Kinetic studies of tyrosinase inhibitory activity of 19 essential oils extracted from endemic and exotic medicinal plants

• 19 essential oils (EOs) were evaluated for any anti-tyrosinase activity.
• EOs showed potent anti-tyrosinase activity comparable to kojic acid.
• Kinetic studies showed competitive inhibition.
• EOs studied could be exploited by the cosmetic, food and pharmaceutical industry.

Essential oils (EOs) extracted from plants have attracted much interest as pharmacologically active compounds and have been recently probed as inhibitors of tyrosinase. The present study was designed to investigate into the tyrosinase inhibitory potential of 19 EOs extracted from exotic and endemic medicinal plants from Mauritius. The nature of inhibition was then evaluated by the double reciprocal Lineweaver–Burk plot in the presence and absence of the active EOs. EOs extracted from Cinnamomum zeylanicum, Citrus grandis and Citrus hystrix showed IC50 comparable to the positive control (kojic acid). Kinetic studies showed that only C. grandis (IC50 of 2.07 ± 0.152 μg/ml compared to kojic acid IC50 of 2.28 ± 0.054 μg/ml) exhibited a competitive type of inhibition. Results from the present study tend to show that EOs extracted from these medicinal plants can exhibit potent anti-tyrosinase activities and may be potential candidates for the cosmetic, food and pharmaceutical industries.