phytochemical profiling and skin cancer-related bioactivity of 𝑺𝒂𝒓𝒈𝒂𝒔𝒔𝒖𝒎 𝒄𝒓𝒂𝒔𝒔𝒊𝒇𝒐𝒍𝒊𝒖𝒎 lipophilic extract

Macroalgae contain bioactive metabolites, including lipid-derived compounds. this study presents a comprehensive analysis of phytochemical profiling and skin cancer-related bioactivity evaluation of sargassum crassifolium, a brown macroalgae abundantly found on lombok coast, indonesia. sargassum crassifolium was extracted with chloroform:methanol:water until the lipophilic extract was obtained. it was then subjected to phytochemical analysis using thin layer chromatography (tlc) and gas chromatography–mass spectrometry (gc-ms)-based untargeted metabolomics. the skin cancer-related bioactivity of the lipophilic extract was analysed, including the spf and uva-pf value using the uv spectrophotometric method. the cytotoxic analysis towards b16-f10 melanoma cells was performed using the resazurin bioassay. both tlc and metabolomics analyses revealed that the lipophilic extract contains lipid-derivative compounds. gc-ms-based untargeted metabolomics data showed that the major compound was isofucosterol (stigmasta-5,24(28)-dien-3-ol, (3b, 24z)-). bioactivity screening revealed that the lipophilic extract exhibited low cytotoxic activity with an ic50 value greater than 1 mg/ml, and had photoprotective activity, with an spf value of 12.73 ± 0.29 and a critical wavelength above 370 nm. these findings suggest that s. crassifolium lipophilic extract does not exhibit effective cytotoxic activity in its crude form. however, it possesses moderate and broad uv protection capability, as indicated by the spf and uva-pf values. the photoprotective ability could be attributed to the phytosterol compound. therefore, s. crassifolium lipophilic extract would be a promising photo-protective agent for dermatology and pharmaceutical formulations. further in vivo experimental studies would be necessary to strengthen these results.