Clerodendrum trichotomum Extract Attenuates UV-B-Induced Skin Impairment in Hairless Mice by Inhibiting MAPK Signaling.

Background: Exposure to solar ultraviolet-B (UV-B) radiation significantly accelerates skin aging by inducing the expression of matrix metalloproteinases (MMPs) such as MMP-1, leading to alterations in the extracellular matrix and consequent photoaging. Some plant components, renowned for their UV-absorbing and antioxidative properties, show potential for mitigating photoaging by reducing UV-B-induced MMP levels. In this context, we explored the inhibitory effects of Clerodendrum trichotomum extract (CTE) on UV-B-induced skin damage.

Methods: The mechanism of CTE was predicted using network pharmacology approach. Also, antiaging efficacy was evaluated by mouse model and cellular system using human epidermal keratinocytes (HEKa), including its modulation of mitogen-activated protein kinase (MAPK) signaling pathways.

Results: CTE effectively counters UV-B-induced skin damage, as evidenced by the suppression of MMP-9 and MMP-1 expression in mice. We found that each fraction and chemical constituents of CTE suppressed UV-B-induced MMP-1 secretion in HEKa cells.

Conclusion: CTE inhibits UV-B-induced skin aging by partially suppressing MMP-1 and MMP-9 secretion via the modulation of MAPK signaling pathways.