<p>Oxyresveratrol, a natural derivative of resveratrol, has been shown to possess antimelanogenic properties. However, the underlying mechanism and its effect on melanin transfer remain poorly understood. In this study, the effects and mechanisms of oxyresveratrol on melanogenesis, dendrite formation, and melanosome transport were investigated. In vitro assays indicated that oxyresveratrol is a potent inhibitor of human tyrosinase, with an IC₅₀ value of 2.27&#xa0;µg/mL. Treatment of B16F10 melanoma cells with oxyresveratrol suppressed melanogenesis through the down-regulation of the MC1R/cAMP/MITF signaling pathway. In a co-culture model of B16F10 and HaCaT cells, oxyresveratrol inhibited both melanin transfer and dendrite formation by down-regulating the expression of small GTPases (CDC42, RAB17, RAB11B, RAC1) and the kinesin KIF5B. These findings suggested that oxyresveratrol may serve as a promising therapeutic agent for pigment-related disorders by inhibiting melanogenesis, dendrite formation, and melanosome transport.</p>