22 research outputs found
New cytotoxic fatty acid esters from the black coral, Antipathes dichotoma
Purpose: To isolate new fatty acid esters from Antipathes dichotoma and investigate their cytotoxic effects on HepG2, WI-38, VERO and MCF-7 cells.Methods: Antipathes dichotoma was collected using scuba at a depth of 10 to 20 m from the Red Sea, and the lyophilized sample (1500 g) was exhaustively extracted thrice using a mixture of chloroform and methanol (1:1, v/v). The extract was concentrated using a vacuum rotatory evaporator to obtain a brown gummy paste which was fractionated on a silica gel chromatography column and further purified using preparative thin layer chromatography (PTLC). The chemical structures of the newly isolated compounds were elucidated by spectroscopic methods such as infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS). The cytotoxicity of the isolated compounds was examined in HepG2, WI 38, VERO and MCF-7 cell lines.Results: Three new aliphatic esters namely, (4Z, 7Z, 10Z, 13Z, 16Z)-1-hydroxynonadeca-4, 7, 10, 13, 16-pentaen-2-yl octanoate (1); (4Z, 7Z, 10Z, 13Z, 16Z)-1-hydroxynonadeca-4, 7, 10, 13, 16-pentaen-2- yl decanoate (2) and 1-hydroxynonadecan-2-yl-octanoate (3) were isolated from A. dichotoma. 1 and 2 displayed moderate cytotoxic activities against the examined cell lines with half-maximal inhibitory concentration (IC50) ranging from 30.1 to 43.0 μg/mL, while compound 3 exhibited poor anti-cancer activity.Conclusion: The results indicate that A. dichotoma is a reservoir of new compounds that have potential anticancer effects.Keywords: Red Sea, Black coral, Antipathes dichotoma, Esters, Cytotoxicit
Cytotoxic effect of acetogenins and sesquiterpenes obtained from the Red alga Laurencia majuscula
Purpose: To evaluate the cytotoxicity of n-hexane extract and its metabolites obtained from the red alga, Laurencia majuscula, against three cancer cell lines HCT-116 (colon cancer), PC-3 (prostate cancer) and HepG2 (liver cancer) cells; and to identify the phytochemical compound(s) involved.
Methods: Solvent extraction, thin layer chromatography, aluminum oxide column chromatography, and preparative thin layer chromatography (PTLC) were employed for isolating pure compounds from nhexane extract of Laurencia majuscula. Nuclear magnetic resonance (NMR) and mass spectrometry (MS) measurements were used for structural elucidation of the compounds. The cytotoxicity of the nonpolar extract and isolated compounds were evaluated against HCT, PC-3, and HepG2 cells using MTT assay, relative to the standard cytotoxic drug (cisplatin).
Results: Three sesquiterpenes (1, 2 and 8), and five acetogenins (3-7) were isolated from the n-hexane extract. The n-hexane extract showed higher potent cytotoxic effect than sesquiterpenes and the acetogenins (3-7).
Conclusion: These results indicate that the n-hexane extract of Laurencia majuscula exerts significant cytotoxicity against HCT-116, PC-3 and HepG2 cell lines, thus suggesting that the plant extract may be effective chemotherapeutic agents for the management of colon, postrate and liver cancer.
Keywords: Red Sea alga, Rhodomelaceae, Polyketides, Terpenes, Anticance
Bodybuilders' accounts of synthol use: The construction of lay expertise online.
