Protective effects of Astragaloside IV against UVA-induced oxidative stress and apoptosis in HaCaT keratinocytes: an integrated in silico and in vitro study.

Objectives

Ultraviolet A (UVA) radiation induces oxidative stress and apoptosis in keratinocytes, contributing to skin photodamage. Astragaloside IV (ASIV) has antioxidant and cytoprotective activities. This study investigated whether ASIV protects human keratinocytes against UVA-induced oxidative injury and explored potential associated signaling pathways.

Methods

Network pharmacology and molecular dynamics simulations were used to identify core intersecting targets between ASIV and skin photodamage and assess the binding stability of ASIV with key target proteins. In vitro, HaCaT cells were pretreated with 60 μg/mL ASIV and then exposed to 6 J/cm2 UVA. Cell viability, proliferation, migration, apoptosis, and cell cycle progression were evaluated by CCK-8, colony formation, scratch wound healing, and flow cytometry. SOD, GSH, MDA, ROS, and mitochondrial membrane potential (MMP) were measured to assess oxidative stress and mitochondrial function. PI3K/AKT and apoptosis-related proteins were detected by western blotting.

Results

UVA irradiation increased p-PI3K/PI3K, p-AKT/AKT, and cleaved caspase-3/caspase-3 ratios and decreased the BCL-2/BAX ratio. ASIV pretreatment reduced p-PI3K/PI3K and p-AKT/AKT ratios, decreased caspase-3 cleavage, and increased the BCL-2/BAX ratio compared with the UVA group. These changes were accompanied by improved antioxidant status, preserved MMP, and reduced apoptosis.

Conclusions

ASIV pretreatment attenuated UVA-induced injury in HaCaT keratinocytes, reflected by improved antioxidant status, preserved MMP, and reduced apoptosis. These effects were accompanied by altered PI3K/AKT phosphorylation, although causal regulation of PI3K/AKT signaling was not established. ASIV may warrant further investigation as a protective compound against skin photodamage.