Dong Qiang,Xian Zhiming,Zheng Chao,Chen Ping

Tianjin Yumeijing Group Co.,Ltd.,China

Ma Xue,Pan Yao

Department of Cosmetics,College of Chemistry and Materials Engineering,Beijing Technology and Business University,China

Abstract This study evaluated the effect of a fresh-milk cream on reducing skin erythema response in 30 subjects(23.87 ± 0.34 years) by objective instrumental method.The model of skin erythema was established by tape stripping and histamine stimulation.Herein the skin erythema index(EI),skin sensitivity value and skin images of subjects were measured.The data was statistically analyzed by SPSS software.The results showed that the fresh-milk cream could continuously decrease the value of the histamine-stimulated area’s erythema index and skin sensitivity,and relieve the skin redness.It indicated that the fresh-milk cream had the functions of reducing skin erythema response and soothing the skin sensitivity.

Key words fresh-milk cream; histamine; skin erythema; skin sensitivity

Skin is the first line of defense for the human body.Compared with other organs,the skin is in direct contact with the external environment and may become sensitive to the influence of the external environment[1].Symptoms of skin sensitivity include itching,tingling,tightness,burning,and so on[2]Histamine which can mediate acute allergic reactions and cause skin sensitivity,has been demonstrated to affect chronic inflammatory reactions by regulating the proliferation of different immune cells and inducing the expression of adhesion molecules and the secretion of cytokines.[3-5]A certain concentration of histamine can induce skin flushing reaction which is caused by axon reflex-mediated vasodilation.[6,7]Falcone et al.found[8]that histamine skin test can be used as an in vivo model to induce the acute inflammation of local skin.Compared with tape stripping and topical application of irritants,this method has less mechanical or chemical damage to the skin barrier.

In recent years,people pay more attention to skin health problems,and the demand for the cosmetics with soothing effect is also increasing.Milk is a nutritious substance,contains proteins,fats,amino acids and trace elements,and has the effect of skin care.[10]In this research,we evaluate the soothing effect of creams containing fresh milk by in vivo method.First,the skin barrier of subject was destroyed by tape striping,and then histamine was used to stimulate the skin to cause erythema.It is hope that the soothing effect of cream containing fresh milk could be demonstrated by studying the variations of subjects’skin erythema index (EI),skin sensitivity and skin image through histamine skin test.

1 Experimental Section

1.1 Reagents and Instruments

Fresh-milk Cream (the other main ingredients are glycerin,mineral oil,etc.) and placebo sample (no fresh milk,other ingredients are same with fresh-milk cream) were provided by Tianjin Yumeijing Group Co.,Ltd.; Histamine,Sigma-Aldrich,USA.

Mexameter MX 18,Courage ＆ Kahazaka,Koln,Germany; TiVi 700,WheelsBridge,Sweden.

1.2 Subjects

Thirty subjects were enrolled with the following rules:healthy female with dry skin and desquamation,self-reported skin sensitivity,no history of cosmetic allergy,aged 18 to 55 years old.Exclusion criteria:Participate in other clinical trial studies at present or before the beginning of this study; those who are in pregnancy,lactation or within half a year after delivery;taking corticosteroids,antibiotics,tretinoin or other drugs in the past 2 weeks or anti-acne drug treatment;subjects suffering from uncured active skin diseases; the test area has undergone the therapy of laser beauty or chemical peels.This study complies with the provisions of the Declaration of Helsinki revised in 2013.All subjects understood the purpose and process of the research and signed an informed consent form.

1.3 Experiment

1.3.1 Test method

Four areas (6 cm2) on the inner side of the subject’s forearm were picked up as test areas,and were assigned random numbers according to SPSS.These areas were randomly labeled as experiment group,placebo group,negative group and blank group.The erythema index (EI) and skin sensitivity of each area were measured as the base value before the experiment.The skin barrier of test areas for each group (except the blank group) was destroyed by tape stripping.Then 1.7 mg/mL histamine was used to stimulate these areas.After modeling,the EI and sensitivity of these areas were measured.The cream sample was used to treat the area of experiment group,and placebo sample for placebo group.The negative group and the blank group are not treated.The data was measured at 30 min and 60 min after using the samples.During the test,the temperature of environment was maintained at 20.0～22.0 ℃,and relative humidity was maintained at 40.0%～60.0%.

1.3.2 Data collection

The erythema index (EI) was measured by Mexameter MX 18,and the average value was taken after 3 measurements.The skin sensitivity and the image of the test area were measured by TiVi 700.

