肾着祛斑汤对紫外线诱导的小鼠B-16黑素瘤细胞株黑素合成的抑制作用

肾着祛斑汤是欧阳恒教授多年来用于治疗黄褐斑的经验处方，我们研究该方对紫外线诱导的小鼠B-16黑素瘤细胞株细胞增殖、酪氨酸酶(TYR)活性及黑素合成的影响，以期探讨治疗黄褐斑的机制。     

中药桂枝抑制黑素生成的作用机理研究

目的研究中药桂枝对小鼠黑素细胞系M el-a黑素生成、酪氨酸酶活性及基因表达的影响,阐明桂枝抑制黑素生成的机理。方法用药物处理M el-a细胞后进行黑素含量、L-DOPA染色、放免法测定酪氨酸酶活性,western b lot和实时RT-PCR分别测酪氨酸酶及酪氨酸酶相关蛋白的蛋白和mRNA表达水平。选取熊果苷作为阳性对照。结果10μg/m l浓度的桂枝提取物在细胞培养水平对黑素生成有明显地抑制作用,强于20μg/m l浓度的熊果苷。桂枝可以抑制酪氨酸酶mRNA表达;减少这种限速酶的蛋白产量,在细胞量相同的情况下,桂枝明显抑制酪氨酸酶的氧化活性。结论中药桂枝有很强的抑制黑素产生的作用,其作用是通过抑制酪氨酸酶的基因表达、蛋白合成和氧化活性这三方面来实现。     

白茯汤治疗黄褐斑20例临床疗效观察

黄褐斑俗称肝斑、蝴蝶斑 ,是常见的面部色素沉着性疾病 ,属中医“黧黑斑”、“面尘”范畴 ,皮损为面部对称性黄褐斑片 ,以面部两颊最为多见 ,其发病率有逐年增加的趋势 ,多发于青年女性 ,严重影响美容 ,目前缺乏理想的治疗方法 ,患者压力较大 ,治疗迫切。为了寻找治疗黄褐斑的有效药物和方法 ,我们选择下调酪氨酸酶活性抑制黑素生成的中药白术、茯苓、山茱萸、猪苓、沙苑蒺藜、甘草等组成中药复方 (白茯汤 ) ,采用其水煎剂口服 ,治疗黄褐斑患者 30例 ,并与六味地黄汤口服比较 ,取得满意疗效 ,报告如下。1　病例与方法1.1　一般资料　黄褐斑…     

酪氨酸酶抑制剂及对黑素生物合成的影响

酪氨酸酶是皮肤黑素生物合成的关键酶、限速酶，可以酪氨酸酶为靶点筛选增白美容的药物，用于治疗色素沉着性皮肤病。综述了已用于临床的氢醌、熊果苷、曲酸、壬二酸等药物。以及近年来通过各种途径筛选得到的酪氨酸酶抑制剂及其脱色素的机制。     

川芎嗪对正常人黑素细胞黑素合成的抑制作用

目的　了解川芎嗪对黑素细胞增殖、酪氨酸酶活性及黑素合成的影响。方法　采用黑素细胞体外纯培养技术 ,在药物处理后的细胞中掺入3H TdR测定细胞增殖情况 ,用氧化DOPA反应测定酪氨酸酶活性 ,NaOH法测量黑素生成量。结果　随着药物浓度增加 ,黑素细胞增殖降低 ,但浓度过高 ( >5 0 0 μg/ml)则显示其毒性作用。细胞酪氨酸酶活性及黑素生成量同药物浓度成反比。结论　川芎嗪在较低的相对安全浓度下 ( 5 0～ 40 0 μg/ml)即可有效抑制黑素细胞增殖 ,降低酪氨酸酶活性 ,从而减少黑素合成。     

