Introduction: Glycogen synthase kinase-3 (GSK-3) is an important immune regulator that controls inflammation via inhibition of its protein kinase activities. Persistent inflammatory responses through the activation of immune cells and excessive production of immune mediators may cause tissue destruction and implicated in the development of chronic inflammatory diseases. The objective of this study was to examine the role of Tideglusib, a GSK-3 inhibitor, in inflammatory responses elicited through macrophage activation by investigating the expression of cell surface biomarkers and inflammatory molecule levels. Method: The effects of GSK-3 inhibition by Tideglusib on the expression of CD11b and CD40 and secretion of pro-inflammatory cytokines in the lipopolysaccharide (LPS)-activated macrophage-derived RAW 264.7 cells were determined by flow cytometry, while the presence of nitric oxide (NO) was determined by Griess assay. Results: Stimulation of RAW 264.7 cells with LPS increased substantial levels of CD11b and CD40 expressions, and secretion of NO, TNF-α, and MCP-1. However, the expression of these molecules was suppressed through inhibition of GSK-3. Conclusion: These findings suggest the significant role of Tideglusib to limit the upregulation of immune responses in activated macrophages, and as a potential anti-inflammatory drug for the intervention and treatment of inflammatory diseases.

Introduction: Ultraviolet (UV) A is the longest wavelength of UV radiation, accounts for approximately 95% of the radiation reaching the earth's surface. It can penetrate deeply into the skin layer and able to induce photoaging and photocarcinogenesis through the activation of reactive oxygen species (ROS). Polysaccharides-containing Pleurotus flabellatus (known as a pink oyster mushroom) has antioxidative properties and may inhibit free radical activities generated from UV radiation. Hence, this present study was to evaluate the antioxidative and photoprotective properties of exopolysaccharides (ExPFE) and exopolysaccharides (EnPFE) of Pleurotus flabellatus extracts on UVA irradiated human dermal fibroblast (HS-27) cell line. Methods: The antioxidant level of ExPFE and EnPFE was determined using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, while both cytotoxicity and photoprotective effects of the extracts on the HS-27 cell line were determined using CellTiter-Blue® cell viability assay. The effects of ExPFE and EnPFE on the HS-27 cell migration was evaluated using the scratch assay. Results: Both ExPFE and EnPFE exhibited respectable antioxidant and scavenging activity in DPPH. The extracts also demonstrated a non-cytotoxicity, but photoprotective effects to the HS-27 cells by increasing the percentage of cell viability and enhancing cell migration activity upon UVA exposure. Conclusion: The ExPFE and EnPFE exhibit antioxidative and photoprotective effects on UVA irradiated HS-27 cell line. This study suggests that pink oyster polysaccharides could be a potential natural bioactive compound for skin protection against UVA radiation.