Antioxidant Activity of Ethanol Extract of Secang Wood (Caesalpinia sappan L.) and Its Effects on Cell Viability and Collagen Synthesis in Blue Light-Exposed Fibroblasts

Abstract

Exposure to blue light (400-500 nm), derived from sunlight and artificial light sources such as electronic devices and indoor lighting, has been linked to harmful biological effects. Prolonged exposure can reduce antioxidant capacity, leading to oxidative stress, cellular dysfunction, and DNA damage. Caesalpinia sappan (secang wood) contains flavonoids and phenolic compounds with known antioxidant properties. This study aimed to evaluate the antioxidant activity of the ethanol extract of Indonesian secang wood and its effects on fibroblast viability and collagen synthesis following blue light exposure. Phytochemical analysis was performed to determine flavonoid and phenolic content, while antioxidant activity was assessed using the DPPH assay. Fibroblast viability was analysed using the MTT assay, and collagen synthesis was measured using the Sirius Red assay. The extract demonstrated high flavonoid (5.93 mg QE/100 g) and phenolic content (2.86 mg GAE/100 g), along with strong antioxidant activity (IC₅₀: 7.8 µg/mL), exceeding that of the reference herbal extract (Artemisia capillaris). In fibroblasts exposed to blue light, treatment with secang wood extract significantly improved cell viability and collagen synthesis compared to untreated controls. In conclusion, secang wood ethanol extract exhibits potent antioxidant activity and enhances fibroblast function after blue light exposure.