淫羊藿苷抑制正常黑素细胞黑素合成的研究

目的:观察中药单体淫羊藿苷对体外培养的正常黑素细胞黑素合成和酪氨酸酶活性的影响。方法:选择高、中、低3个浓度的中药单体作用于体外培养的黑素细胞,测定细胞酪氨酸酶活性、黑素含量和细胞增殖率。采用间接免疫荧光染色法对药物作用的黑素细胞和对照的酪氨酸酶(tyrosinase熏TYR)、酪氨酸酶相关蛋白-1(tyrosinaserelatedprotein-1熏TRP-1)、TRP-2进行标记,然后采用激光共聚焦显微镜半定量分析淫羊藿苷作用后细胞内3种成分表达量的变化。结果:淫羊藿苷明显抑制酪氨酸酶活性和黑素的生成(P<0.01),且呈浓度依赖性,但淫羊藿苷抑制黑素生成的作用较氢醌弱(P<0.01);淫羊藿苷以浓度依赖的方式促进细胞的增殖,氢醌则抑制了细胞的增殖;淫羊藿苷对黑素细胞内TYR和TRP-2的表达没有明显影响,但是对TRP-1的表达却明显增加了。结论:淫羊藿苷能够抑制黑素合成和酪氨酸酶活性,这种抑制可能主要通过抑制酪氨酸酶活性起作用。     

倍他米松对毛囊外毛根鞘无色素黑素细胞激活的试验研究

目的：研究倍他米松（betamethasone，BT）对毛囊无色素黑素细胞（amelanotic melanocytes，AMMC）的激活作用。方法：以高、中、低3种不同浓度的BT作用于培养的人毛囊外毛根鞘AMMC，测定药物作用前后酪氨酸酶（tyrosinase，TYR）活性和黑素生成的变化。通过间接免疫荧光法结合激光共聚焦显微镜半定量分析药物作用前、后AMMC TYR、酪氨酸酶相关蛋白（tyrosinase related protein，TRP）-1和TRP-2表达的变化，透射电镜分析黑素小体在药物作用前后的变化。结果：BT促进了AMMC表达TYR和TRP-1，并且以剂量依赖方式促进TYR活性，诱导黑素生成。AMMC主要含有Ⅰ、Ⅱ和Ⅲ期黑素小体，但是BT作用后AMMC含有大量Ⅲ或Ⅳ期黑素小体，并且以Ⅳ期黑素小体为主。结论：BT能够激活AMMC，这可能部分解释了糖皮质激素治疗白癜风的机制。     

橙皮苷对人黑素细胞黑素合成和酪氨酸酶活性的影响

目的:观察橙皮苷对人原代黑素细胞酪氨酸酶及黑素合成的影响,探讨其作用机制.方法:选择50、100、200、300、400、500 和600 mg/L 7 个浓度的橙皮苷作用于体外培养的人表皮黑素细胞72 h,分别测定细胞增殖活性、酪氨酸酶活性及黑素含量.结果:橙皮苷显著抑制黑素合成和酪氨酸酶活性,且呈浓度依赖性.结论:橙皮苷可抑制黑素合成和酪氨酸酶活性.     

山柰素与熊果苷对体外培养人正常黑素细胞的作用

目的比较山柰素与熊果苷对体外培养人正常黑素细胞增殖、黑素合成及其酪氨酸酶活性的影响,为探索色素沉着性皮肤病的发病机制以及筛选新的治疗药物提供理论依据。方法以不同浓度(1～100μmol/L)山柰素与熊果苷干预体外培养的人正常黑素细胞,比较两者对黑素细胞的黑素含量、细胞增殖及其酪氨酸酶活性的影响。结果对于黑素细胞酪氨酸酶活性和黑素含量的抑制作用,山柰素在各个浓度均优于熊果苷,差异有统计学意义(P<0.05),山柰素对细胞增殖抑制率无明显影响,而熊果苷在各浓度对细胞增殖抑制作用显著,且随其浓度增加,抑制率逐渐增强。结论山柰素对黑素细胞酪氨酸酶活性及黑素合成的抑制作用强于熊果苷,并对黑素细胞的增殖及形态无明显的负面影响,是一种有良好应用前景的酪氨酸酶抑制剂。     

