ABSTRACT
Objective: To prepare the taxifolin and determine its apparent oil-water partition coefficient in different media, and to study the mechanism of absorption and transport of taxifolin in Caco-2 cell model. Methods: Taxifolin was prepared by enzymolysis. HPLC was used to determine the saturated solubility of taxifolin in 37 ℃, different pH buffer solution and water, apparent oil-water distribution coefficient of taxifolin obtained by calculation formula of oil-water distribution coefficient; CCK-8 experiment was used to investigate the safe concentration range of taxifolin in Caco-2 cells, and then the single-layer model of Caco-2 cells was used to study the mechanism of bilateral transmembrane absorption and transport. CCK-8 experiment was used to investigate the safe concentration range of taxifolin in HDMEC cells. The inflammatory model of HDMEC cells induced by lipopolysaccharide was established, and the activity of lactic dehydrogenase was detected by the intervention of floxacin. The activity of lactic dehydrogenase was detected by lactic dehydrogenase kit. Results: The lgP values of taxifolin in the following solvents were 0.29 (0.1 mol/L hydrochloric acid), 0.48 (pH 2.0), 0.46 (pH 5.8), 0.34 (pH 6.8), 0.26 (pH 7.4), and 0.38 (water), respectively; There was no significant toxic effect on Caco-2 cells in the range of 50-500 μg/mL; There was no significant difference in Papp value of bilateral transport between different concentrations of taxifolin in Caco-2 monolayer cell model, and it was less than 1 × 10-6 cm/s and ER was less than 2. There was no significant toxic effect on HDMEC cells in the range of 50-300 μg/mL; After treatment with taxifolin, compared with LPS stimulation group, the activity of LDH in each treatment group was decreased significantly (P < 0.05), and the activity of LDH was decreased significantly in the range of 50-100 μg/mL, and tended to be stable in the range of 100-250 μg/mL. Conclusion: Taxifolin is a kind of drug which is difficult to absorb in the intestine. The mechanism of transmembrane transport is passive transport. It can inhibit the inflammation of hdmec cells induced by LPS and has anti-inflammatory activity.
ABSTRACT
Chinese materia medica is mostly taken orally. The permeability of a drug’s biofilm (e.g. cell membrane) reflects its ability of absorption and transportation in the body. It is of guiding significance to evaluate the membrane permeability of the active components of Chinese materia medica by using appropriate drug permeation model, so as to clarify, the oral absorption and transport mechanism of active ingredients, pharmacodynamic substance basis and dosage form design. The evaluation method of oral drug membrane permeability, as well as the application of various methods in Chinese medicine was summarized for reference in this review.
ABSTRACT
To establish MDCK-pHaMDR cell model and standard operation procedure for assessing the blood-brain barrier permeability of chemical components of traditional Chinese medicine. MDCK-pHaMDR cell model was evaluated by determining the morphology features, transepithelial electrical resistance, bidirectional transport and intracellular accumulation of Rhodamine 123 and the apparent permeability of positive control drugs caffeine and atenolol. The MDCK-pHaMDR cell model had satisfactory integrity and tightness, and stable expression of P-gp. In addition, the transport results of the positive control drugs were consistent with the reported values in literature. All the parameters tested of the MDCK-pHaMDR cell model were consistent with the requirements, so the model can be used to study the blood-brain barrier permeability of chemical components of traditional Chinese medicine.
ABSTRACT
Taurine is one of the extremely important amino acids in the body,and is also the most abundant free amino acids in the central nervous system(CNS).Taurine as a conditional essential amino acids exerts a wide range of physiological and pharmacological effects.Taurine,especially as a neurotransmitter in the developing CNS,can maintain the structural integrity of the membrane,regulate calcium transport and calcium homeostasis,also as nutritional factors,osmolyte,neuromodulator,neuroprotective agents,plays an important role.In this paper,physiological and biochemical properties of taurine,source and distribution in vivo,synthesis and metabolism,absorption and transport,and its protective effect on the CNS are reviewed.