Animals

Thirty male SPF Sprague-Dawley (SD) rats aged 4–5 weeks were prepared, with an average weight of about 120–130 g, all of which were purchased from Sibeifu Biotechnology Co., Ltd (licence No. SCXK Beijing 2016–0002, Beijing, China). The rats were raised in the SPF-grade animal room of Beijing University of Chinese Medicine in an environment with daily illumination of 10–12 h, indoor humidity of 55–60%, and temperature of 22–26 °C.

Firstly, animals were fed with deionized water and solid feed for 7 days’ adaptation. The experimental scheme was approved by the Experimental Animal Ethics Committee of Beijing University of Chinese Medicine (Ethical number: BUCM-4-2019091105-3064) and followed the guidelines for the ethical review of laboratory animal welfare People’s Republic of China National Standard GB/T 35892-2018.