Sea bass (Lateolabrax maculatus) accelerates wound healing: A transition from inflammation to proliferation

Sea bass (Lateolabrax maculatus) has been used for dietary therapy practice for wound healing of puerperal or surgery patients in China. Traditional Chinese medicinal books also documented that sea bass can be used to manage inflammation-associated conditions such as wound, miscarriage and cough. Some studies also proved that dietary supplement with fish benefited for treating many inflammatory - associated conditions, such as cardiovascular disease, ulcerative colitis and hyperlipidemia. However, the studies on the pharmacological mechanisms of wound healing efficacy of sea bass remain lack of investigation.

The aim of this study is to investigate the molecular mechanisms of sea bass on wound healing efficacy. Establishing a further justification for clinical application of aqueous extract of sea bass (ASB) in treating wound healing.

Transition from inflammation to proliferation phase treated as the critical step in wound repair which were investigated via in vitro and in vivo study. A series of inflammatory mediators associated with wound healing and proliferation effects of fibroblasts upon treatments were studied via Western blotting, enzyme-linked immunosorbent assay (ELISA), real time reverse transcription-polymerase chain reaction (RT-PCR) and scratch assay. The cutaneous wound model was applied on skin wound healing study to observe the healing process in C57BL/6 mice upon ASB treatments. Hematological parameters and tumor necrosis factor-α (TNF-α) secretions in serum were determined. Histopathological examinations were conducted by hematoxylin and eosin (H&E) staining and Masson staining. Immunofluorescence were performed to identify infiltrating neutrophils (MPO) and α-smooth muscle actin (α-SMA).

Results showed that ASB significantly reduced the production of inflammatory mediators cyclooxygenase-2 (COX-2), nitrite oxide (NO) production and TNF-α. The phosphorylation and nuclear protein levels of transcription factor nuclear factor-κB (NF-ĸB) in toll-like receptor 4 (TLR4) signaling were decreased by ASB treatment as well. Wound closure rate and cyclin D1 expression level of fibroblasts were significantly increased by ASB treatments. Moreover, cutaneous wound model in C57BL/6 mice presented many similarities in appearance to the process of wound healing.

The in vitro study demonstrated an inhibitory effect of ASB on the inflammatory mediators regulated by TLR4 signaling pathways, providing evidence that ASB treatment potentially accelerate the wound healing through migration and proliferation enhancement. Additionally, the in vivo study suggested that ASB treatment has a potential in accelerating the proliferation phase of wound healing via well-organized abundant collagen deposition, angiogenesis and re-epithelialization in wounds. The present findings can be treated as a pharmacological basis for the folk use of sea bass and further studies in biological and medical fields.