Efeito da fração não-oleosa doRicinus communisna biodistribuição comTecnécio-99m em camundongos / Effect of non-oily fraction ofRicinus communis on the bio distribution with Technetium-99m in mice

RESUMO Ricinus communisé uma planta pertence à família Euforbiaceae. A partir de seus frutos é extraído o óleo de rícino e outra fração altamente tóxica (fração não-oleosa). Neste estudo, foi avaliado o efeito da fração não oleosa de R. communis(FNORC) na biodistribuição do Tc-99m em camundongos sadios e em animais transplantados com Sarcoma-180 (S180). Para avaliação da biodistribuição do Tc-99m, o percentual de atividade radioativa total injetada (ATI%) foi mensurada utilizando um contador gama. Os resultados mostraram que, em animais sadios, houve aumento da captação do Tc-99m após o tratamento com FNORC pelos rins, cérebro e estômago. Apenas houve diminuição da absorção deste radioisótopo nos músculos. Em animais com tumor, houve redução significativa da captação do Tc-99m no coração, pulmões e tumor, e foi observado o aumento da captação apenas nos rins. Foi observada também a diminuição da concentração das proteínas plasmáticas totais em animais com tumor após tratamento com FNORC e atividade antitumoral significativa. Diante desses dados, conclui-se que fração não oleosa de R. communis possui atividade antitumoral significativa, porém altera a biodistribuição do Tc-99m, fato este que pode resultar em falhas nos processos de diagnóstico por imagem que utilizem este radioisótopo como marcador.

ABSTRACT Ricinus communis is a plant belonging to the Euforbiaceae family. From its fruits, it is extracted the castor oil and another highly toxic fraction (non-oily fraction). In this study, we evaluated the effect of the non-oily fraction of R. communis (NOFRC) on the bio distribution of Tc-99m in healthy mice and in animals transplanted with Sarcoma-180 (S180). To evaluate the bio distribution of theTc-99m, the percentage of the total injected radioactivity (% TIR) was measured through a gamma counter. There was an increase in the capitation of Tc-99m after the treatment with NOFRC in the kidneys, brain, and stomach of healthy animals. A decrease in the reception of this radionuclide was only found in the muscles. In animals with tumour, there was a significant reduction in the uptake of Tc-99m in the heart, lungs and tumour. An increase in the capitation was only observed in the kidneys. It was also observed a reduction in the total plasma protein concentration in animals with tumours after the treatment with NOFRC, besides significant antitumor activity. We concluded that there is antitumor activity in the NOFRC, but that it alters the biodistribution of Tc-99m, a fact which may result in failures in the diagnostic imaging process using this radioisotope as a marker.

Biokinetics and dosimetric studies about 99mTc(V)-DMSA distribution.

Research for radiodiagnostic agents should considerate biological critical parameters which will give own contribution on the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with (99m)Tc(V) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in evaluation of bone metastasis. This work studied the biokinetics and dosimetry of (99m)Tc(V)-DMSA by animal model. The (99m)Tc(V)-DMSA was prepared from a (III)DMSA kit alkalized. Mice (n=5) received (99m)Tc(V)DMSA i.v., they were sacrificed (30 min, 1h, 5h and 12h), the organs excised and the activities measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated (MIRDOSE 3.0 program) by extrapolation of data from animal to human scale. The results showed the majority of organs reached the top uptake at 30 min, the greatest kidney uptake was (4.81 +/- 1.38)% activity/g, while the bone presented its highest uptake at 1h (5.49+/- 0.47)% activity/g, after 1h all the organs had activity exponential decrease. The biokinetic profile of (99m)Tc(V)-DMSA was well established, allowing quantifying of residence time, and the radiation dose estimates were made for this agent. About the absorbed dose, the preliminary results showed higher value to bone, being the soft tissue dose relatively low.

Effects of the electromagnetic field, 60 Hz, 3 microT, on the hormonal and metabolic regulation of undernourished pregnant rats.

