Cryptotanshinone inhibits chemotactic migration in macrophages through negative regulation of the PI3K signaling pathway.
OBJECTIVE
Cryptotanshinone, the major tanshinone isolated from Salvia miltiorrhiza Bunge, exhibits anti-inflammatory activity. However, there is no report on the effect of cryptotanshinone on recruitment of leukocytes to inflammatory sites. We therefore assessed the effects of cryptotanshinone on macrophage chemotaxis.


METHODS
Macrophage migration induced by complement 5a (C5a) or macrophage inflammatory protein-1alpha (MIP-1alpha) was measured in vitro. Intracellular kinase translocation and phosphorylation was assessed by Western blotting.


RESULTS
RAW264.7 cell migration towards C5a (1 microg ml(-1)) was significantly inhibited by cryptotanshinone (1, 3, 10 and 30 microM) in a concentration-dependent manner. Primary human macrophages stimulated by C5a were similarly inhibited. C5a-evoked migration in RAW264.7 cells was significantly suppressed by wortmannin (phosphatidylinositol 3-kinase (PI3K) inhibitor), PD98059 (MEK1/2 inhibitor) and SB203580 (p38 mitogen-activated protein kinase (MAPK) inhibitor), but not by SP600125 (c-Jun N-terminal kinase (JNK) inhibitor), suggesting that activation of PI3K, ERK1/2 and p38 MAPK signal pathways was involved in responses to C5a. Western blotting revealed that cryptotanshinone significantly inhibited PI3K-p110gamma membrane translocation and phosphorylation of Akt (PI3K downstream effector protein) and ERK1/2 induced by C5a. However, neither p38 MAPK nor JNK phosphorylation was affected by cryptotanshinone. Wortmannin significantly attenuated C5a-induced PI3K-p110gamma translocation, Akt and ERK1/2 phosphorylation. PD98059 suppressed ERK1/2 phosphorylation but failed to modify PI3K-p110gamma translocation by C5a stimulation. Furthermore, MIP-1alpha-induced cell migration and PI3K-p110gamma translocation were also inhibited by cryptotanshinone in a concentration-dependent manner.


CONCLUSIONS
Inhibition of macrophage migration by cryptotanshinone involved inhibition of PI3K activation with consequent reduction of phosphorylation of Akt and ERK1/2.
Don
M-J
MJ
National Research Institute of Chinese Medicine, Taipei, Taiwan, Republic of China.
Liao
J-F
JF
Lin
L-Y
LY
Chiou
W-F
WF
D000730:Androstadienes / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D015936:Complement C5a / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D019402:Macrophage Inflammatory Proteins / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects*; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D010616:Phenanthrenes / Q000302:isolation & purification / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D027544:Salvia / Q000737:chemistry; D015398:Signal Transduction / Q000187:drug effects*; D000077191:Wortmannin
D000730:Androstadienes; D000894:Anti-Inflammatory Agents, Non-Steroidal; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D004791:Enzyme Inhibitors; D005419:Flavonoids; D019402:Macrophage Inflammatory Proteins; D010616:Phenanthrenes; C037886:cryptotanshinone; D015936:Complement C5a; D011494:Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D000077191:Wortmannin