Comparative pharmacokinetic and bioavailability study of lobetyolin in rats after administration of lobetyolin and Codonopsis pilosula extract by ultra-performance LC-tandem mass spectrometry.

Codonopsis pilosula (CP) is a traditional Chinese medicine used to invigorate spleen, replenish lung, nourish blood and engender fluid. A rapid, selective and sensitive ultra-performance LC-tandem mass spectrometry method was developed and validated to determine lobetyolin in rat plasma. The calibration curve showed good linearity over a concentration range of 0.46-1000 ng/mL for lobetyolin. The extraction recovery ranged from 72.5% to 89.1% with matrix effects of 81.6%-107.8%. The intra- and inter-batch precision and accuracy were 0.02-14.4% and -13.9% to -1.36%, respectively. The method was successfully applied for the bioavailability study of lobetyolin in rats after oral administration of pure lobetyolin and CP extract. Results showed that the elimination half-time (t1/2 ) and the area under the concentration-time curve from zero to infinity of lobetyolin in CP extract were statistically different from those of the pure monomer (P < 0.05). However, the time to reach the maximum plasma concentration (Tmax ) and the maximum concentration (Cmax ) showed no significant differences between the two treatments. Furthermore, the bioavailability of lobetyolin in the experimental group was only 3.90%, significantly lower than that of the CP extract group (6.97%). The low bioavailability indicated that this component may be absorbed poorly or metabolized extensively in rats. Our results will provide useful information for further preclinical studies and formulation preparation of lobetyolin.

Synergetic Inhibition of Human Colorectal Cancer Cells by Combining Polyyne-Enriched Fraction from Oplopanax elatus and Irinotecan.

Although irinotecan is an important anticancer drug for treating colorectal cancer, its dose-dependent side effects limited its clinical application. Thus, it's important to develop low-toxic candidates to enhance the efficacy of irinotecan. Polyynes from genus Oplopanax were reported to possess potential anticancer effects on colorectal cancer. Hereby, we evaluated the synergetic inhibition of human colorectal cancer cells by combining polyyne-enriched fraction from Oplopanax elatus (the dichloromethane fraction of Oplopanax elatus, OED) and irinotecan. The results showed that 5 µg/ml of OED combined with 40 µM of irinotecan possessed significant synergetic inhibition on SW-480 cells with a combination index (CI) of 0.56. Besides, the percentage of apoptotic cells was significantly increased from 69.57% (40 µM of irinotecan) or 72.7% (5 µg/ml of OED) to 95.6% after treatment of OED combined with irinotecan (OCI), suggesting OED and irinotecan possess the synergistic apoptotic effect (P < 0.01). Furthermore, Caspase-3 was significantly activated in OCI group (P < 0.05). Besides, the percentage of apoptotic cells of OED or/and irinotecan significantly decreased after inhibition of caspase-3. These data indicated that OED could enhance antiproliferative effects of irinotecan on colorectal cancer cells, which was related with induction of apoptosis and regulations of activity of caspase-3.

Dietary polyacetylenes, falcarinol and falcarindiol, isolated from carrots prevents the formation of neoplastic lesions in the colon of azoxymethane-induced rats.

Falcarinol (FaOH) and falcarindiol (FaDOH) are found in many food plants of the Apiaceae family. Carrots are a major dietary source of these polyacetylenes. Feeding azoxymethane (AOM)-induced rats with carrots and purified FaOH have previously been shown to inhibit neoplastic transformations in the colon. FaOH and FaDOH have also shown to have a synergistic effect in vitro, resulting in a significant increased cytotoxic activity. Based on these findings the antineoplastic effect of FaOH and FaDOH (purity > 99%) was investigated in the AOM-induced rat model. Twenty rats received rat diet containing 7 µg FaOH per g feed and 7 µg FaDOH per g feed and 20 rats were controls receiving only rat diet. Then carcinogenesis was induced in all 40 rats with the carcinogen AOM. All animals received the designated diet for 2 weeks before AOM induction and continued on the designated diet throughout the experiment. Rats were euthanized 18 weeks after the first AOM injection and macroscopic polyp/cancers were measured, harvested and stained for histology. The difference in sizes of aberrant crypt foci (ACF) were analysed in a Wilcoxon rank sum test, in which the median number of small ACF was 218 in controls and 145 in polyacetylene treated rats (P < 0.001). Fifteen control rats and 8 treated rats had macroscopic tumors (P = 0.027). The number of tumors larger than 3 mm were 6 and 1 in control and treated rats, respectively (P = 0.032). In conclusion dietary supplements with FaOH and FaDOH reduced the number of neoplastic lesions as well as the growth rate of the polyps suggesting a preventive effect of FaOH and FaDOH on the development of colorectal cancer.

