RESUMO
This study was carried out to investigate the effect of oral dietary supplementation with ginger on cadmium-induced toxic effects on biochemical, hematological, and pathophysiological indices of albino rats. The effect of cadmium and cadmium/ginger treatment on lipid peroxidation was measured by malondialdehyde (MDA) levels in testes and kidney; serum activities of alkaline phosphatase (ALP), acid phosphatase (ACP), and prostatic acid phosphatase (PAP) enzyme were investigated alongside hematological indices. The results showed that cadmium induces a significant increase in both testicular and kidney MDA, whereas cadmium/ginger treatment produced a significant reversal of the effect of lipid peroxidation (P=.004). Cadmium treatment induced 75%, 78%, and 22% increases in activities of ACP, PAP, and ALP, respectively, whereas the cadmium/ginger-treated group reversed these values for enzyme activities (P=.001). Results of organ weight and hematological indices analysis in the cadmium-treated rats showed a decrease in organ weight and distortion of the hemopoietic features, whereas the cadmium/ginger-treated rats showed an improvement in organ weight and hematological indices (P=.04 and .001, respectively). The reversal of the toxic effects of cadmium in the cadmium/ginger-treated albino rats heralds the antioxidant potency of ginger toward cadmium toxicity-associated oxidative stress.
Assuntos
Cádmio/toxicidade , Fármacos Hematológicos/farmacologia , Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Testículo/metabolismo , Zingiber officinale/química , Animais , Antioxidantes/farmacologia , Humanos , Técnicas In Vitro , Rim/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Modelos Animais , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Testículo/efeitos dos fármacosRESUMO
In this study, gasoline vapors-induced hematotoxicity, growth-depression and weight-loss reversal effect of vitamins A (retinol) and E (α-tocopherol) was assessed in female Wistar albino rats. The rats were exposed to gasoline vapors (17.8 ± 2.6 cm(3)/h/m(3)/day), 6 hours/day, 6 days/week, for 20 weeks. Vitamins A and E at prophylactic dosage (400 and 200 IU/kg/day, respectively) were orally administered to the rats, separately, in the last 2 weeks of exposure. The levels of hemoglobin (Hb), hematocrit or packed cell volume (PCV), red blood cells (RBC), growth rate and weight gain in the rats exposed to the vapors were significantly lower (p < 0.05) compared, respectively, to the levels obtained for control rats. On the other hand, the levels of white blood cells (WBCs) in the test rats were significantly higher (p < 0.05) compared, respectively, with the level obtained for female control rats. These observations indicated that exposure to gasoline vapors may cause hematotoxicity, growth depression and weight loss in female rats. However, administration of vitamins A and E was observed to produce a significant recovery (p < 0.05) in hematotoxicity, growth depression and weight loss observed to be associated with exposure to gasoline vapors, although the rats administered with vitamin E were noted to respond more favorably than those administered with vitamin A. This suggests that although retinol and α-tocopherol may be used to reverse or prevent hematotoxicity, growth depression and weight loss in subjects exposed to gasoline vapors, the reversal potency of α-tocopherol is higher than that of retinol.
Assuntos
Índices de Eritrócitos/efeitos dos fármacos , Gasolina/toxicidade , Vitamina A/farmacologia , Vitamina E/farmacologia , Redução de Peso/efeitos dos fármacos , Análise de Variância , Animais , Estudos de Casos e Controles , Feminino , Gases/toxicidade , Exposição por Inalação , Contagem de Leucócitos , Leucócitos/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Evaluations of the effect of prolong cooking on the nutrient and antinutrient composition ofbeniseed and beniseed soup were carried out in this study. Proximate, mineral, vitamin A and C and antinutrient compositions of raw beniseed (BS-R), beniseed boiled (BSB) for 15, 30, 45 and 60 min and beniseed soup (BSS) cooked for the same intervals of time were assessed. Results of the proximate composition analyses showed that raw and boiled beniseed had lower moisture content (5.39-5.51%) than beniseed soups (10.06-15.20%). Nitrogen-free extract (total carbohydrates), fats and phosphorus contents were improved in both the boiled beniseed and beniseed soup while calcium and potassium were increased in the boiled seeds and soup samples respectively. Moisture (in the raw and boiled beniseed), ash, magnesium, zinc, iron contents in both the seed and soup were unchanged in all the samples. Vitamins A and C levels of both boiled beniseed and beniseed soup samples were reduced with increase in cooking time. Beniseed soup had higher protein contents than both the raw and boiled beniseed which decreased with increase in cooking time. Beniseed samples provided good sources of energy (572.97-666.05 kcal/100 g). Except for phytate, the levels of antinutrients tested were lower in the raw and boiled beniseed than in the soup samples which decreased with increase in cooking time. The results are discussed with reference to the effect of prolonged cooking on the nutrient requirements of consumers.
