Abstract
Crassostrea sikamea (C. sikamea) is used as an important edible and medicinal seafood in China. In the present study, an aqueous extract of C. sikamea (AECs) was prepared, and its immunomodulatory effects on rat splenocytes were studied. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay revealed that AECs was able to promote splenocyte proliferation. Moreover, flow cytometry revealed that AECs treatment markedly altered the populations of splenic lymphocyte subtypes. Data from real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) showed that AECs promoted the mRNA expression and secretion of TNF-α, IL-2, IL-6, IL-12, and IFN-γ. Mechanistically, p38 MAPK phosphorylation in splenocytes was significantly upregulated under AECs treatment and p38 MAPK inhibitor reversed the promoting effect of AECs on the expression of inflammatory cytokines. Collectively, our novel evidence suggests that AECs exhibits immunomodulatory activity in vitro, supporting the further application of C. sikamea as a potential functional food.