The Antioxidant Cerebralcare Granule® Attenuates Cerebral Microcirculatory Disturbance During Ischemia-Reperfusion Injury

Abstract

Cerebralcare Granule (CG) is a compound Chinese medicine used for treatment of headache and dizziness associated with cerebrovascular diseases. To clarify the mechanism underlying the clinical outcome of CG, this study investigated the effects of CG on the structure and function of cerebral microvasculature during I/R injury. A total of 138 Mongolian gerbils were included and divided into four groups, each composed of 36 or 30 animals, for evaluating various parameters of concern. A skull window was prepared for microcirculatory observation in animals, which were subjected to I/R with or without pretreatment with CG (0.4 or 0.8 g/kg). The velocity of red blood cells in the venules was observed by a high-speed video camera system, along with intravital confocal microscopic measurements of microvascular diameters, adherent leukocytes, and albumin leakage in the brain cortex. Changes in the fluorescence intensity of dihydrorhodamine 123 in cerebral microvessels and malondialdehyde level in the cortex were measured. The ultrastructure of the microvessels in the cerebral cortex was analyzed using both transmission and scanning electron microscopy. In addition, cerebral blood flow was monitored using the laser Doppler imaging technique. Pretreatment with CG (0.4 or 0.8 g/kg) significantly alleviated I/R injury-induced disorders in cerebral microvasculature, as evidenced by the data observed at 60 min of reperfusion wherein the values in CG (0.4 g/kg) pretreatment group, CG (0.8 g/kg) pretreatment group, and I/R group were 2.43 +/- 0.24, 2.28 +/- 0.18, and 6.00 +/- 0.35 for leukocyte adhesion, 2.51 +/- 0.40, 2.33 +/- 0.29, and 4.77 +/- 0.24 for albumin leakage, 7.06 +/- 0.81, 5.93 +/- 0.42, and 28.38 +/- 2.70 for dihydrorhodamine 123 fluorescence intensity in cerebral microvessels, 16.35 +/- 0.52, 14.34 +/- 0.68, and 21.46 +/- 0.71 for malondialdehyde level in the cortex, and 0.43 +/- 0.07, 0.46 +/- 0.02, and 0.17 +/- 0.08 for cerebral blood flow, respectively. I/R injury-elicited ultrastructural alterations in microvessels in cerebral cortex were also mitigated impressively by CG administration, manifested as attenuation of the reduced number of opening capillaries and the altered fine structures in endothelium, which were characterized by rough inner surface, increased intracellular vesicles, hypertrophy of digitations of intercellular contact, and swollen perivascular astroglial processes. Cerebralcare Granule is able to attenuate I/R injury-induced functional and structural changes in microvessels in the cerebral cortex of gerbils, an ability that is most likely correlated with its antioxidant potential.

Cerebralcare Granule®, a Chinese herb compound preparation, improves cerebral microcirculatory disorder and hippocampal CA1 neuron injury in gerbils after ischemia–reperfusion

“…For the animals in I/R group, cerebral ischemia was induced via occluding bilateral common carotid arteries for 30 min, and the occlusion was then released for reperfusion (Choki et al, 1984;Xu et al, 2009). The incision on the neck was closed and the animals were allowed to recover.…”

“…The cerebral microcirculation was observed using an upright intravital fluorescent microscopy (BX51WT, Olympus, Japan). Venules with diameter ranging from 30 to 50 m and length of 200 m were selected for study (Xu et al, 2009). One venule was selected in the cerebral cortex of each animal for evaluation of a microcirculatory variable and the values from six animals of a group were averaged.…”

“…CG was packed with aluminum foil composite (4 g/bag). The compound was dissolved in saline to a concentration of 80 mg/ml or 160 mg/ml before use (Xu et al, 2009).…”

“…The composed herbs were manufactured by dynamic cycle extraction and concentration through evaporating and spray drying, resulting in granules of CG as product. Pretreatment with CG has been demonstrated to prevent cerebral microcirculatory disturbance and inflammatory injury caused by ischemia-reperfusion (I/R) (Xu et al, 2009). However, preventive approach is feasible only when the occurrence of ischemia is predictable.…”

“…Compared with ischemia, the onset and progress of reperfusion can be better controlled, and drugs able to restrain the progress of reperfusion injury would be of great benefit to the stroke patients. Han et al (2008) and Xu et al (2009) The objective of the current study is to test the potential therapeutic effect of CG on I/R-induced cerebral microcirculatory disorders in a Mongolian gerbil model of global ischemia and reperfusion. We administrated CG 3 h after the onset of reperfusion and evaluated its effects on I/R-elicited insults in cerebral microcirculation and hippocampal CA1 neuron 5 days after reperfusion.…”