Structural analysis and antitussive evaluation of five novel esters of verticinone and bile acids

Network Pharmacology and Experimental Verification Reveal the Regulatory Mechanism of Chuanbeimu in Treating Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder in pulmonology. Chuanbeimu (CBM) is a traditional Chinese medicinal herb for treating COPD and has been widely utilized in clinical practice. However, the mechanism of CBM in the treatment of COPD remains incompletely understood. This study aims to investigate the underlying therapeutic mechanism of CBM for COPD using network pharmacology and experimental approaches.

Methods

Active ingredients and their targets were obtained from the Traditional Chinese Medicine Systems Pharmacology database. COPD-associated targets were retrieved from the GeneCards database. The common targets for CBM and COPD were identified through Venn diagram analysis. Protein-protein interaction (PPI) networks and disease-herb-ingredient-target networks were constructed. Subsequently, the results of the network pharmacology were validated by molecular docking and in vitro experiments.

Results

Seven active ingredients and 32 potential targets for CBM were identified as closely associated with COPD. The results of the disease-herb-ingredient-target network and PPI network showed that peimisine emerged as the core ingredient, and SRC, ADRB2, MMP2, and NOS3 were the potential targets for CBM in treating COPD. Molecular docking analysis confirmed that peimisine exhibited high binding affinity with SRC, ADRB2, MMP2, and NOS3. In vitro experiments demonstrated that peimisine significantly upregulated the expression of ADRB2 and NOS3 and downregulated the expression of SRC and MMP2.

Conclusion

These findings indicate that CBM may modulate the expression of SRC, ADRB2, MMP2, and NOS3, thereby exerting a protective effect against COPD.

Advances of antitumor drug discovery in traditional Chinese medicine and natural active products by using multi-active components combination

The antitumor efficacy of Chinese herbal medicines has been widely recognized. Leading compounds such as sterols, glycosides, flavonoids, alkaloids, terpenoids, phenylpropanoids, and polyketides constitute their complex active components. The antitumor monomers derived from Chinese medicine possess an attractive anticancer activity. However, their use was limited by low bioavailability, significant toxicity, and side effects, hindering their clinical applications. Recently, new chemical entities have been designed and synthesized by combining natural drugs with other small drug molecules or active moieties to improve the antitumor activity and selectivity, and reduce side effects. Such a novel conjugated drug that can interact with several vital biological targets in cells may have a more significant or synergistic anticancer activity than a single-molecule drug. In addition, antitumor conjugates could be obtained by combining pharmacophores containing two or more known drugs or leading compounds. Based on these studies, the new drug research and development could be greatly shortened. This study reviews the research progress of conjugates with antitumor activity based on Chinese herbal medicine. It is expected to serve as a valuable reference to antitumor drug research and clinical application of traditional Chinese medicine.

Bulbus Fritillariae Cirrhosae as a Respiratory Medicine: Is There a Potential Drug in the Treatment of COVID-19?

Bulbus fritillariae cirrhosae (BFC) is one of the most used Chinese medicines for lung disease, and exerts antitussive, expectorant, anti-inflammatory, anti-asthmatic, and antioxidant effects, which is an ideal therapeutic drug for respiratory diseases such as ARDS, COPD, asthma, lung cancer, and pulmonary tuberculosis. Through this review, it is found that the therapeutic mechanism of BFC on respiratory diseases exhibits the characteristics of multi-components, multi-targets, and multi-signaling pathways. In particular, the therapeutic potential of BFC in terms of intervention of “cytokine storm”, STAT, NF-κB, and MAPK signaling pathways, as well as the renin-angiotensin system (RAS) that ACE is involved in. In the “cytokine storm” of SARS-CoV-2 infection there is an intense inflammatory response. ACE2 regulates the RAS by degradation of Ang II produced by ACE, which is associated with SARS-CoV-2. For COVID-19, may it be a potential drug? This review summarized the research progress of BFC in the respiratory diseases, discussed the development potentiality of BFC for the treatment of COVID-19, explained the chemical diversity and biological significance of the alkaloids in BFC, and clarified the material basis, molecular targets, and signaling pathways of BFC for the respiratory diseases. We hope this review can provide insights on the drug discovery of anti-COVID-19.

