RESUMO
Introduction: Rana dybowskii Guenther (RDG), as a traditional Chinese medicine, has been shown to have antioxidant effects. However, studies on the anti-aging effect of RDG are still limited. Methods: In this study, we prepared polysaccharides from the skin of RDG (RDGP) by hot water extraction, alcohol precipitation, ion-exchange chromatography and gel chromatography. The proteins were removed using the Sevage method in combination with an enzymatic method. The structural features were analyzed using high-performance gel permeation chromatography, ß-elimination reaction and Fourier transform infrared spectra. The anti-aging effect of RDGP was investigated by using D-Gal to establish an aging model in mice, and pathological changes in the hippocampus were observed under a microscope. Results: We obtained the crude polysaccharide DGP from the skin of RDG, with a yield of 61.8%. The free protein was then removed by the Sevage method to obtain DGPI and deproteinated by enzymatic hydrolysis combined with the Sevage method to further remove the bound protein to obtain the high-purity polysaccharide DGPII. Then, DGPIa (1.03 × 105 Da) and DGPIIa (8.42 × 104 Da) were obtained by gel chromatography, monosaccharide composition analysis showed that they were composed of Man, GlcA, GalNAc, Glc, Gal, Fuc with molar ratios of 1: 4.22 : 1.55: 0.18 : 8.05: 0.83 and 0.74 : 1.78: 1: 0.28: 5.37 : 0.36, respectively. The results of the ß-elimination reaction indicated the presence of O-glycopeptide bonds in DGPIa. The Morris water maze test indicated that mice treated with DGPIIa exhibited a significantly shorter escape latency and increased time spent in the target quadrant as well as an increase in the number of times they traversed the platform. Pathologic damage to the hippocampus was alleviated in brain tissue stained with hematoxylin-eosin. In addition, DGPIIa enhanced the activities of SOD, CAT, and GSH-Px and inhibited the level of MDA in the serum and brain tissues of aging mice. Discussion: These results suggest that RDGP has potential as a natural antioxidant and provide useful scientific information for anti-aging research.
RESUMO
Ranae Oviductus has a high economic and social value, but its adulterants are more numerous, which causes a great confusion to the market. Using DNA bar code technology based on COI sequence for PCR amplification and sequencing of the identified Rana dybowskii, R. chensinensis, R. huanrensis and R. amurensiss, the COI gene database of four species of Rana was established, and comparing the measured sequence with the sequence of GenBank, four kinds of Rana were identified. The MEGA (molecular evolutionary genetics analysis) 7 .0 software was used to calculate the genetic distance of K2P and construct the NJ (neighbor-joining) system cluster tree. The sequence of the four species of Rana measured were clustered into one group with the sequence of the four kinds of Rana downloaded from GenBank, but separated from the two outer groups downloaded from GenBank. The COI gene of the R. dybowskii was likely to have regional differences, however this technique failed to distinguish male and female Rana. The results showed that DNA bar code technology could accurately identify the base of original animal of R. oviductus. It indicates that DNA bar code COI provides a new method for the identification of R. oviductus.