Abstract: 【Abstract】 Objective To evaluate the effect of pomegranate peel polyphenols on sebum secretion in golden hamsters, and to explore its possible mechanisms. Methods Thirty golden hamsters were randomly and equally divided into 5 groups: （ointment） vehicle group, 0.48%-, 0.96%-, 1.92%-pomegranate peel polyphenol ointment groups, and retinoic acid cream group. Corresponding cream or ointments were applied to bilateral sebaceous gland spots of the golden hamsters at a dose of 1 gram twice a day for 4 consecutive weeks. The area of bilateral sebaceous gland spots was measured on days 0, 7, 14, 21 and 28 after the start of treatment, which was calculated by the maximum longitudinal diameter multiplied by the maximum transverse diameter. Twenty-four hours after the last treatment, immunohistochemical study was conducted to determine the expression of AKT/Sox9 signaling pathway in sebaceous gland spots resected from the golden hamsters. The area of sebaceous gland spots in these groups at different time points was compared by repeated measures analysis of variance, and other data were analyzed by one-way analysis of variance or Kruskal-Wallis H test. Results The area of sebaceous gland spots was significantly smaller in the 0.96%-, 1.92%-pomegranate peel polyphenol ointment groups （50.48 ± 2.41 mm2, 48.24 ± 2.56 mm2, respectively） and retinoic acid cream group （48.31 ± 2.76 mm2） than in the vehicle group （57.99 ± 3.29 mm2; t = 2.69, 3.98, 3.65, P = 0.012, 0.001, 0.001, respectively）. Sox9 expression was significantly lower in the 1.92%-pomegranate peel polyphenol ointment group （0.39 ± 0.04） and retinoic acid cream group （0.38 ± 0.03） than in the vehicle group （0.44 ± 0.02, P = 0.040）. However, there was no significant difference in AKT expression among the 5 groups （F = 1.645, P = 0.199）. Conclusion Pomegranate peel polyphenols can reduce the sebaceous gland spot area and inhibit sebum secretion in golden hamsters, which may be related to the inhibition of Sox9 expression.

Key words: Acne vulgaris, Pericarpium granati, Sebaceous glands, Sebum, SOX9 transcription factor, Mesocricetus