Multivariate Analysis Revealed Ultrasonic-Assisted Extraction Improves Anti-Melanoma Activity of Non-Flavonoid Compounds in Indonesian Brown Algae Ethanol Extract.

Indonesia has high biodiversity of algae that are under-utilised due to limitations in the processing techniques. Here, we observed the effect of two different extraction methods (cold maceration and ultrasonic-assisted extraction (UAE)) on multiple variables of Indonesian brown algae ethanol extracts (Sargassum polycystum, Sargassum cristaefolium, Sargassum aquifolium and Turbinaria ornata). The variables observed included metabolites screening by untargeted metabolomics liquid chromatography-high-resolution mass spectrometry (LC-HRMS), observation of total phenolic content (TPC), total flavonoid content (TFC), anti-oxidant and B16-F10 melanoma cells cytotoxicity. UAE extracts had higher extraction yield and TPC, but no TFC difference was observed. UAE extract had more lipophilic compounds, such as fatty acids (Palmitic acid, Oleamide, Palmitoleic acid, Eicosapentaenoic acid, α-Linolenic acid, Arachidonic acid), lipid-derived mediators (11,12-Epoxyeicosatrienoic acid ((±)11(12)-EET)), steroid derivatives (Ergosterol peroxide), lipophilic metabolite (Fucoxanthin), and lipid-soluble vitamins (all-trans-retinol). Principle component analysis (PCA) revealed that TPC, not TFC, in the UAE extracts was correlated with the anti-oxidant activities and cytotoxicity of the extracts towards B16-F10 melanoma cells. This means other non-flavonoid phenolic and lipophilic compounds may have contributed to its bioactivity. These results suggest that out of the two methods investigated, UAE could be a chosen method to extract natural anti-melanogenic agents from brown algae.

Macroalgae Sargassum cristaefolium Extract Inhibits Proinflammatory Cytokine Expression in BALB/C Mice.

Ultraviolet radiation (UVR) which could induce skin damage and skin disease is a growing concern due to the increase in global warming. Brown macroalgae Sargassum cristaefolium has been recognized to exhibit UV protective activities. However, the mechanism of its photoprotective activity remains unclear. The purpose of this study is to investigate the potential mechanism of S. cristaefolium's photoprotective activity against UV radiation. Phytochemical analyses revealed valuable bioactive compounds in SCE, such as fucoxanthin which is widely known as an anti-inflammatory carotenoid. Treatment with SCE before UV-A radiation show reduced levels of wrinkles and desquamation. Interestingly, SCE treatment induces the skin healing process after UV radiation. SCE effectively inhibited proinflammatory TNF-α and IL-6 expression while increasing IL-10 production in the BALB/c mice skin. Current results suggest that SCE potentially protects the skin by attenuation of inflammatory cytokines. In addition, SCE demonstrates promising antibacterial activity (MIC = 1.302 µg/mL) against Staphylococcus aureus. Overall, SCE could be a source of an effective anti-inflammatory agent protecting against UV irradiation-induced skin damages.