Preliminary study on the antioxidant activity of sulfated polysaccharides from marine sources in vitro
Reactive oxygen species (ROS) are natural secondary products of oxygen metabolism, serving as important “redox messengers” in cellular signaling and homeostasis. Recent studies have shown that ROS is closely related to many pathological and physiological phenomena, such as tumors, inflammation, aging, and circulatory disorders. When the dynamic balance of oxidation and antioxidant in the body is disrupted, the overloaded ROS attacks target organs, triggering a chain reaction of unsaturated alkyl radicals. The resulting peroxides can cause lipid peroxidation of the cell membrane, damage the nucleic acid backbone and protein peptide bonds, and lead to cell apoptosis. Antioxidants can be classified into natural and synthetic sources. Natural antioxidants such as tocopherols, flavonoids, and sulfated polysaccharides, as well as synthetic antioxidants such as tert butylhydroquinone (TBHQ), propyl gallate (PG), butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA). Artificially synthesized antioxidants have some serious toxic side effects on the liver and kidneys, posing safety hazards in their use, while natural antioxidants can avoid these side effects. Therefore, it is of great significance to discover natural antioxidants that can effectively block oxygen free radical reactions and have low toxic side effects for the prevention and treatment of diseases related to free radical imbalance. Marine organisms are highly valued for their diverse nutritional components and physiologically active substances, some of which are not present in terrestrial plants. In research, it has been found that marine organisms such as seaweed and sea cucumber widely contain natural antioxidant active substances. Their tissues contain many free radical scavengers and antioxidants that directly eliminate free radicals or enhance the body’s own antioxidant defense system. Therefore, this article intends to start with the extraction of bioactive substances from three types of seaweed (seaweed, seaweed, and sheep’s seaweed) and one type of sea cucumber (rough sea cucumber), and systematically isolate and detect them. The focus is on studying the antioxidant effects of these marine derived sulfated polysaccharides, and screening out antioxidant substances that inhibit free radical and polyphenol oxidase activity, in order to expand the biological resources of medicinal natural antioxidants.

Polysaccharides are high molecular weight polymers composed of ten or more monosaccharides linked by glycosidic bonds, and have a wide range of pharmacological activities. Numerous studies have shown that this highly efficient and low toxicity free radical scavenger protects the body from oxygen damage, has antioxidant effects on clearing superoxide anions, stabilizing free radicals and other ROS in the body, and thus participates in various important physiological and pathological processes such as antithrombotic, lipid-lowering, hypoglycemic, immune regulation, anti-tumor, anti-inflammatory, anti-aging, etc. In our research results, UPSP and PSP showed certain antioxidant effects, and combined with data from SFSP and HSSP, it was found that these marine derived sulfated polysaccharides have significant effects in scavenging free radicals, suggesting that these sulfated polysaccharides may have anti-inflammatory, anti-aging and other activities. In recent years, there have been some reports on the antioxidant effects of polysaccharides from natural sources, with terrestrial plants and traditional Chinese medicine still accounting for a certain proportion. Polysaccharides from marine sources are mainly sourced from algae, while reports on sea cucumber sources are relatively rare. The results of this study indicate that sulfated polysaccharides derived from seaweed and sea cucumber can exert antioxidant effects by clearing stable free radicals and superoxide anions, and inhibiting polyphenol oxidase activity. In the future, research will be conducted on the composition and structure of these sulfated polysaccharides, as well as their relationship with ROS and polyphenol oxidase inhibitory activity, in order to further explore their mechanisms of enhancing the body’s antioxidant capacity at the in vivo level. In summary, this study obtained good antioxidant activity data through the detection of these four systems, indicating that these marine derived sulfated polysaccharides have the potential to be developed as natural and efficient antioxidants for medicinal and health functions, and thus applied in food, pharmaceuticals, and food additives.