Synthol is an injectable oil used by bodybuilders to make muscles appear bigger. Widely available on the Internet, it is reported to carry a wide range of health risks and side effects such as localised skin problems, nerve damage and oil-filled cysts, as well as muscle damage and the development of scar tissue. Given the tension between health risk and quick muscle enlargement, how lay users explain and justify their synthol intake becomes an important question. Drawing on discourse analysis, we focus on how lay expertise is worked up by users in the absence of available specialist knowledge by invoking medical and pharmaceutical discourses as legitimation, providing novices with support, gaining trust through positive personal narratives and thus gaining credibility as experts. Results have clear implications for health promotion interventions with bodybuilders
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
Mathematical Approach for Effect of Growth on the Mechanical Stresses during Soft Tissues and Avascular Tumor
In this Paper, the mathematical model for the study of the distribution of mechanical stresses by the cells within the soft tissues and tumor tissue is discussed. To describe the impact of isotropic growth on the mechanical stresses based on the linear elasticity theory and to study the process of continuous growth. Constitutive law to describe a linearly elastic tumor with continuous volume growth is combined in the model. Two examples is discussed, First case, in one dimensional model of tumor growth in rectangular tube, The model is solved in terms of radial displacement and stresses. In the second case, the effect of isotropic growth during a compressible material is solved in terms of radial displacement and stresses. The implications of two examples and possible model developments are investigated. Comparisons are made with the results in the two cases and numerical results are given and illustrated graphically for each case considered
Mathematical Model for Problem of Stresses in ThermoMagneto-Piezoelectric Material
In this paper, an analytical solution for the stresses in a homogeneous, transversely isotropic, piezo-thermo-elastic material has investigated. The generalized theories of thermo-elasticity have used to investigate the problem. The surface subjected to thermally insulated or isothermal and electrically shorted boundary conditions. Finally, in order to illustrate the analytical development, numerical solution has carried out piezo - thermo-elastic material. The corresponding simulated results of various physical quantities such as displacements and stresses have presented graphically
Biomechanischer Vergleich der Primärstabilität von Kurzschäften vs. Standardschäften
Influence of Vanadium and Niobium Carbide Particles on the Mechanical, Microstructural, and Physical Properties of AA6061 Aluminum-Based Mono- and Hybrid Composite Using FSP
The ceramic particle reinforcement process is one of the most utilized techniques to enhance the metal surface. The current investigation uses vanadium and niobium carbides to reinforce the AA6061 alloy using the friction stir process (FSP). The mechanical properties are evaluated using ultrasound and conventional compressive tests; furthermore, the microstructure and physical properties are carried out to show the effect of single and hybrid additives of ceramic particles on the surface composites of aluminum alloy. Scanning electron microscopy (SEM) is utilized to examine the presence and distribution of the reinforcement VC and NbC particles inside the composite matrix. The microstructure examination revealed a good dispersion and homogenized distribution of the reinforcement particles. The results indicated that reinforcement particles significantly enhanced the mechanical and physical properties. The VC and NbC particles play an important role in improving the surface hardening behavior and grain refinement by restricting grain growth during the dynamic recrystallization process in the FSP action. The hybrid composited AA6061/NbC + VC recorded an increase in the compressive stress, yield stress, and hardness of 25%, 20%, and 50%, respectively, relative to the base metal, in addition to a 55% decrease in the coefficient of the thermal expansion (CTE) was reported. Moreover, the hybrid composite AA6061/NbC + VC significantly affected the corrosion rate with a reduction of 45%
A comprehensive study of Al-Cu-Mg system reinforced with nano-ZrO2 particles synthesized by powder metallurgy technique
Abstract More focus has recently been placed on enhancing the strength, elastic modulus, coefficient of thermal expansion (CTE), wear and corrosion resistance, and other qualities of aluminum (Al) alloys by varying the quantity of ceramics added for a range of industrial uses. In this regard, Al-4.2-Cu-1.6Mg matrix nanocomposites reinforced with nano-ZrO2 particles have been created using the powder metallurgy approach. The microstructure and particle size distributions of the produced powders were analyzed using a diffraction particle size analyzer, XRD, TEM, and SEM. To achieve good sinterability, the powders were compacted and sintered in argon. The sintered nanocomposites' mechanical, elastic, and physicochemical characteristics were measured. Additionally, the behavior of corrosion, wear, and thermal expansion were examined. The results showed a decrease in the particle sizes of the Al-Cu-Mg alloy by adding ZrO2 nanoparticles up to 45.8 nm for the composite containing 16 wt.% ZrO2. By increasing the sintering temperature to 570 °C, the densification of nanocomposites was enhanced. Also, the coefficient of thermal expansion and wear rate remarkably decreased by about 28 and 37.5% by adding 16 wt.% ZrO2. Moreover, microhardness yield, strength, and Young’s modulus were enhanced to 161, 145, and 64%, respectively, after adding 16 wt.% ZrO2. In addition, increasing the exposure time was responsible for decreasing the corrosion rate for the same sample