western blot analysis, and the effects were enhanced by CQ treatment. The number of increased cytoplasm vacuoles and lysosomes increased was confirmed by phase contrast and fluorescence microscope respectively. The increased autolysosome was detected by electron microscopy, this phenomenon could be reversed by CQ treatment. These data demonstrated that sodium nitrite enhanced the autophagic flux and decomposition of triglycerides in steatotic L-02 cells.

Methemglobinemia from Antifreeze Containing Sodium Nitrite

Sodium nitrite is commercially used as a coloring agent, food preservative, and corrosion inhibitor. Accidental poisoning with sodium nitrite from contaminated food and water causes gastrointestinal irritation, vasodilatation, and methemoglobinemia with subsequent tissue hypoxia. We describe an outbreak case of sodium nitrite-induced methemoglobinemia following the ingestion of noodles contaminated with industrial antifreeze. The eEight patients involved initially complained that their noodles tasted 'unpleasant' and soon afterwards experienced nausea, vomiting, dizziness, and fatigue. Some of them noted cyanosis on their lips and fingers. Subsequent investigations demonstrated a high methemoglobin concentration which was corrected by the intravenous administration of methylene blue three hours after the onset of symptoms. The patients made a prompt, uncomplicated recovery and were discharged home 4 four days later. Industrial antifreeze contains sodium nitrite and calcium nitrite. Because an accidental poisoning of industrial antifreeze causes fatal methemoglobinemia, emergency physicians should promptly identify its symptoms and institute treatment with methylene blue promptly. In addition, industrial agencies must caution construction businesses against such contamination events.

Antidotes of cyanide intoxication

Cyanide poisoning can occur from industrial disasters, smoke inhalation from fire, food, and multiple other sources. Cyanide inhibits mitochondrial oxidative phosphorylation by blocking mitochondrial cytochrome oxidase, which in turn results in anaerobic metabolism and depletion of adenosine triphosphate in cells. Rapid administration of antidote is crucial for life saving in severe cyanide poisoning. Multiple antidotes are available for cyanide poisoning. The action mechanism of cyanide antidotes include formation of methemoglobin, production of less or no toxic complex, and sulfane sulfur supplementation. At present, the available antidotes are amyl nitrite, sodium nitrite, sodium thiosulfate, hydroxocobalamin, 4-dimethylaminophenol, and dicobalt edetate. Amyl nitrite, sodium nitrite, and 4-dimethylaminophenol induce the formation of methemoglobin. Sodium thiosulfate supplies the sulfane sulfur molecule to rhodanese, allowing formation of thiocyanate and regeneration of native enzymes. Hydroxocobalamin binds cyanide rapidly and irreversibly to form cyanocobalamin. Dicobalt edetate acts as a chelator of cyanide, forming a stable complex. Based on the best evidence available, a treatment regimen of 100% oxygen and hydroxocobalamin, with or without sodium thiosulfate, is recommended for cyanide poisoning. Amyl nitrite and sodium nitrite, which induce methemoglobin, should be avoided in victims of smoke inhalation because of serious adverse effects.

The jejunoileal bypass provokes morphological changes in the large intestine? An experimental study in rats / A derivação jejuno-ileal provoca alterações morfológicas no intestino grosso? Estudo experimental em ratos

PURPOSE: To analyse histopathological alterations characterized by the mitotic index in the mucosa of the large intestine in Wistar rats submitted to jejunoileal bypass operation after continued administration of sodium nitrite and vitamin C to different groups. METHODS: Eighty male Wistar rats were employed and separated into 12 groups. In the control group (20 rats): five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the sham group (20 rats), the animals were anesthetized and underwent midline laparotomy and only intestinal manipulation was performed: five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the operated group 40 rats underwent a jejunoileal bypass surgery: ten animals ingested only water; ten animals received vitamin C; ten animals received sodium nitrite and ten received sodium nitrite + vitamin C. The mean weight of the animals was measured weekly. The large intestine was subdivided into cecum (S1), ascending colon (S2), transverse colon (S3), descending colon (S4) and rectum (S5) for histopathological analysis and mitotic counts. The statistical analysis was used to compare the mitotic indices. The level of significance was 5%. RESULTS: The mean of all the segments indicates that the sodium nitrite+vitamin C group obtained the lowest mitotic index compared to the other treatments in the control group. The segments S1 and S2 showed a statistical difference with the vitamin C treatment: a higher mitotic index and better preservation of the mucosa in the operated group. In the sham group the main statistical difference occurred only in the sodium nitrite+vitamin C group between the means of the segments. CONCLUSIONS: The comparison of all the colonic segments of the various groups revealed a lower mitotic index in the animals treated with sodium nitrite+vitamin C. In addition, it was found that vitamin C did not present a statistically significant inhibiting effect on the preservation of the mucosa and the mitotic index.

