2.2. Animals

The experiments were performed using 8-week-old male Sprague Dawley (SD) rats, which were obtained from the Medical Laboratory Animal Center of Guangxi Medical University, China (using number SCXK-Gui-2009-0002). The body weights of the rats were 150~180 g. At least 3 animals were needed for the experiment. The animal studies were performed in the Animal Research Center at Guangxi University of Chinese Medicine (Nanning, Guangxi) and approved by the Institutional Animal Ethics Committee of Guangxi University of Chinese Medicine, China. All authors ensured that all experiments were performed in accordance with the approved guidelines and regulations. All animals were maintained under standard conditions (22°C and 12 h light/dark cycles) for further experiments.