Inhibitory Effects Of Extracts From Cuminum Cyminum L. On Tyrosinase And Melanogenesis In B16 Melanoma Cells

Cumin?Cuminum cyminum L.?is an annual or biennial herbaceous plant and belongs to Apiaceae family.Cumin is native to Mediterranean region mainly produced in Xinjiang of China.Cumin has a variety of active ingredients,and more attention is paid to it owing to its medical and edible values,which makes it has great application value in food,medicine and agriculture.Searching for green,natural,safe and stable whitening agents has become a trend in the cosmetics industry.Therefore,natural plant resources become a good source of whitening agents.In this paper,we used cumin as raw material to optimize the extraction process of cumin extract on anti-tyrosinase activity and determine the content of main active components.The inhibition mechanism of cumin extract on tyrosinase activity and the effect on melanin synthesis of B16 murine melanoma cells were studied.In addition,the antioxidant and anti-tyrosinase effect from different polar fractions of cumin extract were investigated in order to provide the basis for the application of cumin as a natural whitening material to the cosmetics industry.The main findings are as follows:1.Ethanol was selected from ethanol,acetone and water as the best extraction solvent for the inhibition of tyrosinase activity.Response surface methodology was adopted to optimize the extraction process of cumin extract on anti-tyrosinase activity,which was based on the single factor experiment.The results revealed that the optimized extraction conditions were as follows:ethanol concentration 71%?v/v?,liquid-solid ratio 16:1?m L/g?,extraction time 2.2h and extraction temperature 83?.Under these conditions,the inhibition rate of cumin extract on tyrosinase activity was up to?42.61±0.56?%,which was very close to the predicted value.It was demonstrated that the analysis results of response surface methodology were reliable.2.Using the method of Folin-Ciocalteu colorimetry,Na NO2-Al?NO3?3-Na OH colorimetry,vanillin colorimetry,phenol-sulfuric acid colorimetry to determine the content of polyphenols,flavonoids,saponins and polysaccharides,respectively.The results showed that the content of polyphenols,flavonoids,saponins and polysacchar-ides of cumin extract were?1.35±0.03?%,?4.40±0.29?%,?0.76±0.04?%and?4.89±0.28?%,respectively.3.The results of the inhibitory effect of cumin extract on tyrosinase activity showed that cumin extract exhibited concentration-dependent inhibitory effect on both monophenolase and diphenolase activities of mushroom tyrosinase,IC₅₀0 values were 1.027mg/m L and 0.977mg/m L,respectively.It was discovered that the cumin extract can prolong the lag time in the process of enzymatic oxidation,and the lag time increased with a concentration-dependent manner.Kinetic study on diphenolase activity of mushroom tyrosinase showed that cumin extract was a reversible mixed-type inhibitor,and the inhibition constant?K_I?was determined to be0.62mg/m L.4.Effect of cumin extract on melanin synthesis of B16 murine melanoma cells was studied.The results indicated that cumin extract had no noticeable effect on cell growth and cell viability.Meanwhile,cumin extract significantly suppressed melanin production and cellular tyrosinase activity of B16 murine melanoma cells in a concentration and time dependent manner without cytotoxicity.5.Different polar fractions of cumin extract exerted great inhibitory effect on tyrosinase and scavenging capacity on DPPH,hydroxyl and superoxide anion radicals.The order of different extracts on anti-tyrosinase and antioxidant activity was as follow:ethyl acetate fraction>n-butanol fraction>petroleum ether fraction>water fraction.In addition,there was a strong correlation between anti-tyrosinase and antioxidant activity in different fractions of cumin extract.Ethyl acetate fractions possessed greater anti-tyrosinase and antioxidant activities than that of others,which can demonstrate that the components on anti-tyrosinase and antioxidant activity were concentrated at the ethyl acetate fractions of cumin extract.The above-mentioned research demonstrated that cumin extract can significantly inhibit mushroom tyrosinase activity and melanin synthesis in melanocytes,and it has strong antioxidant activity.So,the study provides a scientific basis for cumin in the application of whitening cosmetics.