Cancer:
Myeloid leukemia, cervical., glioblastoma, gastric, sarcoma
Action: Immunosuppressive activity
Corosolic Acid is isolated from Lagerstroemia speciosa [(L.) Pers.] and Crataegus pinnatifida var. psilosa (C. K. Schneider).
Sarcoma; Immunosuppressive Activity
The results from an in vivo study showed that Corosolic acid (CA) administration did not suppress the tumor proliferation index, but significantly impaired subcutaneous tumor development and lung metastasis.
CA administration inhibited signal transducer and activator of transcription-3 (Stat3) activation and increased in the number of infiltrating lymphocytes in tumor tissues. Ex vivo analysis demonstrated that a significant immunosuppressive effect of MDSC in tumor-bearing mice was abrogated and the mRNA expressions of cyclooxygenase-2 and CCL2 in MDSC were significantly decreased by CA administration.
Furthermore, CA enhanced the anti-tumor effects of adriamycin and cisplatin in vitro. Since Stat3 is associated with tumor progression not only in osteosarcoma, but also in other malignant tumors, these findings indicate that CA might be widely useful in anti-cancer therapy by targeting the immunosuppressive activity of MDSC and through its synergistic effects with anti-cancer agents (Horlad et al., 2013).
Cervical Cancer
Xu et al. (2009) investigated the response of human cervix adenocarcinoma HeLa cells to Corosolic acid (CRA) treatment. These results showed that CRA significantly inhibited cell viability in both a dose- and a time-dependent manner. CRA treatment induced S cell-cycle arrest and caused apoptotic death in HeLa cells. It was found that CRA increased in Bax/Bcl-2 ratios by up-regulating Bax expression, disrupted mitochondrial membrane potential and triggered the release of cytochrome c from mitochondria into the cytoplasm.
These results, taken together, indicate CRA could have strong potentials for clinical application in treating human cervix adenocarcinoma and improving cancer chemotherapy.
Glioblastoma
Tumor-associated macrophages (TAMs) of M2 phenotype promote tumor proliferation and are associated with a poor prognosis in patients with glioblastoma.
The natural compounds possessing inhibitory effects on M2 polarisation in human monocyte-derived macrophages were investigated. Among 130 purified natural compounds examined, corosolic acid significantly inhibited the expression of CD163, one of the phenotype markers of M2 macrophages, as well as suppressed the secretion of IL-10, one of the anti-inflammatory cytokines preferentially produced by M2 macrophages, thus suggesting that corosolic acid suppresses M2 polarisation of macrophages.
Furthermore, corosolic acid inhibited the proliferation of glioblastoma cells, U373 and T98G, and the activation of Signal transducer and activator of transcription-3 (STAT3) and Nuclear Factor-kappa B (NF-κB), in both human macrophages and glioblastoma cells. These results indicate that corosolic acid suppresses the M2 polarisation of macrophages and tumor cell proliferation by inhibiting both STAT3 and NF-κB activation. Therefore, corosolic acid may be a new tool for tumor prevention and therapy (Fujiwara et al., 2010).
Gastric Cancer
Corosolic acid (CRA) suppresses HER2 expression, which in turn promotes cell-cycle arrest and apoptotic cell death of gastric cancer cells, providing a rationale for future clinical trials of CRA in the treatment of HER2-positive gastric cancers. CRA combined with adriamycin and 5-fluorouracil enhanced this growth inhibition, but not with docetaxel and paclitaxel (Lee et al., 2010).
Leukemia
Corosolic acid displayed about the same potent cytotoxic activity as ursolic acid against several human cancer cell lines. In addition, the compound displayed antagonistic activity against the phorbol ester-induced morphological modification of K-562 leukemic cells, indicating the suppression of protein kinase C (PKC) activity by the cytotoxic compound (Ahn et al., 1998).
References