Tumor-cell targeting polydiacetylene micelles encapsulated with an antitumor drug for the treatment of ovarian cancer.

Peptide functionalized polydiacetylene (PDA) micelles encapsulated with camptothecin (CPT) kill ovarian cancer cells by the lysosome release of anticancer drug CPT. Moreover, the sub-30 nm PDA micelles penetrate efficiently into a tumor for enhanced therapeutic efficacy.

Pharmacokinetic profiles of falcarindiol and oplopandiol in rats after oral administration of polyynes extract of Oplopanax elatus.

Polyynes, such as facarindiol (FAD) and oplopandiol (OPD), are responsible for anticancer activities of Oplopanax elatus (O. elatus). A novel approach to pharmacokinetics determination of the two natural polyynes in rats was developed and validated using a liquid chromatography-electrospray ionization-mass spectrometry (LC-MS) method. Biosamples were prepared by liquid-liquid extraction using ethyl acetate/n-hexane (V : V = 9 : 1) and the analytes were eluted on an Agilent ZORBAX Eclipse Plus C18 threaded column (4.6 mm × 50 mm, 1.8 µm) with the mobile phase of acetonitrile-0.1% aqueous formic acid at a flow-rate of 0.5 mL·min(-1) within a total run time of 11 min. All analytes were simultaneously monitored in a single-quadrupole mass spectrometer in the selected ion monitoring (SIM) mode using electrospray source in positive mode. The method was demonstrated to be rapid, sensitive, and reliable, and it was successfully applied to the pharmacokinetic studies of the two polyynes in rat plasma after oral administration of polyynes extract of O. elatus.

Sensing and antibacterial activity of imidazolium-based conjugated polydiacetylenes.

In the current study, we report the first example of polydiacetylenes (PDAs), where our PDA-based system acts as both a sensing probe and killer for bacteria. The contact of imidazolium and imidazole-derived PDA with various bacterial strains including MRSA (methicillin-resistant Staphylococcus aureus) and ESBL-EC (extended-spectrum ß-lactamase-producing Escherichia coli) results in a distinct blue-to-red colorimetric change of the solution as well as a rapid disruption of the bacterial membrane, which is demonstrated by transmission electron microscopy and confocal microscopy. Zeta potential analysis supports that antibacterial activity of the PDA solution originates from an electrostatic interaction between the negatively charged bacterial cell surface and the positively charged polymers. These results suggest that the PDA has a great potential to carry out the dual roles of a probe and killer for bacteria.

Anticancer activities of polyynes from the root bark of Oplopanax horridus and their acetylated derivatives.

Six polyynes OH-1~6, some of which are occur naturally in acetylated form, had been isolated and identified from the root bark of Oplopanax horridus (Devil's Club), a natural dietary supplement and medicinal plant in North America. During the evaluation of the polyynes' potential anticancer activities, sixteen more acetylated derivatives OHR-1~16 have synthesized and their anti-proliferation activity on MCF-7, MDA-MB-231, A549, HepG2 and LO2 cells assayed to elucidate their structure-activity relationships. The results showed that OH-1 ((3S, 8S)-falcarindiol) had the most potent anticancer activity, with IC50 values of 15.3, 23.5, 7.7 and 4.7 µM on MCF-7, A549, HepG2 and MDA-MB-231 cells, respectively. For the primary structure-activity relationship, the anticancer activities of polyynes become weaker if their hydroxyl groups are acetylated, the terminal double bonds transformed into single bonds or they contain one more methylene group in the main skeleton chain.

Tumor-targeted polydiacetylene micelles for in vivo imaging and drug delivery.

