جستجوی مقالات مرتبط با کلیدواژه "seaweeds" در نشریات گروه "پزشکی"

Cancer is considered as one of the major health problems worldwide. So far, no completely effective method has been found for cancer treatment. Therefore, the rise of using natural products has been proposed as an alternative therapy in this regard. For many years, the seaweed has been a source of many functional bioactive compounds including polysaccharides, polyphenols, pigments, terpenes, and many others. These compounds have shown many bioactivities including anticancer activity against different kinds of cancer. Bioactive compounds obtained from the seaweed have been demonstrated to cause apoptosis in cancer cells and trigger cell cycle arrest with low cytotoxicity against normal cells. In this review, it was attempted to shed light on the anticancer activity of some seaweed-derived bioactive compounds.

The present study was intended to standardize the protocol for the synthesis of silver nanoparticles (AgNPs) using aqueous extract of Dictyota bartayresiana J.V. Lamouroux and evaluate cytotoxic potentials using brine shrimp bio-assay activity and trypan blue dye exclusion method. The reduction of pure Ag ions was monitored by measuring the UV-Vis spectrum of the solution at 200-900 nm and the characteristic peaks were detected. FTIR analysis was used to detect the characteristic peaks and their functional groups. The powder method of diffraction was employed for structural characterisation of AgNPs . The cytotoxic and anticancer potentials were evaluated by, the brine shrimp bio-assay and trypan blue dye exclusion method against DLA cell lines, repectively . When the D. bartayresiana aqueous extract was mixed with 1 mM AgNO3 solution, the colour of the solution changed from pale yellow to yellowish brown colour. The AgNPs synthesized from aqueous extract of D. bartayresiana showed an absorption of 0.639 at 410 nm. The broadening of peaks indicated that the particles are polydispersed. The capping was confirmed by the existence of bands at 1019.19, 1642.09, 1643.05 and 3401.82 cm–1. The D. bartayresiana AgNPs illustrated nine peaks at 2θ values were 26.661°, 28.388°, 29.947°, 32.244°, 40.553°, 46.223°, 50.19°, 54.78°, 57.448° and 76.67° corresponding to 208, 509, 149, 1681, 257, 833, 178, 275, 272 and 256 planes of silver, respectively. The AgNPs of D. bartayresiana revealed 50% mortality (LC50) of brine shrimp nauplii at 196.5 µl/l. Concentration needed for 50% inhibition of growth of DLA cells was found to be 296.14 µl/l of D. bartayresiana AgNPs. The results of the present study demonstrated a simple, rapid and economically cheap route to synthesize AgNPs using aqueous extract of Dictyota bartayresiana thallus. Cytotoxic studies against Artemia salina confirmed that AgNPs are capable of rendering high cytotoxic activity and hence has a great potential in the preparation of anti-cancer drugs. The synthesized AgNPs may improve the therapeutic and medicinal values of Dictyota bartayresiana.

The antioxidant activity, contents of total phenolics and flavonoids were quantified in the methanolic extracts of four Ulva species(U.clathrata,U.linza,U.flexuosa and U.intestinalis) grown at different parts of northern coasts of the Persian Gulf in south of Iran.The seaweeds were collected from Dayyer,Taheri and Northern Ouli coasts in April 2011. Methanolic extracts of the seaweeds were assessed for their antioxidant activity using DPPH radical scavenging assay and was performed in a microplate reader. All species exhibited a DPPH radical scavenging activity, and among the species, Ulva clathrata demonstrated greater antioxidant potential with a low IC50 (0.881 mg ml-1) in comparison with the other species. Also the highest phenolic content (5.08 mg GAE g-1) and flavonoid content (30.31 mg RE g-1) were observed in U.clathrata.The phenolic and flavonoid contents showed positive correlations with the DPPH radical scavenging activity (p<0.01) and negative correlations with IC50 (p<0.01).The results suggest that these edible green seaweeds possess antioxidant potential which could be considered for future applications in medicine, dietary supplements, cosmetics or food industries.