OBJETIVO: Analisar as alterações histopatológicas caracterizada pelo índice mitótico na mucosa do intestino grosso em ratos Wistar submetidos a operação de bypass jejunoileal após a administração continuada de nitrito de sódio e vitamina C para diferentes grupos. MÉTODOS: Oitenta ratos Wistar foram utilizados e separados em 12 grupos. No grupo controle (20 ratos): cinco animais ingeriram apenas água; cinco animais receberam vitamina C, cinco animais receberam nitrito de sódio e cinco receberam nitrito de sódio + vitamina C. No grupo sham (20 ratos), os animais foram anestesiados e submetidos a laparotomia mediana e só a manipulação intestinal foi realizada: cinco animais ingeriram apenas água; cinco animais receberam vitamina C, cinco animais receberam nitrito de sódio e cinco receberam nitrito de sódio + vitamina C. No grupo operado 40 ratos foram submetidos a uma cirurgia de bypass jejunoileal: dez animais ingeridos apenas água; dez animais receberam vitamina C, dez animais receberam nitrito de sódio e dez nitrito de sódio + vitamina C. O peso médio dos animais foi medido semanalmente. O intestino grosso foi subdividido em ceco (S1), cólon ascendente (S2), cólon transverso (S3), cólon descendente (S4) e reto (S5) para análise histopatológica e contagem das mitoses. A análise estatística foi utilizado para comparar os índices mitóticos. O nível de significância foi de 5%. RESULTADOS: A média de todos os segmentos indica que o grupo que ingeriu nitrito de sódio + vitamina C obteve o menor índice mitótico em relação aos demais tratamentos no grupo controle. Os segmentos S1 e S2 mostraram uma diferença estatística com a vitamina C de tratamento: um maior índice mitótico e melhor preservação da mucosa no grupo operado. No grupo sham a principal diferença estatística ocorreu apenas no grupo que ingeriu nitrito de sódio + vitamina C entre as médias dos segmentos. CONCLUSÕES: A comparação de todos os segmentos do colon dos vários grupos revelaram um menor índice de mitose nos animais tratados com nitrito de sódio + vitamina C. Além disso, a vitamina C não apresentou efeito inibidor, estatísticamente significativo, na preservação da mucosa e do índice de mitoses.

Protective effects of sodium nitrite preconditioning against alcohol-induced acute liver injury in mice / 生理学报

The purpose of the present study was to investigate the effect of sodium nitrite (SN) on alcohol-induced acute liver injury in mice. Forty male C57bL/6 mice were randomly divided into 4 groups. Acute alcohol-induced liver injury group were injected intraperitoneal (ip) with alcohol (4.5 g/kg); SN preconditioning group were pretreated with SN (16 mg/kg, ip) for 12 h, and received alcohol (4.5 g/kg, ip) injection; Control and SN groups were treated with saline and SN, respectively. After the treatments, liver index (liver/body weight ratio) was determined. Colorimetric technique was performed to measure the serum alanine transaminase (ALT), aspartate transaminase (AST), liver superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities, as well as malondialdehyde (MDA) content. The pathological index of liver tissue was assayed by HE and TUNEL fluorometric staining. Using Western blot and immunohistochemistry staining, the expression of hypoxia-inducible factor-1α (HIF-1α) protein was detected. The results showed that, compared with acute alcohol-induced liver injury group, pretreatment with low doses of SN decreased liver index and serum levels of ALT and AST, weakened acute alcohol-induced hepatocyte necrosis, improved pathological changes in liver tissue, increased live tissue SOD, GSH-Px and CAT activities, reduced MDA content and apoptosis index of hepatocytes, and up-regulated HIF-1α protein level in liver tissue. These results suggest that the pretreatment of SN can protect hepatocytes against alcohol-induced acute injury, and the protective mechanism involves inhibition of oxidative stress and up-regulation of HIF-1α protein level.

