Contact dermatitis is a common inflammatory skin disorder characterized by erythematous and pruritic lesions caused by irritant exposure. Ohwia caudata, a traditional medicinal plant, possesses anti-inflammatory and antioxidant properties, but its dermatoprotective potential remains unclear. To investigate the protective effects and mechanisms of Ohwia caudata leaves’ hydroethanolic extract in a murine model of TPA-induced contact dermatitis. Major phytochemicals in Ohwia caudata extract were identified by HPLC–MS. SKH1/J hairless mice were topically treated with Ohwia caudata extract following TPA stimulation. Skin barrier function was assessed by transepidermal water loss and hydration. Inflammatory (IL-6, TNF-α, TGF-β), antioxidant (SIRT1, Nrf2, HO-1), and ERK-related (p-ERK, eIF2α, ATF-4, CHOP) proteins were analyzed by immunoblotting and immunofluorescence. HPLC–MS revealed harmine, swertisin, isoliquiritigenin, eupatilin, 3′,4′-dimethoxyflavone, and nerolidol as key constituents. The extract significantly reduced transepidermal water loss and enhanced hydration, indicating improved barrier integrity. It downregulated IL-6 and TNF-α while restoring TGF-β expression. ERK and downstream eIF2α/ATF-4/CHOP activation were suppressed, whereas SIRT1/Nrf2/HO-1 antioxidant signaling was enhanced. Ohwia caudata leaves hydroethanolic extract protects against TPA-induced dermatitis by improving skin barrier function, suppressing inflammation, and activating antioxidant defense, supporting its potential as a natural therapeutic for inflammatory skin diseases.

Chronic diabetic wounds are characterized by persistent inflammation, impaired angiogenesis, oxidative stress, and defective tissue remodeling, leading to delayed healing. Cordyceps militaris, a medicinal fungus with known anti-inflammatory and antioxidant properties, has shown therapeutic potential in metabolic disorders; however, its role in diabetic wound repair remains unclear. In this study, we evaluated the wound-healing effects of an aqueous extract of C. militaris using in vitro keratinocyte models and a streptozotocin-induced diabetic mouse model. C. militaris treatment significantly accelerated wound closure, improved epidermal regeneration, and enhanced skin barrier integrity. Mechanistically, C. militaris restored HIF-1α and TGF-β1 expression, promoted cell proliferation and fibroblast activation, and increased the expression of matrix metalloproteinases MMP-1 and MMP-2, indicating enhanced extracellular matrix remodeling. In parallel, excessive inflammatory responses were attenuated, as evidenced by reduced IL-6 and TNF-α levels, along with activation of SIRT1/Nrf2/HO-1 antioxidant signaling pathways. Collectively, these findings demonstrate that C. militaris promotes a balanced wound-healing microenvironment and represents a promising natural therapeutic candidate for the treatment of diabetic wounds.