Steroidal glycosides from Ornithogalum thyrsoides bulbs and their cytotoxicity toward HL-60 human promyelocytic leukemia cells and SBC-3 human small-cell lung cancer cells.

Ornithogalum thyrsoides Jacq belongs to the Asparagaceae family and is cultivated for ornamental purposes. The authors have previously reported several cholestane- and spirostan-type steroidal glycosides from O. thyrsoides. Conventional TLC analysis of the methanolic bulb extract of O. thyrsoides suggested the presence of unprecedented compounds; therefore, a detailed phytochemical investigation of the extract was performed and 35 steroidal glycosides (1-35), including 21 previously undescribed ones (1-21) were collected. The structures of 1-21 were determined mainly by analyses of their 1H and 13C NMR spectra with the aid of two-dimensional NMR spectroscopy. The isolated compounds were classified into three distinct groups: furostan-type (1, 2, 8-12, and 22), spirostan-type (3-7 and 23-26), and cholestane-type (13-21 and 27-35). Although the C/D-ring junction of the steroidal skeleton is typically trans-oriented, except for some cardiotonic and pregnane-type steroidal derivatives, 7 possess a cis C/D-ring junction. This is the first reported instance of such a configuration in spirostan-type steroidal derivatives, marking it as a finding of significant interest. Compounds 1-35 were evaluated for cytotoxicity against HL-60 human promyelocytic leukemia cells and SBC-3 human small-cell lung cancer cells. Compounds 3-6, 9, 17-21, 23-25, and 30-35 demonstrated cytotoxicity in a dose-dependent manner with IC50 values ranging from 0.000086 to 18 µM and from 0.00014 to 37 µM toward HL-60 and SBC-3 cells, respectively. Compound 19, which is obtained in a good yield and shows relatively potent cytotoxicity among the undescribed compounds, induces apoptosis in HL-60 cells, accompanied by arresting the cell cycle of HL-60 cells at the G2/M phase. In contrast, 19 causes oxidative stress-associated necrosis in SBC-3 cells. The cytotoxic mechanism of 19 is different between HL-60 and SBC-3 cells.

Cholestane glycosides from Ornithogalum saundersiae bulbs and the induction of apoptosis in HL-60 cells by OSW-1 through a mitochondrial-independent signaling pathway.

A search for cytotoxic cholestane glycosides from Ornithogalum saundersiae bulbs resulted in the isolation of three new OSW-1 analogues (1-3), a new cholestane bisdesmoside (4), a 5ß-cholestane diglycoside (5), and four new 24(23 → 22)-abeo-cholestane glycosides (6-9), together with 11 known cholestane glycosides (10-20), including OSW-1 (11). The structures of 1-9 were determined based on conventional spectroscopic analysis and chemical evidence. As expected, based on previous data, 1-3 exhibited potent cytotoxic activity against HL-60 human promyelocytic leukemia cells and A549 human lung adenocarcinoma cells. Furthermore, the ability of OSW-1 to induce apoptosis in HL-60 cells was examined. Aggregation of nuclear chromatin, accumulation of the sub-G1 cells, DNA fragmentation, and caspase-3 activation were assessed in HL-60 cells treated with OSW-1, providing evidence for OSW-1-induced apoptosis in HL-60 cells. No mitochondrial membrane potential or release of cytochrome c into the cytoplasm were observed in the OSW-1-treated apoptotic HL-60 cells, indicating that a mitochondria-independent signaling pathway is involved in apoptotic cell death.

Identification of phenolic compounds, antioxidant activity and anti-cancer effects of the extract obtained from the shoots of Ornithogalum narbonense L.

