Antibacterial and cytotoxic properties of isoprenoids from the red sea soft coral, Lobophytum sp

Purpose: To evaluate the antibacterial and cytotoxic activities of the secondary metabolites of Lobophytum sp.Methods: Maceration with methanol: chloroform (1:1) was applied to extract the coral material. Chromatographic and spectroscopic techniques were employed for fractionation, isolation and elucidation of pure compounds. Antibacterial activities were performed by well diffusion method against three Gram-positive and four Gram-negative bacteria. Brine shrimp lethality test was employed to predict toxicity, while antitumor activity were tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) method against Ehrlich carcinoma cells.Results: Four sesquiterpenes, one cembranoid type diterpenes and two steroids were isolated. 1 exhibited significant antibacterial activity against four tested bacteria (P. aeruginosa, S. aureus, S. epidermis, and S. pneumonia) with MIC value of 15 μg/mL. Moreover, 1 showed high diameter zone of inhibition ranging from 16 - 18 mm against test bacteria. Compounds 4 and 5 displayed moderate antibacterial activity against all test bacteria with inhibition zone diameter (IZD) ranging from 11 – 15 mm and MIC values of 30 μg/mL. 2, 3, 6 and 7 exhibited weak antibacterial activity (IZD, 7 - 11 mm; MIC ≥ 30 μg/mL). In addition, only diterpene compound (4) showed high toxicity against A. Salina and antitumor activity against Erhlich carcinoma cells with the LD50 of 25 and 50 μg/mL, respectively.Conclusion: This study reveals the strong antibacterial activity of sesquiterpene alismol (1) and the potential antibacterial and antitumor activity of cembranoid type diterpene, cembrene A (4).Keywords: Soft coral, Lobophytum sp., Red Sea, Antibacterial, Cytotoxicity, Sesquiterpene Alismol, Cembranoid, Diterpene, Cembren

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

Costus speciosus J Koenig (Costaceae) exerts anti-proliferative effect on breast cancer cells via induction of cell cycle arrest and inhibition of activity of metalloproteinase-2

Purpose: To Investigate the antiproliferative effect of n-hexane-diethyl ether fraction of Costus speciosus (NP) on triple negative breast cancer (MDA-MB-231) cells, and the mechanism involved. Methods: Maceration with methanol (CH3OH) was used for extraction of Costus speciosus rhizomes. Chromatographic separation was used to obtain the non-polar fraction (NP) via elution with n-hexane:(C2H5)2O at a volume ratio of 9:1. The cytotoxic effect of NP was evaluated against two breast cancer cell lines i.e., triple negative (MDA-MB-231) and positive ER (MCF-7) employing 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT) assay, and the IC50 values were estimated. Cell cycle was determined with flow cytometry, while the likely mechanism involved in the cytotoxic effect was investigated using comet assay, immunofluorescence, clonogenic and scratch assays, zymography and detection of the antioxidant markers. Results: NP produced potent cytotoxicity against MDA-MB-231, with IC50 value of 4 ± 0.03 μg/mL, whereas its IC50 for MCF-7 was 27 ± 1.3 μg/mL. It induced apoptosis via cell cycle arrest at G1 phase. Moreover, NP markedly decreased levels of superoxide dismutase (SOD), reduced glutathione (GSH), and matrix metalloprotease-2 (MMP-2), in MDA-MB-231 cells. Moreover, it inhibited cancer cell migration and colony formation. Conclusion: Non-polar fraction of Costus speciosus (NP) exerted cytotoxic effect on triple negative breast cancer cells (MDA-MB-231) and positive ER (MCF-7). It inhibited cancer cell migration and colony formation. Interestingly, NP arrested the breast cancer cell cycles at sub-G1 phase, inhibited SOD and MMP-2, and decreased GSH levels. It induced apoptosis via DNA damage, downregulation of mutant p53, and over-expressions of the cell cycle inhibitors p21 and p27

Vincamine and 14-epi-vincamine indole alkaloids from Ambelania occidentalis

AbstractTwo indole alkaloids, Vincamine 1 and 14-epi-vincamine 2 were isolated here for the first time from Ambelania occidentalis. The structures of these compounds were elucidated by one and two dimension NMR and MS spectroscopy