Epidemiological studies have implicated maternal protein-calorie deficiency as an important public health problem in developing countries. Over the last decades, a remarkable diffusion of electricity and an increased level of the electromagnetic field (EMF) in the environment have characterized modern societies. Therefore, researchers are concerned with the biological effects of 50-60 Hz, EMF. The aim of this paper is to show the effects of EMF of 60 Hz, 3 muT, exposure for two hours per day in the regulation of the hormonal and metabolic concentrations in pregnant rats, which were fed by Regional Basic Diet (RBD) during their pregnancy as compared with pregnant rats fed a standard diet. Pregnant rats exposed to EMF of 60 Hz, 3 muT, over the pregnancy and fed with RBD presented an increase in glucose release when compared with the Group subjected only to the RBD ration. Rats fed RBD presented a decrease in their insulin and cortisol serum levels when compared with the Group fed with casein. The T3 and T4 concentrations presented the greatest variation among the Groups. The relation T4:T3 was much exaggerated in the Group subjected to RDB and exposed to EMF when compared to the others. In conclusion, the group subjected to the association of EMF and undernutrition suffered a decrease in its serum concentration of T4 and T3 when compared to the well-nourished group and the relationship T4:T3 in the former group was almost eighteen-fold the later one.

Effects of the Electromagnetic field, 60 Hz, 3 µT, on the hormonal and metabolic regulation of undernourished pregnant rats / Efeitos do campo eletromagnético, 60 Hz, 3µT, na regulação hormonal e metabólica de ratas prenhes desnutridas

Epidemiological studies have implicated maternal protein-calorie deficiency as an important public health problem in developing countries. Over the last decades, a remarkable diffusion of electricity and an increased level of the electromagnetic field (EMF) in the environment have characterized modern societies. Therefore, researchers are concerned with the biological effects of 50-60 Hz, EMF. The aim of this paper is to show the effects of EMF of 60 Hz, 3 μT, exposure for two hours per day in the regulation of the hormonal and metabolic concentrations in pregnant rats, which were fed by Regional Basic Diet (RBD) during their pregnancy as compared with pregnant rats fed a standard diet. Pregnant rats exposed to EMF of 60 Hz, 3 μT, over the pregnancy and fed with RBD presented an increase in glucose release when compared with the Group subjected only to the RBD ration. Rats fed RBD presented a decrease in their insulin and cortisol serum levels when compared with the Group fed with casein. The T3 and T4 concentrations presented the greatest variation among the Groups. The relation T4:T3 was much exaggerated in the Group subjected to RDB and exposed to EMF when compared to the others. In conclusion, the group subjected to the association of EMF and undernutrition suffered a decrease in its serum concentration of T4 and T3 when compared to the well-nourished group and the relationship T4:T3 in the former group was almost eighteen-fold the later one.

Estudos epidemiológicos têm mostrado que a deficiência proteico-calórica é um importante problema nos países em desenvolvimento. Durante as últimas décadas, a sociedade moderna tem sido caracterizada pelo aumento no número de equipamentos elétricos e como consequência um aumento no nível do campo eletromagnético (CEM) no ambiente. No entanto, os pesquisadores estão preocupados com os efeitos biológicos dos CEM de 50-60 Hz. O objetivo deste artigo é mostrar os efeitos do CEM de 60 Hz, 3 μT, nas concentrações hormonais e metabólicas de ratas prenhes, expostas duas horas por dia ao CEM, alimentadas pela Dieta Básica Regional (DBR) comparando com ratas submetidas às mesmas condições, mas alimentas com dieta padrão. Ratas prenhes expostas ao CEM de 60 Hz, 3 μT, durante a prenhez e alimentadas com a DBR apresentaram um aumento na liberação de glicose quando comparadas com o grupo alimentado pela DBR sem CEM. As ratas alimentadas pela DBR apresentaram uma diminuição nos níveis de insulina e cortisol quando comparadas com o grupo alimentado pela caseína. As concentrações de T3 e T4 apresentaram a maior variação entre os grupos. A relação T4:T3 foi muito exagerada no grupo alimentado pela DBR e exposto ao CEM quando comparado com os outros. Conclusão, os animais que foram submetidos à desnutrição e ao CEM sofreram uma diminuição na concentração sérica de T4 e T3 quando comparados com os animais bem nutridos e a relação T4:T3 no primeiro grupo foi quase 18 vezes a relação de T4:T3 no grupo bem nutrido.

Influence of a 60 Hz, 3 microT, electromagnetic field on the somatic maturation of wistar rat offspring fed a regional basic diet during pregnancy.

