Anticancer Properties of Ulvan: Molecular Mechanisms, Experimental Evidence, and Translational Potential

Abstract

Ulvan is a sulfated heteropolysaccharide mainly found in the cell wall of green macroalgae belonging to the genus Ulva. Because of its unusual composition, which includes rhamnose, glucuronic and iduronic acids, xylose, and sulfate groups, ulvan has attracted increasing interest as a biologically active marine polysaccharide. A growing body of experimental work suggests that ulvan may interfere with several processes involved in cancer development and progression, including cell proliferation, apoptosis, oxidative stress, inflammation, and cellular signaling. These effects have been reported in different cancer models, including hepatocellular, breast, cervical, colorectal, gastric, prostate, melanoma, and leukemia models. Importantly, the biological activity of ulvan is not uniform and appears to depend strongly on its molecular weight, degree of sulfation, monosaccharide composition, algal species, and extraction procedure. Recent studies have begun to move beyond simple cytotoxicity assays and have identified more specific molecular events, including the miR-542-3p/SLC35F6/TP53 axis in hepatocellular carcinoma. Ulvan-based biomaterials have also opened another line of research in which the polysaccharide is used as a drug-delivery or local treatment platform. Despite these encouraging findings, most available evidence remains preclinical, and questions related to structural standardization, pharmacokinetics, bioavailability, safety, and clinical efficacy remain unresolved. This review summarizes the current evidence on the anticancer activity of ulvan, with particular emphasis on its molecular mechanisms, structure–activity relationships, and possible translational applications.