Hydrolyzed low-molecular-weight polysaccharide from Enteromorpha prolifera exhibits high anti-inflammatory activity and promotes wound healing

Increased anti-inflammatory activity is key to accelerating wound healing. In this study, we prepared three types of water-soluble polysaccharides from Enteromorpha prolifera (PEPs) with different molecular weights by hydrochloric acid hydrolysis and evaluated their anti-inflammatory activity and wound-healing effects. The results showed that, under in vitro conditions, the low molecular-weight polysaccharide (LPEP) exhibited high anti-inflammatory activity and suppressed the production of nitric oxide (NO), tumour necrosis factor α (TNF-α), and interleukins (IL-1β, and IL-6) from macrophage RAW 264.7 cells through the TLR2-dependent NF-κB, PKC/ERK/MAPK, and PI3K/Akt signalling cascades, in a dose-dependent manner. Under in vivo conditions, the LPEP showed remarkable anti-inflammatory activity, effectively reduced TNF-α production within 14 days, and significantly promoted wound healing to reach wound closure rates of up to 99.0%. Further, a higher number of fibroblast cells and a lower number of inflammatory cells were observed around the wound site in LPEP- and amoxicillin-treated rats than in 0.9% NaCl-treated rats. Similarly, faster tissue regeneration and more skin appendages were found for these two treatment groups. This study demonstrates the potential of LPEP as an effective anti-inflammatory agent to reduce inflammation and promote wound healing.