The aim of the present study was to observe how the exposition of pregnant rats to an electromagnetic field (EMF), with frequency of 60 Hz, and a magnetic field of 3 microT for 2 hours per day and/or using the so-called Regional Basic Diet (RBD), influenced the somatic maturation in their offspring. Four groups were formed: Group A (casein), B (casein and EMF), C (RBD) and D (RBD and EMF). The diet manipulation occurred during pregnancy. The somatic maturation indexes--assessed daily between 12:00 AM and 2:00 PM--were: Eye Opening (EO), Auricle Opening (AO), Auditory Canal Opening (ACO), Low Incisor Eruption (LIE), and Upper Incisor Eruption (UIE). The association between EMF and deficient diet caused a delay in all Somatic Maturation Indexes (SMI) and the RBD caused delay only in the AO. Furthermore, the EMF caused delay in AO, ACO, LIE. In relation to the body weight, the EMF associated with the deficient diet caused change in the twenty-first day of life. The RBD, during pregnancy, caused lower body weight in the offspring in the first and third day of life. The body weight of the offspring whose mothers were fed casein and exposed to the EMF during pregnancy was lower in the third and sixth day of life. In conclusion, the EMF associated with under-nutrition caused delay in all SMI. In relation to the body weight, the EMF associated with under-nutrition caused a decrease in the body weight at the sixth day of life.

Influence of a 60 Hz, 3 µT, electromagnetic field on the somatic maturation of wistar rat offspring fed a regional basic diet during pregnancy / Influência do campo eletromagnético de 60 Hz, 3 µT, na maturação somática de filhotes de ratos wistar alimentados pela dieta básica regional durante a prenhez

The aim of the present study was to observe how the exposition of pregnant rats to an electromagnetic field (EMF), with frequency of 60 Hz, and a magnetic field of 3 µT for 2 hours per day and/or using the so-called Regional Basic Diet (RBD), influenced the somatic maturation in their offspring. Four groups were formed: Group A (casein), B (casein and EMF), C (RBD) and D (RBD and EMF). The diet manipulation occurred during pregnancy. The somatic maturation indexes - assessed daily between 12:00 AM and 2:00 PM - were: Eye Opening (EO), Auricle Opening (AO), Auditory Canal Opening (ACO), Low Incisor Eruption (LIE), and Upper Incisor Eruption (UIE). The association between EMF and deficient diet caused a delay in all Somatic Maturation Indexes (SMI) and the RBD caused delay only in the AO. Furthermore, the EMF caused delay in AO, ACO, LIE. In relation to the body weight, the EMF associated with the deficient diet caused change in the twenty-first day of life. The RBD, during pregnancy, caused lower body weight in the offspring in the first and third day of life. The body weight of the offspring whose mothers were fed casein and exposed to the EMF during pregnancy was lower in the third and sixth day of life. In conclusion, the EMF associated with under-nutrition caused delay in all SMI. In relation to the body weight, the EMF associated with under-nutrition caused a decrease in the body weight at the sixth day of life.

O objetivo deste estudo foi observar a influência do campo eletromagnético (CEM), com freqüência de 60Hz, campo magnético de 3 µT, durante 2 horas por dia, associado ou não à dieta básica regional (DBR) no desenvolvimento somático da prole. Quatro grupos foram formados: Grupo A (caseína), B (caseína e CEM), C (DBR) e D (DBR e CEM). A manipulação dietética ocorreu durante a prenhez. Os índices de maturação somática - Abertura dos Olhos (AO), Abertura do Pavilhão Auditivo (APA), Abertura do Conduto Auditivo (ACA), Erupção do Incisivo Inferior (EII), e Erupção do Incisivo Superior (EIS) - foram avaliados diariamente entre 12 e 14 horas. A associação entre o CEM e a dieta deficiente causou retardo em todos os índices de maturação somática (IMS) e a DBR causou retardo somente na APA. O CEM causou retardo na APA, ACA, EII. Em relação ao peso corporal, o CEM associado à dieta deficiente causou mudanças no 21º dia de vida. A DBR, durante a prenhez, causou diminuição do peso corporal dos filhotes no 1º e no 3º dia de vida. O peso corporal dos filhotes, cujas mães foram alimentadas pela caseína e expostas ao CEM, durante a prenhez, apresentaram uma diminuição no 3º e 6º dia de vida. Conclusão: o CEM, associado com a desnutrição, causou retardo em todos os IMS. Em relação ao peso corporal, o CEM, associado à desnutrição, causou uma diminuição no peso corporal no 6º dia de vida.

Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves.

Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.

Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves

Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.

Assessment of the effect of Punica granatum (pomegranata) on the bioavailability of the radiopharmaceutical sodium pertechnetate (99mTc) in Wistar rats.