Sodium nitrite induces PC12 cell differentiation / 药学学报

To investigate the potential ability of the nitrite to induce neuronal differentiation of PC12 cells, cultured PC12 cells planted on matrigel in the presence or absence of sodium nitrite were employed as model, nerve growth factor (NGF) served as a positive control. After 48 h, sodium nitrite enhanced cell viability and vascular endothelial growth factor (VEGF) secretion. Same as the effect of NGF, sodium nitrite (1.4 mmol x L(-1)) treated cultures contained a greater proportion of cells bearing neurites and neurites were much longer than those found in negative control cultures (P < 0.05). Compared with the negative control, sodium nitrite (1.4 mmol x L(-1)) also upregulated the expression of VEGF mRNA (P < 0.05) and hypoxia inducible factor 1 alpha (HIF-1 alpha) or VEGF protein expression (P < 0.05) in cultures of PC12 cells. On the other hand, these effects of the sodium nitrite were likely mediated by HIF-1alpha, since their effects were antagonized by addition of HIF-1alpha inhibitor YC-1. Taken together, these results suggest that low doses of sodium nitrite could induce neurite outgrowth in PC12 cells by activating the HIF-1alpha-VEGF pathway.

Sodium nitrite improves epithelial-mesenchymal transition of hepatoma cells in mice bearing H22 / 药学学报

This study is to report the determination of the effect of sodium nitrite induced oxygen species (ROS) on the epithelial-mesenchymal transition in hepatoma cells in mice bearing H22 and investigation of its role in hypoxia-inducible factor 1alpha (HIF-1alpha) in this process. Mice hepatocarcinoma cell line H22 was inoculated subcutaneously into right axillary of sixty male Kunming mice and then randomly divided into four groups: control group; low-dose sodium nitrite group (10 mg x kg(-1)), medium-dose sodium nitrite group (20 mg x kg(-1)) and high-dose sodium nitrite group (30 mg x kg(-1)). Sodium nitrite group was given (ig) sodium nitrite with 10-30 mg x kg(-1) x d(-1) for 21 days. Compared with control group, there was no obvious difference between the two groups in the volume or weight of xenografts, but in sodium nitrite treatment group, the activity of SOD and CAT decreased and contents of MDA or nitrite increased in tumor tissue of mice bearing H22; epithelial-mesenchymal transition (EMT) of hepatoma cells was induced, the EMT-phenotype tumors displayed a greater degree of local aggressiveness, with dissection through adjacent fascia and skeletal muscle. The increased expression of HIF-la and vimentin and declination of E-cadherin were confirmed by immunohistochemistry and Western blotting. These data indicate sodium nitrite treatment could improve the epithelial-mesenchymal transition of xenografts in mice bearing H22, which might relate to the fact that ROS mediated signal pathway increased the expression of HIF-1alpha.

Study on eliminating sodium nitrite and blocking nitrosamine synthesis by anthocyanin from skin of Alpinia galanga / 中国中药杂志

This study was performed to determine the ability of eliminating sodium nitrite and blocking nitrosamine synthesis by anthocyanin from the skin of Alpinia galanga. purified by macroporous resin. The test was conducted under the condition of the simulated human gastric juice (pH 3.0, 37 degrees C) with VitC as positive control. The results showed that the max capability of eliminating sodium nitrite was 87.14%, which is 1.6 times sronger than that of VitC, and the max capability of blocking nitrosamine synthesis was 97.82%, which is 8 times sronger than that of VitC.

