The pomegranate phenolics are reported to have cutaneous benefits and to be effective in treating skin disorders, including hyperpigmentation. In this context, a preparation method was developed by which to obtain phenolic-rich pomegranate peel extract. Sinapic acid was presented as the major pomegranate peel phenolics, followed by gallic and ellagic acids, and 4 additional phenolics. The extract exhibited strong antioxidant activity with an in vitro tyrosinase inhibitory effect. The skin hyperpigmentation treating potency was confirmed by the suppression of cellular melanogenesis through tyrosinase and TRP-2 inhibitions as examined in the B16F10 melanoma cells. Cellular antioxidant and proliferative activities of the extract toward human dermal fibroblasts were evidenced, as well as an inhibitory effect against MMP-2. The extract was developed into the stable serum and mask. The products were proved to be non-irritated in 30 Thai volunteers participating in a single application closed patch test. A split-face, randomized, double-blind, placebo-controlled test of the skin lightening effect was evaluated in the 30 volunteers over 28 consecutive daily treatments and monitored by the Mexameter MX 18. The active serum and mask were better in facial skin lightening efficacy than the placebo (p < 0.005). That was in accordance with the sensory evaluation scored by the volunteers. Phenolic-rich pomegranate peel extract is evidenced as a safe herbal derived material promising for skin hyperpigmentation treatment. Supportive information regarding chemical and biological profiles is presented with the confirmed safety and cutaneous benefits in volunteers.

中文翻译：

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富含酚类的石榴皮提取物：用于皮肤色素沉着过度治疗的体外、细胞和体内活性

据报道，石榴酚类物质对皮肤有益，可有效治疗皮肤病，包括色素沉着过度。在此背景下，开发了一种获得富含酚类的石榴皮提取物的制备方法。芥子酸是主要的石榴皮酚类物质，其次是没食子酸和鞣花酸，以及 4 种额外的酚类物质。该提取物具有很强的抗氧化活性，具有体外酪氨酸酶抑制作用。如在 B16F10 黑色素瘤细胞中检查的那样，通过酪氨酸酶和 TRP-2 抑制作用抑制细胞黑色素生成，证实了皮肤色素沉着过度治疗的效力。证明了提取物对人真皮成纤维细胞的细胞抗氧化和增殖活性，以及​​对 MMP-2 的抑制作用。提取物被开发成稳定的血清和面膜。30 名泰国志愿者参加了单次应用封闭斑贴试验，结果证明这些产品是无刺激性的。对 30 名志愿者进行了连续 28 天的每日治疗并通过 Mexameter MX 18 监测，对皮肤美白效果进行了分脸、随机、双盲、安慰剂对照测试。活性血清和面膜在面部皮肤美白方面效果更好疗效优于安慰剂（p < 0.005）。这与志愿者的感官评价一致。富含酚类的石榴皮提取物被证明是一种安全的草本衍生材料，有望用于治疗皮肤色素沉着过度。有关化学和生物特征的支持信息与已确认的志愿者的安全性和皮肤益处一起呈现。