ABSTRACT
Objective To investigate the effect of phenolic alkaloids from Menispermum dauricum( PAMd)on the mRNA expression of the glutamate transporter EAAC1 in hippocampal neurons of rats subjected to focal cerebral ischemia and to elucidate its neuroprotective mechanisms. Methods A total of 42 Sprague Dawley(SD)rats were randomly divided into three groups:sham group,model control group,and PAMd(10 mg·kg-1 ,i.g)group(n = 14 each).The focal cerebral ischemia model of rat was induced by the middle cerebral artery occlusion( MCAO). The 2,3,5-triphenyltetrazolium chloride( TTC) staining was applied to measure the cerebral infarct size and the reverse transcriptase-polymerase chain reaction(RT-PCR)assay to detect EAAC1 mRNA expression in hippocampal neurons. Results After 24 h ischemia,the cerebral infarct volumes were (0.0±0.0)%,(35.3±2.9)% and(21.3±3.8)% in sham group,model control group and PAMd group,respectively(P<0.05). The relative expression levels of EAAC1 mRNA were 0.97±0.04,2.46±0.13,and 1.91±0.15 in the three groups,respectively (P<0. 05). Conclusion PAMd may protect against cerebral ischemia by up-regulating EAAC1 mRNA expression and alleviating the excitotoxicity of glutamic acid.
ABSTRACT
Objective To compare the antioxidant activity between phenolic and nonphenolic alkaloids in Nelumbo Nucifera Gaertn.in vitro. Methods DPPH, ABTS, hydroxyl radical scavenging, super oxygen anion from oxidation, reducing power and beta carotene bleaching test methods were used to evaluate the antioxidant activity of the alkaloids. Results Half maximalinhibitory concentration ( IC50 ) of DPPH among total alkaloid, phenolic alkaloids and nonphenolic alkaloids was 21.89, 27.10 and 32.87 μg·mL-1 , respectively;IC50 of ABTS free radicals was 14.25, 20.55, 25.94μg·mL-1;The hydroxyl radical scavenging IC50 was 0.03, 0.03, 0.08 μg·mL-1; The auto-oxidation rate of super oxygen was 8.72×10-4, 5.87×10-4, 6.68× 10-4;The total alkaloid had the best reducing power, while the non-phennolic alakloids had the worst; Lipid inhibition rate of three alkaloids were 89.63%, 85.85% and 83.78% respectively. Conclusion Phenolic alkaloids are better than non-phenolic alkaloids in hydroxyl radical scavenging, reducing power and anti-lipid peroxidation, resulting in a promising prospect.