RESUMO
The consumption of hypercaloric diets is related to the development of obesity, favoring the etiology of gastrointestinal disorders. In this context, Spirulina platensis (SP), some blue-green algae with antioxidant action, appears as a potential therapeutic alternative to prevent obesity and associated intestinal disorders. Thus, the present study is aimed at evaluating the deleterious effects of the hypercaloric diet on the contractile and relaxing reactivity of the ileum of rats, as well as the possible preventive mechanisms of dietary supplementation with SP. Wistar rats were divided into three groups: fed a standard diet (SD), a hypercaloric diet (HCD), and/or supplemented with 25 mg/kg SP (HCD + SP25) for 8 weeks. The hypercaloric diet was effective in promoting obesity in rats, as well as decreasing potency and ileal relaxing and contractile efficacy. In contrast, dietary supplementation with SP was able to prevent some of the parameters of experimental obesity. In addition, SP prevented the reduction of intestinal reactivity, possibly due to a positive modulation of voltage-gated calcium channels (CaV) and negative regulation of muscarinic receptors (M3). Thus, food supplementation with Spirulina platensis becomes a promising alternative in the prevention of gastrointestinal diseases induced and/or aggravated by obesity.
Assuntos
Antioxidantes/farmacologia , Canais de Cálcio/metabolismo , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Obesidade/prevenção & controle , Receptor Muscarínico M3/metabolismo , Spirulina/fisiologia , Animais , Canais de Cálcio/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Ratos , Ratos Wistar , Receptor Muscarínico M3/genética , Spirulina/químicaRESUMO
This study aimed to investigate the effects of magnetic field (MF) application (1, 12 and 24 h day -1) to Spirulina sp. LEB 18 in different photosynthesis cycles (dark and/or light) during short (15 days) and long periods (50 days) of cultivation. MF application was performed via two sources: ferrite magnets and solenoids. At the end of cultivation, the biomass was characterized in terms of lipids, proteins, and carbohydrates. In the 15 day cultures, the highest maximum biomass concentrations (2.06 g L-1 and 1.83 g L-1) were observed when 30 mT was applied for 24 h day -1 or 12 h day -1 (on the light cycle), respectively. MF application throughout cultivation (24 h day -1) for more than 30 days is not recommended. In all conditions, there was an increase in the lipid concentration (from 14 to 45%). The protein profile suggested important changes in photosystems I and II due to MF application. Cell morphology was not altered by MF application. In conclusion, the effects on the metabolism of Spirulina sp. are directly related to the photosynthesis cycle and time period in which the MF was applied.
Assuntos
Metabolismo dos Lipídeos , Campos Magnéticos , Spirulina/crescimento & desenvolvimento , Proteínas de Bactérias/metabolismo , Biomassa , Metabolismo dos Carboidratos , Escuridão , Fotossíntese , Spirulina/metabolismo , Spirulina/fisiologiaRESUMO
The worldwide obesity pandemic requires the use of anti-obesity drugs. Sibutramine is an anti-obesity drug that has been used worldwide but is indiscriminately consumed in Brazil. Several studies have demonstrated that sibutramine promotes weight loss and weight maintenance, but several side effects have been associated with its systematic consumption. For this reason, sibutramine was withdrawn from the European and American markets, but still remains legal for use in Brazil. Studies have shown that a 5-10% reduction in body weight results in outstanding health benefits for obese patients. However, in order to promote significant weight loss, it is necessary to use sibutramine for at least 2 years. This long-term exposure has carcinogenic potential, as sibutramine causes DNA damage. Thus, this study evaluated the in vivo mutagenic potential of sibutramine alone (5, 7, 10, 15, and 20 mg/kg) and in association with Spirulina maxima (150 and 300 mg/kg), a cyanobacterium with antioxidant potential, using the polychromatic erythrocyte micronucleus test. Our results reinforced the mutagenic potential of sibutramine alone, which showed a time-dependent action. Combinatory treatments with S. maxima were not able to reduce the genotoxicity of sibutramine. These results were confirmed in vitro with the cytokinesis-blocked micronucleus test. In conclusion, our data showed that new alternative anti-obesity treatments are needed since the consumption of sibutramine can increase the risk of cancer in overweight patients.
