Cancer:
Prostate, breast, cervical., leukemia, hepatocellular carcinoma
Action: Anti-inflammatory, cell-cycle arrest, inhibits dihydrotestosterone (DHT), anti-proliferative, hepato-protective
Cryptotanshinone is a major constituent of tanshinones from Salvia miltiorrhiza (Bunge).
Tanshinone IIA and cryptotanshinone could induce CYP3A activity (Qiu et al., 2103).
Anti-proliferative Agent
Cryptotanshinone (CPT), a natural compound, is a potential anti-cancer agent. Chen et al., (2010) have shown that CPT inhibited cancer cell proliferation by arresting cells in G(1)-G(0) phase of the cell-cycle. This is associated with the inhibition of cyclin D1 expression and retinoblastoma (Rb) protein phosphorylation.
Furthermore, they found that CPT inhibited the signaling pathway of the mammalian target of rapamycin (mTOR), a central regulator of cell proliferation. This is evidenced by the findings that CPT inhibited type I insulin-like growth factor I- or 10% fetal bovine serum-stimulated phosphorylation of mTOR, p70 S6 kinase 1, and eukaryotic initiation factor 4E binding protein 1 in a concentration- and time-dependent manner. Expression of constitutively active mTOR conferred resistance to CPT inhibition of cyclin D1 expression and Rb phosphorylation, as well as cell growth. The results suggest that CPT is a novel anti-proliferative agent.
Anti-inflammatory; COX-2, PGE2
Cyclooxygenase-2 (COX-2) is a key enzyme that catalyzes the biosynthesis of prostaglandins from arachidonic acid and plays a critical role in some pathologies including inflammation, neurodegenerative diseases and cancer. Cryptotanshinone is a major constituent of tanshinones and has well-documented anti-oxidative and anti-inflammatory effects.
This study confirmed the remarkable anti-inflammatory effect of cryptotanshinone in the carrageenan-induced rat paw edema model. Since the action of cryptotanshinone on COX-2 has not been previously described, in this study, Jin et al. (2006) examined the effect of cryptotanshinone on cyclooxygenase activity in the exogenous arachidonic acid-stimulated insect sf-9 cells, which highly express human COX-2 or human COX-1, and on cyclooxygenases expression in human U937 promonocytes stimulated by lipopolysaccharide (LPS) plus phorbolmyristate acetate (PMA).
Cryptotanshinone reduced prostaglandin E2 synthesis and reactive oxygen species generation catalyzed by COX-2, without influencing COX-1 activity in cloned sf-9 cells. In PMA plus LPS-stimulated U937 cells, cryptotanshinone had negligible effects on the expression of COX-1 and COX-2, at either a mRNA or protein level. These results demonstrate that the anti-inflammatory effect of cryptotanshinone is directed against enzymatic activity of COX-2, not against the transcription or translation of the enzyme.
Prostate Cancer
Cryptotanshinone was identified as a potent STAT3 inhibitor. Cryptotanshinone rapidly inhibited STAT3 Tyr705 phosphorylation in DU145 prostate cancer cells and the growth of the cells through 96 hours of the treatment. Inhibition of STAT3 Tyr705 phosphorylation in DU145 cells decreased the expression of STAT3 downstream target proteins such as cyclin D1, survivin, and Bcl-xL.
Cryptotanshinone can suppress Bcl-2 expression and augment Fas sensitivity in DU145 prostate cancer cells. Park et al. (2010) show that JNK and p38 MAPK act upstream of Bcl-2 expression in Fas-treated DU145 cells, and that cryptotanshinone significantly blocked activation of these kinases. Moreover, cryptotanshinone sensitized several tumor cells to a broad range of anti-cancer agents. Collectively, the data suggest that cryptotanshinone has therapeutic potential in the treatment of human prostate cancer (Park et al., 2010).
Cryptotanshinone was colocalized with STAT3 molecules in the cytoplasm and inhibited the formation of STAT3 dimers. Computational modeling showed that cryptotanshinone could bind to the SH2 domain of STAT3. These results suggest that cryptotanshinone is a potent anti-cancer agent targeting the activation STAT3 protein. It is the first report that cryptotanshinone has anti-tumor activity through the inhibition of STAT3 (Shin et al., 2009).
