[Absorption mechanism of dragon's blood phenolic extracts in Caco-2 cells].

The purpose of this study was to study the absorption characteristics of eight main components from dragon's blood phenolic extracts in Caco-2 cells based on the humancolon cancer cell Caco-2 model, and to clarify the oral absorption mechanism of such phenolic extracts. UPLC-MS/MS was used in this study to determine the content of 8 active ingredients including thevetiaflavone, 7,4'-dihydroxyflavone, 7,4'-dihydroxy-5-methoxyhomoisoflavanone, 7,4'-dihydroxyhomoisoflavanone, loureirin C, loureirin A, loureirin B and pterostilbene from dragon's blood phenolic extracts, and Caco-2 cells were used to investigate the effects of incubation time, concentration, temperature, P-gp inhibitor, MRP inhibitor, OCTN1 inhibitor and OCTN2 inhibitor on the absorption of each component. In addition, the transport experiment was conducted to measure the apparent permeability coefficient P_(app) and transport rate of the eight main components to predict the oral absorption mechanism of dragon's blood phenolic extracts. The experimental results showed that the cell uptake of the eight main components in dragon's blood phenolic extracts was time-dependent and concentration dependent, and the uptake of each component did not need to consume energy, which was consistent with the passive diffusion process. P-gp inhibitor, MRP inhibitor and OCTN1 inhibitor had no effect on the cell uptake of each component, only the addition of OCTN2 inhibitor significantly reduced the uptake of pterostilbene(P<0.05). In the transport results, the ER values of the outflow rates of the eight components were all less than 1.5. The above results show that the absorption mechanism of the eight components in Draconis resina phenolic extract may be passive diffusion, and pterostilbene may be the substrate of OCTN2.

Optimization of extraction technology of two immune active proteins from Astragalus membranaceus var. mongholicus / 中草药

Objective: To optimize the extraction technology of immune active glycoproteins AmPR10-16kD and HQGP-2 from Astragalus membranaceus var. mongholicus (AMM). Methods: The optimized extraction temperature conditions were investigated by circular dichroism of water-soluble protein involving in AmPR10-16kD and HQGP-2 with secondary structure from AMM. The optimized extraction technology was investigated using single factor test and orthogonal test with gray value of water-soluble protein AmPR10-16kD and HQGP-2 as the index which was determined by Image of gel graphical analysis software. In this study, the effects of temperature, solid-liquid ratio, time, solvent, granularity, and times on gray value were investigated, for which the inhibitory effect of water-soluble protein was determined as an evidence by CCK-8 method, and the content of water-soluble protein is determined as an evidence by BCA method. Results: The optimized extraction technique for proteins AmPR10-16kD and HQGP-2 in AMM was established, that was 5.0 g powder of AMM over the No.4 sieve, olvent Tris-HCl, solid-liquid ratio 1:16 and 60 min for extraction at the temperature of 40 ℃ and being mixed under 100 r/min. The water-soluble protein extract rate in the orthogonal test analysis was 65 mg/g, of which inhibitory effect was 90.90% at a concentration of 90 μg/mL. Conclusion: The optimal extraction conditions could accurately reflect the relative amounts of AmPR10-16kD and HQGP-2 maximum extraction rate, providing a stable, reasonable, and feasible extraction process for further study of the bioactive substance of AMM.