Effect of APP17 peptide and jiunao yizhi capsule on expression of protein phosphatase 1 in hippocampus of aging mice induced by D-galactose

Yaping LEI; Shan LU; Yanjun CUI; Pengwen WANG; Shuli SHENG

ABSTRACT

BACKGROUND:

D-galactose-induced aging animal model is similar tohuman natural aging. Whether the expression of protein phosphatase-1(PP-1) in the brain of D-galactose-induced aging mice is related to cerebralaging process or not should be researched further.

OBJECTIVE:

To investigate the effect of the APP17 peptide and theliquid extract ofjiunao yizhi capsule on regulating the expression of PP-1 inhippocampal neurons of the aging mice induced by the D-galactose (D-gal).

DESIGN:

A random controlled study.

SETTING:

Department of Pathology, College of Basic Medical Sciences, Capital University of Medical Sciences and Beijing Research Laboratory forBrain Aging, Xuanwu Hospital of Capital University of Medical Sciences. MATERIALS The study was completed between July 2003 and July2004 in the Experimental Center of Capital University of Medical Sciences. Forty male Kunming mice (SPF grade) with a body mass fron 28 g to 32 gwere purchased from Chinese Academy of Medical Sciences Institute ofMaterial Medical.

METHODS:

Kunming mice were randomly divided into 5 groups control group, D-gal group, APP17 peptide treatment group, low dose herb treatment group, and high dose herb treatment group with 8 mice in each group. In Dgal group, APP17 peptide treatment group, low dose herb treatment group and high dose herb treatment group, galactose was injected subcutaneously (50 nmg/kg). Meanwhile, 0.1 mL normal saline containing 0.35 μg of APP17 peptide was injected subcutaneously into the mice in APP17 peptide treatment group, once a day for 3 months; liquid extract of jiunao yizhi capsule (provided by Beijing Chaoyangmen Hospital and Shanxi Quwo Traditional Medical Institute; the main component dangshen, baizhu, guijia and chuanshanjia, etc.) was perfused by stomach (0.3 g/kg and 1.0 g/kg respectively) in low dose herb treatment group and high dose herb treatment group, once a day. And equivalent normal saline was injected and perfused in the two control groups. After 3 months of survival, the mice were killed and their brains were cut into sections. The immunohistochemical staining of these sections was then performed with PP-1 antibody.MAIN OUTCOME

MEASURES:

The results of immunohistochemical staining analysis of PP-1.

RESULTS:

Forty mice entered the final analysis without any loss. PP-1 positive cells in the hippocampus were poorly stained in the D-gal mice. In contrast, PP-1 positive neurons were widely distributed in the hippocampus of those normal mice, the APP17 peptide-treated D-gal mice and the high liquid extract of raw herb-treated D-gal mice. These cells were darkly stained in cytoplasm. The unexpected result was that in the low liquid extract of raw herb-treated D-gal mice the number of PP-1 positive neurons did not increase to normal.

CONCLUSION:

The results demonstrated that the expression of PP-1 decreased in the hippocampus of D-gal mice. The APP17 and low dose liquid extract of raw herbs can regulate the distribution of PP-1 in the brain of D-gal mice and make them recover to normal situation.