title: Antioxidant synergism between ethanolic Centella asiatica extracts and α-tocopherol in model systems.
abstract: The synergistic antioxidant effects of ethanolic extracts of Centella asiatica (CE), and α-tocopherol have been studied. The types of interactions exhibited by CE and α-tocopherol combined at different ratios were measured using three assays: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical-scavenging capacity, the β-carotene bleaching system and liposome peroxidation assays. Fixed-fraction isobolographic analysis was used to detect any inducement of the antioxidant activity compared with the individual activities of CE and α-tocopherol. Of all synergistic combinations of CE and α-tocopherol, only fraction 2/3 showed the synergistic combination that fits well in three different assays and can be explained by the regeneration of α-tocopherol by CE despite the interaction effect of β-carotene present in the analytical assay. This phenomenon involved complex interactions between CE and α-tocopherol to exhibit different degrees of interactions that eventually increased antioxidant activity.
authors: Department of Food Technology, Faculty of Food Science & Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors: Yin Yin
authors: YY
authors: Thoo
authors: Faridah
authors: F
authors: Abas
authors: Oi-Ming
authors: OM
authors: Lai
authors: Chun Wai
authors: CW
authors: Ho
authors: Jie
authors: J
authors: Yin
authors: Rikke V
authors: RV
authors: Hedegaard
authors: Leif H
authors: LH
authors: Skibsted
authors: Chin Ping
authors: CP
authors: Tan
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D028041:Centella / Q000737:chemistry*; D004357:Drug Synergism; D015227:Lipid Peroxidation / Q000187:drug effects; D008954:Models, Biological; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D024502:alpha-Tocopherol