ABSTRACT
The key to maximize the sensitivity of inner filter effect ( IFE)-based assay is to enlarge the overlap between the absorption spectra of the absorber and the excitation or emission spectra of the fluorophore. In this work, Mn-doped ZnS quantum dots ( QDs) were chosen for IFE-based detection of β-glucuronidase ( GUS) , since the excitation of QDs was perfectly overlapped with the absorption of the substrate of GUS, namely 4-nitrophenyl-β-D-glucuronide ( PNPG) . In addition, the phosphorescence emission from Mn-doped ZnS QDs could eliminate the fluorescence background from biological samples. Therefore, a simple turn-on phosphorescent GUS assay was developed, with the linear range of 10-300 U/L and limit of detection of 7 U/L (S/N=3).
ABSTRACT
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.
ABSTRACT
To compare the effects of different preparation technologies on the concentrations of puerarin and catalpol in plasma and brain of rats after oral administration, in order to lay an experimental basis for developing new oral Zige preparations. The nanocrystal, self-microemulsions (tween-80 and Cremophor RH-40 as emulsifiers) and inclusion complex of HP-β-CD containing puerarin and catalpol were prepared. The concentrations of puerarin and catalpol in plasma and brain of rats after oral administration were determined by HPLC-MS/MS method. The pharmacokinetic parameters and brain target index were compared. The results showed that preparation technologies had different influences on the concentrations of puerarin and catalpol in plasma and brain. The self-microemulsion (tween-80) could significantly increase the oral absorption of puerarin than other technologies(P<0.05), and inclusion complex could remarkably increase the oral absorption of catalpol than nanocrystal(P<0.01). For puerarin, the brain targeting index of inclusion complex was the highest (P<0.05); but for catalpol, the brain targeting index of inclusion complex and self-microemulsions were both higher than nanocrystal (P<0.05). The self-microemulsion(tween-80) had the highest AUCbrain of puerarin than other groups (P<0.01); the inclusion complex had the highest AUCbrain for catalpol, but there was no significant difference compared with self-microemulsions. In conclusion, the self-microemulsion (tween-80) technology could increase the amount of puerarin and catalpol in brain, and was expected to be used in new oral Zige preparations.
ABSTRACT
To study the interaction of drugs of different properties, namely puerarin, borneol and catalpol in the process of in- clusion, in order to explore the inclusion regularity of multi-component and multi-property traditional Chinese medicine compound in- clusions. With HP-β-CD as the inclusion material, the freeze-drying method was used to prepare the inclusion. The inclusion between puerarin, borneol and catalpol was tested by measuring the inclusion concentration, DSC and X-ray diffraction. According to the find- ings, when insoluble drugs puerarin and borneol were included simultaneously, and puerarin was overdosed, puerarin included was almost equal to puerarin included, and borneol was not included. When puerarin was under-dosed, and HP-β-CD was overdosed, borne- ol was included, and the simultaneous inclusion was lower than the separate inclusion of borneol. When water-soluble drug catalpol was jointly included with puerarin or borneol, the simultaneous inclusion was almost the same with their separate inclusion, without charac- teristic peak of catalpol in DSC and X-ray diffraction patterns. There is a competition in the simultaneous inclusion between water-solu- ble drugs puerarin and borneol and a stronger competition in puerarin. The water-soluble drug catalpol could be included with HP-β-CD with no impact on the inclusion of puerarin or borneol.