ABSTRACT
Objective: To investigate the chemical constituents in the stems of Ilex cornuta and the ability of scavenging free radicals of compounds 1-9. Methods: The compounds were isolated and purified by silica gel, medium pressure column chromatography, and semi-preparative liquid chromatography, and their structures were elucidated by chemical properties and spectroscopic analyses. The antifreeradical efficiency of compounds 1-9 was evaluated by DPPH radical scavenging assay. Results: Fifteen compounds were isolated and their structures were identified as isochlorogenic acid B (1), 3,4,5-tricaffeoylquinic acid (2), 4,5-di-O-caffeoyl quinic acid methyl ester (3), 3,4-di-O-caffeoyl quinicacid methyl ester (4), 3,5-di-O-caffeoyl quinicacid methyl ester (5), 3,4,5-tri-O-caffeoyl quinic acid methyl ester (6), 3,5-dimethoxy-4-hydroxybenzaldehyde (7), ethyl gallate (8), dihydrosyringenin (9), 2,6-dimethoxy-1,4-benzoquinone (10), arctigenin (11), 1-O-(vanillic acid)-6-O-(3″, 5″-dimethoxy-galloyl)-β-D-glycoside (12), (+)-1-hydroxypinoresinol-1-O-β-D-glucopyranoside (13), (+)-(7S,8S)-syringylglycerol 8-O-β-D-glucopyranoside (14), and schaftoside (15). Compounds 1-7 had good antifreeradical efficiency. Conclusion: Compounds 6,8-10,14, and 15 are obtained from the plants of Ilex L. the first time, and compounds 2,7,11, and 12 are obtained from this plant for the first time. Compounds 1-6 have good antifreeradical efficiency.
ABSTRACT
BACKGROUND: 1-Methyl-4-phenylpyridinium (MPP+) causes a neuronal cell injury that is similar to the findings observed in Parkinson's disease. Caffeoylquinic acid derivatives have demonstrated anti-oxidant and anti-inflammatory effects. Nevertheless, the effect of 3,4,5-tricaffeoylquinic acid (3,4,5-triCQA) on the neuronal cell death due to exposure of parkinsonian toxin MPP+ remains unclear. METHODS: Using differentiated PC12 cells, the preventive effect of 3,4,5-triCQA on the MPP+-induced cell death in relation to apoptotic process was examined. RESULTS: MPP+ induced a decrease in Bid, Bcl-2 and survivin protein levels, increase in Bax levels, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases (-8, -9 and -3), cleavage of PARP-1, and an increase in the tumor suppressor p53 levels. 3,4,5-Tricaffeoylquinic acid attenuated the MPP+-induced changes in the apoptosis-related protein levels, formation of reactive oxygen species, depletion of GSH, nuclear damage and cell death. 3,4,5-Tricaffeoylquinic acid attenuated another parkinsonian neurotoxin rotenone-induced cell death. CONCLUSIONS: 3,4,5-Tricaffeoylquinic acid may attenuate the MPP+-induced apoptosis in PC12 cells by suppressing the activation of the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The preventive effect seems to be ascribed to its inhibitory effect on the formation of reactive oxygen species and depletion of GSH.