The preparation of electrophoretic microcolumn and its application to the electrophoretic separation of amino acids with a 2-mm I.D. fused-silica microcolumn packed with uniform quartz microncrystal prepared by hydrothermal synthesis are reported. With 1.5 mmol/L disodium phosphate buffer solution (pH 11.5) containing 30% (V/V) methanol, the tryptophan, phenylalanine and tyrosine were separated by the microcolumn electrophoresis and detected by an UV spectrophotometer without derivatization. The limits of detection were 0.038, 0.21 and 0.20 mol/L, respectively. The separation efficiency of tryptophan was 4.4×104 plates/m. The sample capacity of the electrophoretic microcolumn achieved 35 μL. The precisions of the microcolumn electrophoresis were satisfactory. The thermal effects of the electrophoretic microcolumn that without packing, packed with 360 μm quartz sand and with 9 μm length quartz microncrystal were discussed, respectively. It was found that the electrophoretic microcolumn packed with quartz microncrystal was able to inhibit Joule heat, increase sample capacity and enhance detection sensitivity. The microcolumn electrophoresis is one of the high-performance separation techniques for an in-situ, real-time and portable electrokinetic flow analysis system.

Objective To explore the neuroprotective effect of curcumin(Cur)on Parkinson's disease model and its mechanism.Methods Sprague-Dawley rats were randomly divided into the control(CON)group,the model(PD)group,and the low-,medium-,and highdose curcumin(Cur)groups,with ten rats in each group.Lipopolysaccharide was injected into the substantia nigra to establish a Parkinson's disease model.Rats in the Cur groups were administered Cur intraperitoneally at doses of 20 mg/kg,40 mg/kg,and 60 mg/kg daily for 21 days.α-synuclein(α-syn),nuclear transcription factor κB proteins(NF-κB,IKBα,p-NF-κB,p-IKBα)and the activation levels of astrocytes were detected in rat brain tissues by immunohistochemistry(IHC).mRNA levels of pro-inflammatory cytokines(TNF-α,IL-β,IFN-γ,IL-6),inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),NADPH oxidase complex(gp47phox,gp91phox,gp67phox),and apoptosis-related factors(Bax,Bcl-2,Caspase-3,and Caspase-9)were measured by quantitative reverse transcription polymerase chain reaction(qRT-PCR).The rotarod and pole climbing tests were used to evaluate the motor coordination of the rats.Results Compared to the CON group,PD rats showed significantly increased levels of α-syn,p-NF-κB,p-IKBα proteins,activation of astrocytes,TNF-α,IL-β,IFN-γ,IL-6,iNOS,COX-2,Bax,Caspase-3,Caspase-9,gp47phox,gp91phox and gp67phox mRNA levels(P<0.05);while the Bcl-2 level was significantly decreased(P<0.05).Compared with the PD group,the medium-and high-dose Cur treatment groups inhibited the aggregation of α-syn protein,reduced the activation of the NF-κB pathway,and the expression of inflammatory and apoptosis-related factors(P<0.05).Moreover,medium and high doses of Cur significantly improved the motor coordination in rats,and compared with the PD group,the performance of rotarod and pole climbing tests was significantly improved(P<0.05).Conclusion cur may inhibit the aggregation of α-syn by suppressing neuroinflammation and oxidative stress responses,thereby improving motor coordination in Parkinson's disease rats and exerting neuroprotective effects.