Multiple Activities of Punica granatum Linne against Acne Vulgaris

Abstract

Acne is a common skin condition with sebum overproduction, hyperkeratosis, <i>Propionibacterium acnes</i> (<i>P</i>. <i>acnes</i>) and <i>Staphylococcus aureus</i>, and inflammation. <i>Punica granatum</i> (pomegranate) is well-known for its anti-inflammatory effects; however, few studies have discussed the anti-acne effects of pomegranate. In this study, we found that pomegranate extract (PG-E) significantly reduced <i>P</i>. <i>acnes</i>-induced edema in Wistar rat ears. Therefore, an evaluation platform using multiple pathogenic mechanisms of acne was established to explore the anti-acne effects of pomegranate. Results showed that PG-E inhibited bacterial growth and lipase activity. Through a bioguided-fractionation-isolation system, four hydrolysable tannins, punicalagin (<b>1</b>), punicalin (<b>2</b>), strictinin A (<b>3</b>), and granatin B (<b>4</b>), were isolated. Compounds <b>1</b> and <b>2</b> had greater anti-bacterial activities and anti-testosterone-induced HaCaT proliferative effects than the others. Compounds <b>1</b>, <b>3</b>, and <b>4</b> displayed lipase inhibitory effects. Compound <b>4</b> decreased cyclooxygenase-2 expression and downregulated prostaglandin E₂ production in heat-killed <i>P</i>. <i>acnes</i>-treated RAW 246.7 cells. In conclusion, PG-E is abundant in hydrolysable tannins that display multiple anti-acne capacities, including anti-bacterial, anti-lipase, anti-keratinocyte proliferation, and anti-inflammatory actions. Hence, PG-E has great potential in the application of anti-acne and skin-care products, and punicalagin (<b>1</b>), the most effective component in PG-E, can be employed as a quality control marker.