Supercritical fluid extraction of Eucalyptus globulus bark: a promising approach for triterpenoid production

Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids). In this work, the supercritical fluid extraction (SFE) of Eucalyptus globulus deciduous bark was carried out with pure and modified carbon dioxide to recover this fraction, and the results were compared with those obtained by Soxhlet extraction with dichloromethane. The effects of pressure (100-200 bar), co-solvent (ethanol) content (0, 5 and 8% wt), and multistep operation were studied in order to evaluate the applicability of SFE for their selective and efficient production. The individual extraction curves of the main families of compounds were measured, and the extracts analyzed by GC-MS. Results pointed out the influence of pressure and the important role played by the co-solvent. Ethanol can be used with advantage, since its effect is more important than increasing pressure by several tens of bar. At 160 bar and 40 degrees C, the introduction of 8% (wt) of ethanol greatly improves the yield of triterpenoids more than threefold

A Novel Triterpenoid Isolated from the Root Bark of Ailanthus excelsa Roxb (Tree of Heaven), AECHL-1 as a Potential Anti-Cancer Agent

We report here the isolation and characterization of a new compound Ailanthus excelsa chloroform extract-1 (AECHL-1) (C(29)H(36)O(10); molecular weight 543.8) from the root bark of Ailanthus excelsa Roxb. The compound possesses anti-cancer activity against a variety of cancer cell lines of different origin.AECHL-1 treatment for 12 to 48 hr inhibited cell proliferation and induced death in B16F10, MDA-MB-231, MCF-7, and PC3 cells with minimum growth inhibition in normal HEK 293. The antitumor effect of AECHL-1 was comparable with that of the conventional antitumor drugs paclitaxel and cisplatin. AECHL-1-induced growth inhibition was associated with S/G(2)-M arrests in MDA-MB-231, MCF-7, and PC3 cells and a G(1) arrest in B16F10 cells. We observed microtubule disruption in MCF-7 cells treated with AECHL-1 in vitro. Compared with control, subcutaneous injection of AECHL-1 to the sites of tumor of mouse melanoma B16F10 implanted in C57BL/6 mice and human breast cancer MCF-7 cells in athymic nude mice resulted in significant decrease in tumor volume. In B16F10 tumors, AECHL-1 at 50 microg/mouse/day dose for 15 days resulted in increased expression of tumor suppressor proteins P53/p21, reduction in the expression of the oncogene c-Myc, and downregulation of cyclin D1 and cdk4. Additionally, AECHL-1 treatment resulted in the phosphorylation of p53 at serine 15 in B16F10 tumors, which seems to exhibit p53-dependent growth inhibitory responses.The present data demonstrate the activity of a triterpenoid AECHL-1 which possess a broad spectrum of activity against cancer cells. We propose here that AECHL-1 is a futuristic anti-cancer drug whose therapeutic potential needs to be widely explored for chemotherapy against cancer

Triterpenoids Display Single Agent Anti-tumor Activity in a Transgenic Mouse Model of Chronic Lymphocytic Leukemia and Small B Cell Lymphoma

The synthetic triterpenoid 2-Cyano-3,12-Dioxooleana-1,9-Dien-28-Oic Acid (CDDO) and derivatives display anti-tumor activity against a variety of cultured tumor cell lines and in mouse xenografts. In this report, we have studied the effects of CDDO and its imidazolide derivative (CDDO-Im) on chronic lymphocytic leukemia (CLL), using patients' CLL cells and a mouse model of CLL and small B cell lymphoma (SBL).CDDO and CDDO-Im efficiently induced apoptosis of malignant human and mouse B-cells ex vivo, although CDDO-Im was over 10-fold more potent than CDDO. Treating mice with CLL/SBL with liposome-formulated CDDO or CDDO-Im resulted in significant reductions of B cells in blood, spleen and lung. CDDO-Im was shown to be more potent than CDDO, while treatment with empty liposomes had no impact on disease. CDDO-Im treatment initially resulted in an increase of circulating B cells, which correlates with a reduction in resident lymphocytes in spleen, and lungs, suggesting that CDDO-Im induces mobilization of tumor cells from lymphoid organs and infiltrated tissues into the circulation. Analysis of blood cells recovered from treated mice also showed that CDDO-Im is a potent inducer of tumor cells death in vivo. Furthermore, CDDO-Im efficiently eradicated mouse CLL/SBL cells but had little effect on the viability of normal B and T cells in vivo.The presented data demonstrate that triterpenoids CDDO and CDDO-Im reduce leukemia and lymphoma burden in vivo in a transgenic mouse model of CLL/SBL, and support the clinical testing of CDDO-based synthetic triterpenoids in patients with CLL

Maslinic Acid, a Natural Triterpene, Induces a Death Receptor-Mediated Apoptotic Mechanism in Caco-2 p53-Deficient Colon Adenocarcinoma Cells

Maslinic acid (MA) is a natural triterpene present in high concentrations in the waxy skin of olives. We have previously reported that MA induces apoptotic cell death via the mitochondrial apoptotic pathway in HT29 colon cancer cells. Here, we show that MA induces apoptosis in Caco-2 colon cancer cells via the extrinsic apoptotic pathway in a dose-dependent manner. MA triggered a series of effects associated with apoptosis, including the cleavage of caspases -8 and -3, and increased the levels of t-Bid within a few hours of its addition to the culture medium. MA had no effect on the expression of the Bax protein, release of cytochrome-c or on the mitochondrial membrane potential. This suggests that MA triggered the extrinsic apoptotic pathway in this cell type, as opposed to the intrinsic pathway found in the HT29 colon-cancer cell line. Our results suggest that the apoptotic mechanism induced in Caco-2 may be different from that found in HT29 colon-cancer cells, and that in Caco-2 cells MA seems to work independently of p53. Natural antitumoral agents capable of activating both the extrinsic and intrinsic apoptotic pathways could be of great use in treating colon-cancer of whatever origin.This study was supported by grants Group BIO 157 from the Technology and Innovation Council of the Andalucian regional government and AGL2006-12210-C03-02/ALI, SAF2005-01627, ISCIII-RTICC (RD06/0020/0046) from the Spanish government and European Union FEDER funds

Triterpenoid modulation of IL-17 and Nrf-2 expression ameliorates neuroinflammation and promotes remyelination in autoimmune encephalomyelitis

Inflammatory cytokines and endogenous anti-oxidants are variables affecting disease progression in multiple sclerosis (MS). Here we demonstrate the dual capacity of triterpenoids to simultaneously repress production of IL-17 and other pro-inflammatory mediators while exerting neuroprotective effects directly through Nrf2-dependent induction of anti-oxidant genes. Derivatives of the natural triterpene oleanolic acid, namely CDDO-trifluoroethyl-amide (CDDO-TFEA), completely suppressed disease in a murine model of MS, experimental autoimmune encephalomyelitis (EAE), by inhibiting Th1 and Th17 mRNA and cytokine production. Encephalitogenic T cells recovered from treated mice were hypo-responsive to myelin antigen and failed to adoptively transfer the disease. Microarray analyses showed significant suppression of pro-inflammatory transcripts with concomitant induction of anti-inflammatory genes including Ptgds and Hsd11b1. Finally, triterpenoids induced oligodendrocyte maturation in vitro and enhanced myelin repair in an LPC-induced non-inflammatory model of demyelination in vivo. These results demonstrate the unique potential of triterpenoid derivatives for the treatment of neuroinflammatory disorders such as MS