Coeloglossum viride var. bracteatum extract attenuates d-galactose and NaNO2 induced memory impairment in mice

The aim is to study the neuroprotective effects of CE, a special extract from Coeloglossum viride (L.) Hartm. var. bracteatum (Willd.), on memory deficits in senescent mice induced by consecutive injection of d-galactose and NaNO2 for 60 days. Oral administration of CE (2.5 mg kg−1, 5 mg kg−1) started from 47th day of the experiment. Water maze test was used to evaluate the learning and memory function of mice. The contents of MDA and GSH and the activities of SOD and GSH-px in brain tissue were determined using different biochemical methods. The alterations in hippocampus morphology were assessed. Immunoreactive cells of Tau-2 and NT-3 in the hippocampus were counted by immunohistochemical staining. The results indicated that combined injection of d-galactose and NaNO2 induced memory impairment of mice. In addition, SOD and GSH-px activities and GSH level decreased while MDA level increased in mouse brain. Tau-2 positive neurons increased while NT-3 positive neurons decreased remarkably in the hippocampus. Administration of CE for 14 days significantly improved the cognitive deficits and the biochemical markers mentioned above and reduced the histological lesions in mouse brain. These results suggest that CE is worth testing for further preclinical study aimed for senescence and dementia.