Assuntos
Depressores do Apetite/farmacocinética , Ciclobutanos/farmacologia , Mutagênicos/farmacologia , Spirulina/fisiologia , Adolescente , Adulto , Fármacos Antiobesidade/farmacologia , Fármacos Antiobesidade/toxicidade , Depressores do Apetite/administração & dosagem , Depressores do Apetite/toxicidade , Brasil , Ciclobutanos/administração & dosagem , Ciclobutanos/toxicidade , Feminino , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Masculino , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Testes para Micronúcleos , Mutagênicos/administração & dosagem , Mutagênicos/toxicidade , Reticulócitos/efeitos dos fármacos , Reticulócitos/metabolismo , Adulto JovemRESUMO
Semicontinuous cultures were carried out at different dilution rates (D) and light intensities (I) to determine the maximum productivity of Arthrospira platensis cultivated in helicoidal photobioreactor up to the achievement of pseudo-steady-state conditions. At I=108 µmol photons m(-2) s(-1), the semicontinuous regime ensured the highest values of maximum cell concentration (X(m)=5772±113 mg L(-1)) and productivity (P(XS)=1319±25 mg L(-1) d(-1)) at the lowest (D=0.1 day(-1)) and the highest (D=0.3 day(-1)) dilution rates, respectively. A kinetic model derived from that of Monod was proposed to determine the relationship between the product of light intensity to dilution rate (ID) and the cell productivity, which were shown to exert a combined influence on this parameter. This result put into evidence that pseudo-steady-state conditions could be modified according to circumstances, conveniently varying one or other of the two independent variables.
Assuntos
Modelos Biológicos , Fotobiorreatores/microbiologia , Spirulina/fisiologia , Spirulina/efeitos da radiação , Proliferação de Células/efeitos da radiação , Simulação por Computador , Luz , Doses de RadiaçãoRESUMO
UNLABELLED: BACKGROUND/AIM OF THE STUDY: This study evaluates the effects of the blue green alga spirulina as the sole dietary source of protein on muscle protein in weaning rats. METHODS: Young (30 days) Wistar rats were fed, during 60 days, with 17% protein spirulina (S) and compared to rats fed 17% protein casein (C). We evaluated the muscle total protein and DNA contents and the in vitro protein synthesis and degradation rates as well the myosin protein expression. RESULTS: The groups presented similar body weight (C = 427.3 +/- 8.6; S = 434.6 +/- 7.7 g) and length (C = 25.4 +/- 0.2; S = 25.6 +/- 0.2 cm). Soleus muscle total protein (C = 2.9 +/- 0.1; S = 2.7 +/- 0.1 mg/100 mg) and DNA (C = 0.084 +/- 0.005; S = 0.074 +/- 0.005 mg/100 mg) contents were also similar in both groups. Protein degradation (C = 427.5 +/- 40.6; S = 476.7 +/- 50.5 pmol/mg(-1) h(-1)) did not differ between the groups but protein synthesis (C = 17.5 +/- 1.0; S = 25.2 +/- 1.9 pmol/mg(-1) h(-1)) and myosin content (western blot analyses) were higher (P < 0.05, t test) in spirulina group. CONCLUSIONS: Although the spirulina proved adequate protein quality to maintain body growth, the muscle protein synthesis rates were increased by the ingestion of the experimental diet in young rats.
Assuntos
Proteínas Alimentares/administração & dosagem , Proteínas Musculares/metabolismo , Miosinas/biossíntese , Ratos Wistar/crescimento & desenvolvimento , Spirulina/fisiologia , Animais , Proteínas Alimentares/metabolismo , Masculino , Distribuição Aleatória , Ratos , DesmameRESUMO
This study dealt with the influence of both the feeding time and light intensity on the fed-batch culture of the cyanobacterium Spirulina (Arthrospira) platensis using ammonium chloride as a nitrogen source. For this purpose, a 2(2) plus star central composite experimental design combined with response surface methodology was employed, and the maximum cell concentration (X(m)), the cell productivity (P(X)), and the yield of biomass on nitrogen (Y(X/N)) were selected as the response variables. The optimum values of X(m) (1,833 mg L(-1)) and Y(X/N) (5.9 g g(-1)) estimated by the model at light intensity of 13 klux and feeding time of 17.2 days were very close to those obtained experimentally under these conditions (X(m) = 1,771 +/- 41 mg L(-1); Y(X/N) = 5.7 +/- 0.17 g g(-1)). The cell productivity was a decreasing function of the ammonium chloride feeding time and a quadratic function of the light intensity. The protein and lipid contents of dry biomass collected at the end of cultivations were shown to decrease with increasing light intensity.