Oxidative stress associated with repeated chemical hair treatments contributes to hair damage and may impair follicular function, creating a need for safer multifunctional materials for hair repair and growth support. This study evaluated the antioxid...
Oxidative stress associated with repeated chemical hair treatments contributes to hair damage and may impair follicular function, creating a need for safer multifunctional materials for hair repair and growth support. This study evaluated the antioxidant activity of an ethanolic extract of Sigesbeckia pubescens (SPE) and examined its effects on chemically damaged hair ex vivo and hair growth in C57BL/6 mice in vivo. Antioxidant activity was assessed using DPPH and ABTS assays. Hair-repair effects were evaluated by methylene blue absorbance, tensile-strength testing, and low-voltage scanning electron microscopy (LV-SEM) in bleached hair fibers. Hair-growth activity was assessed by gross observation, histopathology, and ImageJ-based follicle-length measurements in depilated mice. SPE showed strong radical-scavenging activity, with DPPH and ABTS scavenging rates of 81.24 ± 2.11% at 1.0 ㎎/mL and 89.97 ± 3.76% at 0.25 ㎎/mL, respectively. In damaged hair, 5% SPE reduced methylene blue absorbance to 0.34 ± 0.04, compared with 0.52 ± 0.04 in the damaged control, indicating structural improvement of up to 45%. The same treatment increased tensile strength to 229.15 ± 16.56 N/㎟, corresponding to a 64.41% increase over the damaged control and recovery to 95.20% of the virgin-hair level. LV-SEM confirmed concentration-dependent realignment of disrupted cuticles. In vivo, topical SPE accelerated post-depilation skin darkening from day 7 and increased mean follicle length to 678.68 ± 151.59 ㎛ in the 30% SPE group, compared with 152.14 ± 23.02 ㎛ in the vehicle control and 279.38 ± 38.79 ㎛ in the 5% minoxidil group. These findings suggest that SPE has antioxidant, hair-repairing, and hair-growth- promoting activity and may serve as a promising natural ingredient for functional hair-care formulations.