| Background and Objective Borneol has been used combined with other Chinese material medica in clinic to treat some brain disorders.And many experimental study data indicated that Borneol can increase blood-brain barrier(BBB) permeability of some kinds of substances include some medicine,and has neuroprotective effects combined with other Chinese material medica .But so far the mechanism is not well known.The purpose of the present study was to observe the effects of Borneol to a BBB in vitro model,explore the mechanism that Borneol increase the permeability of other substances through the BBB.And explore the neuroprotective effects and mechanism of Borneol or combined with Salvianolic acid B(SalB) extracted from Chinese material medica DANSHEN(Radix salviae Miliorrhizae) and saponins of Panax notoginseng(PNS) extracted from SANQI (Radix Notoginseng) to ischemia/reperfusion rats.Methods In in vitro study, rat brain microvessel endothelial cells (BMEC) and astrocytes (AC) are respectively isolated and purified, an in vitro BBB model was established use co-culturing method which BMEC was seeded on the upper surface of 1 -um pore polycarbonate filter of cell inserts(BD,France), .and AC on the under surface allowing glial processes to contact the basal surface of the endothelium or its basal lumina. Transendothelial electrical resistance (TEER), y -glutamyl transpeptidase (Y ~GT) and alkaline phosphatase (ALP) activity of the BBB, immunohistochemistry staining of ZO-1, expression of mdrla mRNA are act as the evaluating criterion of the BBB model. The effects of Borneol independently or combined with SalB to the BBB are also investigated. In in vivo study, 2 hours of Middle Cerebral Artery Occlusion model in male Wistar rats was established by Intraluminal Suture method and reperfused 24,48 and 72 hours. Borneol, SalB/PNS mixture and the mixture of the three was administrated orally respectively. Rats were sacrificed at 24,48 and 72 hours of reperfusion. The inducing effects of neurotrophic facto^s(NGF^ BDNF^ GDNF^ bFGF, VEGF) in the injured brain hemisphere by Borneol or combined with SalB and PNSwere observed use immunohistochemistry staining and RT-PCR method.Results 1. The BMEC and AC are isolated and purified, in vitro BBB model was established by means of co-culturing BMEC and AC use porous filter. TEER and Y -GT,ALP activity measurement of the BBB model indicate that the model has the BBB property and the property was maintained better than that of endothelium monolayer. 2. Borneol couldn't change the TEER in vitro BBB model within 60 minutes and after 24 hours in 5ug/ml concentration. 3. Borneol combined with SalB can significantly down-regulated the mdrla mRNA expression in BMEC of the in vitro BBB model, neither Borneol nor SalB has that effect. The in vivo study indicated that Borneol orally can induce the expression of NGF, BDNF,GDNF, bFGF and VEGF mRNA at 72h of reperfusion. Borneol administrated orally combined with SalB and PNS can induce the expression of GDNF,VEGF at 72h of reperfusion,and can enhance the expression of bFGF, BDNF> NGFmRNA at 48h of reperfusion.Conclusions: 1. Borneol couldn't induce the opening of tight junction in BBB. 2. Borneol used combined with SalB can significantly downregulated mdrla mRNA expression in BMEC of the in vitro BBB model, which may be one of the mechanisms of Borneol increased other substances through the BBB. 3. Borneol or combined with SalB and PNS can induce the expression of endogenous neurotrophic factors . Borneol can induce endogenous neuroprotective factors at the time of 72h after reperfusion to promote the repair of the injured brain, while combined with SalB and PNS, it can enhance the anti-injury ability at the time of 48h after reperfusion as well.This may be one of the neuroprotec mechanisms of bornoel ,SalB and PNS.
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