This study aimed to examine the anti-cancer and antioxidant properties and identify the phenolic content of methanolic extract obtained from the shoots of the Ornithogalum narbonense L. (OR) species, which is used for folk-medicine and food in the Sanliurfa region of Turkey. The antioxidant activity of the extract was investigated using total phenolics, flavonoids, ABTS and CUPRAC methods. Phenolic component analysis of the plant extract was performed by LC-MS/MS. The anti-cancer property of OR extract was investigated on human colon (DLD-1), endometrium (ECC-1) cancer cells and embryonic kidney (HEK-293) cells. Cytotoxic effects were defined with MTT, apoptotic activity with DNA fragmentation ELISA and AO/EB fluorescent staining, the genotoxic effect with the comet assay and the intracellular oxidative status with TAS and TOS methods. As a result of the study, it was determined that OR extract showed an antioxidant effect, and as a result of the content analysis made with LC-MS/MS, phenolic components were determined, the most abundant being cosmosiin, followed by cinnamic acid, p-coumaric acid and quinic acid. OR extract showed cytotoxic activity on DLD-1 and ECC-1 cancer cells, while the cytotoxic effect on HEK-293 cells was determined to be low. It was determined that through OR extract, by increasing the intracellular amount of free radicals on cancer cells, led to DNA damage, which consequently led to apoptosis of the cancer cells.

[Research ontherapeutics effect of extract of Ornithogalum caudatum on liver fibrosis].

Rat models of liver fibrosis were made by carbon tetrachloride, and the serum levels of AST, ALT, γ-GT, MDA, GSH-px, SOD were detected, serum markers of PCⅢ, IV-C, LN, HA were detected by ELISA method. HE and Masson staining were conducted in hepatic tissues to observe pathological variations. Collagen Ⅲ, TGF-ß, α-SMA, E-cadherin were detected by Western blot. The curative effect of the extract of Ornithogalum caudatum on rat liver fibrosis induced by CCl4was observed and the mechanism was discussed. The experiment results showed that the extract of O. caudatum (50, 150, 500 mg•kg⁻¹) obviously decreased the serum levels of AST, ALT, γ-GT, MDA, increased the serum levels of GSH-px, SOD, decreased the expression of serum markers of PCⅢ, IV-C, LN, HA, and improved the liver pathological variations of fibrotic rats. The experiment proved that the extract of O. caudatum could treat the liver fibrogenesis induced by CCl4 in rats. The positive medicine may inhibit accumulation of extracellular and activate hepatic stellate cell and epithelial-mesenchymal transition.

Steroidal glycosides from the bulbs of Ornithogalum thyrsoides.

Phytochemical analyses have been carried out on the fresh bulbs of Ornithogalum thyrsoides with particular attention to the steroidal glycoside constituents, resulting in the isolation of four new spirostanol saponins and seven new cholestane glycosides, together with three known steroidal compounds. The structures of the new glycosides were determined on the basis of their spectroscopic data, including 2D NMR spectroscopy, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activities against HL-60 human promyelocytic leukemia cells and HSC-2 human oral squamous cell carcinoma cells.

Investigation of the antimutagenic effects of selected South African medicinal plant extracts.

Dichloromethane extracts from different parts of Rhamnus prinoides, Ornithogalum longibracteatum, Gardenia volkensii, Spirostachys africana, Diospyros whyteana, Syzigium cordatum and Prunus africana were investigated for mutagenic and antimutagenic effects in Salmonella/microsome and micronucleus tests. None of the extracts tested in the Ames test were found to induce mutations or to modify the effect of the mutagen 4-nitroquinoline-oxide (4NQO). In the micronucleus test, extracts from twigs/bark of R. prinoides, twigs of D. whyteana, P. africana and S. cordatum significantly lowered the effect of the mutagen mitomycin C (MMC). Extracts from twigs/bark of G. volkensii and S. africana were genotoxic in the micronucleus test, while extracts of O. longibracteatum leaves potentiated the genotoxicity of MMC. This preliminary investigation shows that plant extracts used in traditional medicine may have particular effects with regard to mutagenicity and antimutagenicity indicating careful use in some instances and the need to isolate their active principles for further research.