In vivo tumor targeting and drug delivery properties of small polymerized polydiacetylene (PDA) micelles (∼10 nm) is investigated in a murine MDA-MB-231 xenograft model of breast cancer. Three micelles with different surface coatings are synthesized and tested for their ability to passively target tumor through the enhanced permeability and retention effect. After injection (24 h), fluorescence diffuse optical tomographic imaging indicates a tumor uptake of nearly 3% of the injected dose for the micelles with a 2 kDa poly(ethylene glycol) (PEG)-coating (PDA-PEG2000). The uptake of PDA micelles in tumors is confirmed by co-localization with [(18) F]-fluorodeoxyglucose (FDG) positron emission tomography. Although FDG has a higher diffusion rate in tumors, 40 ± 19% of the retained micelles is co-registered with the tumor volume visualized by FDG. Finally, PDA-PEG2000 micelles are loaded with the hydrophobic anticancer drug paclitaxel and used in vivo to inhibit tumor growth. These findings demonstrate the potential of PDA-PEG2000 micelles for both in vivo tumor imaging and drug delivery applications.

Polyacetylene diols with antiproliferative and driving Th1 polarization effects from the marine sponge Callyspongia sp.

A screening of 30 crude extracts of marine sponges against human promyelocytic leukemia cells (HL-60) yielded an EtOAc extract of the sponge Callyspongia sp. (Callyspongiidae) with significant activity. Further bioassay-guided fractionation of the EtOAc extract led to the isolation of three polyacetylene metabolites: a new polyacetylene diol, callyspongidiol (1), along with two known compounds, siphonodiol (2) and 14,15-dihydrosiphonodiol (3). Their structures were determined by a combination of spectroscopic analyses. Compounds 1-3 exhibited antiproliferative activity against HL-60 with IC(50) values of 6.5, 2.8, and 6.5 microg/ml, respectively. These metabolites induce apoptosis in HL-60 cells. Dendritic cells (DC) differentiated with 1-3 enhance the differentiation of naïve T cells towards the Th1 type.

Cytotoxic activity of polyacetylenes and polyenes isolated from roots of Echinacea pallida.

BACKGROUND AND PURPOSE: The n-hexane extracts of the roots of three medicinally used Echinacea species exhibited cytotoxic activity on human cancer cell lines, with Echinacea pallida found to be the most cytotoxic. Acetylenes are present in E. pallida lipophilic extracts but essentially absent in extracts from the other two species. In the present study, the cytotoxic effects of five compounds, two polyacetylenes (namely, 8-hydroxy-pentadeca-(9E)-ene-11,13-diyn-2-one (1) and pentadeca-(9E)-ene-11,13-diyne-2,8-dione (3)) and three polyenes (namely, 8-hydroxy-pentadeca-(9E,13Z)-dien-11-yn-2-one (2), pentadeca-(9E,13Z)-dien-11-yne-2,8-dione (4) and pentadeca-(8Z,13Z)-dien-11-yn-2-one (5)), isolated from the n-hexane extract of E. pallida roots by bioassay-guided fractionation, were investigated and the potential bioavailability of these compounds in the extract was studied. EXPERIMENTAL APPROACH: Cytotoxic effects were assessed on human pancreatic MIA PaCa-2 and colonic COLO320 cancer cell lines. Cell viability was evaluated by the WST-1 assay and apoptotic cell death by the cytosolic internucleosomal DNA enrichment and the caspase 3/7 activity tests. Caco-2 cell monolayers were used to assess the potential bioavailability of the acetylenes. KEY RESULTS: The five compounds exhibited concentration-dependent cytotoxicity in both cell types, with a greater potency in the colonic cancer cells. Apoptotic cell death was found to be involved in the cytotoxic effect of the most active, compound 5. Compounds 2 and 5 were found to cross the Caco-2 monolayer with apparent permeabilities above 10 x 10(-6) cm s(-1). CONCLUSIONS AND IMPLICATIONS: Compounds isolated from n-hexane extracts of E. pallida roots have a direct cytotoxicity on cancer cells and good potential for absorption in humans when taken orally.

