BALB/c nude male mice, aged 4–6 weeks and weighing 18–20 g, were purchased from Sino-British SIPPR/BK lab Animal Co., Ltd (Shanghai, China, license No. SCXK 2008–0016). All animal protocols were approved by the Institutional Animal Use and Care Committee of Shanghai University of Traditional Chinese Medicine. Breeding conditions of the SPF Animal Laboratory were: free access to food and water, ventilation, humidity at 50–65%, temperature at 22–24°C, 12 h of light/dark. The animal laboratory abided by related regulations of the Animal Ethics Committee.