Abstract This study aimed to evaluate the inhibitory effects of water-soluble uronans (the low-molecular-weight analogues of alginic acids) isolated from Alaria fistulosa on ROS generation and MMP-1 expression in vitro using an immortalized human keratinocyte cell line. HaCaT cells were pretreated with A. fistulosa uronans (0.1, 1 and 10 μg/ml, respectively) prior to UVB irradiation and incubated for 24 h. ROS production was determined via the DCFH-DA method. MMP-1 mRNA and protein were determined by RT-PCR and Western blot analysis, respectively. The effect of A. fistulosa uronans on MMP-1 promoter activity was measured by luminometer. Pretreatment with 10 μg/ml uronans significantly inhibited UVB-induced ROS generation and MMP-1 expression relative to UVB irradiation alone (p<0.05). Uronans significantly reduced MMP-1 mRNA expression and inhibited UVB-induced MMP-1 promoter activity at concentrations of 1 and 10 μg/ml relative to UVB irradiation alone (p<0.05). Therefore, the results suggest that A. fistulosa uronans may be a potential therapeutic agent for the prevention and treatment of skin photoaging.
Keywords Uronan, Reactive oxygen species, Matrix metalloproeinase-1, Photoaging.