ABSTRACT
<p><b>OBJECTIVE</b>To study whether Danggui Shaoyao Powder (DSP) is by way of improving pineal function to realize its anti-aging effects.</p><p><b>METHODS</b>Forty aged rats were randomly divided into the sham operated group (A), the pinealectomized group (B), the sham medicated group (C), the pinealectomized and medicated group (D). The medication given was gastric perfusion of DSP for 3 weeks. Learning and memory ability of rats was observed using Morris water maze and the serum melatonin (MLT) concentration of the rats was measured by radio-immunoassay.</p><p><b>RESULTS</b>The average escape latency in Group B was significantly longer than that in other groups (P <0.05). The times of passing through the platform and the percentage of swimming distance in Group C were significantly higher than those in other groups (P <0.05). The serum MLT was higher at daytime than at night in Group C and D (P <0.05); that at daytime in Group C was higher than Group A (P <0.05) and also higher in Group D than Group B; that at daytime was higher in Group C than Group D; that at night markedly decreased in Group D as compared with Group B (P <0.05).</p><p><b>CONCLUSION</b>DSP could increase the melatonin secretion and improve learning and memory ability. Since its effects reduced after pinealectomy, it could be deduced that improving pineal function should be one of the action mechanisms for anti-aging.</p>