Antiproliferative effects of isoprenoids from Sarcophyton glaucum on breast cancer MCF-7 cells

Purpose: To evaluate the anticancer activity of isoprenoids of Sarcophyton glaucum on MCF-7 cells and to investigate the potential synergistic effect of doxorubicin.Methods: Isolation and purification of isoprenoids were performed by applying different planar chromatographic methods (CC and PTLC). Further analyses of the isoprenoids by nuclear magnetic resonance (NMR) and mass spectrometry (MS) carried out to identify the compounds. Sulforhodamine- B (SRB) assay was used to determine the cytotoxic activity of the compounds against the MCF-7 human cell line. Flow cytometric analysis was used to assess their impact on cell cycle of  MCF-7. Combination index (CI), when the compounds were combined with  doxorubicin, was calculated to determine possible synergism. The isoprenoid  compounds were also incubated at ¼ or ½ of their respective half-maximal  concentration (IC50) with equimolar concentrations of doxorubicin.Results: Four known isoprenoid derivatives (1-4) were identified as 10(14)-aromadendrene (1), sarcophinediol (2), ent-deoxysarcophine (3) and sarcotrocheliol acetate (4). It was observed that cells accumulated in pre-G phase as well. CI of compound 3 with doxorubicin was 0.67 and 0.79, respectively, at ¼ and ½ of IC50, indicating overt synergism. This was confirmed by re-assessing the cell cycle stages of MCF-7 cells.Conclusion: The results indicate that compound 3 exhibits promising cytotoxicity as well as synergism with doxorubicin in MCF-7 cells. This is attributed, at least partly, to its ability to generate intercellular apoptosis induction.Keywords: Sarcophyton glaucum, Combination index, Antiproliferation, Isoprenoidal derivatives, 10(14)-Aromadendrene,Sarcophinediol, Deoxysarcophine,  Sarcotrocheliol acetate, Doxorubici

Bioactivities of Lyngbyabellins from Cyanobacteria of Moorea and Okeania Genera

Cyanobacteria are reported as rich sources of secondary metabolites that provide biological activities such as enzyme inhibition and cytotoxicity. Ten depsipeptide derivatives (lyngbyabellins) were isolated from a Malaysian Moorea bouillonii and a Red Sea Okeania sp.: lyngbyabellins G (1), O (2), P (3), H (4), A (7), 27-deoxylyngbyabellin A (5), and homohydroxydolabellin (6). This study indicated that lyngbyabellins displayed cytotoxicity, antimalarial, and antifouling activities. The isolated compounds were tested for cytotoxic effect against human breast cancer cells (MCF7), for antifouling activity against Amphibalanus amphitrite barnacle larvae, and for antiplasmodial effect towards Plasmodium falciparum. Lyngbyabellins A and G displayed potent antiplasmodial effect against Plasmodium, whereas homohydroxydolabellin showed moderate effect. For antifouling activity, the side chain decreases the activity slightly, but the essential feature is the acyclic structure. As previously reported, the acyclic lyngbyabellins are less cytotoxic than the corresponding cyclic ones, and the side chain increases cytotoxicity. This study revealed that lyngbyabellins, despite being cytotoxic agents as previously reported, also exhibit antimalarial and antifouling activities. The unique chemical structures and functionalities of lyngbyabellin play an essential role in their biological activities