Assuntos
Culinária , Valor Nutritivo , NigériaRESUMO
Serum creatine kinase (CK), creatine kinase isoenzyme (CK-MB) and aspartate aminotransferase (AST) are key players in the diagnostic study of cardiac complications. These enzymes are specific diagnostic markers of myocardial infarction and hypertension is a disease condition characterized with a wide range of complications, including myocardial infarction. In this study, we determined the effects of interaction of vitamin A and Rauwolfia vomitoria (RV) root bark extract on marker enzymes of cardiac diseases. CK and CK-MB activities had significant decrease in the group of animals with concomitant administration of vitamin A (40 IU/kg body wt.) and 150 mg/kg body wt. of RV root bark extract. At the interaction of vitamin A with 300 mg/kg body wt. RV root bark extract, CK-MB only showed significant (p ≥ 0.05) decrease while CK decreased insignificantly. Also at the interaction of vitamin A with 300 mg/kg body wt. RV root bark extract, AST increased significantly but decreased significantly at the interaction of vitamin A (40 IU/kg body wt.) and 150 mg/kg body wt. of RV root bark extract. Our findings showed that vitamin A dose did not lower the activities of cardiac marker enzymes. However, concomitant administration of RV root bark extract at 150 mg/kg body wt. with vitamin A shows significant reduction in the activities of CK, CK-MB and AST. These findings suggest that interaction of vitamin A with RV root bark extract would be a meaningful ethno-pharmaceutical approach in the management of myocardial infarction and treatment of hypertension.
RESUMO
The atherogenic potentials of peeled grated cocoyam (Xanthosoma maffafa scot) "ekpang nkukwo", pounded yam (Discorea spp) with plain soup "afia efere", and plantain porridge (Musa paradisiaca) "iwuk ukom" meals were investigated. The three meals were fed to three different groups of albino rats of Wistar strain for a period of twenty eight days. A fourth group which served as control was feed with normal rat pellet. The mean total plasma cholesterol level in the pounded yam with plain soup fed group was significantly lower [P < 0.05] when compared to the control and peeled grated cocoyam fed groups. The mean total plasma triglyceride (MTPTG) level in the pounded yam with plain soup fed group was significantly lower [P < 0.05] when compared to the control group. However the MTPTG level in the peeled grated cocoyam and plantain porridge fed groups were comparable to control. The mean HDL-cholesterol level in the peeled grated cocoyam and plantain fed groups were comparable control. The mean LDL-cholesterol level in the peeled grated cocoyam and plantain porridge fed groups was significantly lower [P < 0.05] than the control group. The LDL-cholesterol and VLDL-cholesterol in the pounded yam with plain soup fed group was significantly lower [P < 0.05] when compared to control. These findings suggest low atherogenic potentials of the pounded yam with plain soup meal compared to the peeled grated cocoyam and plantain porridge meals.
