Treatment of actinic keratoses with birch bark extract: a pilot study

Background: Birch bark contains a variety of apoptosis‐inducing and anti‐inflammatory substances such as betulinic acid, betulin, oleanolic acid and lupeol. Therefore, birch bark extract may be effective in the treatment of actinic keratoses. To address this issue, a pilot study using a standardized birch bark ointment was performed. Methods: Twenty‐eight patients with actinic keratoses were enrolled in this prospective, non‐randomized pilot study. Fourteen patients were treated with birch bark ointment only; fourteen patients received a combination therapy with cryotherapy and birch bark ointment. Treatment response was assessed clinically after two months. Results: Clearing of more than 75 % of the lesions was seen in 79 % of the patients treated with birch bark ointment monotherapy. The response rate of the combined treatment modality was 93 %. Therapy with birch bark ointment was well tolerated. Conclusion: In this pilot study, a standardized birch bark extract was effective in the treatment of actinic keratoses. This therapy is easy to perform and it has no side effects. Birch bark ointment may be a new therapeutic option for actinic keratoses.     

Simultaneous determination of betulin and betulinic acid in white birch bark using RP-HPLC

A simple procedure is described for the simultaneous extraction and determination of betulin and betulinic acid in white birch bark. The extraction was checked using different solvents: dichloromethane, ethyl acetate, acetone, chloroform, methanol and 95% ethanol (aqueous solution, v/v). It was found 95% ethanol was a good extraction solvent that allowed extraction of triterpenoid with a highest content. Separation was achieved on a reversed phase C(18) column with acetonitrile-water 86:14 (v/v). Detection was accomplished with UV detection at lambda=210 nm. Using this method, the bioactive triterpenoid in white birch bark were simultaneously determined. Significant variations in the content of betulin and betulinic acid in white birch bark growing in different locations of China were also observed.     

白桦酯醇对卵巢癌裸鼠皮下移植瘤组织中MMP-2和MMP-9表达的影响及意义

目的 探讨白桦酯醇对卵巢癌SKOV3细胞裸鼠皮下移植瘤组织中基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶-9（MMP-9）表达的影响和意义。方法 建立卵巢癌SKOV3细胞裸鼠移植瘤模型,将30只裸鼠随机分为白桦酯醇高剂量组（80mg／kg）、中剂量组（40mg／kg）、低剂量组（20mg／kg）以及对照组（生理盐水）和紫杉醇组（135mg／m2）,每组6只,腹腔给药02ml/只,隔日1次,连续21d。停药后第2d处死裸鼠,测量其移植瘤体积和瘤重;用免疫组织化学法检测移植瘤组织中MMP-2和MMP-9蛋白的表达并计算表达率。结果 白桦酯醇处理组和紫杉醇组的移植瘤体积和瘤重均小于对照组（P＜0.05）;白桦酯醇中、高剂量组的抑瘤率分别为44.5％和51.4％,均高于其低剂量组的17.5%（P＜0.05）。与对照组比较,白桦酯醇处理组和紫杉醇组移植瘤组织中MMP-2和MMP-9蛋白表达水平均减弱;白桦酯醇低、中、高剂量组移植瘤组织中MMP-2和MMP-9蛋白的表达率（％）分别为47.13±8.67和53.82±7.41、38.29±4.37和48.79±4.63、26.88±5.12和38.93±2.82,均低于对照组的56.78±6.42和69.35±5.03,且白桦酯醇3组之间的差异均有统计学意义（P＜0.05）。结论 白桦酯醇对卵巢癌SKOV3细胞皮下移植瘤的生长有抑制作用,其机制可能与下调MMP-2和MMP-9蛋白的表达有关。     

白桦脂醇对人皮肤成纤维细胞胶原蛋白及相关蛋白酶基因的调控机制研究

目的：研究白桦脂醇对人皮肤成纤维细胞(ESF-1)相关抗衰老基因 mRNA 的调控作用,探讨白桦脂醇对皮肤皱纹的修复机制。方法将细胞分为空白对照组,雌二醇组,白桦脂醇高、中、低剂量组。采用MTT法测定各组细胞活力,RT-PCR法测定各组细胞中Ⅰ型及Ⅲ型胶原蛋白(collagen, Col)、基质金属蛋白酶抑制剂(tissue inhibitors of matrix metalloproteinase, TIMP)1和2、基质金属蛋白酶1(matrix metalloproteinase 1, MMP-1)mRNA的表达水平。结果与空白对照组比较,雌二醇组与白桦脂醇中剂量组细胞增殖率[(0.455±0.037)、(0.445±0.040)比(0.385±0.601)]增高(P＜0.05);ColⅠmRNA[(0.960±0.012)、(0.929±0.015)比(0.842±0.014)],Col Ⅲ mRNA[(0.892±0.009)、(0.824±0.022)比(0.768±0.025)]、TIMP-1 mRNA[(0.938±0.026)、(0.878±0.035)比(0.796±0.022)]、TIMP-2 mRNA[(0.557±0.025)、(0.506±0.036)比(0.436±0.063)]表达水平均升高(P＜0.01)。结论白桦脂醇通过促进细胞增殖,提高Col合成及相关蛋白酶的表达等途径发挥对皱纹的修复作用。     

白桦酯醇对人卵巢癌裸鼠移植瘤的抑制作用

目的：观察白桦酯醇对人卵巢癌裸鼠移植瘤的抑制作用及对Bcl-2和Caspase-3表达的影响.方法：建立卵巢癌SKOV3裸鼠移植瘤模型,将30只荷瘤鼠随机分为5组：空白对照组、白桦酯醇高、中、低浓度组和顺铂组（阳性对照）.21天后处死裸鼠,称取瘤重量,观察抑瘤率;免疫组织化学SP法检测移植瘤Bcl-2和Caspase-3的表达.结果：高、中、低组抑瘤率为54.19％、35.75％、20.67％,与空白对照组比较差异有统计学意义（P＜0.05）;高剂量组抑瘤率与顺铂组无差异（P＞0.05）.免疫组化显示,各治疗组Bcl-2的表达较空白对照组明显下调;Caspase-3的表达较空白组明显活化,其高剂量组表达与阳性药物顺铂相当.结论：白桦酯醇有一定的抑制卵巢癌生长的作用,可能与其诱导细胞凋亡有关.     

