A Ramos

Colon cancer chemoprevention by sage tea drinking: decreased DNA damage and cell proliferation

Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2O2‐induced and azoxymethane‐induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption. Copyright

Cytotoxic activity of Secondary Metabolites from Marine-derived Fungus Neosartorya siamensis in Human Cancer Cells.

Compounds isolated from the marine sea fan‐derived fungus Neosartorya siamensis (KUFA 0017), namely, 2,4‐dihydroxy‐3‐methylacetophenon (1), chevalone C (2), nortryptoquivaline (4), tryptoquivaline H (6), tryptoquivaline F (7), fiscalin A (8), epi‐fiscalin A (9), epi‐neofiscalin A (11) and epi‐fiscalin C (13) were tested for anti‐proliferative activity by MTT assay, DNA damage induction by comet assay, and induction of cell death by nuclear condensation assay on colon HCT116, liver HepG2 and melanoma A375 cancer cell lines. Compounds 2, 4, 8, 9, 11 and 13 presented IC50 values ranging from 24 to 153 μM in the selected cell lines. Cell death was induced in HCT116 by compounds 2, 4 and 8. In HepG2, compounds 4, 8, 9 and 11 were able to induce significant cell death. This induction of cell death is possibly not related to genotoxicity because none of the compounds induced significant DNA damage. These results suggest that selected compounds present an interesting anti‐proliferative activity and cell death induction, consequently showing potential (specifically epi‐fiscalin C) as future leads for chemotherapeutic agents. Further studies on mechanisms of action should ensue. Copyright

Anticancer effects of seaweed compounds fucoxanthin and phloroglucinol, alone and in combination with 5-fluorouracil in colon cells

ABSTRACT Colorectal cancer therapy with 5-fluorouracil (5-Fu) frequently become ineffective due to resistance to this drug; and thus other effective compounds are essential for therapy. It is well-known marine brown seaweeds contain antioxidant compounds the carotenoid fucoxanthin (Fx) and polyphenolic compound phloroglucinol (Ph) which exerted diverse biological activities including antioxidant and anticancer. The aim of this study was to determine the anticancer activities of Fx or Ph alone as well as combination of each chemical with 5-Fu on two human colorectal cancer cell lines (HCT116 and HT29), with comparison to responses in a normal colon cell line (CCD-18Co). Effects of these compounds on cell viability, induction of DNA damage, and cell death were evaluated using MTT assay, comet assay, nuclear condensation assay, and Western blot. 5-Fu decreased cell viability in a concentration-dependent manner in HCT116 and HT29 cells but was not cytotoxic in CCD-18Co cells. 5-Fu induced DNA damage in HCT116 cells with induction of cell death, while no marked effects on DNA damage and cell death were observed in HT29 cells. Fx or Ph alone also reduced cell viability in both cancer cell lines but no apparent cytotoxic effect in CCD-18Co cells, except for Fx at 50 and 100 µM. Diminished cell viability was accompanied by induction of DNA damage (by Fx) and induction of cell death (by Ph). In combination with 5-Fu, Fx at 10 µM (in HCT116 and HT29 cells), and Ph at 300 µM (in HT29 cells) enhanced the cytotoxic effect of 5-Fu; however, no marked cytotoxicity was noted in CCD-18Co cells. Since Fx and Ph alone reduced cancer cell line viability without an effect on normal cells and when in combination enhanced the cytotoxic effect of 5-Fu only in colon cancer cells, these compounds seem promising as anticancer agents.

Bis-Indolyl Benzenoids, Hydroxypyrrolidine Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus Aspergillus candidus KUFA0062

A previously unreported bis-indolyl benzenoid, candidusin D (2e) and a new hydroxypyrrolidine alkaloid, preussin C (5b) were isolated together with fourteen previously described compounds: palmitic acid, clionasterol, ergosterol 5,8-endoperoxides, chrysophanic acid (1a), emodin (1b), six bis-indolyl benzenoids including asterriquinol D dimethyl ether (2a), petromurin C (2b), kumbicin B (2c), kumbicin A (2d), 2″-oxoasterriquinol D methyl ether (3), kumbicin D (4), the hydroxypyrrolidine alkaloid preussin (5a), (3S, 6S)-3,6-dibenzylpiperazine-2,5-dione (6) and 4-(acetylamino) benzoic acid (7), from the cultures of the marine sponge-associated fungus Aspergillus candidus KUFA 0062. Compounds 1a, 2a–e, 3, 4, 5a–b, and 6 were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only 5a exhibited an inhibitory effect against S. aureus ATCC 29213 and E. faecalis ATCC29212 as well as both methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) strains. Both 1a and 5a also reduced significant biofilm formation in E. coli ATCC 25922. Moreover, 2b and 5a revealed a synergistic effect with oxacillin against MRSA S. aureus 66/1 while 5a exhibited a strong synergistic effect with the antibiotic colistin against E. coli 1410/1. Compound 1a, 2a–e, 3, 4, 5a–b, and 6 were also tested, together with the crude extract, for cytotoxic effect against eight cancer cell lines: HepG2, HT29, HCT116, A549, A 375, MCF-7, U-251, and T98G. Except for 1a, 2a, 2d, 4, and 6, all the compounds showed cytotoxicity against all the cancer cell lines tested.