止血环酸抑制黑色素合成的实验研究

目的 观察止血环酸抑制黑素瘤细胞的黑素合成作用并探讨其机理。方法 比色法和免疫组化法分别用于B16黑素瘤细胞黑素含量测定和酪氨酸酶测定，氨基酸自动分析仪和高效液相色谱用于酪氨酸酶代谢的测定。结果 止血环酸虽不能抑制B16黑素瘤细胞生长和减少黑素瘤细胞酪氨酸酶含量，但能干扰酪氨酸酶对酪氨酸的催化作用，减少黑素合成。结论 止血环酸是通过干扰酪氨酸酶的酪氨酸催化作用抑制黑素合成。     

联合治疗黄褐斑的研究进展

黄褐斑是一种常见的皮肤色素代谢障碍性疾病,因病因及发病机制复杂,单药治疗疗效不佳或不良反应较大,而联合治疗因疗效佳、不良反应小受到医生的亲睐。目前黄褐斑的治疗多样,主要有口服、外用药物,激光或光子疗法,多种方案联合治疗等。黄褐斑的治疗需根据患者病因、病程、临床分型、既往治疗情况等制定个性化治疗方案。多重治疗、序贯治疗或补充治疗应纳入黄褐斑治疗中。     

A comparative study of 20% azelaic acid cream monotherapy versus a sequential therapy in the treatment of melasma in dark-skinned patients

BACKGROUND: Melasma is a commonly found hyperpigmentary disorder in dark-complexioned persons, which is rather difficult to treat. Azelaic acid (AZA) 20% is considered efficacious in the treatment of melasma, although the response is rather slow. It has also been combined synergistically with topical retinoic acid, where the results were satisfactory. OBJECTIVE: The study was done to evaluate the usefulness of a sequential therapy of potent topical steroids +20% AZA cream versus only 20% AZA cream in the treatment of melasma. METHODS: This was a prospective, single-blind, right-left comparison pilot study with (1). twice daily application of 20% AZA to one half of the face for 24 weeks and (2). a potent topical steroid, 0.05% clobetasol propionate cream, to be applied for 8 weeks only and then to be followed by 20% AZA cream only for the next 16 weeks on the other half. Concomitant use of a broad-spectrum sunscreen was also mandatory. Thirty Indian patients (25 females, 5 males), whose ages ranged from 21 to 45 years and who were not pregnant, nursing or on any concurrent therapy, completed the study. Clinical evaluation, photography and the overall response were assessed at 4, 8, 16 and 24 weeks. RESULTS: At 4, 8 and 16 weeks, the lightening of melasma was significantly more marked on the side receiving the sequential therapy rather than the side receiving only 20% AZA cream (p < 0.001). However, at 24 weeks, although the difference was still significant (p = 0.0052), as many as 96.7 and 90% of patients of each group (sequential therapy and AZA) had good to excellent responses to treatment. The side-effects noted were mostly mild and transient and mainly local irritant effects. CONCLUSIONS: A sequential therapy of topical potent steroids +20% AZA cream can be considered as another alternative treatment for melasma, which combines the beneficial effects of both besides perhaps increasing the compliance of the patients. 20% AZA monotherapy itself is also an effective and well-tolerated therapy for melasma in dark-skinned races.     

强脉冲光单独或联合其他疗法治疗黄褐斑的研究进展

【摘要】 黄褐斑病因复杂,目前治疗手段较多,但均无确切、满意的疗效。近年来,强脉冲光治疗黄褐斑取得了良好的疗效。本文综述近年来单用强脉冲光及联合激光、外用药和系统用药治疗黄褐斑取得的进展。     

Split-face comparative study of 1550 nm fractional photothermolysis and trichloroacetic acid 15% chemical peeling for facial melasma in Asian skin

