Oridonin promotes CD4+/CD25+ Treg differentiation, modulates Th1/Th2 balance and induces HO-1 in rat splenic lymphocytes.
OBJECTIVE
Oridonin is an ent-kaurene diterpenoid extracted from Isodon Serra, and we have previously demonstrated its immunosuppressive effect. Our goal was to study how Oridonin impacts CD4+/CD25+ regulatory T cells (Tregs) and Th1/Th2 balance, as well as its effect on the anti-inflammatory target HO-1.


METHODS
Splenic lymphocytes were prepared from male 6-8-week-old SD rats.


METHODS
Cells were cultured in four groups as Oridonin-L (Oridonin 12.5 micromol/l), Oridonin-H (Oridonin 25 micromol/l), Cobalt protoporphyrin (Copp 50 micromol/l) and control (DMSO) with stimulation of ConA (5 microg/ml) for 48 h or with no stimulation for 12 h.


METHODS
We set up a model of Th1 polarization in vitro using ConA stimulation; ratios of CD4+/CD25+ Tregs (confirmed by the expression of Foxp3) were measured by flow cytometry, and levels of IL-2, IFN-gamma, TGF-beta and IL-10 were measured by ELISA. In addition, HO-1 expression was measured without stimulation with ConA by RT-PCR and Western blotting, and HO-1 level in vitro was then measured by enzyme activity assay. p<0.05 (t-test) was taken as the level of statistical significance.


RESULTS
Oridonin promoted differentiation towards CD4+/CD25+ Tregs, inhibited IL-2 and IFN-gamma but induced TGF-beta and IL-10, thus rectified the Th1 polarization. Moreover, Oridonin induced the expression of HO-1 mRNA and protein, and HO-1 activity in vitro was enhanced accordingly.


CONCLUSIONS
The results suggest that Oridonin has a distinct effect on promoting CD4+/CD25+ Treg differentiation and modulating Th1/Th2 balance, and this effect may be achieved via inducing the anti-inflammatory target HO-1.
Hu
A-P
AP
State Key Laboratory of Bioreactor Engineering & School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.
Du
J-M
JM
Li
J-Y
JY
Liu
J-W
JW
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D045786:Diterpenes, Kaurane / Q000494:pharmacology*; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D016753:Interleukin-10 / Q000378:metabolism; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018417:Th1 Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018418:Th2 Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
D045786:Diterpenes, Kaurane; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C011959:oridonin; D016753:Interleukin-10; D051547:Heme Oxygenase-1