Comprehensive Assessment Of Lemon Essential Oil As Mushroom Tyrosinase Inhibitors And Its Application In Nanoemulsion

Lemon essential oil are a rich source of bioactive properties, including antioxidant, radical-scavenging and antimicrobial. Lemon essential oil, a natural antiseptic, antioxidant and fragrances, was applied in cosmetics, food and flavor industries. However, the tryosinase inhibitory of lemon essential oil were estimated seldom in cosmetics. Based on above described, the present work aimed to estimate the tyrosinase inhibitory activity for lemon essential oil and prepare stability of lemon essential oil nanoemulsions.Four lemon essential oils obtained from different areas were determinated by Gas Chromatography and Mass Spectrometry (GC/MS). The results indicated essential oils were consistsed of more than 30 kinds of volatile compounds and similar, inculding monoterpene hydrocarbons(e.g.y-Terpinene; α-and β-Pinene; D-Limonene etc.), oxygenated monoterpenes (e.g.Neryl acetate; Geranyl acetate; Citral etc.), sesquiterpene (e.g. Caryophyllene; Limonene oxide etc.). The major volatile component of oil was d-limonene (61.4% w/w). The remaining compounds were less than 15%.Lemon essential oil, D-Limonene, P-Pinene, Neryl acetate; Geranyl acetate; Citral and Camphene were evaluated in vitro by measuring tyrosinase inhibitory activity, DPPH radical scavenging activity and chelating copper ability. The experiments indicated that Lemon essential oil and some volatile flavor constituents of oil significantly inactivated tyrosinase. The inhibition dot indicated Lemon essential oil exhibited various effects on tyrosinase depended on the concentration and the time. The inhibition kinetics determined by a Linewear-Burk plot showed that Lemon essential oil was a noncompetitive inhibitor. In the light of DPPH radical scavenging, lemon essential oil and citral which showed relatively higher antioxidant properties than the other components estimated, it aslo hinted these ingredients could reduce oxygen free radicals to inhibit tyrosniase activity. According to chelating copper, all ingredients could not chelate copper in the tyrosinase, although those showed remarkable inhibition. The result could further suggest these ingredients were noncompetitive comprised with substance in enzyme reaction and inactived tyrosniase through steric hindrance.The Lemon essential oil nanoemulsions (O/W) were prepared by high pressure homogenization. The process parameters and formulation composition were investigated on particle size and polydispersity index (PDI). The composition of optimal formulation was determined as 2%(w/w) jojoba oil,1.5%(w/w) emulsifier(Tween 80:Span 80=3:2), and 3%Lemon essential oil with a particle size of 150nm and PDI of 0.2 at a feed pressure of 60MPa of pressures,4 of process cycles. The permeability of nanoemulsion and emulsion was compared through Franz diffusion transdermal, the results suggested nanoemulsion could improve the penetration in vitro and storage stability of lemon essential oil.