Does Trigonelline Help Skin Tone? Molecular Docking Studies of Trigonelline on the Human Tyrosinase, Formulation, Optimization and Characterization of an Emulgel Containing Trigonella foenum-graecum L. fenugreek Standardized Hydroalcoholic Extract.

This study aimed to perform molecular docking studies to identify possibilities of the inhibitory potential of the trigonelline present in fenugreek seeds on the human tyrosinase, standardize fenugreek extract, formulate, and characterize an emulgel containing fenugreek extract-entrapped niosomal vesicles. The docking study was performed using AutoDock software. The extract was standardized by the RP-HPLC method. Emulgels containing fenugreek extract and fenugreek extract-entrapped niosomes were optimized by the D-optimal method. In vitro characterization and stability studies were also carried out. The lowest energy docked poses of trigonelline on the human tyrosinase complex was calculated -5.8 kcal/mol. Also, in vitro assessment of the tyrosinase inhibitory effect of trigonelline and comparison of IC50 values of trigonelline and kojic acid revealed that the enzyme inhibition efficacy of trigonelline was stronger than that of kojic acid. Optimization led to emulgels with desired viscosity, droplet size, and spreadability values. The release study showed that trigonelline was released from the niosomes at a lower rate compared to extract containing emulgel. Permeation investigations revealed that trigonelline in niosomes has a higher ability to permeate through the skin. In conclusion, in silico and in vitro studies have shown that trigonelline can be assumed as an appropriate candidate for developing new cosmetic preparations and nonionic surfactant vesicles help trigonelline to permeate through the skin to a higher extent. However, clinical trials should be performed to confirm these findings.