Assuntos
Aterosclerose/etiologia , Dieta Aterogênica , Dioscorea/efeitos adversos , Musa/efeitos adversos , Xanthosoma/efeitos adversos , Animais , Aterosclerose/sangue , Biomarcadores/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , VLDL-Colesterol/sangue , Culinária , Modelos Animais de Doenças , Frutas/efeitos adversos , Masculino , Nigéria , Tubérculos/efeitos adversos , Ratos , Ratos Wistar , Triglicerídeos/sangueRESUMO
Effect of alcohol-kolanut interaction on sodium pump activity in wistar albino rats was studied. Thirty wistar albino rats were divided into six groups of five (5) rats per group and used for the study. The control group (1) received via oral route a placebo (4 ml of distilled water). Groups 2 to 6 were treated for a period of 21 days, with (10% v/v) of alcohol (group 2), 50mg/kg body weight of kolanut (group 3), 50 mg/kg body weight of caffeine (group 4), 4 ml of 10% v/v of alcohol and 50 mg/kg body weight kolanut (group 5), 4 ml of 10% v/v of alcohol and 50 mg/kg body weight of caffeine in 4.0 ml of the vehicle via gastric intubation respectively. A day after the final exposure, the brain of each rat was harvested and processed to examine several biochemical parameters, i.e., total ATpase, ouabain-insensitive ATpase, ouabain sensitive ATpase (Na(+)-K(+)ATPase), non-enzymatic breakdown of ATP and inorganic phosphate (Pi) released. The results showed that the essential enzyme of the brain responsible for neuronal function, Na(+)-K(+)ATPase, was inhibited by alcohol-kolanut co-administration relative to control, resulting in a decrease in Na(+)-K(+)ATPase activity, ATP production, ion transport and action potential, leading to loss of neuronal activities.
Assuntos
Encéfalo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Inibidores Enzimáticos/farmacologia , Etanol/farmacologia , Interações Ervas-Drogas , Malvaceae , Preparações de Plantas/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Animais , Encéfalo/enzimologia , Cafeína/farmacologia , Hidrólise , Cinética , Nozes , Ouabaína/farmacologia , Fosfatos/metabolismo , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
Effect of alcohol and kolanut interactions on biochemical indices of neuronal gene expression in Wistar albino rats was studied. Thirty Wistar albino rats were divided into six groups of five (5) rats per group. The control group (1) received via oral route a placebo (4 ml of distilled water). Groups 2-6 were treated for a period of 21-days with (10 % v/v) 50 mg/kg body weight of alcohol, 50 mg/kg body weight of kolanut, 50 mg/kg body weight of caffeine, 50 mg/kg body weight of alcohol and 50 mg/kg body weight of kolanut, and 50 mg/kg body weight of alcohol and 50 mg/kg body weight of caffeine in 4.0 ml of the vehicle via gastric intubation respectively. One day after the final exposure, the brain of each rat was harvested and processed to examine several biochemical parameters namely total protein, DNA, RNA and protein/RNA ratios. The status of neuronal gene expression was monitored through assessment of these parameters. The results showed that alcohol-kolanut co-administration decreased brain total protein, DNA, RNA levels and protein/RNA ratios, and inhibited gene expression. These effects, in turn, inhibited DNA transcription, MRNA splicing and protein synthesis, and polypeptide expression, which are necessary for the growth, development, differentiation and cell survival.
Assuntos
Encéfalo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Interações Ervas-Drogas , Malvaceae , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Preparações de Plantas/farmacologia , Animais , Encéfalo/metabolismo , Cafeína/farmacologia , DNA/metabolismo , Regulação para Baixo , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Nozes , Splicing de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Transcrição Gênica/efeitos dos fármacosRESUMO
Aqueous extract of the leaf and root ofNauclea latifolia Sm. (Rubiaceae) is used in Nigerian folk medicine for the treatment of hypertension. This work is carried out to investigate the effect ofNauclea latifolia leaf extract on lipid profile and cardiovascular activity of rats. Normal and 10% coconut oil fed rats were treated with the water-soluble fraction of the ethanol extract ofNauclea latifolia leaf for 2 weeks. Forty-eight mature male albino rats of the Wistar strain were divided into two experiments of four groups, each group having 6 animals. Experiment I animals were treated with the water-soluble fraction of the ethanol extract whilst experiment II animals were fed 10% coconut oil meal before treatment with the water-soluble fraction of the ethanol extract. A single oral dose ofNauclea latifolia was 170, 340 and 510 mg/kg body wt/day of the extracts respectively for 2 wks. There was no significant change in the lipid profile of the experimental animals as compared with the controls. There was about 40% relaxation on contracted thoracic aorta that was pre-contracted with 2 µM phenylephrine. The viability of the tissue was tested against 10 µM of acetylcholine. There was no significant (P>0.05) change in Na(+) concentration in the serum. However, the K(+) concentration in the serum of the experimental animals showed a significant increase. The study shows that ethanol extract ofNauclea latifolia has vasodilator action on the aorta and that lipid profiles of experimental rats were not affected. Furthermore, the increase in the K(+) may be contributing to the vasodilator effect ofNauclea latifolia.