Sodium nitrite induces epithelial-mesenchymal transition of SMMC-7721 cells / 药学学报

This study is to find out the induction by sodium nitrite of epithelial-mesenchymal transition (EMT) in human hepatocellular carcinoma cells, SMMC-7721. After treatment of SMMC-7721 with 0.25 - 25 mmol.L-1 sodium nitrite for 48 h, the assays used include enzyme-linked immunosorbent assay (ELISA) for evaluation of TGF-beta1, IL-6 and IL-8 level in the conditioned medium, phase-contrast microscopy for morphology observation, and scratch wound healing as well as transwell migration assays for measurement of migration and metastatic potential. Additionally, the hallmarks of EMT, p-AKT and its downstream signaling molecules were examined by Western blotting. The results showed that TGF-beta1 secreted by SMMC-7721 elevated significantly in a dose-dependent fashion, whereas the increased IL-8 and IL-6 did not show dose-dependent response. The EMT was induced by exposure of SMMC-7721 with 0.25 mmol.L-1 of sodium nitrite, which was characterized by increased level of Vimentin, decreased E-cadherin and elevated activity of migration and metastatic potential. The results suggest that sodium nitrite could induce SMMC-7721 EMT by increased secretion of TGF-beta1 and IL-8.

Sodium nitrite-induced hypoxic injury in rat hippocampus

To explore the effect of sodium nitrite-induced hypoxia on the hippocampus and the dentate gyrus in adult rats. Adult male albino rats, weighing 180-200 gm were divided into two groups and treated as follows: Group I: served as control and received normal saline, Group II: served as hypoxic rats and received sodium nitrite [75 mg/kg] subcutaneously. One hour after sodium nitrite injection, rats were decapitated. The brains were removed and placed overnight in fixative containing 10% formalin. These were paraffin- embedded for hematoxylin and eosin staining and cut at 5 micro in the coronal plane. Sections passing through bregma level -2.8 to -3.3 mm were used to count the neurons in the CA1, CA2, CA3, and CA4 subsectors and the dentate gyrus. Round, clear and medium or large neurons with distinct nucleus were counted. Cells with darkly stained shrunken nuclei and cells with fragmented nuclei were excluded from the count. Cytological examination of hypoxic brains depicted degeneration in hippocampus and dentate gyrus. Cell density was comparatively lesser in all the sub regions of hippocampus i.e. CA1-CA4 and Dg in the hypoxic brains. The degeneration was evident by presence of pyknotic nuclei, darkly stained cells, cells with condensed nuclei, as well as vacuolated spaces. The changes were more marked in CA3, CA4 and dentate gyrus. It is concluded that pyramidal neurons of the hippocampus and granular neurons of the dentate gyrus are very vulnerable to hypoxia and show regional differences in their vulnerability

Effects of sodium nitrite-induced hypoxia on cerebellar Purkinje cells in adult rats

To explore the changes in Purkinje cells in adult rats after inducing chemical hypoxia by sodium nitrite Adult male albino rats, weighing 180-200 gm were used in this study. The animals were fasted for three hours prior to drugs administration. One hour after sodium nitrite [75 mg/kg] subcutaneous injection, rats were decapitated. The brains were removed and placed overnight in fixative containing 10% formalin. Cerebellum were paraffin-embedded for hematoxylin and eosin staining and cut at 5 micro m in the coronal plane. Fifty Purkinje cells along the line of cells from two randomly chosen portions of each section were counted at a magnification of x20. Cells in a total of five sections were counted to compute the ratio of damaged cells to intact neurons. There was no marked difference in the general appearance and thickness of the cerebellar cortices of the control and the sodium nitrite treated rats. The principal findings in the treated group were that almost all the Purkinje cells showed autolytic changes. Their arrangement as a single layer was also deranged in certain areas. Some areas showed complete loss of Purkinje neurons. Sodium nitrite-induced hypoxia results in severe damage to the Purkinje neurons

Determination of sodium nitrite residues in some cured meat products during chilling storage at +4°C

Cured meats represent a large portion of the consumed processed meat products. These processed meats are attractive in their color, flavor, texture and are popular because they combine variety with convenience reliability. Despite its numerous benefits and multifunctional properties in processed meat products, nitrite has often been a source of concern due to its health hazards. This study was conducted to investigate the level of sodium nitrite in some cured meat products during their chilling storage period. Results showed that the means [ +/- S. E.] of the sodium nitrite residues [mg/kg] of the Bastrami, Salami, Luncheon, Sausage and Smoked meat samples were [174.6 +/- 9.27; 100.5 +/- 4.46; 116.9 +/- 4.12; 94.8 +/- 4.17 and 79.1 +/- 2.90] respectively at zero time and these values decreased significantly during all chilling the storage time till it reached [50.7 +/- 2.57; 28.1 +/- 1.23; 40.8 +/- 1.78; 35.1 +/- 2.06 and 14.5 +/- 1.02] respectively at the end of the chilling storage period [4 months

