The Role and Mechanism of Borneol to Open the Blood-Brain Barrier.

The blood-brain barrier (BBB) is the greatest challenge in the treatment of intracranial malignant tumors.

The aim of this study is to determine the role of borneol in opening the BBB and elucidate the underlying mechanisms.

Twenty Sprague-Dawley (SD) rats were randomized into borneol group intragastrically administered with 10% borneol corn oil (2 mL/kg) and control group. After 30 minutes, 2% Evans blue (4 mL/kg) was injected. Thirty minutes later, brain tissue was analyzed using the Evans blue standard curve. Another 40 SD rats were randomized into high-, medium-, and low-dose borneol groups and a control group. Each rat in the experimental groups was intragastrically administered with 10% borneol corn oil (2 mL/kg, 1.25 mL/kg, and 0.5 mL/kg, respectively). The control group was injected with corn oil of 1.25 mL/kg. After 30 minutes, the rats were killed, and the brain tissues were collected. The expression of occludin, occludens-1, nitric oxide synthase, P-glycoprotein, and intercellular cell adhesion molecule-1 (ICAM-1) was detected by immunohistochemy.

The concentration of Evans blue in the borneol group was higher than in the control group ( P < .05). The mean density of ICAM-1 expression was higher in the experimental group than in the control group ( P < .05). In contrast, significant differences of positive area and total density of ICAM-1 were shown only between the high-dose group and the control group ( P < .05).

Borneol can open the BBB, which might be related with the increased expression of ICAM-1.