School of Medicine and Institute for Nuclear Science and Technology , Jeju, 690-756 , Korea.
Int J Radiat Biol. 2014 Oct;90(10):928-35. doi: 10.3109/09553002.2014.911990. Epub 2014 Jun 6.
Previously we demonstrated that phloroglucinol (1,3,5-trihydroxybenzene) protected human HaCaT keratinocytes against ultraviolet B (UVB, 280-320 nm)-induced oxidative stress in vitro by scavenging intracellular reactive oxygen species (ROS). The current study investigated whether phloroglucinol could similarly protect the mouse skin against UVB-induced oxidative tissue damage in vivo.
Male 7-week-old Balb/c mice were divided into the following untreated normal control, phloroglucinol only-treated, vehicle plus UVB (30 or 60 mJ/cm(2))-exposed, and phloroglucinol (10 or 50 mg/ml) plus UVB (30 or 60 mJ/cm(2))-treated groups. Following UVB exposure, phloroglucinol or phosphate buffered saline vehicle was applied to the dorsal skin of each mouse daily for 3 days. Studies were conducted at 24 h after the last of the UVB exposures. Histopathological analyses of dorsal skin lesions were performed on all mice. In addition, the levels of UVB-provoked injury to cellular components, including DNA, proteins, and lipids were detected by levels of 8-oxoguanine (8-oxoG), protein carbonyls, and 8-isoprostane. Apoptosis were assessed by using western blot for B-cell lymphoma-2-associated X protein (Bax) and activated caspase-3 expression, by using immunohistochemistry.
UVB radiation increased the thickness of the epidermis and the dermis, and also stimulated the accumulation of mast cells in the irradiated skin. However, treatment with phloroglucinol significantly decreased all of these parameters. Furthermore, phloroglucinol decreased UVB-provoked injury to cellular components, including DNA, proteins, and lipids; down-regulated the expression of phospho-histone H2A.X in the injured skin; and reduced the UVB-generated levels of 8-oxoG, protein carbonyls, and 8-isoprostane, which are all markers of oxidative stress. In addition, phloroglucinol attenuated the UVB-induced expression of the pro-apoptotic proteins, Bax protein, and activated caspase-3.
These results suggest that phloroglucinol safeguards the mouse skin against UVB-induced oxidative stress and apoptosis.
此前我们证明，间苯三酚（1,3,5-三羟基苯）通过清除细胞内活性氧（ROS），在体外保护人 HaCaT 角质形成细胞免受紫外线 B（UVB，280-320nm）诱导的氧化应激。本研究探讨了间苯三酚是否同样可以保护小鼠皮肤免受体内 UVB 诱导的氧化组织损伤。
雄性 7 周龄 Balb/c 小鼠分为未处理的正常对照组、仅给予间苯三酚处理组、赋形剂加 UVB（30 或 60mJ/cm(2)）照射组和间苯三酚（10 或 50mg/ml）加 UVB（30 或 60mJ/cm(2)）照射组。UVB 照射后，每日向每组小鼠背部皮肤涂抹间苯三酚或磷酸盐缓冲盐水赋形剂，连续 3 天。末次 UVB 照射后 24h 进行研究。对所有小鼠的背部皮肤损伤进行组织病理学分析。此外，通过 8-氧鸟嘌呤（8-oxoG）、蛋白羰基和 8-异前列腺素的水平检测细胞成分（包括 DNA、蛋白质和脂质）的 UVB 损伤程度。通过 Western blot 检测 B 细胞淋巴瘤-2 相关 X 蛋白（Bax）和活化半胱天冬酶-3 的表达，评估细胞凋亡。
UVB 辐射增加了表皮和真皮的厚度，并刺激了照射皮肤中肥大细胞的积累。然而，间苯三酚处理显著降低了所有这些参数。此外，间苯三酚降低了细胞成分（包括 DNA、蛋白质和脂质）的 UVB 损伤程度；下调了损伤皮肤中磷酸化组蛋白 H2A.X 的表达；并降低了 UVB 产生的 8-氧鸟嘌呤、蛋白羰基和 8-异前列腺素水平，这些都是氧化应激的标志物。此外，间苯三酚减弱了 UVB 诱导的促凋亡蛋白 Bax 蛋白和活化半胱天冬酶-3 的表达。
这些结果表明，间苯三酚可保护小鼠皮肤免受 UVB 诱导的氧化应激和细胞凋亡。