Chemical composition of corals in Saudi Red Sea Coast

Three species of corals Stylophora pistillata, Lobophyllia corymbosa and Echinopora gemmacea were collected from Sharm Obhur to study their chemical composition. This information was important in the investigation of their metabolic pathways and their mode of feeding. The concentrations of amino acids in these species were 9.37, 21.35 and 3.09 mg.g(-1) dry weight of coral respectively. Plant pigments were highest in E. gemmacea followed by S. pistillata and then by L. corymbosa. Lipid concentrations in S. pistillata, L. corymbosa and E. gemmacea were 1.90, 8.58 and 1.32 mg.g(-1) of total coral respectively. The fatty acid methyl esters were analyzed in these species and the most abundant saturated acids were 16:0 and 18:0, while unsaturated acids included 16:1, 18:1 and 19:3. The carbohydrate concentrations were 559, 425 and 859 mu g.g(-1) of total coral dry weight. Residual matter was 42.5, 32.8 and 41.39 per cent by weight of total coral. These data suggest a greater reliance on autotrophic feeding in E. gemmacea and S, pistillata and mostly heterotrophic feeding in L. corymbosa.Trois espèces de coraux, Stylophora pistillata, Lobophyllia corymbosa et Echinopora gemmacea ont été prélevés à Sharm Obhur afin d'étudier leur composition chimique. Cette information est utile pour l'étude du métabolisme et du mode de nutrition des coraux. Les concentrations en acides aminés des trois espèces étaient respectivement de 9,37; 21,35 et 3,09 mg·g−1. Les pigments végétaux sont plus importants chez E. gemmacea suivi par S. pistillata puis par L. corymbosa. Le contenu lipidique chez S. pistillata, L. corymbosa et E. gemmacea était respectivement de 1,9; 8,58 et 1,32 mg·g−1 du corail total. L'ester méthylique des acides gras a été analysé chez les trois espèces; les plus abondants parmi les acides saturés étaient le 16:0 et le 18:0, alors que les acides saturés comprenaient le 16:1, le 18:1 et le 19:3. Les contenus en hydrates de carbone des trois espèces étudiécs étaient respectivement de 559, 425 et 859 μg·g−1; dans le même ordre la matière résiduelle représentait 42,5, 32,8 et 41,39% du poids total du corail. Ces données suggèrent une plus grande dépendance d'une nutrition autotrophe chez E. gemmacea et S. pistillata et une nutrition partiellement hétérotrophe chez L. corymbosa

Mycosporine-like amino acids in six scleractinian coral species

Mycosporine-like amino acids (MAAs) were studied in stony coral species (Fungiidae) along the Eastern coast of the Red Sea. Six species - Fungia scutaria, F. danai, F. corona, F. repanda, Ctenactis echinata and Lithophyllor lobata - were examined for MAAs at water depths of 5, 10, 15 and 20 m. Protein and chlorophyll were also determined and showed higher contents in winter than in summer. Generally, the total content of MAAs in summer was found to be approximately three times greater than in winter. Overall, concentrations of MAAs were greatest at a depth of 5 m. Porphyra-334 was the most abundant MAA in F. Scutaria and F. Danai, whereas asterina-330 was either not detectable (e.g. L. lobata) or present in low concentrations (e.g. F. danai, F. repanda and C. echinata). Shinorine was not detected in F. danai or L. lobata. Both C. echinata and L. Lobata had the lowest concentrations of MAAs, presumably because of their large calcareous skeletons. The variation in MAA concentrations among seasons and water depths is probably due to a number of factors, including the intensity of solar radiation, turbidity and phylogenetic variation

In vitro Cytotoxic, Antibacterial and Antiviral Activities of Triterpenes from the Red Sea Sponge, Siphonochalina siphonella

Purpose: To study the phytochemical composition of Siphonochalina siphonella sponge from the western coast of the Red Sea and to evaluate the isolates for possible in vitro cytotoxic, antibacterial and antiviral activities.Methods: The compounds obtained were isolated and purified by different chromatographic means. Their structures were established by means of spectral analysis including 1D 1H and 13C and 2D correlation nuclear magnetic resonance (NMR) and high resolution mass spectroscopy (HR-MS). Crystal violet staining method (CVS) was used for the assessment of the cytotoxic activity against HepG-2 and MCF-7 human cell lines, while agar-well diffusion method was employed to measure antimicrobial activity against two Gram-positive and two Gram-negative bacteria. The antiviral activity was determined by the inhibition of cytopathic effect (CPE) in susceptible mammalian cells.Results: Four triterpenes, possessing two different skeletons, were isolated and identified as sipholenone A, sipholenol A, neviotine A and sipholenol L. All four compounds were significantly cytotoxic to MCF-7 and HepG-2 cancer cell lines (p < 0.05) in a concentration-dependent  manner with IC50 (the inhibitory concentration required to reduce cell survival by 50 %) in range 2.8 - 19.2 μg/mL. The highest antibacterial activity was observed for neviotine A (Compound 3) against Bacillis subtilis (17.2 ± 0.58). On the other hand, all the compounds showed moderate to weak anti-viral activity.Conclusion: The findings reveal the strong cytotoxic activity of all the isolated triterpenes from the Red Sea Sponge, S. siphonella. Sipholenone A (Compound 1) displayed significant cytotoxic activity towards MCF-7 and HepG-2 cancer cell lines with IC50 = 3.0 and 2.8 μM, respectively.Keywords: Red Sea Sponge, Siphonochalina siphonella, Triterpenes, Cancer cells, Cytotoxic, Antibacterial, Antivira