title: The antioxidant effects of garlic saponins protect PC12 cells from hypoxia-induced damage.
abstract: Hypoxia frequently occurs under several different cellular circumstances. Excess reactive oxygen species that are induced by hypoxia may result in cell injury and dysfunction. Recently, garlic has been found to possess some biological and pharmacological activities. The present study examined the effects of garlic saponins (GSP) on the survival of differentiated PC12 (dPC12) cells and the oxidative-antioxidant system. dPC12 cells were exposed to 2 % O2 in order to establish a neuronal insult model. Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction assay and lactate dehydrogenase (LDH) release assay. The expression of selected genes (catalase (CAT), p65 and neuron-specific class III β-tubulin) was evaluated by real-time PCR and immunoblot assays. CAT activity, malondialdehyde (MDA) and 8-hydroxy-deoxyguanosine (8-OH-dG) concentrations were also determined. The data showed that hypoxia dramatically damaged dPC12 cells, while treatment with approximately 5 × 10- 2-10 ng/ml GSP improved cell viability, decreased LDH leakage and caused the cells to maintain neuronal-like characteristics in hypoxia. The production of MDA and 8-OH-dG was attenuated by GSP. CAT activity in dPC12 cells pretreated with GSP was higher than that of the hypoxic control. Moreover, GSP up-regulated CAT expression and decreased the total protein expression as well as the nuclear expression of p65 in hypoxic cells. These data indicate that GSP has antioxidant properties that can protect dPC12 cells from hypoxia-induced damage, which may be related to the up-regulation of CAT expression and activity as well as a decrease in the expression and nucleus distribution of p65 through effects on redox-sensitive signalling pathways.
authors.affiliation: Department of High Altitude Military Hygiene, College of High Altitude Medicine, Third Military Medical University, Chongqing 400038, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Luo
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Wei-Gong
authors.initials: WG
authors.lastname: Liao
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Huang
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Gao
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D015687:Cell Hypoxia / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005737:Garlic / Q000737:chemistry*; D005786:Gene Expression Regulation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D016716:PC12 Cells; D018517:Plant Roots / Q000737:chemistry*; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012503:Saponins / Q000302:isolation & purification / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; C498145:Rela protein, rat; D012503:Saponins; D051996:Transcription Factor RelA; C488416:Tubb3 protein, rat; D014404:Tubulin; D008315:Malondialdehyde; D000080242:8-Hydroxy-2'-Deoxyguanosine; D002374:Catalase; D003849:Deoxyguanosine