Anti-inflammatory, expectorant, and antitussive properties of Kyeongok-go in ICR mice

CONTEXT

Kyeongok-go (KOG) is a traditional mixed herb preparation consisting of Panax ginseng CA Meyer (Araliaceae), Poria cocos Wolf (Polyporaceae), Rehmannia glutinosa (Gaertner) Liboschitz ex Steudel (Orobanchaceae), and honey. Various pharmacological effects of KOG are reported, but the efficacy on respiratory diseases has not been evaluated.

OBJECTIVE

The anti-inflammatory, expectorant, and antitussive properties of KOG were examined using animal models of respiratory diseases.

MATERIALS AND METHODS

KOG (100, 200, and 400 mg/kg) was orally administered to ICR mice (n = 8) once a day for 11 days. Anti-inflammatory effects of vehicle, xylene, KOG and DEXA (1 mg/kg) were determined by monitoring edoema and redness of treated ears, and measuring the relative and absolute weight of each ear. Expectorant properties of vehicle, KOG and AM (250 mg/kg) were evaluated by observing body surface redness, and the amount of mucous secreted by the trachea. The antitussive potential of vehicle, NH₄OH, KOG and TB (50 mg/kg) was evaluated by monitoring changes in the number of coughs (for 6 min).

RESULTS

KOG (400 mg/kg) treated mice showed 31.29% and 30.72% (p < 0.01) decreases in the relative and absolute weights of each ear relative to xylene control mice, 39.06% increases (p < 0.01) in TLF OD values relative to intact vehicle control mice, and 59.53% decrease (p < 0.01) in coughing compared to NH₄OH control mice. Dose-dependent changes were observed in all experimental models.

CONCLUSIONS

KOG may be a potential therapeutic agent for the treatment of various respiratory diseases, particularly those caused by environmental toxins.

Antitussive, expectorant, and anti-inflammatory effects of Adenophorae Radix powder in ICR mice

ETHNOPHARMACOLOGICAL RELEVANCE

Adenophora triphylla var. japonica is frequently used as an oriental medicinal plant in Korea, China, and Japan for its anti-inflammatory, antitussive, and hepatoprotective effects.

AIM OF THE STUDY

In the present study, the antitussive, expectorant, and anti-inflammatory effects of AR powder were investigated using animal models to evaluate their potential to treat respiratory disorders.

MATERIALS AND METHODS

AR powder was administered orally to mice once daily for 11 days, at dose levels of 400, 200, and 100 mg/kg. Theobromine (TB), ambroxol (AM) and dexamethasone (DEXA) were used as standard drugs for antitussive effects, expectorant effects and anti-inflammatory effects, respectively. Evaluations of antitussive effects were based on changes in body weight, the number of cough responses and the histopathology of the lung and trachea. Expectorant effects were based on changes in the body weight, macroscopic observations of body surface redness, the mucous secretion of the trachea and histopathology of lung (secondary bronchus). Anti-inflammatory effects were based on changes in the body weight, macroscopic observations involving redness and edema of the treated ear, absolute and relative ear weights and histopathology of the treated ears.

RESULTS

Allergic acute inflammation and coughing induced by exposure to NH₄OH and symptoms of xylene-induced contact dermatitis were significantly inhibited by treatment with AR powder in a dose-dependent manner. Histological analyses revealed that AR powder decreased the OD values in trachea lavage fluid, reduced body surface redness, thicknesses of intrapulmonary secondary bronchus mucosa, and the number of PAS-positive mucous producing cells. Overall, AR powder administered at 200 mg/kg displayed superior antitussive and expectorant effects as compared to TB (50 mg/kg), and AM (250 mg/kg). At the highest concentration (400 mg/kg) AR powder displayed only moderately improved anti-inflammatory activities as compared to DEXA (1 mg/kg).

CONCLUSION

The results obtained in this study suggest that AR powder exerts dose-dependent, favorable antitussive, expectorant, and anti-inflammatory activities achieved through modulation of the activity of mast cells and respiratory mucous production. Therefore, AR powder may serve as a therapeutic agent in various respiratory disorders, especially those that occur as a result of environmental toxicants.

Antitussive and expectorant activities of Potentilla anserina

Context The root of Potentilla anserina L. (Rosaceae) is an herbal medicine that has been used as an antitussive and expectorant drug for thousands of years in Chinese folk medicine.