Fractional photothermolysis (FP) therapy and chemical peels have been reported to be effective in patients with recalcitrant melasma. However, there is little information to compare the efficacy of single treatment session in Asian women. The aim of this study was to examine the efficacy, long-lasting outcomes and safety of a single session of 1550-nm erbium-doped FP in Asian patients, compared with trichloroacetic acid (TCA) peel with a medium depth. Eighteen Korean women (Fitzpatrick skin type III or IV) with moderate-to-severe bilateral melasma were randomly treated with a single session of 1550-nm FP on one cheek, and with a 15% TCA peel on the other cheek. Outcome measures included an objective melasma area severity index and subjective patient-rated overall improvement at 4 and 12 weeks after treatment. Melasma lesions were significantly improved 4 weeks after either treatment, but melasma recurred at 12 weeks. Post-inflammatory hyperpigmentation developed in 28% of patients at 4 weeks but resolved in all but one patient by 12 weeks. There was no difference between FP treatment and TCA peeling with respect to any outcome measure. FP laser and TCA peel treatments were equally effective and safe when used to treat moderate-to-severe melasma, but neither treatment was long-lasting. We suggest that multiple or periodic maintenance treatments and/or supplemental procedures may be required for the successful treatment of melasma in Asian women.     

The treatment of melasma: a review of clinical trials

Melasma is an irregular brown or grayish-brown facial hypermelanosis, often affecting women, especially those living in areas of intense UV radiation. The precise cause of melasma remains unknown; however, there are many possible contributing factors. Because of its dermal component and tendency to relapse, melasma is often difficult to treat. The use of broad-spectrum (UVA + UVB) sunscreen is important, as is topical hydroquinone, the most common treatment for melasma. Other lightening agents include retinoic acid (tretinoin) and azelaic acid. Combination therapies such as hydroquinone, tretinoin, and corticosteroids have been used in the treatment of melasma, and are thought to increase efficacy as compared with monotherapy. Kojic acid, isopropylcatechol, N-acetyl-4-cysteaminylphenol, and flavonoid extracts are other compounds that have been investigated for their ability to produce hypopigmentation, but their efficacy, safety, or trial design indicates that the interventions would need further study before they could be recommended. Chemical peels, laser treatments, and intense pulsed light therapy are additional therapeutic modalities that have been used to treat melasma.     

Induction of melasma by 1064‐nm Q‐switched neodymium:yttrium–aluminum–garnet laser therapy for acquired bilateral nevus of Ota‐like macules (Hori nevus): A study on related factors in the Chinese population

Laser treatment has emerged as a common treatment modality for acquired bilateral nevus of Ota‐like macules (ABNOM). To identify the ratio of melasma induction and exacerbation before and after laser therapy for ABNOM and to observe the risk factors related to the induction and exacerbation of melasma by laser therapy, we analyzed related factors of 1268 adult Chinese patients who underwent 1064‐nm Q‐switched neodymium:yttrium–aluminum–garnet (Nd:YAG) laser (QNYL) treatment using case series and case–control studies. Overall, 24.0% of the ABNOM patients had mixed melasma. Among the ABNOM patients without melasma, after laser therapy the development of melasma was more frequently noted in patients older than 35 years (P < 0.0001), as well in patients whose ABNOM was less than 10 cm² (P = 0.027), ABNOM were light (similar to yellow‐brown) in color (P = 0.021) and skin types were closer to type IV (P < 0.0001). New melasma lesions also appeared most frequently in the zygomatic region (P < 0.0001). Among the ABNOM patients with melasma, 89.5% experienced worsening of their melasma, irrespective of their related factors above. We concluded that the risk of inducing melasma is great after 1064‐nm QNYL treatment in ABNOM patients, and particularly in the patients with both ABNOM and melasma. ABNOM patients should be treated as early as possible and before the age of 35 years.     

A Face-Split Study to Evaluate the Effects of Microneedle Radiofrequency with Q-Switched Nd:YAG Laser for the Treatment of Melasma