RESUMO
The impact of feeding of dietary palm oil supplements on plasma vitamin A profile was investigated in animals. Four-week-old Wistar albino rats (n = 8 per group) were maintained for 28 days on standard rat food (4.7% fat by weight) supplemented (10%, 20% and 30% by weight) with red palm oil (RPO) and refined palm olein (REFPO). Plasma beta-carotene and vitamin A concentrations of rats fed RPO-based diets were higher than in rats fed REFPO and control diets. Animals fed 30% RPO-containing diets had lower plasma beta-carotene concentrations than those fed 20% RPO-containing diets. The results suggest that consumption of palm oil in moderate amounts enhances growth of tissues and bioavailability of beta-carotene, which may combat vitamin A deficiency in developing countries, in view of the fact that performed vitamin A in animal products (namely meat, liver, eggs and fatty fish) is out of the reach of economically deprived people.
Assuntos
Gorduras Insaturadas na Dieta/farmacocinética , Óleos de Plantas/farmacocinética , Vitamina A/sangue , Animais , Dieta , Ingestão de Alimentos , Ingestão de Energia , Avaliação Nutricional , Óleo de Palmeira , Óleos de Plantas/química , Ratos , Ratos Wistar , Aumento de Peso , beta Caroteno/administração & dosagem , beta Caroteno/análise , beta Caroteno/sangueRESUMO
The effects of free radical toxicity as induced by chronic consumption of thermoxidized palm oil (TPO) diet on organ size of normal animals, their first filial offspring and malnourished rats, were studied. Tissue- and sex-specific toxicity was revealed. The TPO diet significantly (P<0.01) reduced lung and kidney mass in normal male rats but female rats remained unaffected. Hearts of first filial offspring of both male and female rats were, however, enlarged while lung, liver and kidneys of first filial female offspring were additionally reduced in size (P<0.01). This information suggests that the observed toxicities could be cumulative for female offspring. Malnutrition protected against toxic injury because none of the kwashiorkoric animals rehabilitated on the toxic diet showed any overt symptoms of toxicity.
Assuntos
Temperatura Alta , Kwashiorkor , Óleos de Plantas/toxicidade , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/patologia , Dieta , Feminino , Radicais Livres/toxicidade , Rim/efeitos dos fármacos , Rim/patologia , Kwashiorkor/reabilitação , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Óleo de Palmeira , Óleos de Plantas/administração & dosagem , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Reprodução/efeitos dos fármacos , Caracteres SexuaisRESUMO
Caffeine and theobromine contents (mg/g) were determined in samples of selected Nigerian beverage products. The beverages were cocoa (Milo, Bournvita, Rosevita and Enervita), coffee (Nescafe, Bongo, and Maxwell House decaffeinated) and tea (Lipton). The theobromine contents of samples of Milo, Bournvita, Rosevita, Enervita, Nescafe, Bongo, Maxwell House decaffeinated coffee and Lipton were 62.10+/-5.21, 64.80+/-6.72, 82.80+/-4.43, 80.37+/-6.80, 27.00+/-4.31, 14.67+/-2.90, 23.46+/-3.13 and 12.60+/-1.52, respectively. The corresponding caffeine contents of these samples were 2.78+/-0.43 (Milo), 3.17+/-0.36 (Bournvita), 0.92+/-0.51 (Rosevita), 1.05+/-0.68 (Enervita), 93.66+/-8.91 (Nescafe), 6.47+/-2.42 (Bongo), 37.22+/-5.34 (Lipton), and 0.21+/-0.11 (Maxwell House decaffeinated coffee). Semi-processed cocoa beverages (Rosevita and Enervita) had significantly (p < 0.05) higher levels of theobromine compared with the finished cocoas (Milo and Bournvita). Similarly, Nescafe contained significantly (p < 0.05) higher levels of caffeine compared to Maxwell House (decaffeinated coffee) and Bongo. Levels of caffeine in Lipton tea were moderate.
