Abstract:Objective To investigate the mechanism of water extract of Zuogui Decoction in delaying senescence of rats with kidney Yin deficiency. Methods Sprague-Dawley rats were randomly divided into normal group, model group, and high-, middle-, and low-dose Zuogui Decoction groups. The rats in the model group were given thyroxine suspension 150 mg/kg every day by gavage, and those in the high-, middle-, and low-dose Zuogui Decoction groups were given water extract of Zuogui Decoction at a dose of 31, 20.67, and 13.78 g/(kg·d), respectively, by gavage. The course of treatment was 7 consecutive days. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), creatinine (Cr), blood urea nitrogen (BUN), cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP) were measured, and cAMP/cGMP ratio was calculated. Results Compared with the model group, the high-, middle-, and low-dose Zuogui Decoction groups had a significant reduction in the serum level of cAMP (P<0.05); the three Zuogui Decoction groups had no significant change in the level of cGMP, with a significant reduction in cAMP/cGMP ratio (P<0.05). Compared with the model group, the middle- and high-dose Zuogui Decoction groups had significant increases in the serum levels of SOD, CAT, and GSH-Px (P<0.05) and a significant reduction in MDA level (P<0.05). Compared with the model group, the low-, middle-, and high-dose Zuogui Decoction groups had significant reductions in the serum levels of Cr and BUN (P<0.05). Conclusion Zuogui Decoction can delay senescence of rats with kidney Yin deficiency by exerting an antioxidant effect.