[Borneol promotes oral absorption and penetration into brain of puerarin and catalpol].

To investigate the effect of borneol on the oral absorption and penetration into brain of puerarin and catalpol from cell level and animal level, and screen the concentration of borneol that is suitable for Zige compound oral preparation. Blood-brain barrier(BBB) model was established by co-culture of primary brain microvessel endothelial cells(BMEC) and astrocytes(As) in rats, and it was used to investigate the effect of borneol(concentration from 6.25 to 100 mg•L⁻¹) on the transport of puerarin and catalpol. The pharmacokinetics of puerarin and catalpol in plasma and brain of rats were compared after intragastric administration of borneol solution (0, 25, 50 and 100 mg•kg⁻¹) immediately followed by puerarin(200 mg•kg⁻¹) and catalpol(45 mg•kg⁻¹) nanocrystal suspension. Barrier function was basically formed after co-culturing of brain microvascular endothelial cells and astrocytes for 7 d. The permeability of puerarin and catalpol across blood-brain barrier was increased significantly(P<0.05) and transendothelial electrical resistance(TEER) values at 2 h were decreased significantly(P<0.01) when the concentration of borneol was between 12.5 to 100 mg•L⁻¹ as compared with the control group. Borneol at the dose of 50 mg•kg⁻¹ and 100 mg•kg⁻¹ could significantly increase the oral absorption of puerarin(P<0.05), but there was no obvious effect for catalpol. AUCbrain/AUCblood for puerarin was highest with borneol at dose of 100 mg•kg⁻¹ (P<0.05), while AUCbrain/AUCblood for catalpol was highest with borneol at dose of 50 mg•kg⁻¹ (P<0.05). AUCbrain was highest at 100 mg•kg⁻¹ for puerarin(P<0.05); while for catapol, it was highest at 50 mg•kg⁻¹, but it was not significantly different from 100 mg•kg⁻¹. In conclusion, borneol could increase the amount of puerarin and catalpol in brain after oral administration and the optimized dose shall be 100 mg•kg⁻¹.