## 2 Results and Discussion
### SBP-III-3 Increased Liver and Muscle Glycogens
#### 2.4.3 SBP-III-3 Enhanced the Antioxidant Enzymes and Decreased the Malondialdehydedehyde (MDA)  
Growing evidence indicates that reactive oxygen species (ROS) are responsible for exercise-induced protein oxidation, and contribute strongly to muscle fatigue [35]. ROS, including free radicals such as peroxyl radicals (ROO\(\bullet\)), hydroxyl radicals (HO\(\bullet\)), nitric oxide radicals (NO\(\bullet\)), and superoxide radicals (O\({}_{2}^{-}\bullet\)), are physiological metabolites formed during aerobic life as a result of the metabolism of oxygen [5]. Under normal conditions, ROS are effectively eliminated by antioxidant defense systems, such as antioxidant enzymes and non-enzymatic factors. However, the balance between the generation and elimination of ROS is broken under pathological conditions, as a result of these events; bio-macromolecules are damaged by ROS-induced oxidative stress [36]. Muscle cells contain complex endogenous cellular defense mechanisms to clear up ROS to protect the body from exercise-induced oxidative injuries and DNA damages. For example: GSH-Px accelerates the reaction between H\({}_{2}\)O\({}_{2}\) and glutathione (GSH) and converts them into H\({}_{2}\)O and oxidized GSH, SOD scavenges the O\({}_{2}^{-}\bullet\), and CAT decomposes the HO\(\bullet\). Thus, the improvement in the activities of these defense mechanisms can help to fight against fatigue. Therefore, the present study investigated the activity of GSH-Px, SOD, and CAT to evaluate the anti-fatigue effects of SBP-III-3 on mice. As shown in Table 2, the SOD activities of SBP-III-3-HG and SBP-III-3-MG significantly increased by 44.2% and 15.7%, respectively, compared to the NCG (_p_ < 0.05), while the SOD activity of SBP-III-3-LG increased by 4.2% and was without statistical significance compared to that of the NCG (_p_ > 0.05). Moreover, the SOD activities between SBP-III-3-HG and SBP-MG showed a statistical difference (_p_ < 0.01). The activities of GSH-Px and CAT showed a similar trend in the SOD activities. The GSH-Px activities of mice treated with SBP-III-3-HG, SBP-III-3-MG, and SBP-III-3-LG increased by 240.5%, 136.1%, and 66.3%, respectively, compared to that of the NCG. In addition, the CAT activities of SBP-III-3-HG, SBP-III-3-MG, and SBP-III-3-LGsignificantly increased by 159.5%, 87.9% and 74.7%, respectively, compared to that of the NCG (_p_ < 0.05 or \(p\) < 0.01). These results suggested that SBP-III-3 could exert its anti-fatigue effects by enhancing the activities of antioxidant enzymes for eliminating the superfluous free radicals in organism.  
Fatigue results in the release of ROS which cause lipid peroxidation of membrane structure. MDA, an oxidative degradation product of cell membrane lipids, is generally considered as an indicator of lipid peroxidation. In fatigue conditions, MDA level is increased and accompanied with a decrease in levels of the antioxidant enzymes GSH-Px and SOD [37]. Therefore, MDA is used as a biomarker to measure the level of oxidative stress in an organism. As shown in Table 2, the MDA levels in mice liver and plasma were decreased with the increase of SBP-III-3 dosage. In mice liver, the MDA levels of SBP-III-3-HG, SBP-III-3-MG, and SBP-III-3-LG significantly decreased by 53.6%, 49.9%, and 28.0%, respectively, compared to that of the NCG (_p_ < 0.01). In addition, the MDA levels of SBP-III-3-HG, SBP-III-3-MG, and SBP-III-3-LG significantly lessen by 52.3%, 48.5%, and 41.0%, respectively, compared to that of the NCG in mice plasma (_p_ < 0.01). The present data were in line with the decrease in levels of the antioxidant enzymes GSH-Px and SOD. These results indicated that SBP-III-3 might induce the MDA level by inhibiting lipid peroxidation of cell membrane lipids.