Abstract: 【Abstract】 Objective To investigate the effect of milk on sebum secretion in golden hamsters, and to explore its possible mechanism of action. Methods Eighteen golden hamsters were randomly and equally divided into 3 groups: blank control group receiving no intervention, whole-milk group gavaged with whole milk, and skimmed-milk group gavaged with skimmed milk. The gavage feeding was performed at a dose of 2.5 ml twice a day for 4 consecutive weeks. The maximum transverse diameter and maximum longitudinal diameter of bilateral sebaceous gland spots were measured on days 0, 7, 14, 21 and 28 after the start of intervention, and the area of sebaceous gland spots was calculated; at 24 hours after the last gavage, the bilateral sebaceous gland spot tissues were resected, and subjected to immunohistochemical study to determine the expression of insulin-like growth factor-1 （IGF-1）/sterol regulatory element-binding protein-1 （SREBP-1）/acetyl-coenzyme A carboxylase （ACC-1） signaling pathway in sebaceous gland spots. Statistical analysis was carried out by using repeated measures analysis of variance, one-way analysis of variance for independent groups, Kruskal-Wallis H test, and least significant difference-t test for multiple comparisons. Results Repeated measures analysis of variance showed that there was no significant difference in the area of sebaceous gland spots of golden hamsters among the 3 groups （F = 0.96, P = 0.417）. The IGF-1 expression was significantly higher in the skimmed-milk group （0.39 ± 0.03） than in the blank control group （0.35 ± 0.03, t = 2.62, P = 0.021） and whole-milk group （0.33 ± 0.02, t = 3.82, P = 0.002）; compared with the blank control group（0.36 ± 0.02）, the skimmed-milk group showed significantly increased SREBP-1 expression （0.42 ± 0.04, t = 2.64, P = 0.021）; the ACC-1 expression was significantly higher in the skimmed-milk group （0.40 ± 0.03） and whole-milk group （0.40 ± 0.05） than in the blank control group （0.34 ± 0.03; t = 2.39, 2.47, P = 0.031, 0.026, respectively）. Conclusion Milk may promote sebum secretion in golden hamsters through the IGF-1/SREBP-1/ACC-1 signaling pathway.

Key words: Acne vulgaris, Milk, Mesocricetus, Sebaceous glands, Sebum, Insulin-like growth factor 1, Sterol regulatory element-binding protein 1, Acetyl-CoA carboxylase