Melanogenesis-stimulating activity of Nigella sativa extract in B16F10 cells: Optimising detection wavelengths for enhanced precision

¹ Doctoral Program, School of Veterinary Medicine and Biomedical Sciences, IPB University, Bogor 16680, Indonesia
² Primate Research Center Animal Studies, IPB University, Bogor 16129, Indonesia
³ Faculty of Medicine, State Islamic University Syarif Hidayatullah, Jakarta, Indonesia
⁴ Division of Pathology, School of Veterinary Medicine and Biomedical Sciences, IPB University, Bogor 16680, Indonesia

^* Corresponding author: dianpratiwi@apps.ipb.ac.id

Abstract

Vitiligo is a chronic depigmentation disorder with limited effective treatments, particularly in low-resource settings. Nigella sativa (black cumin) has shown melanogenesis-modulating potential, largely attributed to thymoquinone (TQ). This study investigates the melanogenesis-stimulating activity of 96% ethanol extract of N. sativa (EE BCS), with optimized spectrophotometric detection wavelengths to improve assay precision. Phytochemical screening and HPLC identified flavonoids, saponins, alkaloids, steroids, and a TQ content of 0.04%. B16F10 melanoma cells were assessed for viability (MTT assay), tyrosinase activity (L-DOPA at 490 nm), and melanin content (405 nm). EE BCS showed >90% viability up to 12.50 ppm, with significant increases in tyrosinase activity at 6.25 ppm (143.57%) and 12.50 ppm (224.29%), and melanin content at 3.13 ppm (123.40%), 6.25 ppm (226.30%), and 12.50 ppm (260.50%). Wavelength optimisation enhanced assay specificity, supporting more precise melanogenic assessment. The study demonstrates that EE BCS stimulates melanogenesis in-vitro despite low TQ content, likely due to synergistic phytochemical interactions, making EE BCS a promising candidate for vitiligo therapy. Additionally, the use of compound-specific detection wavelengths (490 nm and 405 nm) enhances assay reliability and highlights the importance of methodological standardization in pigmentation research.