Assuntos
Bebidas/análise , Cafeína/análise , Teobromina/análise , Cacau , Café , Manipulação de Alimentos , Humanos , Nigéria , CháRESUMO
Repeatedly thermoxidized palm oil (TPO), simulating local culinary practice, was fed for eight weeks at 15% of a balanced basal diet to two sets of male and female weanling albino rats of Wistar strain. The first set of animals were normal and healthy while the second set were kwashiorkoric. Primary controls (PC) of all rats were fed a balanced basal diet of commercial rat pellets while secondary controls (SC) were fed the balanced basal diet supplemented with 15% untreated palm oil. The findings indicate that fertility, as expressed by the pregnancy rate of healthy test rats, was 78% when compared with 80% in PC (p < 0.05). Fetotoxicity was additionally observed in that neonatal birth weights and litter size in test rats (4.92 g and 6.70, respectively) were inferior (p < 0.05) to both SC and PC (4.96 g and 8.40; 5.38 g and 9.25, respectively). Protein energy malnutrition worsened the observed TPO-induced reproductive toxicities in that reproductive capacities of the rehabilitated animals were inferior to that of the healthy animals. Pregnancy rates in test animals were reduced by as much as 55% (p < 0.01) while fetotoxicities were also more pronounced (p < 0.05).
Assuntos
Gorduras Insaturadas na Dieta , Temperatura Alta , Infertilidade Feminina/etiologia , Óleos de Plantas/toxicidade , Desnutrição Proteico-Calórica/fisiopatologia , Animais , Peso ao Nascer , Feminino , Morte Fetal/etiologia , Tamanho da Ninhada de Vivíparos , Masculino , Nigéria , Oxirredução , Óleo de Palmeira , Óleos de Plantas/química , Gravidez , Ratos , Ratos WistarRESUMO
During iron deficiency rat and human erythrocyte membrane enzyme activities (Total ATPase and Ouabainsensitive Na+.K+ ATPase) showed significant (P < 0.001) decrease. The influence of iron deficiency on erythrocyte Na+ and K+ was also studied in rats and humans. The former parameter showed a significant (P < 0.01) increase while the latter showed a downward trend. Plasma Fe and Total Iron Binding capacity (TIBC) in iron deficiency varied significantly (P < 0.05) from normal values. These results suggest a defect in erythrocyte membrane function and a possible potentiating effect of intracellular Na+, plasma Fe and TIBC on ATPase activity in iron deficiency. Values obtained for rats and humans showed differences in the activities of membrane ATPase in iron deficiency anaemia.
