Sime Suzann, Reeve Vivienne E
Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
Photochem Photobiol. 2004 Feb;79(2):193-8. doi: 10.1562/0031-8655(2004)079<0193:pfiiac>2.0.co;2.
Pycnogenol is a standardized extract of the bark of the French maritime pine, Pinus pinaster Ait., that has multiple biological effects, including antioxidant, anti-inflammatory and anticarcinogenic properties. This study describes the effect of topical application of lotions containing Pycnogenol to Skh:hr hairless mice undergoing minimally inflammatory daily exposures to solar-simulated UV radiation (SSUV). We report that concentrations of Pycnogenol of 0.05-0.2% applied to the irradiated dorsal skin immediately after exposure resulted in dose-dependent reduction of the inflammatory sunburn reaction, measured as its edema component. When mice received three consecutive daily exposures of minimally edematous SSUV, their ability to raise a contact hypersensitivity (CHS) reaction was suppressed by 54%. Pycnogenol lotions applied postirradiation reduced this immunosuppression to 22% (0.05% Pycnogenol) and 13% (0.1% Pycnogenol). Furthermore, when CHS was suppressed by 71% with exogenous treatment with cis-urocanic acid, the putative epidermal mediator of photoimmunosuppression, 0.2% Pycnogenol lotion reduced the immunosuppression to 18%. Chronic exposure to SSUV on 5 days/week for 10 weeks induced skin tumors from 11 weeks in both control mice and in mice receiving daily applications of 0.05% Pycnogenol, but tumor appearance was significantly delayed until 20 weeks in mice receiving 0.2% Pycnogenol. Furthermore, whereas 100% of control mice had at least one tumor by 30 weeks, and mice treated with 0.05% Pycnogenol by 33 weeks, the maximum tumor prevalence in mice treated with 0.2% Pycnogenol was significantly reduced to 85%, with some mice remaining tumor free. Average tumor multiplicity was also significantly reduced by 0.2% Pycnogenol, from 5.2 in control mice to 3.5 at 35 weeks. Thus, topical Pycnogenol offered significant and dose-dependent protection from SSUV-induced acute inflammation, immunosuppression and carcinogenesis, when applied to the skin after daily irradiation. Pycnogenol, therefore, in addition to its recognized health benefits in other organs, appears to have potential in providing photoprotection for humans in a complementary role with sunscreens, having demonstrable activity when applied to the skin after, rather than before, UV exposure.
碧萝芷是法国滨海松（Pinus pinaster Ait.）树皮的标准化提取物，具有多种生物学效应，包括抗氧化、抗炎和抗癌特性。本研究描述了将含碧萝芷的乳液局部应用于每天接受轻度炎症性模拟太阳紫外线辐射（SSUV）的无毛小鼠（Skh:hr）的效果。我们报告称，在暴露后立即将浓度为0.05 - 0.2%的碧萝芷应用于受照射的背部皮肤，可导致炎症性晒伤反应呈剂量依赖性降低，以水肿成分来衡量。当小鼠连续三天每天接受轻度水肿性SSUV照射时，它们引发接触性超敏反应（CHS）的能力被抑制了54%。照射后应用碧萝芷乳液可将这种免疫抑制分别降至22%（0.05%碧萝芷）和13%（0.1%碧萝芷）。此外，当用顺式尿刊酸（假定的光免疫抑制表皮介质）进行外源性处理使CHS被抑制71%时，0.2%碧萝芷乳液可将免疫抑制降至18%。每周5天、持续10周长期暴露于SSUV会使对照小鼠和每天应用0.05%碧萝芷的小鼠从第11周开始诱发皮肤肿瘤，但在接受0.2%碧萝芷的小鼠中，肿瘤出现明显延迟至第20周。此外，到30周时100%的对照小鼠至少有一个肿瘤，到33周时接受0.05%碧萝芷处理的小鼠也是如此，而接受0.2%碧萝芷处理的小鼠的最大肿瘤发生率显著降至85%，有些小鼠没有肿瘤。平均肿瘤多发性也因0.2%碧萝芷而显著降低，从对照小鼠的5.2降至35周时的3.5。因此，当在每天照射后应用于皮肤时，局部应用碧萝芷可对SSUV诱导的急性炎症、免疫抑制和致癌作用提供显著且剂量依赖性的保护。因此，碧萝芷除了在其他器官中已被认可的健康益处外，似乎在与防晒霜起到互补作用为人类提供光保护方面具有潜力，在紫外线暴露后而非之前应用于皮肤时具有可证明的活性。
