The effect of red betel (Piper crocatum) water fraction as tyrosinase inhibitors: In vitro, molecular docking, and molecular dynamics studies

Abstract

Objective: Excessive melanin expression can lead to dermatological conditions such as Riehl melanosis, lentigo, freckles, and melasma post-inflammatory hyperpigmentation. Targeting melanogenesis, the synthesis of melanin, and inhibiting tyrosinase have been explored to mitigate its effects. However, many existing anti-melanogenic agents exhibit severe adverse side effects, necessitating searching for alternative options. In this study, we aimed to investigate the anti-tyrosinase activity of red betel leaves and identify bioactive compounds responsible for their inhibitory effects. Methods: A 70% ethanol extract of red betel leaves, and its fractions (n-hexane, ethyl acetate, and water) were evaluated for their anti-tyrosinase activity. The inhibitory concentration (IC50) was measured using mushroom tyrosinase as the target enzyme. Subsequently, the bioactive compounds in the water fraction were identified through ultra-high-performance liquid chromatography (UHPLC) analysis. Computational docking analysis was performed on the identified compounds to assess their inhibitory potential against tyrosinase. Additionally, ADMET and molecular dynamics analysis were also performed. Results: The water fraction of the red betel leaf extract exhibited the most robust anti-tyrosinase activity, with an IC50 value of 6.344 ppm. UHPLC analysis of the water fraction revealed the presence of several compounds. Among these, piperine, piperamide-C7:2 (2E,6E), and trichostachine exhibited intense inhibitory activity against tyrosinase, with docking scores of −7.04, −6.87, and −6.79 kcal/mol, respectively. Importantly, all three compounds complied with Lipinski's rules and were classified as non-toxic. Molecular dynamics simulations demonstrated that piperine displayed minimal fluctuation throughout the simulation, as indicated by root mean square deviation (RMSD) and root mean square fluctuation (RMSF) analysis. Conclusions: Red betel leaves, particularly the water fraction, possess anti-melanogenesis activities. Piperine, piperamide-C7:2 (2E,6E), and trichostachine were identified as critical bioactive compounds responsible for the observed inhibitory effects on tyrosinase. These compounds exhibit solid inhibitory activity without violating Lipinski's rules or posing toxic risks. Furthermore, molecular dynamics simulations suggest the stability of piperine during the simulation. These findings highlight the potential of red betel leaves as a promising ingredient in the pharmaceutical and cosmetic industries for combating excessive melanin production.

Keywords

• In silico
• In vitro
• Pigmentation
• Molecular docking
• Molecular dynamics
• Red betel