Extraction Of Astaxanthin From Haematococcus Pluvialis And Astaxanthin Protection For Human Skin Fibroblasts

Astaxanthin (AST) is a kind of red carotenoid, and there are powerful antioxidant and anti-inflammatory effects. It is of particular interest in nutrition and human health. With the development of application of astaxanthin, the solvent safety used to be in the extraction has being become more and more important.In the present paper, in order to get a novel method with the low toxicity and high efficiency, various kinds of solvents were screened, and different extracted conditions on the extraction of astaxanthin from Haematococcus pluvialis were analyzed and optimized, such as solid-liquid ratio, temperature, extraction time.UVA irradiation is regarded as one of main causes of skin photoaging. In the UVA-induced inflammatory responses, intra-cellular reactive oxygen species (ROS) is involved in initiating and triggering the related signaling. ROS can damage the lipids and proteins such as collagen of cells and upregulate the expression of matrix metalloproteinases, finally, result in changes of skin photoaging.Human skin fibroblasts (HSF) cells were employed to set up an UVA-induced cell photoaging model in the study. Morphology of cells was observed under inverted microscope. Cell proliferation and viability was detected by Methyl thiazolyl tetrazolium (MTT) assay. To analyse the effect of AST on UVA-induced skin photoaging, activities of reactive oxygen species, malondialdehyde, and protein carbony were measuring. Combined with the technology of Real-time reverse transcription quantitative polymerase chain reaction and Western blot, the mechanisms of the UVA caused photoaging was conducted.The major results of present study were as follows:1. The orthogonal test results indicated that the most important factor was solid-liquid ratio, followed by extraction time, temperature, solvent in order. Treated the Haematococcus pluvialis with ethylacetate:ethanol(1:1) with solid-liquid ratio 1:100 in water bath (40?,20 min), the optimal extraction yield of astaxanthin was 49.96%. The content of AST in extracts was from 21.15 to 22.32%.2. The effect of UVA and AST treatment on cell viabilityThe result showed that cell toxicity was increased by UVA irradiation in a dose-dependent manner. The viability of cells decreased about 50% under UVA treatment of 10.5 J/cm2. However, AST at a concentration of 6 ?M alleviated the suppression induced by UVA.3. The effect of AST treatment on antioxidant activities of cellsUVA-induced oxidative stress was reversed when the cells were pretreated with AST. The pretreatment with 6 ?M AST decreased levels of intracellular ROS, MDA and protein oxidation by 11.98%,30.25%,30.05%, compared with the control. The result indicated that AST can protect skin from photoaging by alleviate oxidative stress.4. The effect of AST treatment on expression of MMPs genes and collagensWith the pretreatment of AST, the expression levels of MMP-1, MMP-3 were reduced 53.8%,29.5%, in comparison to the control group. At the same time, the mean levels of Collagen ????? were increased by 59%,49%,15%. The result showed that AST had the effect of regulating the expression of collagens by inhibiting the overexpression of MMPs genes induced by UVA.