Objective: To investigate the effect of Dihuang Yinzi on mitochondrial structure and function in central nerve of Alzheimer's disease (AD) rat model induced by intracerebroventricular injection of β-amyloid protein 1-42(Aβ1-42). Method: Totally 120 male rats were randomly distributed into 6 groups:shame operation group

AD model group

positive drug control group (Aricept

0.5 mg·kg-1)

high-

moderate-and low-dosage Dihuang Yinzi groups(3

1.5

0.75 g·kg-1). Except for sham operation rats

all the other rats were injected with maturated Aβ1-42 at left lateral ventricles to establish AD rat model. After administrated with Dihuang Yinzi via intragastric gavage for 30 days

Morris water maze and step-down test were performed to evaluate the effect of Dihuang Yinzi on the learning and memory ability of AD rats; the levels of adenosine triphosphate (ATP)

adenosine diphosphate (ADP)

adenosine monophosphate (AMP) and creatine phosphocreatine (PCr) were determined with high performance liquid chromatography (HPLC)

then energy charge (EC) was calculated; the enzymatic activity of pyruvate dehydrogenase (PDH) and α-ketoglurate dehydrogenase (KGDH)

mitochondria swelling and mitochondrial membrane potential were evaluated with spectrophotometry. Result: It was found that Dihuang Yinzi could improve the learning and memory ability of AD rats significantly

and promote the levels of ATP

ADP

PCr and EC (P<0.05

P<0.01). The key ezymes

PDH and KGDH

in tricarboxylic acid cycle were activated (P<0.05

P<0.01)

the mitochondria swelling was mitigated(P<0.05

P<0.01)

and the mitochondrial membrane potential were elevated (P<0.05

P<0.01) in AD rat with Dihuang Yinzi treatment. Conclusion: It was demonstrated that Dihuang Yinzi could protect the structure and function of mitochondria in central nerve of AD rats

improve the energy metabolism as well as the learning and memory ability in AD rats.