基于豚鼠模型结合网络药理学探究七白粉的皮肤美白作用机制

目的：研究七白粉的皮肤美白作用,并结合网络药理学和分子对接技术预测其达到美白效果的作用机制。方法：采用紫外线B波段（UVB）照射诱导豚鼠皮肤色素沉着,建立动物模型。观察七白粉对模型豚鼠的美白效果,同时检测黑色素细胞数和超氧化物歧化酶（SOD）、丙二醛（MDA）、酪氨酸酶（TYR）及脂褐质（LF）等与皮肤色素沉积相关的生化指标。利用网络药理学预测七白粉美白的作用机制,并通过分子对接和表面等离子体共振（SPR）进行验证。结果：在动物实验中,与模型组比较,七白粉可显著改善皮肤亮度,且黑色素细胞数和TYR、LF、MDA水平均显著降低,而SOD水平显著升高。网络药理学研究发现七白粉通过儿茶素没食子酸酯、茯苓酸C、别欧前胡素等关键成分,作用于蛋白激酶B α（AKT1）、肿瘤坏死因子（TNF）、表皮生长因子（EGFR）等关键靶标,调控磷脂酰肌醇3-激酶-蛋白激酶B（PI3K-AKT）和TNF等信号通路改善黑色素沉积而发挥美白作用。分子对接和SPR结果显示关键成分与关键靶标有较好的亲和力。结论：七白粉可通过抗氧化和抑制TYR的活性达到美白皮肤的效果。此外,七白粉通过多成分作用于多靶点,调控多通路改善黑色素沉积而发挥美白作用,体现了中药复方君臣佐使相互协同,多成分,多靶点,多通路的特点。     

Fam114A1蛋白对黑素细胞生物学功能影响的初步研究

【摘要】 目的 初步探讨Fam114A1对黑素细胞生物学功能的影响。方法 以黑素瘤细胞A375为工具细胞株,通过慢病毒转染的方式构建稳定过表达和抑制Fam114A1蛋白的细胞株,即过表达组和表达抑制组,以转染空载慢病毒的A375细胞作为对照组。实时荧光定量PCR检测Fam114A1对黑素合成相关基因酪氨酸酶（TYR）、酪氨酸酶相关蛋白1（TYRP1）、前黑素小体蛋白（PMEL）、小眼畸形相关转录因子（MITF）和多巴色素异构酶（DCT）mRNA表达的影响,Western印迹法检测TYR、MITF蛋白的表达,MTT法、Transwell迁移和黏附实验分别检测Fam114A1对A375细胞增殖活性、迁移细胞数及黏附能力的影响。统计分析采用单因素方差分析和Dunnett-t检验。结果 荧光显微镜观察慢病毒转染效率均在90%左右。与对照组A375细胞Fam114A1相对表达水平（0.850 ± 0.120）相比,过表达组显著升高（1.507 ± 0.170,t = 5.888,P = 0.001）,而表达抑制组显著降低（0.397 ± 0.120,t = 4.065,P = 0.007）,成功构建稳定过表达和抑制Fam114A1的A375细胞株。实时荧光定量PCR及Western印迹结果显示,表达抑制组TYR和MITF mRNA及蛋白表达均显著低于对照组（均P < 0.01）,而过表达组TYR和MITF mRNA及蛋白表达与对照组差异无统计学意义（均P > 0.05）。与对照组相比,表达抑制组细胞增殖活性和黏附能力显著增强（P = 0.009、0.001）,细胞迁移能力显著减弱（P = 0.005）,而过表达组仅细胞迁移能力显著增强（P = 0.021）。结论 Fam114A1可影响A375的增殖活性、迁移和黏附能力,且影响黑素合成相关蛋白TYR和MITF的表达,可能是一种参与调控黑素细胞生物学活性的功能蛋白。     