Dendrazawaynes A and B, antifungal polyacetylenes from Dendranthema zawadskii (Asteraceae).

Two new C(14) polyacetylenes dendrazawayne A(7) and dendrazawayne B (9) together with known C(13) polyacetylenes (2, 3), C(14) polyacetylenes (1, 4, and 8) and polyacetylene amides (5 and 6) were isolated from the roots of Dendranthema zawadskii. The structures of 7 and 9 were elucidated based on spectroscopic methods including 2D-NMR, HR-TOF-MS, IR, and UV. Compounds 1, 2, 3, 5, and 6 showed moderate activity against tumor cell lines (human small lung cancer cell line A549, melanoma SK-Mel-2, and mouse melanoma B16F1) with IC(50) values in the range of 7.4 - 30 microg/mL. Compounds 7 and 9, including other polyacetylenes, showed strong activity against the fungus Trichophyton (MIC: 5 - 10 microg/mL).

A novel polyacetylene significantly inhibits angiogenesis and promotes apoptosis in human endothelial cells through activation of the CDK inhibitors and caspase-7.

A novel bioactive polyacetylene compound, 1,2-dihydroxy-5(E)-tridecene-7,9,11-triyne (compound 1), was identified from the Bidens pilosa extract using an ex vivo primary human umbilical vein endothelium cell (HUVEC) bioassay-guided fractionation protocol. Our results demonstrate that compound 1 (at 2.5 microg/mL) possessed significant anti-angiogenic effects, as manifested by an inhibition of HUVEC proliferation, migration, and the formation of tube-like structures in collagen gel. Moreover, compound 1 induced HUVECs to undergo cell death in a concentration- and time-dependent manner. The mechanisms underlying these pharmacological effects include reduced expression of cell cycle mediators such as CDK4, cyclins D1 and A, retinoblastoma (Rb) and vascular endothelial growth factor receptor 1 (VEGFR-1), and promotion of caspase-mediated activation of CDK inhibitors p21(Cip1) and p27(Kip). Moreover, apoptotic induction in HUVECs mediated by compound 1 was found to be in part through overexpression of FasL protein, down-regulation of anti-apoptotic Bcl-2, and activation of caspase-7 and poly(ADP-ribose) polymerase. This study demonstrates the potent anti-angiogenic and apoptotic activities of compound 1, suggesting that phytocompounds such as polyacetylenes deserve more attention regarding their potential as candidates for anti-angiogenic therapeutics.

A bioactive polyacetylene compound isolated from Centella asiatica.

A polyacetylene compound was isolated from the aerial parts of Centella asiatica. The chemical structure of this new compound was identified as methyl 5-[(E)-9-hydroxy-1-(1-hydroxyhexyl)-2-methoxyundeca-3,10-diene-5,7-diynyloxy]pentanoate (cadiyenol). This compound induces apoptosis (63%) independent of cell cycle regimen in mouse lymphoma cells (P388D1) at 28 microM (IC (50) = 24 +/- 2 microM) in 24 hours. The compound also reduces nitric oxide production by 70 +/- 2% in lipopolysacharride-activated mouse macrophages at 24 microM with no measurable cytotoxicity.

Cytopiloyne, a polyacetylenic glucoside, prevents type 1 diabetes in nonobese diabetic mice.

Some polyacetylenes from the plant Bidens pilosa have been reported to treat diabetes. In this study, we report that the cytopiloyne from B. pilosa, which is structurally different from the above-mentioned polyacetylenes and inhibits CD4(+) T cell proliferation, effectively prevents the development of diabetes in nonobese diabetic mice as evidenced by a normal level of blood glucose and insulin and normal pancreatic islet architecture. Cytopiloyne also suppresses the differentiation of type 1 Th cells but promotes that of type 2 Th cells, which is consistent with it enhancing GATA-3 transcription. Also, long-term application of cytopiloyne significantly decreases the level of CD4(+) T cells inside pancreatic lymph nodes and spleens but does not compromise total Ab responses mediated by T cells. Coculture assays imply that this decrease in CD4(+) T cells involves the Fas ligand/Fas pathway. Overall, our results suggest that cytopiloyne prevents type 1 diabetes mainly via T cell regulation.