In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabo...In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabolism were reported inrats using a whole SC preparation with no particular constituent specified. Administration of the preparation lowered serumand hepatic cholesterol levels and improved the HDL/LDL ratio. These functions may be attributed to the stimulatory effectof the extract on the secretion of cholesterol in feces. Novel fucosylated chondroitin sulfates (FCSs) from Ludwigothureagrisea significantly induced fibroblast growth factor 2-dependent angiogenesis in human umbilical vein endothelial cells (HU-VECs). The proangiogenetic activity seemed attributable to the action of the sulfated fucose branches on the polysaccharide.SCs contain mycosporine-like amino acids (MAAs) that are capable of absorbing UV. A biogenetic precursor of MAAs wasfirst reported in SCs. The anti-proliferative effects of a branched chain fatty acid from a sea cucumber on prostate cancercells was reported with the activity of 5-lipoxygenase. Glycosphingolipid constituents in SCs have been systematically ana-lyzed over the past ten years. The results showed that the gangliosides in several SCs differed from those of mammals in thata sialic acid of SC gangliosides directly binded to glucose of cerebroside. Neuritogenic activity of the glycosphingolipids wasdemonstrated in vitro experiments and may lead to the development of therapeutic products for neurological disorders. Ourstudy also showed that sphingoid bases, the hydrolyzed products of glycosphingolipids from SCs, induced significant apoptosisin several tumor cell lines.展开更多
In cyanobacteria both photosynthesis and nitrogen fixation can be affected by UV radiation. Two of the most abundant heterocystous cyanobacteria isolates from a temperate ricefield in Uruguay belonging to Anabaena and...In cyanobacteria both photosynthesis and nitrogen fixation can be affected by UV radiation. Two of the most abundant heterocystous cyanobacteria isolates from a temperate ricefield in Uruguay belonging to Anabaena and Calothrix genus were exposed for 1 or 3 hours to UV-B dosis similar to those to which they are exposed in summer. Anabaena survival after 1 h of UV-B exposure was 10% whereas in Calothrix’s was 30%. Both the quantum yields of photosybtem II fluorescence and O2 photoevolution decreased with time of UV-B exposure for Calothrix and only till 1 h for Anabaena. Only the Calothrix strain presented phycoerithryn as antenna pigment and constitutive UV-B screening mycosporine like aminoacids. In the Anabaena strain, nitrogenase activity was drastically reduced with UV-B irradiation but in Calothrix was not affected. Proline content and lipid peroxidation increased after 3 hours of UV-B exposure only in Anabaena sp. The antioxidant enzyme activities evaluated followed different trends for both isolates, with an increase in superoxide dismutase activity in the Calothrix isolate. These results show that the two nitrogen-fixing cyanobacteria studied have different responses to UV-B radiation and that cyanobacteria diversity may be considered when selecting strains to be used as biofertilizers.展开更多
文摘In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabolism were reported inrats using a whole SC preparation with no particular constituent specified. Administration of the preparation lowered serumand hepatic cholesterol levels and improved the HDL/LDL ratio. These functions may be attributed to the stimulatory effectof the extract on the secretion of cholesterol in feces. Novel fucosylated chondroitin sulfates (FCSs) from Ludwigothureagrisea significantly induced fibroblast growth factor 2-dependent angiogenesis in human umbilical vein endothelial cells (HU-VECs). The proangiogenetic activity seemed attributable to the action of the sulfated fucose branches on the polysaccharide.SCs contain mycosporine-like amino acids (MAAs) that are capable of absorbing UV. A biogenetic precursor of MAAs wasfirst reported in SCs. The anti-proliferative effects of a branched chain fatty acid from a sea cucumber on prostate cancercells was reported with the activity of 5-lipoxygenase. Glycosphingolipid constituents in SCs have been systematically ana-lyzed over the past ten years. The results showed that the gangliosides in several SCs differed from those of mammals in thata sialic acid of SC gangliosides directly binded to glucose of cerebroside. Neuritogenic activity of the glycosphingolipids wasdemonstrated in vitro experiments and may lead to the development of therapeutic products for neurological disorders. Ourstudy also showed that sphingoid bases, the hydrolyzed products of glycosphingolipids from SCs, induced significant apoptosisin several tumor cell lines.
文摘In cyanobacteria both photosynthesis and nitrogen fixation can be affected by UV radiation. Two of the most abundant heterocystous cyanobacteria isolates from a temperate ricefield in Uruguay belonging to Anabaena and Calothrix genus were exposed for 1 or 3 hours to UV-B dosis similar to those to which they are exposed in summer. Anabaena survival after 1 h of UV-B exposure was 10% whereas in Calothrix’s was 30%. Both the quantum yields of photosybtem II fluorescence and O2 photoevolution decreased with time of UV-B exposure for Calothrix and only till 1 h for Anabaena. Only the Calothrix strain presented phycoerithryn as antenna pigment and constitutive UV-B screening mycosporine like aminoacids. In the Anabaena strain, nitrogenase activity was drastically reduced with UV-B irradiation but in Calothrix was not affected. Proline content and lipid peroxidation increased after 3 hours of UV-B exposure only in Anabaena sp. The antioxidant enzyme activities evaluated followed different trends for both isolates, with an increase in superoxide dismutase activity in the Calothrix isolate. These results show that the two nitrogen-fixing cyanobacteria studied have different responses to UV-B radiation and that cyanobacteria diversity may be considered when selecting strains to be used as biofertilizers.
