[Effect of Shaoyao Gancao Tang on function and expression of P-glycoprotein in Caco-2 cells].
OBJECTIVE
To investigate the effect of Shao Yao-Gan Cao-Tang on function and expression of P-glycoprotein (P-gp) in Caco-2 cells.


METHODS
3H-digoxin (Dig), a substrate of P-glycoprotein, was used as a probe to measure the P-gp-mediated drug efflux transport, which indicated the function of P-gp in Caco-2 cells, while Verapamil (Ver) was used as a positive P-gp inhibitor. P-gp expression in Caco-2 cells was tested by immunohistochemistry staining. Inhibition effect of SGT on P-gp-mediated drug efflux transport and P-gp expression were investigated.


RESULTS
Dig was shown a positive absorption mode in Caco-2 cell monolayer, characterized as the ratio of apparent permeabilities (Papp) from basolateral side to apical side Papp (BL-->AP) and from apical side to basolateral side Papp (AP-->BL) of Dig was 27.07. Addition of Ver into Dig transport media significantly inhibited P-gp activity which was indicated by increasing the Papp (AP-->BL) of Dig by 3.82 times, whereas Ver had no significant effect on Papp (BL-->AP). SGT (at the concentrations of 1/25 IC5, 1/5 IC5, IC,) could promote Papp (AP-->BL) of Dig by 159.83%, 217.95% ,160.26%. Papp (AP-->BL) of Dig was mildly increased by 59.16%, 50.73% by SGT at 1/25 IC5, 1/5 IC, respectively. Immunohistochemistry staining showed that SGT inhibited the expression of P-gp of Caco-2 cells.


CONCLUSIONS
SGT showed the potential inhibition to the function and expression of P-gp, leading to the increase absorption of P-gp's substrates.
Capital Medical University School of Traditional Chinese Medicine, Beijing 100069, China.
Yinglei
Y
Wang
Jing
J
Zhao
Yong
Y
Zhao
Chunying
C
Li
Yan
Y
Yi
Aihua
A
Liang
Georg Nilsen
GN
Odd
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D004347:Drug Interactions; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans
D018435:ATP Binding Cassette Transporter, Subfamily B; D004365:Drugs, Chinese Herbal