Amylopectin is the anti-fatigue ingredient in glutinous rice

The anti-fatigue activities of glutinous rice (GR) and GR amylopectin (GRA) were investigated in mice by determining tissue glycogen, blood lactate dehydrogenase (LDH), and blood urea nitrogen (BUN) after the weight loaded forced swim test (WFST). GR and GRA were given by gavage at various doses of GR (7.5, 15, 30 g/kg body weight) and GRA (3.8, 7.5, 15 g/kg body weight) every day for 7 days, respectively. The results indicated that the hepatic glycogen levels significantly (P < 0.05) increased 26–44% and 35–60% and the muscle glycogen levels significantly (P < 0.05) increased 36–100% and 67–133% in GR and GRA treatment groups, compared with the negative control group. The GRA treatment groups also had significantly (P < 0.05) higher (9.1–20.3%) blood LDH levels. Meanwhile, the blood LDH activities in GR and GRA treatment groups had a significantly positive correlation with the hepatic glycogen levels (r = 0.978, P < 0.01). Moreover, except of the low-dose GR (7.5 g/kg body weight) supplemented group, mice in all other treatment groups had significantly (P < 0.05) lower (13–23%) BUN levels. Compared with the GR treatment groups, GRA treatment groups had similar or even higher anti-fatigue activities, which demonstrated that GRA might play the most important role on the anti-fatigue activities for GR.