Optimization of extraction process of ethanol extracts from cumin (Cuminum cyminum L.)and measurement of anti-tyrosinase activity

The response surface methodology was adopted to optimize the extraction process of anti-tyrosinase from ethanol extract of cumin, which was based on the single factor experiment. In addition, the content of main active components and the effect on tyrosinase activity from different polar fractions of cumin extract were investigated. The results revealed that the optimized extraction conditions of anti-tyrosinase from ethanol extract in cumin were as follows:ethanol concentration 71% (v/v), liquid-solid ratio 16:1 (mL/g), extraction time 2.2 h and extraction temperature 83℃. Under these conditions, the inhibition rate of ethanol extract (0.8 mg/mL)was up to (42.61%±0.56%), which was very close to the predicted value 43.20%. It was demonstrated that the analysis results of response surface methodology were reliable. The contents of polyphenols, flavonoids, saponins and polysaccharides in cumin ethanol extract were (1.35%±0.03%), (4.40%±0.29%), (0.76%±0.04%), (4.89%±0.28%), respectively. In addition, all the polar fractions of cumin extract had inhibitory effect on tyrosinase with a concentration dependent manner, the value of IC₅₀ in turn was as follow:water fraction, petroleum fraction, n-butanol fraction and ethyl acetate fraction. Therefore, the optimized extraction process of anti-tyrosinase from ethanol extract of cumin was reasonable and feasible. In addition, ethyl acetate and n-butanol fractions possessed greater inhibitory effect on tyrosinase than that of others. Moreover, polyphenols, flavonoids, saponins and polysaccharides may be the effective components of inhibiting tyrosinase activity by cumin extracts.