Abstract: OBJECTIVE: To investigate the antioxidant property and potential ameliorating effective ingredients for high altitude-induced fatigue from Gansu Maxianhao(Pedicularis Kansuensis Maxim.).METHODS: Macroporous adsorptive resin combined with polyamide chromatographic column was used to obtain water extract(P1), high polar part(P2), iridoid glycosides part(P3) and phenylethanoid glycosides part(P4) of Gansu Maxianhao(Pedicularis Kansuensis Maxim.). Antioxidant activity of each part was investigated employing a series of in vitro models. Hematoxylin-eosin staining, analysis of blood biochemical parameters, along with molecular analyses examining oxidative stress makers,metabolite, metabolic enzyme and energy substance in liver, skeletal muscle and/or serum were further measured.RESULTS: The results showed phenylethanoid glycosides(Ph Gs) exhibited more effective with 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability,2-2-Azinbis(3-ehtylbenzothiazolin-6-sulfnic Acid)Diammonium Salt+scavenging activity, hydroxyl radical scavenging activity, reducing ability and antioxidant activity to varying extents. Under a hypobaric hypoxia attack in a hypobaric chamber(8000 m, 7 consecutive days), Ph Gs was administered to BALB/C mice at doses of 50, 200, 400 mg/kg and antifatigue property was evaluated using a swimming test at an altitude of 4000 m. The results showed that Ph Gs of Gansu Maxianhao(Pedicularis Kansuensis Maxim.) could significantly prolong the burden swimming time of mice, reduce the hypoxia-induced oxidative stress, remove the accumulated products of metabolism, improve the energy metabolism as well as improve preservation of endogenous glycogen stores.CONCLUSION: The ameliorating effect against altitude-induced fatigue of Ph Gs from Gansu Maxianhao(Pedicularis Kansuensis Maxim.) might come from the alleviation of oxidative stress, reduction of the adverse metabolic products, normalizing energy metabolism and increasing energy substances reserves. Ph Gs is a potential antioxidant and novel remedy for fatigue due to high-altitude hypoxia.

Key words: Pedicularis, Glycosides, Antioxidants, Fatigue, Hypoxia