The many desirable characteristics of technetium-99m (99mTc) have stimulated the development of labeling techniques for different molecular and cellular structures. It is generally accepted that a variety of factors other than disease can alter the bioavailability of radiopharmaceuticals and one such factor is the drug therapy. The use of medicinal plants has increased in the last decades all over the world. Punica granatum (pomegranata) is used as food or as medication in folk medicine for antiviral, anthelmintic, antifungal, antibacterial and antimicrobial activity. We have studied in rats, the effect of the medicinal plant Punica granatum on the bioavailability of the radiopharmaceutical 99mTc-sodium pertechnetate (Na(99m)TcO4). The infusion of pomegranata was administered by intragastric via into Wistar rats during seven days. After that, the animals received by ocular plexus via, 0.1 ml of the Na(99m)TcO4 (3.7MBq) and the animals were rapidly sacrificed after 5, 20 and 40 min. The organs were isolated (brain, heart, thyroid, liver, lungs, kidneys, stomach, testis, intestines, pancreas, spleen, bladder, muscle and bone), the radioactivity determined in a well counter, the percentages of radioactivity (%ATI) in the organs were calculated and statistical analyses were performed by Wilcoxon test (p < 0.05). The results have shown a significant (p < 0.05) increase of the activity of the Na(99m)TcO4 in spleen, heart, stomach, liver, stout bowel, pancreas, lungs and testis at 5 min. Twenty minutes after the administration of the radiopharmaceutical, the analysis of the results reveals a significant (p < 0.05) increase of the %ATI in heart, stomach, femur, pancreas, lungs and kidneys. Forty minutes after the administration of the Na(99m)TcO4, the results show a significant (p < 0.05) increase in spleen, brain, heart, stomach, liver, stout bowel, muscle, femur, lungs, pancreas, kidneys and testis. These results can be justified by therapeutic effect of this extract and/or by generation of active metabolites capable to interfere with the biodistribution of the studied radiopharmaceutical.

Evaluation of the phytic acid effect on the labeling of blood elements with technetium-99m and on the survival of a strain of Escherichia coli treated with stannous fluoride.

The labeling of red blood cells with technetium-99m (99mTc) depends on a reducing agent and stannous ions, as chloride or fluoride, are widely utilized. This labeling may also be altered by drugs. Moreover, some authors have reported that the survival of Escherichia coli (E. coli) cultures decreases in presence of stannous ions. Phytic acid is present in the daily diet and we evaluated its influence on: (i) the labeling of blood elements with 99mTc and (ii) on the survival of an E. coli strain treated with stannous fluoride. Heparinized whole blood was withdrawn from Wistar rats and it was incubated with stannous chloride and with 99mTc, as sodium pertechnetate, centrifuged and plasma (P) and blood cells (BC) were isolated. Samples of P and BC were also precipitated with trichloroacetic acid, centrifuged and soluble (SF) and insoluble fractions (IF) isolated. E. coli culture was treated with stannous fluoride in presence of phytic acid. As phytic acid altered the fixation of 99mTc on BC, on IF-P and on IF-BC and, moreover, it abolished the lethal effect of stannous fluoride on the E. coli culture, we can suggest that, probably, phytic acid would have chelating properties to the stannous ions.

Assessment of the stannous fluoride and phytic acid effect in the yeast Saccharomyces cerevislae.

Stannous fluoride (SnF2) is a powerful reducing agent in 99mTc-labelled radiopharmaceuticals for nuclear medicine procedures. SnF2 may enhance reactive oxidative species (ROS) in prokaryotic cells. Phytic acid (PA) is a wide-ranging regulator of many important cellular functions such as intracellular regulations of surface receptions channels and it is known to have antioxidant and chelating properties. In order to analyze whether membrane transporters of the facilitator or the ABC type (SNQ1 and SNQ2) have an influence on Sn2+ toxicity in yeast we used the respective mutants and compared their responses to the wild type (WT). Since ABC transporters are YAP1p transcription activator inducible, we included a yap1 mutant in our Sn2+ toxicity assay. Finally, we tested the PA influence on Sn2+ toxicity in these strains. Yeast cells in stationary growth phase were exposed to different concentrations of SnF2 (ranging from 2 to 6 mg/ml) and PA (0.1 M) for one hour. The snq1 mutant exhibited the highest sensitivity to SnF2 while the snq2 and snq3/yap1 mutants had an equally intermediate sensitivity. The presence of PA was not able to produce a significant protection against the cytotoxicity of SnF2. This is probably due to its reduced chelating power in complex liquid media Our results with yeast support the genotoxic effects described for SnF2 in bacteria andindicate that the biological effect of this reducing agent could be related to the generation of reactive oxygen species.