RESUMO
El Smallanthus sonchifolius, oriundo de los Andes y llamado vulgarmente yacón, es conocido por su uso como normoglicemiante e hipolipemiante así como por su utilidad como antioxidante. En la presente investigación evaluamos la toxicidad subcrónica del extracto acuoso de sus hojas, luego de su administración oral en ratas albinas Holtzman. Objetivo: Evaluar la toxicidad del extracto acuoso de las hojas de yacón en ratas albinas sanas. Material y método: Se realizó un estudio experimental en 40 ratas Holtzman, distribuidas en dos grupos (hembras y machos), a las cuales se administró, por vía oral, durante 90 días, dosis de 100, 200 y 500 mg/Kg/día, del extracto acuoso de hojas de yacón. Se tomaron muestras de sangre del plexo orbital del ojo a los 0, 45 y 90 días para llevar a cabo análisis bioquímicos y hermatológicos. Se realizaron, además exámenes histopatológicos de cerebro, hígado y riñones. Resultados: No se encontraron variaciones significativas en ninguno de los exámenes en comparación con las ratas controles (p ø 0.05). Conclusión: El consumo del extracto de hojas de yacón, durante 90 días, no produjo signos de toxicidad en los órganos estudiados.
The Smallanthus sonchifolius, vulgarly known as yacon, an Ades's species is well known for its use as by it's normoglycemic, hipolipemic and antioxidant effects. There are only few studies on this plant. At present we have investigations about it's chemical composition, harverts process, and medical use. In this paper we evaluated the toxicity of the aqueous extract of the organic leaves of Smallanthus sonchifolius on Holtzman albin rats subcronic oral administration of the extract during 90 days. Objective: To evaluate the subchronic toxicity of aqueous extract of the yacon leaves on healthy albina rats. Material and method: An experimental study has been performed on 40 Holtzman rats. Male a female rats were grouped separately. They received oral daily doses of 100, 200 y 500 mg/Kg/ yaconÆs leaves aqueous extract. Blood samples were taken from the rat orbital plexus of the rats at 0,45 and 90 days of treatment for biochemical and haematologic analysis. Histological examination of brain, liver and kigneys was also done. Results: Non significant differences were found in the examinations of the three groups in comparison with control (p ø 0.05). Conclusion: The Smallanthus sonchifolius aqueous extract consumption during 90 days did not produce toxicity signs in the organs studied.
Assuntos
Masculino , Animais , Feminino , Aster/toxicidade , Asteraceae/toxicidade , RatosRESUMO
PURPOSE: To define molecular and ophthalmic features of a rare phenotype in autosomal dominant (ad) retinitis pigmentosa (RP). METHODS: A 32-year-old woman (proband) with adRP and the low-frequency damped electroretinographic (ERG) wavelet phenotype and her mother were studied with optical coherence tomography (OCT), chromatic perimetry and ERG. A previously reported adRP patient with this ERG phenotype (Lam et al) was also studied with OCT. Genotype in the two families was determined with DNA sequencing. RESULTS: ERGs from the proband were identical to those reported previously. Chromatic perimetry and ERG stimulus intensity series indicated that there can be severely reduced rod function in addition to substantial cone dysfunction. A heterozygous deletion in peripherin/RDS (Met152del3 atGAA) was present in the patient and the affected mother. There were foveal cystoid changes and pericentral splitting of the inner nuclear layer. ONL thickness and vision tapered with eccentricity, and 'blind' regions without discernible ONL showed a thickened, delaminated inner retina. Similar OCT findings were present in the reported adRP patient with this ERG; the patient was heterozygous for a 4-bp deletion (Leu107del4 ctGAGT) in PRPF31. CONCLUSIONS: The low-frequency damped ERG wavelet phenotype is genetically heterogeneous. Inner retinal structural abnormalities are also present in this rare disease expression.
Assuntos
Transtornos Cromossômicos/genética , Retinose Pigmentar/genética , Adulto , Eletrorretinografia , Feminino , Heterozigoto , Humanos , LinhagemRESUMO
To explore a new approach for characterizing the molten globule conformation, cyclic voltammetric studies of salt induced transitions at acidic pH of cyt c have been carried out. The use of modified electrodes has made the observation of direct electrochemistry in native cyt c possible. However, most of these electrodes do not show reversible responses at acidic pH, due to the fact that, for this system, a deprotonated electrode surface is needed. In these studies, we have used a 6-mercaptopurine and cysteine-modified gold electrodes which are effective for direct rapid electron transfer to cyt c, even in acid solutions. The change in the absorption bands of cyt c are used to monitor the conformational states and, hence, to compare the voltammetric results. Under the experimental conditions where the A state of cyt c is obtained, a reversible voltammetric signal is observed. The midpoint peak potentials are found to be very close to the formal potential of native cyt c. Results are discussed in terms of a cooperative two-state transition between the acid unfolded and the globular acidic states of cyt c. This finding establishes, for the first time, the similarity of both the native and the molten globule-like conformations in terms of its redox properties.