Facial-Skin Hyperpigmentation： Histological and Computer Geometric Assessment

Hyper-pigmentation is a common, acquired dermatological skin-disorder manifesting and identifiable as irregular brown or greyish-brown facial discolouration, and sometimes referred to as melanosis, melasma or hypermelanosis. Purpose and Objective： To identify the site of melanin deposition in skin-layers regarding facial hyper-pigmentation, based on a histological study of full-thickness skin-facial biopsies in aged Caucasian-cadavers. Hypothesis： Recalcitrant hyper-pigmentation, is chiefly characterised by hyper-melanosis restricted to the dermal-layer of the integument. Method： The histological features of facial hyper-pigmentation and solar-lentigenes were evaluated in a pilot-study of 5-randomly selected Caucasian-cadavers with pigmentation （15 facial biopsies）, ranging in age between 75 and 102 years （mean 77-years）. Selection-criteria included, both genders, age 〉 75, focal and confluent hyper-pigmented lesions, involving sun-exposed areas of skin （centrifacial, scalp, malar, mandibular and cervical）. Study groups included （Grp-1： Control skin-histology in otherwise normal aged, human-cadavers; Grp-2： Histology of pigmented facial skin-lesions in man; Grp-3： Comparative histological skin-controls in non-human primates）. No obvious hepatic disease was evident in the cohort studied. Twenty-five histological controls were obtained from non-pigmented areas. Histological evaluation of full-thickness skin-biopsies （including the lesion, edge and peri-]esion skin）, was under a Leitz~-light-microscope, and staining included H＆E, Masson-trichrome, Masson-fontana, Alcian-blue and Verhoef technology. Histological-scoring used was on histological deposition of melanin in skin-layers： epidermal, dermal, mixed, and indeterminate melanin-deposition （score 1-4）. Controls included cadaveric skin-biopsies of human races of colour and non-human primate, Cercopethicus Aethiops （latter is known to have predominantly dermal-melanin deposition）. Pigmented and non-pigmented areas were compared in both species. Results： The majority of clinically visible individual and confluent areas of hyper-pigmentation studied were maeroscopically present on the forehead, frontal scalp in hair-receded cadavers, molar and temporal zones. Histologically, documented features of age-related changes without pigment were present in almost all the embalmed cadaver-skins, with a melanin-score of 1. Computer enhanced skin geometry and biometrics confirmed the presence of an aged-skin, pigmentation and features of solar damage. The human embalmed-tissue was well preserved and minimal autolytic changes were present. Special stains of full-thickness biopsies （Masson-Fontana）, showed that melanin in the subhuman-primate is lodged in the deep dermis （reticular dermis）, within the extra-cellular matrix （ECM） and superficial to the hypodermal adipose-tissue （melanin-score 3）. Fifteen pigmented lesions studied in five （5） aged-cadavers （forehead, molar and mandibular areas） all showed predominantly epidermal-deposition of melanin in the basal, suprabasal and stratum corneum with tiny focal areas of dermal melanosis in single-cell macrophages in the papillary-dermis but not reticular-dermis （melanin-score 2）. A melanin-deposition localization ratio of epidermis to dermis was approximately 98 to 2% in cadavers with hyper-pigmentation. Conclusion： The skin-strata localization of the melanin with regards hyper-pigmentation of the face and forehead in this aged, human adult Caucasian, cadaveric-study, was predominantly in the epidermis and sparse in the papillary dermis.     

Effect of Cu2+-ions on semiconductor properties of synthetic DOPA melanin polymer

The purpose of the present study was to examine semiconductor properties of synthetic DOPA melanin, which are basic for future biological applications. DC conductivity, electron spin resonance (ESR),and atomic absorption spectroscopy (AAS) measurements have been performed to investigate the effect of Cu²⁺ions on the semiconductor properties of melanin polymer synthesized from DOPA (3,4-dihydroxyphenylalanine). DOPA melanin - Cu²⁺ complexes examined show the decrease of both thermal activation energy ΔE_a and pre-exponential factor σ₀ values upon doping. At the same time no substantial changes in conductivity at 293 K have been observed. Formation of bipolaron states due to chelation of copper ions by melanin orthosemiquinones has been postulated. The Meyer-Neldel rule with a characteristic temperature T₀ equal to 298 K and possible physiological implication of this fact are discussed. These data suggest, that DOPA melanin polymer could be useful as a type of culture substratum.     

The Uncertain Significance of Low Vitamin D Levels in African Descent Populations: A Review of the Bone and Cardiometabolic Literature

Vitamin D levels in people of African descent are often described as inadequate or deficient. Whether low vitamin D levels in people of African descent lead to compromised bone or cardiometabolic health is unknown. Clarity on this issue is essential because if clinically significant vitamin D deficiency is present, vitamin D supplementation is necessary. However, if vitamin D is metabolically sufficient, vitamin D supplementation could be wasteful of scarce resources and even harmful. In this review vitamin D physiology is described with a focus on issues specific to populations of African descent such as the influence of melanin on endogenous vitamin D production and lactose intolerance on the willingness of people to ingest vitamin D fortified foods. Then data on the relationship of vitamin D to bone and cardiometabolic health in people of African descent are evaluated.     

