| Thymus monoglious Romm belongs to the families of Laiatae and Thymus plants.In China,thyme mainly grows in Gansu,Shaanxi,Qinghai,shanxi and inner Mongolia.Thyme has long been used as a kind of spices in the West.Due to many functional properties,thyme has been applied to medicine,food preservation and cosmetics.However,the research of thyme in China has lagged behind the Western countries.Due to the complex compositions and extraction difficulties,the study of thyme oil in China has been in starting stage.Thus,with the thyme collected in Zhenyuan county(Gansu Province)chosen as the materials,this study is to 1)extract thyme oil by using an improved equipment and analyze its compositions;2)assess the anti-oxidatant capacity of the oil by in vitro assays;3)develop a kind of lotions based on the extracted thyme oil.The details are as follows:1)A distilling equipment with automatic exhaust function and coupled with snake-like condense pipes was developed in this study.The equipment was stable to heating,easy to operate,of good seal capability and safety.With this equipment,the extraction of one batch(e.g.,1.0 kg thyme)can be completed in 30 min,and the oil yield was 0.12%;the extraction time was shortened by 50 percent and the yield was increased by 3.5 times.Furthermore,the extraction efficiency was also increased by 142 times,as compared to the conventional distillers.2)The main compositions of the oil were p-Cymene(30.49%),Thymol(16.40%),gamma-Terpinene(11.0%),Eucalyptol(7.91%),Methyl carvacryl ether(3.55%),beta-Bisabolene(2.95%),endo-Borneol(2.86%)and Sabinene hydrate(2.09%),accounting for 77.25%of the oil weight.There were 54 compositions which had been detected,and they accounted for 98.59%of the total thyme oil.Besides,the total polyphenols content was determined to be 0.38±0.04 mgGAE/kg.3)At the concentration of 0.9 mg/mL,the scavenging rate of VC against ·OH was 99.00%,followed by BHT(91.34%)and thyme oil(82.41%).Thyme oil had significant scavenging capacity against O2-·,and its scavenging capacity was insignificant when compared with BHT.At the concentration of 1.5 mg/mL,the scavenging capacity of thyme oil against O2-· was 82.88%.4)At the same concentrations,the scavenging capacity of thyme oil against Fe3+ was lower than VC and BHT;Thyme oil can inhibit the oxidation of ?-carotene,and its inhibition capacity was slightly lower than BHT but significantly higher than VC.At 0.5 mg/mL concentration,the thyme oil had a better capacity against ?-carotene oxidation than at 1.0 mg/mL;Thyme oil can slow the oxidation and rancidity of walnut oil:the higher the concentration,the better the inhibition effect.5)The 300 mg/kg and 500 mg/kg dose of thyme oil exhibited significant liver protection effect on acute liver-injured mice model induced by TAA,and the protection mechanism may be because thyme oil can scavenge the free radicals in liver cells,decrease the consumption of SOD,CAT and GSH-Px,protect the anti-oxidation system GSH,and therefore inhibit the lipid peroxidation in cell membrane system and the further reaction initiated by free radicals.6)Through single factor experiment and orthogonal experiment,the formula of the thyme oil lotion(100 mL)was established:20%of the oil phase,which consisted of squalene,octoic acid,cetylic acid and polydimethylsiloxane(6 mL:5 mL:5 mL:4 mL),0.1%of thyme oil,14%of humectants,which consisted of glycerol,trehalose and propanediol(6 mL:3 mL:5 mL)and the rest was water.Based on range analysis,thyme oil had the greatest effect on the quality of the lotion,followed by the oil phase and then the humectants.Futher investigations suggested that the lotion has good moisture retention capacity and could ameliorate pachulosis,improve skin elasticity and facilitate acne treatment. |
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