Cellulose nanocrystal preparation from Gelidium amansii and analysis of its anti-inflammatory effect on the skin in vitro and in vivo

Treated Gelidium amansii cellulose nanocrystal (TGa CNC) was prepared from treated Gelidium amansii (TGa) and evaluated for its anti-inflammatory effect on human keratinocytes and mice skin. Using three independent cell lines, TGa CNC showed no cytotoxicity in HaCaT, Beas-2B, and Raw 264.7 cells. A non-toxic dose of TGa CNC suppressed ultraviolet (UV) B-induced AP (activated protein)-1, and subsequent cyclooxygenase (COX)-2 gene and protein expression in HaCaT cells. TGa CNC suppressed translocation of c-Jun from the cytosol to the nucleus responds to UVB irradiation. Additionally, TGa CNC suppressed UVB-induced extracellular signal-regulated kinases (ERKs)1/2/MEK/2/B-Raf, c-Jun N-terminal kinase (JNK)1/2/MKK4/7, Akt, and epidermal growth factor receptor (EGFR) phosphorylation in HaCaT cells. Dorsal treatment of TGa CNC significantly suppressed acute UVB-induced increase in epidermal thickness and COX-2 expression in mice skin. Overall, these results indicate that TGa CNC exerts potent anti-inflammatory activity through the inhibition of abnormal COX-2 expression and mitogen-activated protein kinases (MAPK)s signaling pathways.