OBJECTIVE

This study estimated the antitussive and expectorant effects of P. anserina extract to validate its traditional use. Materials and methods The antitussive and expectorant activities of the ethanol extract, aqueous extract, and polysaccharides from P. anserina were evaluated using classical animal models. Results The results showed that in three antitussive tests, the aqueous extract and polysaccharides at high and low doses significantly inhibited the frequency of cough induced by ammonia and sulfur dioxide in mice and by citric acid in guinea pigs, and increased the latent period of cough in guinea pigs. Similarly, the aqueous extract and polysaccharides also showed significant expectorant activity compared with the control in phenol red secretion experiments. Polysaccharides at dose of 600 mg/kg enhanced tracheal phenol red output by 121.1%, the ammonium chloride (positive control) at dose of 1000 mg/kg by 117.4%. However, the ethanol extract at a high dose (600 mg/kg) has antitussive activity only in the sulfur dioxide induced coughing test. Moreover, the polysaccharides at the same dose showed better bioactivity than the aqueous extract in all tests. Discussion and conclusion The results of the present study provide evidence that P. anserina can be used as an antitussive and expectorant herbal medicine and that polysaccharides may be the main active ingredients of P. anserina responsible for its bioactivities.

Extractions of oil from Descurainia sophia seed using supercritical CO2, chemical compositions by GC-MS and evaluation of the anti-tussive, expectorant and anti-asthmatic activities

Descurainia sophia is widely distributed in China and is one of the most troublesome annual weeds. It has diverse medicinal usage. D. sophia has abundant oil, making it an important oil plant in China. The main goal of this study was to obtain the maximum yield of the oil by an optimal selection of supercritical fluid extraction parameters. According to the central composite design and response surface methodology for supercritical fluid extraction method, a quadratic polynomial model was used to predict the yield of D. sophia seed oil. A series of runs was performed to assess the optimal extraction conditions. The results indicated that the extraction pressure had the greatest impact on oil yield within the range of the operating conditions studied. A total of approximately 67 compounds were separated in D. sophia seed oil by GC-MS, of which 51 compounds represented 98.21% of the total oils, for the first time. This study was also aimed at evaluating the anti-asthmatic, anti-tussive and expectorant activities in vivo of D. sophia seed oil which supplied for further research on bioactive constituents and pharmacological mechanisms.

A New Ligustrazine Derivative-Selective Cytotoxicity by Suppression of NF-κB/p65 and COX-2 Expression on Human Hepatoma Cells. Part 3

A new anticancer ligustrazine derivative, 3β-hydroxyolea-12-en-28-oic acid-3,5,6-trimethylpyrazin-2-methylester (T-OA, C₃₈H₅₈O₃N₂), was previously reported. It was synthesized via conjugating hepatoprotective and anticancer ingredients of traditional Chinese medicine. We found that T-OA exerted its anticancer activity by preventing the expression of nuclear transcription factor NF-κB/p65 and COX-2 in S180 mice. However, the selective cytotoxicity of T-OA on various kinds of cell lines has not been studied sufficiently. In the present study, compared with Cisplatin, T-OA was more toxic to human hepatoma cell line Bel-7402 (IC₅₀ = 6.36 ± 1.56 µM) than other three cancer cell lines (HeLa, HT-29, BGC-823), and no toxicity was observed toward Madin–Darby canine kidney cell line MDCK (IC₅₀ > 150 µM). The morphological changes of Bel-7402 cells demonstrated that T-OA had an apoptosis-inducing effect which had been substantiated using 4ʹ,6-diamidino-2-phenylindole (DAPI) staining, acridine orange (AO)/ethidium bromide (EB) staining, flow cytometry and mitochondrial membrane potential assay. Combining the immumohistochemical staining, we found T-OA could prevent the expression of NF-κB/p65 and COX-2 in Bel-7402 cells. Both of the proteins have been known to play roles in apoptosis and are mainly located in the nuclei. Moreover subcellular localization was performed to reveal that T-OA exerts in nuclei of Bel-7402 cells. The result was in accordance with the effects of down-regulating the expression of NF-κB/p65 and COX-2.

