Effect of bioadhesive excipients on absorption of total flavonids from Puerariae Lobatae Radix transporting across Caco-2 cell monolayer

Objective: Pueraria total flavonids(PTF) can treat cardiovascular and cerebrovascular diseases, but it has poor membrane permeability and oral bioavailability. Some excipients, such as carbomer, chitosan, and hydroxypropyl methylcellulose, can improve the oral bioavailability. Traditional in vitro evaluation techniques, including the rat intestinal perfusion and cell line models, cannot evaluate PTF absorption and holistic transporters.Methods: This study evaluated excipients' adhesiveness and effect on PTF transport across Caco-2 cell monolayer. cDNA microarrays identified gene expression changes in Caco-2 cells exposed to PTF and PTF with excipients, and revealed the mechanism underlying the effect of excipients on PTF absorption.Results: In vitro adhesion and transport experiments across Caco-2 showed that excipients had higher adhesiveness to gastric mucosa and transport efficiency across Caco-2 cells than PTF alone. The interaction of PTF with excipients significantly changed the expression of some genes, which might influence the absorption rate of PTF.Conclusion: Different bioadhesive polymers can improve intestinal absorption of PTF, which was related to some genes affiliated to the ATP-binding cassette(ABC) and solute carrier transporter(SLC) to some extent.

Orthogonal Test Design for Optimization of the Extraction of Flavonid from the Fructus Gardeniae

Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9（3）4], including the ratio of buffer solution （Na2B4O7· 10H2O） to raw material, concentration of Fructus Gardeniae in extracting solution, extraction time and pH of buffer solution. An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample. Results The maximum extraction yield of the crude extract was 5.0533 （mg/g） after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4%, the concentration of Fructus Gardeniae in the extraction solution was 1/12 （g/mL）, and pH of buffer solution was 4.5. The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid, and FTIR measurements also identified the presence of flavonoid in the extracts. Conclusion This work is expected to provide a basis for further research, development, and utilization of Fructus gardenia in flavonid extraction.