Box-Behnken design optimization of ulvan extraction from Ulva lactuca: in silico and in vitro biological activities

This investigation focused on optimizing ulvan extraction from the green seaweed Ulva lactuca and evaluating its anticancer properties against human breast adenocarcinoma (MCF-7) and human colorectal adenocarcinoma (Caco-2) cell lines, as well as its antioxidant, antimicrobial, cytotoxicity against CoxB4 virus, and anticoagulant activities. A Box-Behnken design (BBD) was used to assess how temperatures (70, 80, and 90 °C), extraction times (2, 3, and 4 h), and pH levels (3, 5, and 7) affected ulvan yield and sulfate content. FT-IR, ¹H NMR, and HPLC were employed to characterize the structure of the ulvan. Ulvan exhibited strong cytotoxic activity against CoxB4 virus and demonstrated potent antimicrobial effects against Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae) and the fungus Candida albicans, with no effect against Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus). APTT and PT clotting assays revealed that ulvan has significant anticoagulant capacity. In silico studies confirmed that the protein 3hb5 involved in breast cancer had the highest binding affinity energy with ulvan compounds. Both in vitro and in silico findings indicate that sulfated polysaccharides from U. lactuca possess promising potential for diverse biological applications.