2.2. Subjects

Male Sprague Dawley rats, weighing 200–230 g, aged 7-8 weeks, were purchased from the Experimental Center of Beijing Huafu Kang Co. Ltd. (license no. SCXK 2014-0004:11401300091361). Four rats were nourished in individual cages at the room, with controlled temperature (20–22°C) and humidity (40–60%), and were fostered on an alternative 12 h light/dark cycle in the Animal Experimental Center of Medical College of Jinan University SPF animal housing management (ethical number: 20181008-04). All rats were allowed to accommodate to laboratory conditions for 10 days before starting the experiments and were provided with food and water freely. All animal studies conformed to the Regulations of Experimental Animal Administration promulgated by the State Committee of Science and Technology of China on November 14, 1988.