1.3.3 Statistical analysis

IBM SPSS Statistics (version 21.0) was used for statistical analysis.The Shapiro-Wilk Test is used for testing the normality of the data.The Levene test is used for testing the homogeneity of variances.Repeated measure ANOVA is used to compare the difference between the data of each group at different time points,as well as the difference between groups(LSD is used for Paired comparison).Apvalue of<0.05 was considered significant.

2 Results and discussion

A total of 30 subjects were enrolled in the study and the average age was 23.87 ± 0.34 years.All subjects completed the study.

2.1 Erythema index

The lower erythema index of the skin means the sample has the better effect on soothing and reducing skin erythema.The change of EI with time and the comparison of EI within groups were shown in Fig.1.After modeling,the value of all groups are increased.And then the value decreased slowly,regardless of whether the test areas was treated or not.The EI value of experiment group decreased from 190.46± 7.95 AU to 165.66 ± 6.21 AU at 30 min,and there is no significant difference compared with the blank group (p> 0.05).However the significant difference between the other two groups and the blank group disappeared at 60 min (p> 0.05).

Figure 1.The change of erythema index (EI) in each group with time

Figure 2 showed the comparison of EI at different time between groups.The EI value of experiment group is lower than the placebo group and negative group at 30 min,and the difference were significant.It showed that the cream containing fresh milk had the ability to reduce the skin erythema,and restore the skin to normal state in 30 min.The soothing efficacy of cream sample is better than that of placebo sample and the skin self-repairing.

Figure 2.The change of skin erythema index (EI) with time

2.2 Skin sensitivity

The aggregation degree of local red blood cell at subcutaneous can reflect the sensitivity of skin.The image of aggregation at subcutaneous site can obtained through analyzing the data taken by TiVi 700.This method can replace the subjective judgment in skin test by independent quantitative analysis of local skin erythema.The lower value of skin sensitivity means the better effect on soothing and relieving the skin erythema.The change of skin sensitivity with time was shown in Figure 3.The skin sensitivity of all groups decreased slowly with time.The value of experiment group was dropped from 190.27±3.59 to 166.77±2.71 at 30 min (p<0.05),then decreased to 134.43±1.91 at 60 min (p<0.05).A similar phenomenon was observed in the placebo group.However the change of negative group is different from other groups,the value is not reduced significantly until 60 minutes (p<0.05).Fig.4 showed the comparison of skin sensitivity at different time between groups.The sensitivity of experiment group was significant difference from that of the other two groups at 30min and 60 min (p<0.05).It is indicated that the cream containing fresh milk has the ability to inhibit the expansion of subcutaneous blood vessels,and the soothing efficacy of cream sample is better than placebo sample’s and skin self-repairing.

Figure 3.The change of skin sensitivity value in each group with time

Figure 4.The change of skin sensitivity value in with time

2.3 Image analysis

The comparison of the skin sensitive images before and after treating with samples was shown in Figure 5.After treated with the placebo,the redness caused by histamine didn’t reduce at 30 min,the symptoms reduced slightly until 60 min (Figure 5A).The result was consistent with the test of erythema index and skin sensitivity.In contrast,the redness treated with cream containing fresh milk was reduced significantly at 60 min (Figure 5B).

Figure 5.TiVi700 images analysis of skin sensitivity

It can be seen from the results,the fluctuation of the blank group’s EI value and skin sensitivity is around the baseline value at different time points and the difference is not statistically significant (p> 0.05).It is indicated that the skin condition of subjects is stable during the test,and the effect of subjects’skin condition on the results can be negligible.After modeling,the value of EI and sensitivity were significantly difference compared with base value (p>0.05).It is suggested that an acute skin inflammation model was successfully constructed after stimulating the skin with histamine.At the same time,the results showed that fresh milk have the effect on reducing skin erythema and soothing skin sensitivity.

3 Conclusion

In this research,the efficacy of creams containing fresh milk in reducing skin erythema was studied by objective instrumental evaluation methods.The results showed that the use of cream containing fresh milk to treat the erythema reaction caused by histamine,can reduce the skin erythema index and skin sensitivity significantly.The skin can restored to the normal state quickly,and the soothing effect of the fresh milk cream is better than the placebo’s and skin self-repairing.This research indicated that the cream containing fresh milk have the effect of reducing skin erythema and soothing skin sensitivity.