Successful treatment by exchange transfusion of a young infant with sodium nitroprusside poisoning / 소아과

Although sodium nitroprusside (SNP) is often used in pediatric intensive care units, cyanide toxicity can occur after SNP treatment. To treat SNP-induced cyanide poisoning, antidotes such as amyl nitrite, sodium nitrite, sodium thiosulfate, and hydroxycobalamin should be administered immediately after diagnosis. Here, we report the first case of a very young infant whose SNP-induced cyanide poisoning was successfully treated by exchange transfusion. The success of this alternative method may be related to the fact that exchange transfusion not only removes the cyanide from the blood but also activates detoxification systems by supplying sulfur-rich plasma. Moreover, exchange transfusion replaces cyanide-contaminated erythrocytes with fresh erythrocytes, thereby improving the blood's oxygen carrying capacity more rapidly than antidote therapy. Therefore, we believe that exchange transfusion might be an effective therapeutic modality for critical cases of cyanide poisoning.

Sodium nitrite preconditioning protects against ethanol-induced damage in human hepatoma SMMC-7721 cells / 药学学报

This study is to investigate the cytoprotective role of NaNO2 preconditioning against ethanol induced damage in human hepatoma SMMC-7721 cells. The cells were preconditioned with NaNO2 (0.25 mmol x L(-1)) for 24 hours or 4 weeks, and then exposed to ethanol (200 mmol x L(-1)) for additional 12 h and untreated cells served as control. Both temporal and chronic NaNO2 preconditioning could prevent ethanol elicited cytotoxicity as evidenced by thiazolyl blue (MTT). NaNO2 preconditioning also could inhibit ethanol-induced apoptosis, which was confirmed by FITC-Annexin V/PI flow cytometer and Hoechst 33258 and PI staining. Further, simultaneous NaNO2 preconditioning treatment along with ethanol showed protection against ethanol mediated cellular damage as indicated by significantly decreased levels of malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD) and catalase (CAT). Western blotting analysis revealed that in ethanol treated cells preconditioned with NaNO2, the HIF-1alpha and Bcl-2 increased obviously, while the expression of pro-apoptotic proteins, including Bax, Caspase-9, Caspase-3 decreased. The results showed that low doses of NaNO2 preconditioning resistant to ethanol-induced human hepatoma SMMC-7721 cells apoptosis, which mechanism may be related to increased expression of HIF-1alpha in the cells.

[Effect of nisin on decreasing concentration of chemical preservatives]

Because of widespread interests to biopreservatives, several studies have been conducted within last decades that show the nisin has been used as a preservative to control food borne spoilage microorganisms. The aim of this study was to evaluate anti-bacterial activity of nisin and its effect on decreasing concentration of current chemical preservatives. In this experimental study, anti-bacterial activity of nisisn and its effect on decreasing concentration of usual chemical preservatives against Staphylococcus aureus [PTCC 1112] and Listeria monocytogenes [PTCC 1301] were studied. The study was performed in two steps. First, MIC [minimum inhibitory concentration] and MBC [minimal bactericidal concentration] of preservatives, including sodium nitrite, benzoic acid and nisin, were measured in optimum ph [5.5] by serial dilution method. Second, MIC of sodium nitrite and benzoic acid were determined in combination with nisin. Sodium nitrite, benzoic acid and nisin had antibacterial activities against Staphylococcus aureus and Listeria monocytogenes; MIC was 500, 200 and 25 ppm for Staphylococcus aureus, and 100, 200 and 10 ppm for Listeria monocytogenes, respectively. Niacin reduced MIC of sodium nitrite and benzoic acid to 200 and 50 ppm for Staphylococcus aureus, and 25 and 25 ppm for Listeria monocytogenes, respectively. The nisin reduces chemical preservatives concentration required, and it could be used as a safe preservative in food microbiology