Effect of N-acetyl-L-cysteine on bioavailability and brain distribution of curcumin by nasal delivery / 中国中药杂志

Curcumin( Cur) is a natural active substance extracted from the roots or tubers of traditional Chinese medicinal materials. It has anti-inflammatory and anti-tumor activities on brain diseases. Due to the poor stability,low solubility,poor absorption and low bioavailability of curcumin,N-acetyl-L-cysteine( NAC) was used as an absorption enhancer and mixed with curcumin to improve the absorption of curcumin in the body. In this paper,curcumin was smashed by airflow pulverization,and Cur-NAC mixtures were prepared by being grinded with liquid. Then,the raw material and the product were analyzed by differential scanning calorimetry( DSC),X-ray diffraction( XRD) for structural characterization. The dissolution was determined by high performance liquid chromatography( HPLC) analysis. The characteristic peaks of the samples prepared by grinding method were similar to those of the raw materials,while the melting temperature and the accumulated dissolution degree were not significantly changed. The crystal forms of the products were not changed,and no new crystal form was formed after grinding. After the administration of intranasal powder,blood samples were collected from the orbit,while the whole brain tissues were removed from the skull and dissected into 10 anatomical regions. The concentrations of curcumin in these samples were determined by UPLC-MS/MS. The concentrations of curcumin in plasma and brain were compared at different time points. After intranasal administration of two drugs,it was found that the concentration of curcumin after sniffing up the mixtures in plasma was high,and the concentration of the drug in the olfactory bulb,hippocampus,and pons was increased significantly. Within 0. 083-0. 5 h,the olfactory bulb,piriform lobe and hippocampus remained high concentrations,the endodermis,striatum,hypothalamus and midbrain reached high concentrations within 1-3 h; and the cerebellum,pons and brain extension maintained relatively high concentrations within 3-7 h. The experiment showed that nasal administration of Cur-NAC mixtures can significantly improve the bioavailability of curcumin,and lead to significant differences in brain tissue distribution.

Complications of cervical artificial disc replacement / 中国骨伤

Cervical artificial disc replacement (CADR) as a new method for the treatment of cervical spondylosis, is becoming a basic and clinical research. Compared with the anterior cervical discectomy and fusion (ACDF), the biggest difference of CADR lies in the reconstruction of the cervical vertebra height and physiological curvature, retaining the spinal physiological function maximally and reducing the degenerative changes in adjacent segments. A large number of clinical investigation have suggested that ACDR can become an operation method to replace the ACDF. However, the complications and the problems of prosthesis itself are gradually exposed, such as that the prosthesis, can't completely simulate the biological effects of human intervertebral disc, the other factors and including the operation methods and prosthesis itself. At the same time, the problem that how to prevent complications and problems is required to be solved. Whether, the effect of CADR on the activity of the operation segment, and the prevention of adjacent segment degeneration can be guaranteed for a long time has drawn more and more attention from scholars.