Prostate Cancer; Androgen Receptor Positive
Anti-androgens to reduce or prevent androgens binding to androgen receptor (AR) are widely used to suppress AR-mediated PCa growth; however, the androgen depletion therapy is only effective for a short period of time. Xu et al., (2012) found that cryptotanshinone (CTS), with a structure similar to dihydrotestosterone (DHT), can effectively inhibit the DHT-induced AR transactivation and prostate cancer cell growth. Their results indicated that 0.5 µM CTS effectively suppresses the growth of AR-positive PCa cells, but has little effect on AR negative PC-3 cells and non-malignant prostate epithelial cells.
Furthermore, data indicated that CTS could modulate AR transactivation and suppress the DHT-mediated AR target genes expression in both androgen responsive PCa LNCaP cells and castration resistant CWR22rv1 cells. The mechanistic studies indicate that CTS functions as an AR inhibitor to suppress androgen/AR-mediated cell growth and PSA expression by blocking AR dimerization and the AR-coregulator complex formation.
Furthermore, they showed that CTS effectively inhibits CWR22Rv1 cell growth and expressions of AR target genes in the xenograft animal model. The previously un-described mechanisms of CTS may explain how CTS inhibits the growth of PCa cells and help us to establish new therapeutic concepts for the treatment of PCa.
Breast Cancer, Cervical Cancer, Leukemia, Hepatocellular Carcinoma
The three tanshinone derivatives, tanshinone I, tanshinone IIA, and cryptotanshinone, exhibited significant in vitro cytotoxicity against several human carcinoma cell lines (Wang et al., 2007).
Tanshinone I was found to inhibit the growth and invasion of breast cancer cells both in vitro and in vivo through regulation of adhesion molecules including ICAM-1 and VCAM-1 (Nizamutdinova et al., 2008), and induce apoptosis of leukemia cells by interfering with the mitochondrial transmembrane potential (ΔΨm), increasing the expression of Bax, as well as activating caspase-3 (Liu et al., 2010). Tanshinone IIA has been reported to inhibit the growth of cervical cancer cells through disrupting the assembly of microtubules, and induces G2/M phase arrest and apoptosis (Pan et al., 2010).
This compound can also inhibit invasion and metastasis of hepatocellular carcinoma (HCC) cells both in vitro and in vivo, by suppressing the expression of the metalloproteinases, MMP2 and MMP9 and interfering with the NFκB signaling pathway (Xu et al., 2009).
Breast Cancer
Cryptotanshione was reported to induce cell-cycle arrest at the G1-G0 phase, which was accompanied by the inhibition of cyclin D1 expression, retinoblastoma (Rb) protein phosphorylation, and of the rapamycin (mTOR) signaling pathway (Chen et al., 2010).
Hepato-protective Effect
Cryptotanshinone (20 or 40mg/kg) was orally administered 12 and 1h prior to GalN (700mg/kg)/LPS (10µg/kg) injection. The increased mortality and TNF- α levels by GalN/LPS were declined by cryptotanshinone pre-treatment. In addition, cryptotanshinone attenuated GalN/LPS-induced apoptosis, characterized by the blockade of caspase-3, -8, and -9 activation, as well as the release of cytochrome c from the mitochondria. Furthermore, cryptotanshinone significantly inhibited the activation of NF-κB and suppressed the production of pro-inflammatory cytokines.
These findings suggest that the hepato-protective effect of cryptotanshinone is likely to be associated with its anti-apoptotic activity and the down-regulation of MAPKs and NF-κB associated at least in part with suppressing TAK1 phosphorylation (Jin et al., 2013).
References
Nizamutdinova IT, Lee GW, Lee JS, et al. (2008). Tanshinone I suppresses growth and invasion of human breast cancer cells, MDA-MB-231, through regulation of adhesion molecules. Carcinogenesis, 29(10):1885-1892. doi:10.1093/carcin/bgn151
Qiu F, Jiang J, Ma Ym, et al. (2013). Opposite Effects of Single-Dose and Multidose Administration of the Ethanol Extract of Danshen on CYP3A in Healthy Volunteers. Evidence-Based Complementary and Alternative Medicine, 2013(2013) http://dx.doi.org/10.1155/2013/730734
Xu YX, Feng T, Li R, Liu ZC. (2009). Tanshinone II-A inhibits invasion and metastasis of human hepatocellular carcinoma cells in vitro and in vivo. Tumori, 95:789–795.