Seaweed is a great source of biologically active metabolites which could prove interesting in cosmeceutical applications. In this study, seven Icelandic seaweed species (Ascophyllum nodosum, Alaria esculenta, Laminaria hyperborea, Digital Laminaria, Saccharina latissima, Palmaria palmata, and Schizymenia jonssonii) were screened for total polyphenol content, antioxidant properties, and inhibition of skin-degrading enzymes. Antioxidant assays included DPPH (2,2-diphenyl-1-picrylhydrazyl), reducing power, and ORAC (oxygen radical absorbance capacity). In most assays, A. nodosum extracts were the most active. A. nodosum extracts also showed the strongest inhibition of the skin-degrading enzymes elastase and collagenase at low concentrations, demonstrating its skin-protective qualities. To further investigate the activity, A. nodosum was subsequently extracted with solvents with increasing polarity into seven different extracts. Compared to other extracts, the extracts obtained by extraction with acetone and methanol showed the highest activity in all assays. Extracts obtained with room-temperature water and 85 °C water also demonstrated moderate to high activities. The outcomes of this study support the potential utilization of the brown seaweed A. nodosum as a source of natural ingredients in cosmeceuticals.
Tag: Antioxidant
Evaluation of antibacterial and antioxidant properties of different chitosan products
In this study, the bactericidal and antioxidant properties of twelve different chitosan substances from Primex ehf. The effect of viscosity / molecular weight (150-360 KDa) and the degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the activity of the substances were assessed. The effect of pH (6 and 6.5) and temperature (7 and 17 ° C) on bactericidal activity was also examined. Antioxidant activity was assessed by four methods: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. Variable antioxidant activity was found in different chitosan substances. A1 had the highest but actually slight reducing and binding properties, while B3 and B4 had the highest ORAC values. Chitosans with 96-100% deacetylation had the highest in vitro antioxidant activity, regardless of their molecular weight. Similarly, the bactericidal activity of the chitosan substances varied among the bacterial species studied, in addition to which the pH and temperature effects were different. However, some chitosan substances were found to work well on all bacterial species, eg A3 ‐ B2 ‐ B3 ‐ C1.
This report evaluates twelve different types of chitosan products manufactured by Primex ehf and tested for their antibacterial and antioxidant properties in a suitable carrier solution. This study examined the effect of viscosity / molecular weight (150‐360 KDa) and degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the properties evaluated, as well as the influence of pH (6 and 6.5) and temperature (7 and 17 ° C) on the antibacterial activity of the chitosan products. The antioxidant activity was evaluated using four assays: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. The different chitosan products had different antioxidant properties. A1 had both some reducing and chelating ability, while B3 and B4 had some oxygen radical absorbance capacity. The radical scavenging ability of high DDA (96‐100%) chitosan products was emphasized. Similarly, the antibacterial activity of the different chitosan solutions differed among the bacterial species evaluated as well as pH and temperature conditions. Nevertheless, some products demonstrated antibacterial activity towards all strains tested: mainly A3 ‐ B2 ‐ B3 ‐ C1.
Report closed until 01.01.2014