Protection against UVB-Induced Photoaging by Nypa fruticans via Inhibition of MAPK/AP-1/MMP-1 Signaling

Ultraviolet B (UVB) irradiation is major causative factor in skin aging. The aim of the present study was to investigate the protective effect of a 50% ethanol extract from Nypa fruticans (NF50E) against UVB-induced skin aging. The results indicated that NF50E exerted potent antioxidant activity (IC(50) = 17.55 ± 1.63 and 10.78 ± 0.63 μg/mL for DPPH and ABTS-radical scavenging activity, respectively) in a dose-dependent manner. High-performance liquid chromatography revealed that pengxianencin A, protocatechuic acid, catechin, chlorogenic acid, epicatechin, and kaempferol were components of the extract. In addition, the extract exhibited elastase inhibitory activity (IC(50) = 17.96 ± 0.39 μg/mL). NF50E protected against UVB-induced HaCaT cell death and strongly suppressed UVB-stimulated cellular reactive oxygen species generation without cellular toxicity. Moreover, topical application of NF50E mitigated UVB-induced photoaging lesions including skin erythema and skin thickness in BALB/C mice. NF50E treatment inhibited UVB-induced collagen degradation as well as MMP-1 and IL-1β expressions and significantly stimulated SIRT1 expression. Furthermore, the extract treatment markedly suppressed the activation of NF-κB and AP-1 (p-c-Jun) by deactivating the p38 and JNK proteins. Taken together, current data suggest that NF50E exhibits potent antioxidant potential and protection against photoaging by attenuating MMP-1 activity and collagen degradation possibly through the downregulation of MAPK/NF-κB/AP-1 signaling and SIRT1 activation.