Legacy and emerging per- and polyfluorinated alkyl substances (PFASs) in sediment and edible fish from the Eastern Red Sea

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In vitro and in vivo study of cucurbitacins-type triterpene glucoside from Citrullus colocynthis growing in Saudi Arabia against hepatocellular carcinoma

Chromatographic investigation of fruits obtained from Citrullus colocynthis, growing in Saudi Arabia, led to isolation of two compounds; Cucurbitacin E glucoside (Cu E, 1), and Cucurbitacin I glucoside (Cu I, 2). The chemical structures of 1 and 2, were elucidated by spectroscopic analyses include; 1D (H-1 and C-13) and 2D (COSY, HMQC and HMBC) NMR and ESI-MS spectroscopy. The in vitro cytotoxic activity against Hepatoma Cell Line (HepG2) and mice-bearing tumor of Ehrlich's ascites carcinoma (EAC) of the compounds were estimated. Both compounds had potent inhibitory activity on HepG2 with IC50 3.5 and 2.8 nmol/mL, respectively. In addition to these activities, the in vivo study employing EAC, showed the capability of both compounds to prolong the survival time, life span and normalize the biochemical parameters of the infected mice with EAC. (C) 2011 Elsevier B.V. All rights reserved

Antioxidant, cytotoxic, antitumor, and protective DNA damage metabolites from the red sea brown alga Sargassum sp

Background: Macroalgae can be viewed as a potential antioxidant and anti-inflammatory sources owing to their capability of producing compounds for its protection from environmental factors such as heat, pollution, stress, oxygen concentration, and UV radiations. Objective: To isolate major compounds which are mainly responsible for the pharmacological activity of brown alga under investigation, Sargassum sp. Materials and Methods: Algal material was air dried, extracted with a mixture of organic solvents, and fractionated with different adsorbents. The structures of obtained pure compounds were elucidated with different spectroscopic techniques, and two pure materials were tested for protection of DNA from damage, antioxidant, antitumor, and cytotoxicity. Results: Four pure compounds were obtained, of which fucosterol (1) and fucoxanthin (4) were tested; it was found that fucoxanthin has strong antioxidant and cytotoxicity against breast cancer (MCF-7) with IC 50 = 11.5 ΅g/ml. Conclusion: The naturally highly conjugated safe compound fucoxanthin could be used as antioxidant and as an antitumor compound

Green Synthesis of TiO₂ Nanoparticles Using Natural Marine Extracts for Antifouling Activity

Titanium dioxide (TiO2) nanoparticles were synthesized via a novel eco-friendly green chemistry approach using marine natural extracts of two red algae (Bostrychia tenella and Laurencia obtusa), a green alga (Halimeda tuna), and a brown alga (Sargassum filipendula) along with a marine sponge sample identified as Carteriospongia foliascens. X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis, X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the crystal structure, surface morphology, and optical properties of the synthesized nanoparticles. Each of the as-synthesized marine extract based TiO2 nanoparticles was individually incorporated as an antifouling agent to form a newly fabricated marine paint formulation. The newly prepared formulations were applied on unprimed steel panels. A comparative study with a commercial antifouling paint (Sipes Transocean Coatings Optima) was carried out. After 108 days of the coated steel panels’ immersion in the Eastern Harbour seawater of Alexandria-Egypt, the prepared paints using B. tenella and C. foliascens extracts demonstrated an excellent antifouling performance toward fouling organisms by inhibiting their settlement and controlling their adhesion onto the immersed panels. In contrast, heavy fouling with barnacles was observed on the surface of the coated panel with the commercial paint. The physicochemical parameters of the seawater surrounding the immersed coated panels were estimated to investigate the influence of the fabricated paint formulations. Interestingly, no effects of the immersed coated panels on the physicochemical characteristics of the surrounding seawater were observed. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents, which could be attributed to the small crystallite sizes of 22.86 and 8.3 nm, respectively, in addition to the incorporation of carbon in the crystal structure of the nanoparticles