Neuroprotective effects of Sesame seed on in vitro and in vivo ischemia models
Sesame seed (seeds of Sesamum indicum L.) is one of the most important oilseed crops in the world. It is used as a traditional Korean medicine for tonifying Yan and as anti-aging. These traditional medical facts have been proved by various pharmacological researches on antioxidant, anti-mutagenic, anti cancer and hypo-cholesterolemic effects. The purpose of the current study is to investigate whether sesame seed protects against neuronal damage in in vitro and in vivo ischemia models. Sesame seeds were defatted 4 times with n-hexane to obtain defatted sesame flour and then extracted with 80% MeOH to obtain a crude extract (FS). The crude extract was fractionated with a C18 silica gel column eluted by water and MeOH to obtain five different sub-fractions. In vitro ischemia was induced by oxygen-glucose deprivation (OGD, 4h deprivation and 24h reperfusion) in PC12 cell line and cell damage was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. In vivo ischemia was induced by middle cerebral artery occlusion (MCAo, 120min occlusion and 24h reperfusion) and infract volume (%) was measured by triphenyltetrazolium chloride (TTC) staining. All samples (10µg/ml) treated at 30min before OGD showed neuroprotective effects. Polar fractions were more effective than non polar fractions. Oral administration of FS and FS1 300mg/kg twice at 0 and 120min after ischemia showed about 30% of neuroprotective effects on MCAo in rats. Up to now the active components of sesame seed have been supposed to be non-polar lignans like sesamin and sesamolin. However, our results indicated that polar compounds might also be effective.
Acknowledgements: This research was supported by 2nd Stage of Brain Korea 21 Project (Ministry of Education, Korea) and a grant (Code No. 2007101033050) of the Rural Development Administration, Republic of Korea.
References: 1. Namiki, M. (1995) Food Research International, 11:281–329.
2. Rolis, C.H. et al. (2003) Journal of Neuroscience Research 74: 123–133.
3. Longa, E.Z. et al. (1989) Stroke 20: 84–91.