Therapeutic effect of Angelica injection in Parkinsonian rats and the mechanisms

Abstract

Objective To observe the therapeutic effect of Angelica injection in Parkinsonian rats and explore its possible mechanisms. Methods Rat models of Parkinson disease (PD) were established by 6-OHDA injection into the right substantia nigra pars compacta (SNc) and confirmed by weeldy apomorphine-induced rotation test, and the rats with saline injection served as the saline control group (n=8). After the second apomorphine test, the PD rats received daily intraperitoncal Angelica injection at low (12.5%, n=8) or high dose (25%, n=8), or had only saline injection (PD model group, n=8). Another 8 untreated rats were used as the blank control group. After 4 weeks of treatment, the rats were perfused with paraformaldehyde (4%) and the brains were taken for immunohistochemical detection of TH and CD40 expressions in the SNc using SABC method. Results Compared with the rats in the saline control and low-dose Angelica injection groups, those in the high-dose Angelica injection group showed significantly slowed rotation after a 3-week treatment (P<0.05), with further slowing down at 4 weeks (P<0.01). At the fourth week of treatment with high-dose Angelica injection, a significant increase in the numbers of PH- and CD40-positive neurons was found in the right SNc as compared with those in the low-dose Angelica injection group and the PD model group (P<0.01). No CD40-positive microglia were found in the SNc in the saline control or the blank control groups, and the Angelica-treated groups and the PD model group showed no significant difference in the count of CD40-positive microglia in the SNc. Conclusion Angelica injection produces obvious therapeutic effect in Parkinsonian rats possibly by increasing CD40 expression in the neurons. Key words: Parkinson disease; Angelica injection