Animals
Female and male SD rats (body weight 200-250 g) were supplied by the Center of Experimental Animals of Sichuan Academy of Chinese Medicine Sciences (eligibility certification no. SCXK (chuan) 2013-19). The rats were maintained under standard conditions with a 12 h:12 h light–dark cycle in a temperature- and humidity-controlled environment. The rats were provided food and water ad libudum. All animal experiments were performed in accordance with the guidelines of the Ethical Committee for the Care and Welfare of Laboratory Animals from the Sichuan province government.