Synthesis, encapsulation and antitumor activity of new betulin derivatives

Novel betulin derivatives were prepared and tested for their antitumor activity. Starting from 3-O-acetyl- or 3-O-methyl-betulinic aldehyde, the synthesis of C-28 ethynyl derivatives was performed; their subsequent transformation with several 1,3-dipolarophiles afforded pyrazoles and 1,2,3-triazoles. Their screening for antitumor activity was performed in a panel of 15 human cancer cell lines by a colorimetric SRB-assay. Thereby, several compounds revealed a higher cytotoxicity than betulinic acid. In addition, the encapsulation of the lead structure 7 into liposomes was investigated. The results from a dye exclusion test and from DNA laddering experiments provided evidence for an apoptotic cell death.     

Betulin wound gel accelerated healing of superficial partial thickness burns: Results of a randomized,intra‐individually controlled,phase III trial with 12‐months follow‐up

ObjectiveAcceleration of wound healing promises advantages for patients and caregivers in reducing the burden of disease, avoiding complications such as wound infections, and improving the long-term outcome. However, medicines that can accelerate wound healing are lacking. The objective of this open, blindly evaluated, randomized, multicenter phase III study was to compare intra‐individually the efficacy and tolerability of Oleogel‐S10 with fatty gauze dressing versus Octenilin^® wound gel with fatty gauze dressing in accelerating the healing of superficial partial thickness burn wounds.MethodsAcute superficial partial thickness burn wounds in adults caused by fire, heat burn or scalding were divided into 2 halves and randomly assigned to treatment with Oleogel‐S10 or Octenilin^® wound gel. Photos for observer‐blinded analysis of wound healing were taken at each wound dressing change. Percentages of reepithelialization were assessed at defined intervals. Efficacy and tolerability were evaluated based on a 5‐point Likert scale.ResultsOf 61 patients that were enrolled, 57 received the allocated intervention and 48 completed treatment. The percentage of patients with earlier wound healing was significantly higher for Oleogel‐S10 (85.7%, n = 30) compared to Octenilin^® wound gel (14.3%, n = 5, p < 0.0001). The mean intra‐individual difference in time to wound closure was −1.0 day in favour of Oleogel‐S10 (−1.4, −0.6; 95% CI, p < 0.0001). Most investigators (87.0%) and patients (84.8%) evaluated the efficacy of Oleogel‐S10 to be ‘better’ or ‘much better’ than that of Octenilin^® wound gel. Long-term outcome 3 months and 12 months post injury was improved in some patients.ConclusionsOleogel‐S10 (Episalvan) significantly accelerated the healing of superficial partial thickness burn wounds. It was safe and well tolerated.     

Synthesis and Anticancer Activity of Novel Betulinic acid and Betulin Derivatives

A series of novel betulinic acid derivatives 3–11 and betulin derivatives 12–17 were synthesized. The compounds were characterized by the means of ¹H‐ and ¹³C‐NMR spectroscopy as well as mass spectrometry. The compounds have been tested on ten tumor cell lines of different histogenic origin. The most active derivatives, containing a chloroacetyl group on C‐3 in betulinic acid 9 and C‐28 in betulin 15 , were up to ten times more cytotoxic and many fold more selective towards tumor cells in comparison to normal cells (fibroblasts) than betulinic acid. Furthermore, compound 15 was found to possess cell growth inhibition even when treated for a short time on anaplastic thyroid cancer cells (SW1736).     

五环三萜羽扇豆烷型天然产物抗肿瘤活性研究进展

天然产物是抗肿瘤药物的重要来源。三萜化合物是植物体内重要的次生代谢产物,具有广泛的生物活性,其中五环三萜羽扇豆烷型天然产物对多种肿瘤细胞生长均表现出很强地抑制活性,同时由于毒性较低且作用机制独特,使其成为优秀的抗肿瘤先导化合物。近年来,针对羽扇豆烷型天然产物的抗肿瘤机制研究越发深入,对其结构进行衍生化从而提升活性、改善成药性的研究也越来越多。本文综述了五环三萜中白桦酸、23-羟基白桦酸、桦木醇和羽扇豆醇4个天然活性化合物的来源、抗肿瘤活性、作用机制及结构衍生化等方面国内外的研究进展。     

Quantitative Evaluation of Anticancer Marker Levels of an Ayurvedic Preparation, "Virala"

Virala (Diospyros tomentosa Roxb.), an important Ayurvedic preparation, was chemically screened and found to accumulate significant levels of the anticancer markers betulin and betulinic acid. In order to identify the high yielding sample of these two markers, a number of virala samples collected from different parts of India have been screened by high performance thin layer chromatography (HPTLC). The sample collected from local areas (20°15′N, 85°50′E) was found to contain the highest levels of betulinic acid (0.43%), whereas the sample collected from Vijayawada (16°30′N, 80°36′E) was found to contain maximum betulin (1.13%). Interesting correlations have been drawn between accumulations of these two markers versus the height of place above sea level where samples were collected.