Assuntos
Anemia Ferropriva/enzimologia , Membrana Eritrocítica/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Adulto , Anemia Ferropriva/sangue , Animais , Humanos , Potássio/sangue , Ratos , Ratos Wistar , Sódio/sangueRESUMO
The bioavailability of iron in three different rural Nigerian peasant meals was studied. The meals were: pounded yam (Discorea spp) with 'afia efere'--(plain soup); 'ekpang nkukwo'--grated cocoyam (Xanthosoma maffafa Schott) and cocoyam leaves with pepper and plantain porridge (Musa paradisiaca) with water leaf (Talinum triangulare). Analyses of the meals showed the protein content to range from 8.58 +/- 0.01 mg/100 g DM to 11.38 +/- 0.08/100g DM. Iron content ranged from 17.50 +/- 2.50 mg/100 DM to 23.94 +/- 3.56 mg/100g DM. The rehabilitation of mildly anaemic rats with test meals showed the percentage of the ingested iron utilised for haemoglobin synthesis as: 48.08 +/- 0.51 pc; 18.09 +/- 0.41 pc; 19.09 +/- 0.36 pc for the test diets respectively and 60.80 +/- 0.22 pc for the control group. A comparison of the utilization of iron between the test and the control groups showed that there was a significant difference (p < 0.01) between the test and the control groups. The low level of iron enhancers in the meals has been suggested as the possible cause of the marginal level of iron availability from the meals to the test animals.
Assuntos
Dieta , Análise de Alimentos , Hemoglobinas/metabolismo , Ferro/farmacocinética , Animais , Disponibilidade Biológica , Deficiências de Ferro , Nigéria , Pobreza , RatosRESUMO
Daily administration of 2, 5, 10, 15 and 20mg of fenfluramine/kg body weight to adult rats for four weeks resulted in dose dependent decrease in calcium and phosphorus absorption with an inverse correlation of r = -0.94 for calcium and r = -0.93 for phosphorus. Significant (P less than 0.05) increase in the total faecal lipids and moderate decline in plasma calcium levels were also observed in the rats. Adult rats made obese by dietary methods when treated with 10mg and 15 mg of fenfluramine/kg body weight/day for 10 weeks showed a significant reduction (p less than 0.001) in the intestinal absorption of both calcium and phosphorus. The reduction at 15mg/kg drug dose was 10.7 pc for calcium and 9.5 pc for phosphorus. Analyses of the long bones as well as carcasses of the obese rats showed significant decrease (p less than 0.001) in the content of these minerals. Plasma calcium and phosphorus levels were also significantly (p less than 0.001) reduced in the obese-treated rats. However, fenfluramine treatment significantly reduced the plasma calcium but not the phosphorus levels in the non-obese rats. These studies have demonstrated that chronic administration of fenfluramine (greater than or equal to 10mg/kg body weight) to rats, obese or non-obese, impairs calcium and phosphorus metabolism in the body.
Assuntos
Cálcio/metabolismo , Fenfluramina/efeitos adversos , Obesidade/tratamento farmacológico , Fósforo/metabolismo , Animais , Densidade Óssea , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Fenfluramina/administração & dosagem , Absorção Intestinal/efeitos dos fármacos , Obesidade/metabolismo , Ratos , Ratos EndogâmicosRESUMO
During iron deficiency a significant (p less than 0.01) increase in erythrocyte Na+ in vivo was observed in both rats and humans. Erythrocyte K+ was down, but the effect was only significant (p less than 0.05) in rats, under this condition. However, erythrocyte Na+/K+ ratio was significantly (p less than 0.001) higher in iron deficiency when compared to normal values in both rats and humans. Although there was no significant (p greater than 0.05) correlation between Haemoglobin (Hb), Packed cell volume (PCV), Plasma Fe, and Total Iron Binding capacity (TIBC), and erythrocyte Na+ or K+ levels during iron deficiency, analysis of variance showed that Hb, PCV, Plasma Fe and TIBC in concert significantly (p less than 0.05) affected erythrocyte Na+ in iron-deficient rats and humans, whereas K+ was significantly (p less than 0.05) affected only in rats. These studies suggest a defect in erythrocyte membrane function during iron deficiency and imply a concerted potentiating effect of Hb, PCV, Plasma Fe and TIBC on erythrocyte membrane malfunction during iron deficiency. Species difference is also demonstrated in erythrocyte (Na+ and K+) translocation in iron deficiency.
