Physical measurement and evaluation of skin color changes under normal condition and post‐ultraviolet radiation: a comparison study of Chromameter CM 2500d and Maxmeter MX18

Objective: To compare the data correlation between two kinds of instruments, Chromameter CM2500d and Maxmeter MX18, in the measurement of skin color changes under normal condition and post‐ultraviolet (UV) radiation. Method: The data points of Chromameter CM2500d are based on L^*a^* values, while Maxmeter MX18 are based on M and E values, in order to compare the data correlation between these two kinds of instruments in skin color measurement on both non‐exposed and exposed sites. In addition, an evaluation of the correlation of post‐UV irradiation between these two instruments was conducted. Four different kinds of parameters post‐UV radiation were measured including minimal erythema dose (MED), immediate pigmentation dose (IPD), minimal persistent pigmentation dose (MPPD) and repeated UV radiation. The following UV radiation dosages were applied as Day 1=1.0 MED, Day 2=0.5 MED and Day 3=0.5 MED for repeated UV radiation, of which the erythema and pigmentation changes were recorded. Result: Chromameter CM2500d and Maxmeter MX18 showed good data correlation when measuring both non‐exposed and exposed sites on normal skin. L^* values were affected more easily by UV‐induced erythema than M values on skin color changes after 1 MED and repeated UV exposures. IPD, MPPD and the pigmentation data showed good correlations with the measurement of the intensive erythema formation induced by repeated UV exposures. a^* value was shown to be equally effective as E value with skin erythema measurements in response to various MEDs. However, increased erythema induced by repeated UV radiations was able to reduce the correlations between a^* and E values. On the other hand, a^* and E were shown to be equally effective in recording the erythema change courses after strong erythema responses post‐UV radiations. Conclusion: This comparative study showed that the data correlations between the two kinds of instruments were different depending on measurement conditions. Both Chromameter CM2500d and Maxmeter MX18 instrumental measurement results should be carefully evaluated by experimental conditions.     

Sun protective behaviors at an outdoor entertainment event in Australia

An observational study was conducted to examine the use of sun protective hats, clothing, and sunglasses of people attending an outdoor entertainment event in an area of high‐to‐extreme ultraviolet radiation in New South Wales, Australia. Armidale is unique, as it is a highly‐elevated area, almost 1000 m above sea level, and temperatures are often mild with very high‐to‐extreme levels of ultraviolet radiation. Four trained data collectors observed attendees as they entered the event, and recorded their use of sun protective hats, clothing, and sunglasses. While more than half of the attendees wore sun protective hats, only 14% wore sun protective clothing. Broad‐brimmed hats were considered sun protective, while sun protective clothing was defined by shirts with at least three‐quarter‐length sleeves. Females were more likely to wear both a sun protective hat and clothing than males, and children were less protected than adults. Legislative changes are required to ensure that organizers of outdoor events have a legal responsibility to provide a safe environment for attendees, including strategies to help reduce ultraviolet radiation exposure.     

栽培鸡血藤藤茎次生代谢产物的动态积累变化研究

【目的】研究栽培鸡血藤藤茎中次生代谢产物在不同生长期的动态积累变化趋势,为其采收期的合理制定提供科学依据。【方法】参照《中国药典》（2010年版一部）附录XA测定醇溶性浸出物的含量;采用紫外分光光度法测定总黄酮的含量,采用高效液相色谱法同时测定原儿茶酸、儿茶素及表儿茶素的含量。【结果】鸡血藤藤茎中醇溶性浸出物、总黄酮及指标性成分原儿茶酸、儿茶素和表儿茶素的含量均随着生长年限的增加呈递增的趋势;而1年中不同月份样品的醇溶性浸出物、总黄酮、表儿茶素的含量变化均呈抛物线状,7～9月含量达到峰值;儿茶素的含量则一直呈上升状态;7～9月采收的4～6年生鸡血藤样品中醇溶性浸出物已达到现行版《中国药典》的要求。【结论】初步建议栽培鸡血藤藤茎以7年生以上采收为宜,其最佳采收年限与采收月份有待进一步研究确定。     

响应面法优化超声辅助提取南板蓝根多糖工艺

【目的】采用优选超声波法提取南板蓝根多糖的最佳工艺条件,为南板蓝根多糖的开发研究提供理论依据。【方法】选定提取温度、时间及水料比作为影响因素,以南板蓝根多糖提取率为评价指标。在单因素试验的基础上,通过3因素3水平Box-Behnken设计试验,建立多糖提取率的二次多项式回归方程,采用响应面回归分析得到优化组合条件。【结果】最佳提取工艺为提取温度60℃,提取时间35 min,水料比24．5∶1（V∶m, mL/g）,南板蓝根多糖的提取率为83．7 mg/g。【结论】此方法具有简单、快捷、高效等优点,可为南板蓝根多糖的综合开发应用奠定理论基础。     

沙棘总黄酮防紫外线损伤的实验研究

目的：通过中波紫外线（UVB）辐射皮肤损伤模型来探讨沙棘总黄酮对皮肤的保护修复作用,为寻找新型抗紫外线的药物提供实验依据。方法通过 UVB 反复照射,构建 UVB 辐射小鼠皮肤损伤模型,观察各组实验动物皮肤形态学变化、皮肤中超氧化物歧化酶（SOD）活性、皮肤内脂类受过氧化损伤的程度即丙二醛（MDA）的量和胶原蛋白量的变化程度。结果模型组较正常组皮肤形态学变化明显,表皮层增加,真皮层增厚,UVB 辐射皮肤损伤模型构建成功;模型组较正常组 SOD 活性和 MDA的量分别是极显著降低和升高（P＜0．01）,而阳性对照组和沙棘总黄酮给药组较模型组 SOD 的活性和 MDA 的量分别是极显著升高和降低（P＜0．01）;模型组较正常组胶原蛋白量显著降低（P＜0．05）,阳性对照组和沙棘总黄酮给药组胶原蛋白量较高（P＜0．01）,但阳性对照组出现了增生性瘢痕。结论沙棘总黄酮能有效防止 UVB 反复照射对皮肤造成的损伤,提高皮肤组织中SOD 活性和胶原蛋白量,抑制 MDA 的量升高和瘢痕增生,并对 UVB 导致小鼠皮肤光老化有拮抗作用。     

虾青素对人视网膜色素上皮细胞氧化损伤的保护作用

目的：：探讨虾青素(astaxanthin,AST)对过氧化氢(hydrogen peroxide,H2 O2)诱导人视网膜色素上皮细胞( retinal pigment epithelial cells,RPE)氧化损伤的保护作用。方法：人RPE细胞系传代培养,MTT检测细胞活力,流式细胞仪检测细胞凋亡率,透射电镜观察超微结构变化。结果：MTT结果显示用10-8 mol/L和10-4 mol/L AST处理后, RPE 细胞活性分别提高到53.66％±3.25％和70.43％±2.38％,与氧化损伤组(38.76％±3.74％)比较,差异具有统计学意义(P<0.05);流式细胞计数结果显示,预先给予10-8 mol/L和10-4 mol/L的AST作用后, RPE细胞凋亡率分别下降到30.23％±1.91％和12.58％±2.12％,与氧化损伤组(42.50％±1.94％)比较,差异具有统计学意义( P<0.05)。电镜观察结果显示,伴随AST作用浓度的增加,细胞形态亦逐渐得到改善。结论：AST可以抑制H2 O2诱导的人RPE细胞的凋亡,从而为寻求有效的防治视网膜损伤的药物提供可靠的实验依据。