Intravenous transplantation of human umbilical blood mesenchymal stem cells and Baicalin for treating hypoxic-ischemic brain damage in neonatal rats

Xiaohua YAN; Xin XU; Qiwen CHEN; Tao HUANG; Rangxian GUAN

ABSTRACT

BACKGROUND:

Present studies have verified that Baicalin has protective effects on various brain damage in the nervous system.

OBJECTIVE:

To study the possibility of intravenous transplantation of human umbilical blood mesenchymal stem cells (hUBMSCs) and Baicalin after hypoxic-ischemic brain damage (HIBD) in neonatal rats.DESIGN, TIME AND

SETTING:

The randomized controlled animal study was performed at the Laboratory of the Department of Neurology, First Affiliated Hospital, Nanchang University from February 2007 to January 2008.MATERIALS Totally 10 umbilical blood samples from healthy full-term pregnant women were obtained from the Department of Obstetrics, First Affiliated Hospital, Nanchang University. A total of 85 clean Sprague Dawley neonatal rats aged 7 days were randomly assigned to a normal control group (n=15), a model group (n =20), a cell transplantation group (n =25), a cell transplantation + Baicalin group (n =25).

METHODS:

The umbilical blood mononuclear cells were isolated by the gelatin sedimentation + density gradient centrifugation method, and amplified in vitro. Cells at the fifth passage were used for transplantation. Cells were labeled by DAPI at 6-12 hours before use. Neonatal rats in the model, cell transplantation and cell transplantation + Baicalin groups were used to establish HIBD models. Rats in the blank control group were left intact. At 2, 3,4, 5 weeks following model induction, rats in the cell transplantation and cell transplantation + Baicalin groups were injected with DAPI-labeled hUBMSCs (5-10 μL/g) via caudal vein at the density of 1 ×10~9/L. From the first day of transplantation, rats in the cell transplantation + Baicalin group were injected with 120 mg/kg Baicalin via intraperitoneal injection, once a day, for three successive days.MAIN OUTCOME

MEASURES:

The following parameters were measured brain tissue lesion, DAPI-positive cell number, location of hUBMSCs following transplantation.

RESULTS:

Lesion rate of brain tissue was significantly lower in the cell transplantation + Baicalin group compared with the model and cell transplantation groups at 4 weeks following transplantation (P < 0.05). Compared with the cell transplantation group,DAPI-positive cell number was significantly increased in the cell transplantation + Baicalin group at 1, 2, 4 weeks (P < 0.01). From the 3~(rd) week following model induction, abundant DAPI-labeled cells were found surrounding the lesion site, without obvious boundary integrated with the host brain. Few DAPI-positive hUBMSCs were found in non-ischemic region. At 4 and 5 weeks following model induction, DAPI-positive cells were significantly decreased in the lesion site.

CONCLUSION:

The third week following HIBD is an optimal time for cell transplantation. Baicalin can make a large number of hUBMSCs across the blood-brain barrier to distribute and scatter around the disease focus integrated with host brain tissue.