HPLC法测定面条树中的鸭脚树叶碱

目的:建立面条树中鸭脚树叶碱的HPLC含量测定法.方法:色谱柱为Thermo Gold C18(250 mm×4.60 mm,5 μm),检测波长为287 nm,流动相为甲醇-水-三乙胺(47:53:0.005,V/V),流速为1.0 ml·min-1,柱温为35℃.结果:鸭脚树叶碱在0.14～14.00 μg范围内呈良好的线性关系,r=0.999 9;平均回收率为96.98%,RSD=0.9%(n=9).结论:该法简便、准确,可用于面条树的质量控制研究.     

HPLC法同时测定傣药灯台叶中鸭脚树叶碱、齐墩果酸和熊果酸的含量

目的:建立同时测定傣族传统药物灯台叶中鸭脚树叶碱、齐墩果酸和熊果酸含量的方法。方法:采用高效液相色谱法。色谱柱为Agilent ZORBAX Eclipse SB-C18(250mm×4.6mm,5μm),流动相为乙腈-pH7.6的磷酸盐缓冲液(梯度洗脱),检测波长为220nm。结果:鸭脚树叶碱、齐墩果酸和熊果酸3种成分的检测浓度分别在0.01～0.20mg·mL-1(r=0.9997)、0.06～1.20mg·mL-1(r=0.9996)、0.10～2.00mg·mL-1(r=0.9998)范围内与各自峰面积积分值呈良好线性关系;平均加样回收率依次为102.0%、101.1%、99.3%,RSD分别为1.84%、2.00%、0.91%(n均为6)。5批灯台叶中鸭脚树叶碱的含量在0.085%～0.122%之间,齐墩果酸含量在0.517%～0.582%之间,熊果酸含量在1.71%～1.85%之间。结论:本方法简便、准确、精密度高、重复性好,可同时测定灯台叶中鸭脚树叶碱、齐墩果酸和熊果酸的含量,可为灯台叶的质量控制提供科学依据。     

灯台叶中鸭脚树叶碱化学对照品的制备

目的:以灯台叶为原料,研究鸭脚树叶碱对照品的制备与分析技术。方法:用溶剂法提取灯台叶中生物碱,通过色谱方法分离主要成分鸭脚树叶碱,用光谱方法鉴定其结构,并用TLC、HPLC方法检查纯度和标定含量。结果:鸭脚树叶碱对照品经TLC检查无杂质斑点,二维及三维HPLC检查为单一成分,峰纯度因数999.878,含量为99.35%.结论:鸭脚树叶碱对照品已达到中药质量标准用化学对照品技术要求。     

Pharmacological evaluation of Alstonia scholaris: Anti-inflammatory and analgesic effects

Ethnopharmacological relevance

Alstonia scholaris (Apocynaceae) has been historically used in “dai” ethnopharmacy to treat chronic respiratory diseases. The leaf extract, developed as a commercially available traditional Chinese medicine, used to release tracheitis and cold symptom, has also been prescribed in hospitals and sold over the counter in drug stores.

Aim of the study

The investigation evaluated the anti-inflammatory and analgesic activities of the ethanolic extract, fractions and main alkaloids of Alstonia scholaris leaf to provide experimental evidence for its traditional and modern clinical use. Besides, to discover the active fraction and components for further better use in Chinese medicine is hopeful.

Materials and methods

The leaf of Alstonia scholaris was extracted with ethanol and then separated into different fractions. Furthermore, alkaloids were isolated by phytochemical method. The analgesic activities were investigated using acetic acid-induced writhing, hot-plate and formalin tests in mice. The anti-inflammatory activities were carried out in vivo and in vitro, including xylene-induced ear edema and carrageenan-induced air pouch formation in mice, and COX-1, -2 and 5-LOX inhibition.

Results

It has been exhibited that the EtOAc and alkaloid fractions reduced acetic acid-induced writhing response in mice, significantly. The ethanolic extract, EtOAc and alkaloid fractions remarkably inhibited xylene-induced ear edema. Further investigation was focused on the alkaloids fraction and three main alkaloids isolated from the alkaloids fraction, in different animal models. Alkaloids reduced acetic acid-induced writhing response, and xylene-induced ear edema in mice. In the hot-plate test, alkaloids did not increase the latency period of mice obviously. In the formalin test, alkaloids did not inhibit the licking time in first phase, but significantly inhibited the licking time in second phase of mice. Alkaloids increased significantly SOD activity and decreased levels of NO, PGE2 and MDA significantly, in air pouch mice model. Moreover, some alkaloids isolated from the leaf of Alstonia scholaris exhibited inhibition of COX-1, COX-2 and 5-LOX in vitro anti-inflammatory assay, which supported alkaloids as the bioactive fraction.

Conclusions

The alkaloids fraction of Alstonia scholaris leaf, three main alkaloids, picrinine, vallesamine and scholaricine, may produce the anti-inflammatory and analgesic effect peripherally based on several in vivo assays. In in vitro tests, alkaloids exhibited inhibition of inflammatory mediators (COX-1, COX-2 and 5-LOX), which is accordant with results on animal models. Besides, COX-2/5-LOX dual inhibitors found in the experiment, such as 16-formyl-5α-methoxystrictamine, picralinal, and tubotaiwine might be valuable for further attention.     

Pharmacological evaluation of Alstonia scholaris: Anti-tussive,anti-asthmatic and expectorant activities

Ethnopharmacological relevance

Alstonia scholaris (Apocynaceae) was documented as an effective herb for the treatment of chronic respiratory diseases in “dai” ethnopharmacy historically, and its leaf crude extract, used for releasing tracheitis and cold symptom, was approved to be a commercial formulation by State Food and Drugs Administration of China (SFDA).

Aim of the study

The investigation evaluates the anti-tussive and anti-asthmatic activities of the ethanolic extract, fractions and main alkaloids of Alstonia scholaris leaf to provide experimental evidence for its traditional and modern clinical use. For our most interesting, is to reveal the active components for further new drug development.

Materials and methods

The leaf of Alstonia scholaris was extracted with ethanol and then separated into different fractions. Furthermore, alkaloids were isolated by phytochemical method. The anti-tussive activity was evaluated using three different models including ammonia or sulfur dioxide induced mice coughing, and citric acid induced guinea pigs coughing. The anti-asthmatic activity was investigated on guinea pigs bronchoconstraction induced by histamine. The expectorant activity was evaluated by volume of phenol red in mice's tracheas.

Results

The alkaloids fraction significantly inhibited mice's frequency of cough induced by ammonia, increased mice's latent period of cough induced by sulfur dioxide, and increased guinea pigs’ latent period of cough and inhibited frequency of cough. Besides, the alkaloids fraction increased delitescence of convulsion, and tumble of guinea pigs in anti-asthmatic test, and enhanced tracheal phenol red output in expectorant evaluation. Moreover, the main alkaloid, picrinine exhibited anti-tussive and anti-asthmatic activities in vivo.

Conclusions

The alkaloids fraction was anti-tussive, anti-asthmatic and expectorant activities component of Alstonia scholaris leaf, and it may also be a valuable lead material for respiratory diseases drug development. Picrinine, the main anti-tussive and anti-asthmatic compound, could be applied in quality control of products from Alstonia scholaris leaf.