Antioxidant and Anti-Inflammatory Properties of Anthocyanins Extracted from Oryza sativa L. in Primary Dermal Fibroblasts

Abstract

Flavonoids are naturally active substances that form a large class of phenolic compounds abundant in certain foods. Black rice (Oryza sativa L.) contains high levels of anthocyanin polyphenols, which have beneficial effects on health owing to their antioxidant properties. The breakdown of collagenous networks with aging or skin deterioration results in the impairment of wound healing in the skin. Accordingly, reviving stagnant collagen synthesis can help maintain dermal homeostasis during wound healing. This study presents an assessment of the cellular activity of anthocyanins (ANT) extracted from Oryza sativa L., providing information necessary for the development of new products that support natural healing processes. The relative composition of ANT from Oryza sativa L. was determined by high-performance liquid chromatography/diode array detection. ANT promoted the migration of rat dermal fibroblasts (RDFs) and demonstrated antioxidant properties. ANT increased the mRNA expression of collagen type I alpha 2 (COL1A2) and upregulated type I collagen protein levels in H2O2-stimulated RDFs without cytotoxicity. Compared with the untreated group, treatment of RDFs with ANT in the presence of H2O2 led to the activation of signaling pathways, including the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and Akt, whereas it significantly (p<0.001) inhibited the phosphorylation of IκBα and suppressed the activation of the nuclear factor-kappa B (NF-κB) subunits, p50 and p65, which are transcription factors responsible for inflammation. Taken together, our findings suggest that ANT from Oryza sativa L. have anti-inflammatory properties and antiaging potential by modulating type I collagen gene expression and suppressing H2O2-induced NF-κB activation in skin fibroblasts.