Marine sponge Stylissa flabelliformis is a marine sponge species that is widely found in Indonesia. Marine sponges have been proven to have pharmacological activities including wound healing, cytotoxicity and antimicrobial activity. All these activities are related to its antioxidant potential. Antioxidants are important for human health due to its ability to protect cell damage caused by free radicals. The aim of this research was to study the antioxidant activity of marine sponge (Stylissa flabelliformis) and to observe the phytochemical compound of the marine sponge such as the phenolic and flavonoid content. Extraction was performed using cold maceration with 96% ethanol solvent and continued by rotary evaporator to get the concentrated extract. Antioxidants activity was analysed using DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which examines the inhibitory concentration (IC50) of the ethanol extract. Total phenolic content (TPC) was examined using Gallic acid as the standard, while total flavonoid content (TFC) was examined using quercetin as the standard. The result showed a concentration-dependent antiradical activity by reduction of DPPH with an IC50 value 2000 µg/mL. Total phenolic content was 152,67 mg GAE/g, while the total flavonoid content was 155,79 mg QE/g.

Abstract.Collagen is a fibrous protein that has recently gained high attention from the pharmaceutical industry due to its benefits on the skin. Collagen can be isolated from various resources including marine sponges. Marine sponges are found in a large amount in Indonesia and has not been widely explored for its pharmacology benefits. Here we isolate collagen from a marine sponge Stylissa flabelliformis found in North Lombok Indonesia coast. The isolation of collagen was performed followed by total protein content analysis using modified Bradford protein assay and antioxidant activity measurement using 2,2-diphenyl-1-picrylhydrazyl(DPPH) assay. The total yield of the collagen isolate obtained was 3.5% and it had a total of 0.755mg/ml protein. DPPH assay has shown that the collagen isolate had antioxidant activity with an IC50 of 61.5±2.132 ppm. Based on Spearman correlation assay, the antioxidant activity was found to be correlated with the protein content of the isolate (r value=0.8). These results show the potency of using the collagen isolated from marine sponge Stylissa flabelliformis for further antioxidant benefits.