Assuntos
Eritrócitos/metabolismo , Deficiências de Ferro , Potássio/sangue , Sódio/sangue , Adulto , Animais , Transporte Biológico/fisiologia , Feminino , Humanos , Masculino , Ratos , Ratos EndogâmicosRESUMO
The influence of dietary thiocyanate (SCN-) on N-nitrosation in vivo was investigated over 14 min following the administration, by stomach tube, of single doses of sodium nitrite and dimethylamine hydrochloride to male albino Wistar rats whose diet contained appreciable quantities of bound cyanide (cyanogenic glycosides) and free (nonglycosidic) cyanide. The rate of disappearance of the nitrosating agent (NO2-) from the stomach in control animals showed a high linear correlation (r = -0.84) with gastric N-nitrosation, as measured by metabolism (N-demethylation) of 'formed' nitrosamine in liver tissue isolated from these animals. This statistical relationship was significantly increased (r = 0.98), as well as the rate of NO2- utilization and the activity of the N-demethylase enzyme, in animals fed the test diet. Stomach SCN- content was well correlated with both stomach NO2- concentration (r = -0.95) and liver N-demethylase activity (r = +0.93). Interactions, in vivo, between thiocyanate ion and nitrosamine precursors ingested in food may enhance nitrosamine carcinogenesis.
Assuntos
Compostos Nitrosos/metabolismo , Tiocianatos/farmacologia , Animais , Dieta , Mucosa Gástrica/metabolismo , Técnicas In Vitro , Masculino , Manihot , Metiltransferases/metabolismo , Microssomos Hepáticos/enzimologia , Ratos , Ratos EndogâmicosRESUMO
The biliary excretion of linamarin (2[beta-D-glucopyranosyloxy]isobutyronitrile) was studied in male albino Wistar rats injected i.p. with single doses of 300 mg linamarin/kg following cannulation of the bile duct in vivo; 24 hr faeces of uncannulated rats, similarly dosed, was examined for excretory products. Enzymatic and spectrophotometric analyses of the bile exudate showed that glucosidic cyanide (linamarin, and non-glucosidic cyanide were excreted; the elimination of both cyanide forms exhibits biphasic kinetics. Thiocyanate ion was undetectable. T.l.c. of the test bile followed by enzymatic and chemical investigation of the chromatogram confirmed the presence of unchanged linamarin, and four different u.v. fluorescent non-glucosidic cyanide metabolites. Neither linamarin nor cyanide ion was detectable in faeces of the uncannulated rats.
Assuntos
Bile/metabolismo , Nitrilas/metabolismo , Ratos Endogâmicos/metabolismo , Animais , Ratos , Fatores de TempoRESUMO
The effect of graded levels of thiamin on the metabolism of linamarin was investigated in rats. It was observed that on a diet deficient in thiamin, a large amount of linamarin was recovered unchanged in the urine, together with significantly more thiocyanate (SCN-) relative to the control. The least amount of thiocyanate (p less than 0.05 relative to control) was found in animals receiving the highest amount (twice daily requirement) of thiamin in the diet; but the amount of unmetabolized linamarin was similar to the control. It is suggested that thiamin deficiency may be implicated in the aetiology of tropical ataxic neuropathy (TAN) through the thiocyanate overload in people eating large amounts of cassava and cassava derivatives which contain linamarin.
Assuntos
Nitrilas/metabolismo , Tiamina/farmacologia , Animais , Cianetos/urina , Manihot , Doenças do Sistema Nervoso/etiologia , Ratos , Ratos Endogâmicos , Tiamina/administração & dosagem , Deficiência de Tiamina/complicações , Deficiência de Tiamina/metabolismo , Tiocianatos/urinaRESUMO
Cassava leaves, which usually contain large quantities of cyanogenic glycosides, were processed into a Zairian traditional vegetable sauce "Mpondu" by simple methods which included blanching (10 min), mashing and then boiling for 20-80 min. These methods enhanced the detoxification of the leaves, with blanching alone resulting in the loss of 57% of the free (non-glycosidic) cyanide content and of 60% of the bound (glycosidic) cyanide. It is presumed that losses of cyanide during these processes would be accounted for in volatile HCN, its derivatives and in the boiling water.