BackgroundLaser toning using a low-fluence 1,064 nm Q-switched Nd:YAG laser is one of the most frequently used treatment modalities for melasma. However, this therapy is time consuming because it requires a lot of treatment sessions. Recently, it has been reported that transdermal radiofrequency (RF) is effective for the treatment of melasma.ObjectiveTo determine whether microneedle RF conduction could be an adjunct therapy for melasma, we have studied the effect of simultaneous treatments with laser toning and RF for melasma.MethodsFifteen patients with melasma underwent five sessions of laser toning and microneedle RF on the right side of the face, and only laser toning on the left side. Responses to treatments were evaluated using the Mexameter® (Courage Khazaka, Germany) score, the pigmentation and severity index (PSI) score, and the patient''s overall assessment. Additionally, an electron microscopic study of a skin biopsy was performed.ResultsBoth laser toning and combination therapy showed significant decreases in the Mexameter® and PSI score after five treatment sessions. Combination therapy showed a more significant improvement of melasma than laser toning. No remarkable side effects were reported. Electron microscopic analysis showed a greater number of vacuolar changes and increased loosening of melanocytes and adjacent epidermal cells after combination therapy.ConclusionThe combination treatment of laser toning and microneedle RF therapy showed a better therapeutic effect for melasma than laser toning alone. Therefore, the microneedle RF technique could be a new and safe adjunct therapy for the treatment of melasma.     

Novel technique to treat melasma in Chinese: The combination of 2940-nm fractional Er:YAG and 1064-nm Q-switched Nd:YAG laser

Melasma is one of the most common pigmented lesions in Chinese women. Although topical therapies are the mainstay treatment, lasers are being used increasingly to treat pigmented lesions. Laser treatment of melasma is however still controversial. This is because lasers have not been able to produce complete clearance of melasma and recurrence rates are high. Laser treatments also cause complications such as hypopigmentation and post-inflammatory hyperpigmentation. In this article, we report on a novel technique using a combination of fractional 2940-nm Er:YAG and 1064-nm Q-switched Nd:YAG lasers. We achieved a rapid improvement in two cases of melasma in Chinese type III skin. The improvement was seen rapidly within a month of treatment. Follow-up at 6 months showed sustained results with no complications. This novel technique is able to safely confer excellent and sustained clearance within a short treatment time.     

The Role of Topical Retinoids in the Treatment of Pigmentary Disorders

Topical retinoids have been used in the treatment of pigmentary disorders such as melasma, actinic lentigines, and post-inflammatory hyperpigmentation. This article evaluates the clinical efficacy and tolerability of retinoid treatment for pigmentary disorders through an evidence-based approach.We searched the MEDLINE and The Cochrane Library databases using the keywords ‘retinoid’ combined with ‘melasma,’ ‘lentigines,’ or ‘postinflammatory hyperpigmentation.’ For each study, the methodology and outcomes were assessed according to specific criteria. There is fair evidence to support the use of topical tretinoin as a monotherapy in the treatment of melasma as well as in the treatment of lentigines (grade B). Adverse effects of topical retinoids are quite frequent, and include local skin irritation, erythema, and peeling, and their severity is mild to moderate. There is evidence to support the use of topical tretinoin in a fixed, triplecombination therapy (hydroquinone 4%/tretinoin 0.05%/fluocinolone acetonide 0.01%) for the treatment of melasma (grade B). There is poor evidence (grade C) to support the use of combination formulations for the treatment of lentigines, and large, randomized, double-blind, controlled trials are needed to further evaluate their use for this indication. In conclusion, there is evidence to support the use of topical retinoids as monotherapy or in combination with other topical agents in the treatment of pigmentary disorders.     

Mequinol 2%/tretinoin 0.01% topical solution for the treatment of melasma in men: a case series and review of the literature

Melasma is a common hyperpigmentation disorder that typically affects women, though up to 10% of white individuals seeking treatment for melasma are men. Melasma can be a source of embarrassment for men because of its association with women and pregnancy. We performed a case series assessing the use of mequinol 2%/ tretinoin 0.01% topical solution in 5 men with melasma. Four of 5 patients achieved complete clearance of melasma at 12 weeks, and 1 patient showed moderate improvement. Side effects were minimal and consisted of stinging in one patient. All patients maintained results at the 16-week follow-up visit. Mequinol 2%/tretinoin 0.01% topical solution was an effective and well-tolerated treatment of melasma in men. The vehicle resulted in good compliance and minimal adverse effects in patients. This is the first report describing the use of mequinol 2%/tretinoin 0.01% topical solution for the treatment of melasma in men; there are no reports in women.