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 characterize the pedigree, visual function phenotype, and responsible mutation in a large family with autosomal dominant retinitis pigmentosa. METHODS: Pedigree data were obtained by personal interviews and corroborated with community records. One hundred twenty-eight members of the family were examined clinically, and a subset of 12 affected subjects was further studied with dark- and light-adapted static perimetry and electroretinography. The coding region of the rhodopsin gene was polymerase chain reaction (PCR) amplified and resolved by denaturing gradient gel electrophoresis. Genomic DNA samples from nine affected and five unaffected family members were analyzed by PCR amplification and restriction enzyme digestion. RESULTS: A 14-generation pedigree was identified in which retinitis pigmentosa (RP) was inherited in an autosomal dominant fashion. Affected individuals reported early night blindness and showed vessel attenuation and bone spicule-like pigmentary changes. In these individuals, the rod electroretinogram (ERG) was not detectable, and the cone ERG was reduced in amplitude and delayed in timing. With dark-adapted perimetry, rod function could be detected in only one young patient, and it was markedly abnormal. Light-adapted perimetry indicated that cone sensitivity could be relatively well preserved in the central field, but it was diminished in the periphery even in the most mildly affected subjects. A valine345-to-leucine mutation was identified in the rhodopsin gene and shown to cosegregate in the heterozygous condition with the disease. CONCLUSIONS: The natural history of RP in this family begins with a loss of rod function, progresses to involve the cone system, and leads eventually to a severe loss of visual function. The invariance of valine345 in all functional vertebrate visual pigments sequenced to date, and the unusually conservative nature of the valine345-to-leucine mutation suggests that the carboxy terminus of rhodopsin is involved in a highly specific interaction with one or more rod proteins.