Ginseng (Panax ginseng C.A. MEYER, Araliaceae), which contains protopanaxadiol-type and protopanaxatriol-type ginsenosides, has been used for inflammation, fatigue, stress, and tumor in Asian countries. Orally administered ginsenosides are metabolized to their aglycones 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT) by gut microbiota. However, their anti-fatigue effects have not been studied thoroughly. Therefore, we investigated the anti-fatigue activities of PPD and PPT in mice, using the weightloaded swimming (WLS) and the rota-rod tests. Ginseng water extract (GW), ginseng saponin fraction (GWS) and ginseng polysaccharide fraction (GWP) at concentrations of 50 and 100 mg/kg and PPD and PPT at 5 and 10 mg/kg were orally administered to mice once daily for 5 d. GW, GWS, and PPT significantly increased the WLS time, however, GWP and PPD did not cause any significant change. PPT induced the most significant increase in WLS time. PPD (10 mg/kg) and PPT (5 and 10 mg/kg) inhibited the WLS-induced increase in corticosterone, lactate, lactate dehydrogenase (LDH), and creatinine levels as well as the reduction in glucose level. PPT increased the riding time in the rota-rod test, and also inhibited corticosterone, lactate, and creatinine levels. These findings suggest that the anti-fatigue effect of ginseng may be attributable to its saponins, particularly PPT, rather than to its polysaccharides.
Key words Panax ginseng; 20(S)-protopanaxadiol; 20(S)-protopanaxatriol; fatigueFatigue is described as the lack of energy and motivation to initiate and sustain voluntary physical and mental activities.1) Physical fatigue is the transient inability of a muscle to maintain physical performance and is made more severe by physical stress. Mental fatigue is a transient decrease in cognitive performance. Most cases of fatigue may be attributed to lifestyle factors such as alcohol abuse and excessive physical activity, medical conditions such as multiple sclerosis and Parkinson's disease, or psychological problems such as anxiety and stress. Therefore, natural products including ginseng have been studied with the aim of developing anti-fatigue drugs to improve athletic ability, delay fatigue, and enhance the elimination of fatigue in humans. [2][3][4][5][6] Ginseng (the root of Panax ginseng C.A. MEYER, Araliaceae) has been widely used as a traditional Chinese medicine for enhancing body strength, recovering physical balance, and stimulating metabolic function in Asian countries. It contains various active constituents such as ginsenosides, polysaccharides, polyacetylenes, phenolic compounds, and peptides.
7)Of constituents, ginsenosides have been reported to show biological activities, including anti-inflammatory, anti-fatigue, anti-stress, and anti-tumor activities. [8][9][10][11][12] The ginsenosides are classified as protopanaxadiols or protopanaxatriols. Orally administered protopanaxadiol-type and protopanaxatriol-type ginsenosides are metabolized to 20(S)-protopanaxadiol (PPD) via compound K and 20(S)-protopanax...