Marine-derived fungi extracts enhance the cytotoxic activity of doxorubicin in nonsmall cell lung cancer cells A459

Background: Drug resistance is a major concern in the current chemotherapeutic approaches and the combination with natural compounds may enhance the cytotoxic effects of the anticancer drugs. Therefore, this study evaluated the cytotoxicity of crude ethyl extracts of six marine-derived fungi – Neosartorya tsunodae KUFC 9213 (E1), Neosartorya laciniosa KUFC 7896 (E2), Neosartorya fischeri KUFC 6344 (E3), Aspergillus similanensis KUFA 0013 (E4), Neosartorya paulistensis KUFC 7894 (E5), and Talaromyces trachyspermum KUFC 0021 (E6) – when combined with doxorubicin (Dox), in seven human cancer cell lines. Materials and Methods: The antiproliferative activity was primarily assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: Two extracts, E1 and E2, demonstrated a significant enhancement of Doxs cytotoxicity in nonsmall cell lung cancer A549 cells. Accumulation of Dox in the nuclei increased when A549 cells were treated in combination with extracts E1 and E2, with induction of cell death observed by the nuclear condensation assay. The combination of E2 with Dox increased the DNA damage as detected by the comet assay. Ultrastructural observations by transmission electron microscopy suggest an autophagic cell death due to an increase of autophagic vesicles, namely with the combination of Dox with E1 and E2. Conclusion: These findings led to the conclusion that the fungal extracts E1 and E2 potentiate the anticancer action of Dox, through nuclear accumulation of Dox with induction of cell death mainly by cytotoxic autophagy.

Crude Extracts of Marine-derived and Soil Fungi of the Genus Neosartorya Exhibit Selective Anticancer Activity by Inducing Cell Death in Colon, Breast and Skin Cancer Cell Lines.

Background: The crude ethyl acetate extracts of marine-derived fungi Neosartorya tsunodae KUFC 9213 (E1) and N. laciniosa KUFC 7896 (E2), and soil fungus N. fischeri KUFC 6344 (E3) were evaluated for their in vitro anticancer activities on a panel of seven human cancer cell lines. Materials and Methods: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed, after 48 h treatments with different concentrations of extracts, to determine their concentration of the extract or Dox that inhibits cell viability by 50% for each cell line. The effects of the crude extracts on DNA damage, clonogenic potential and their ability to induce cell death were also assessed. Results: E1 was found to the void of anti-proliferative effects. E2 was shown to decrease the clonogenic potential in human colorectal carcinoma cell line (HCT116), human malignant melanoma cell line (A375), human breast adenocarcinoma cell line (MCF7), and human caucasian colon adenocarcinoma Grade II cell line (HT29) cells, whereas E3 showed such effect only in HCT116 and MCF7 cells. Both extracts were found to increase DNA damage in some cell lines. E2 was found to induce cell death in HT29, HCT116, MCF7, and A375 cells while extract E3 increased cell death in MCF7 and HCT116 cell lines. Conclusion: The results reveal that E2 and E3 possess anticancer activities in human colon carcinoma, breast adenocarcinoma, and melanoma cells, validating the interest for an identification of molecular targets involved in the anticancer activity.

Cytotoxic activity of fucoxanthin, alone and in combination with the cancer drugs imatinib and doxorubicin, in CML cell lines

In the present study, we evaluate the in vitro cytotoxicity of fucoxanthin (Fx) on two human leukemia cell lines, K562 and TK6, alone and in combination with the conventional anticancer drugs imatinib (Imat) and doxorubicin (Dox). For the purpose, we assessed the cytotoxic and proliferation effects by cell count, induction of DNA damage by comet assay, and cell death by nuclear condensation, annexin V staining, coupled with propidium iodide uptake, and protein expression of Bax, caspase-3, and Bcl-2 (western blot). Our results show that Imat increased cytotoxicity in TK6 cells and inhibited proliferation in K562 cells, while Dox decreased cell viability and proliferation in both cell lines. Fx per se increased cytotoxicity against K562 cells and decreased cell proliferation of K562 and TK6 cells. The effects were confirmed by phase contrast microscopy. However, the antiproliferative effects are not explained by induction of DNA damage or cell death. In co-incubation, Fx increased antiproliferative effects of both drugs in the cell lines tested, however no differences where observed relative to Fx alone. This study unveiled in vitro cytotoxicity of Fx by inhibition of cell proliferation in both cell lines. Further studies are needed to elucidate the signal transduction pathways and molecular targets involved in that effect.