Preliminary approach to elucidate the role of pigment as a binding site for drugs and chemicals in anagen hair: differential uptake of <Superscript>3</Superscript>H-haloperidol by pigment-producing compared to non-pigment-producing cell lines

A striking difference was observed for cellular-bound drug in HaCaT and Sk-Mel-1 cells for a fixed drug exposure time of 72 h and varying ³H-haloperidol concentrations in the culture media. Drug uptake was dependent on drug concentration and linearly correlated for both the non-pigment- and the pigment-producing cells which however was different in magnitude. In an additional investigation the time course of drug uptake during ³H-haloperidol exposure (400 pmol/ml; 28 days) revealed increasing drug concentrations in the Sk-Mel-1 population, whereas drug concentrations in the keratinocytes reached a plateau within a short time period. In contrast to the HaCaT cells no tendency to saturation was observed for the pigment-producing cell line. At the end of the experiments ³H-haloperidol concentrations in Sk-Mel-1 were found to be approximately tenfold higher than in HaCaT. Received: 7 November 2000 / Accepted: 31 May 2001     

黑素再生中药对白癜风患者免疫功能的影响

目的：探讨黑素再生中药对白癜风患者免疫功能的影响。方法：观察组和对照组健康者均服用黑素再生中药，观察测定黑素再生药品对体液免疫和细胞免疫功能的影响。结果：白癜风患者治疗后的免疫球蛋白IgA、IgG较治疗前有非常显著的改善（P＜0．01），IgM变化无显著性。结论：黑素再生中药能提高机体免疫水平，具有降低体液免疫及增强细胞 免疫等功能。     

叶酸的光降解和皮肤颜色的关系

目的了解叶酸的光降解和皮肤颜色的关系。方法用荧光光谱仪记录和分析叶酸和维生素B2的光降解过程，用Sigmaplot软件描绘紫外线在不同地区对不同肤色的皮肤的穿透程度。结果维生素B2的加入可使叶酸在UVA和蓝色光下发生光降解。紫外线穿透肤色类型2最深，类型4最浅．穿透程度随地方的不同而变化。结论叶酸在紫外线和可见光照射发生降解的事实进一步给“皮肤颜色理论”的可靠性提供了依据。     

Binding of 14C-spermidine to melanin in vivo and in vitro

It has been shown that melanin has the properties of a polyanion and may in vivo and in vitro bind inorganic cations and drugs which are positively charged at physiological pH by a cation-exchange mechanism. In the present study, we explored if the organic aliphatic polycation spermidine would bind to melanin in vivo after administration of ¹⁴C-spermidine to pigmented mice and in vitro at incubations with pigment from beef-eyes. The results showed a high labelling of the pigmented tissues in the mice after the administration of ¹⁴C-spermidine. At long survival intervals, the radioactivity in the melanin was higher than in any other tissue. A strong melanin affinity of ¹⁴C-spermidine was found in vitro. An analysis of the binding by the method of Scale hard showed that the data could be best fitted by the assumption of two classes of binding sites. The in vivo bound material could be displaced by in vitro incubation in solutions containing inorganic cation-chloride salts or HCI and HC1 was also very effective in inhibiting the melanin-binding of ¹⁴C-spermidine in vitro. The results indicate that an electrostatic interaction between spermidine and melanin will occur both in vivo and in vitro.     

Effects of environmental pollution on the liver parenchymal cells and Kupffer-melanomacrophagic cells of the frog Rana esculenta

In vertebrates, the biotransformation processes of xenobiotics are performed mainly by the liver which involves both hepatocytes and Kupffer-melanomacrophagic cells through enzymatic and nonenzymatic mechanisms. In this study, we investigated the liver of Rana esculenta adult frogs collected at two sample rice fields, one heavily polluted and one relatively unpolluted. Water pollution was determined by chemical analysis on tadpoles. The specific activities of some enzymes (glucose-6-phosphate dehydrogenase (G6PDH), acid and alkaline phosphatases (AcPase and AlkPase), succinic dehydrogenase (SDH), and catalase) were studied in the liver of adult frogs to identify the possible changes induced by contamination in the metabolic processes which depend on the function of the liver. The production of reactive oxygen species (ROS) were also evaluated through histochemical techniques. In the polluted samples, hepatocytes showed variations in the activity of G6PDH, AlkPase, and SDH and a moderate to intense ROS expression. Prominent changes were observed in Kupffer cells (KCs) and melanomacrophages (MMPs), both showing intense reactivity for AcPase and catalase and variations in melanin content and distribution. Results thus indicate a general adaptive response of liver parenchyma to environmental pollution. The possible role of both KCs and MMPs as scavengers of foreign substances is discussed.