Chlorella Polysaccharide Extract Attenuates Skin Aging via MAPK Pathway Suppression: Implications for Cosmetic Dermatology.

<h4>Background</h4>Chlorella polysaccharide extract (CPE) is a natural compound with known antioxidant and immunomodulatory properties. This study investigated its anti-aging potential and underlying mechanism, with a focus on dermatological relevance.<h4>Methods</h4>The anti-aging effects of CPE were evaluated using an oxidative stress-induced zebrafish model in vivo. Key parameters assessed included reactive oxygen species (ROS), malondialdehyde (MDA), neutrophil infiltration, pro-inflammatory factors, superoxide dismutase (SOD) and catalase (CAT) activities, anti-inflammatory IL-10 levels, and senescence(definition)-associated β-galactosidase (SA-β-gal) activity. Network pharmacology identified the involved pathways. In vitro validation in oxidatively stressed HaCaT cells measured senescence/inflammation-related genes (P53, c-JUN, STAT3, NF-κB) and MAPK phosphorylation (Jnk, p38).<h4>Results</h4>In the zebrafish model, CPE significantly reduced ROS, MDA, neutrophil infiltration, and pro-inflammatory factors, while enhancing SOD, CAT, and IL-10 levels. Notably, CPE suppressed SA-β-gal activity, indicating a direct anti-aging effect. Network pharmacology identified the MAPK signaling pathway as central to CPE's mechanism of action. In HaCaT cells, CPE downregulated P53, c-JUN, STAT3, and NF-κB, and specifically inhibited the phosphorylation of Jnk and p38 kinases within the MAPK cascade.<h4>Conclusions</h4>CPE exerts potent anti-oxidative, anti-inflammatory, and anti-aging activities primarily through suppression of the MAPK signaling pathway, leading to reduced expression of downstream mediators. These findings highlight CPE as a promising bioactive ingredient for dermatological applications and functional skincare products.