Antinociceptive and anti-tussive activities of the ethanol extract of the flowers of Meconopsis punicea Maxim

BACKGROUND

As an important traditional Tibetan (veterinary) medicine, the flowers of Meconopsis punicea (family Papaveraceae) have been used to treat pain, fever, cough, inflammation, liver heat and lung heat of humans and animals by local people for thousands of years. In this paper, we aimed to investigate the antinociceptive and anti-tussive activities of the ethanol extract of M. punicea (EEM).

METHODS

Firstly, HPLC was used to analyze the main constituents of the ethanol extract of M. punicea. In animal experiments, the acetic acid-induced writhing response test, hot plate test, barbiturate-induced sleeping time and formalin tests were used to evaluate the antinociceptive activity. Then, ammonia-induced coughing and sulfur dioxide-induced coughing tests in mice as well as the phenol red secretion in trachea test were used to investigate the anti-tussive activity of the extract. Finally, an acute toxicity study was carried out.

RESULTS

The results showed that alkaloids and flavonoids were the main compounds in the ethanol extract of M. punicea flowers. The extract at 125, 250 and 500 mg/kg had good antinociceptive and anti-tussive activities in mice with a dose-dependent manner.

CONCLUSIONS

These findings suggested that EEM has significant bioactivities, and the active components of M. punicea should be studied further.

Expectorant, antitussive, anti-inflammatory activities and compositional analysis of Aster tataricus

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Aster tataricus L. f., recorded in all versions of Chinese Pharmacopoeia, is a traditional Chinese medicine with the function of dispelling phlegm and relieving cough for more than 2000 years. This study was designed to evaluate the expectorant, antitussive, and anti-inflammatory activities of the root of A. tataricus and to explore the chemical substances responsible for these activities.

MATERIALS AND METHODS

The 70% ethanol extract of the root of A. tataricus (RA-70) was divided into three fractions, Fr-0, Fr-50 and Fr-95. They were all orally administrated to the mice to investigate their potential expectorant activities by a tracheal phenol red secretion method. The most effective fraction, together with shionone, was evaluated the expectorant, antitussive and anti-inflammatory activities by the mouse models of phenol red secretion, ammonia-induced cough, and xylene-induced ear swelling. Furthermore, the chemical components of the effective fraction were analyzed and identified by an HPLC-Q-TOF/MS method.

RESULTS

Treatment with RA-70, Fr-0 and Fr-50 increased the amount of phenol red secretion by 65.3%, 56.5%, and 76.9%, respectively. Fr-50 was chosen for the further investigation and the results showed that Fr-50 at 40, 80 mg/kg significantly enhanced the phenol red secretion of tracheas, increased the latent period and decreased the frequency of cough and inhibited the ear edema in mice. Shionone at 80 mg/kg showed the trend of enhancing sputum secreting, but had no effect on ammonia-induced cough and xylene-induced ear edema. HPLC-Q-TOF/MS analysis indicated that Fr-50 was mainly composed of 12 caffeoylquinic acids (40.8%, in relative peak area), 7 astersaponins (12.0%) and 13 astins/asterinins (pentapeptides, 26.5%).

CONCLUSIONS

The root of A. tataricus has significant expectorant, antitussive and anti-inflammatory effects. Caffeoylquinic acids, astersaponins, and aster peptides, rather than shionone, may be the main constituents responsible for the expectorant and antitussive activities of A. tataricus and act in a synergistic way.

Synthesis and protective effect of new ligustrazine derivatives against CoCl2-induced neurotoxicity in differentiated PC12 cells. Part 2

The novel ligustrazine derivatives were synthesized and displayed the remarkable protective effect (highest EC₅₀ = 0.719 μM) on PC12 cells damaged by CoCl₂.

Pharmacokinetics, tissue distribution and excretion of verticinone from F. hupehensis in rats

Verticinone, the main active component in F. hupehensis, exhibits potent antitussive and expectorant effects. Here, a LC-MS method was developed and applied to study the pharmacokinetics, tissue distribution and excretion of verticinone in rats, and its plasma protein binding in vitro. A significant gender difference in the pharmacokinetics of verticinone in rats was observed, as its absolute oral bioavailability in male and female rats was 45.8% and 2.74%, respectively. The relative bioavailability of verticinone was significantly lower in female rats as compared to male, following intragastrical (i.g.) and intravenous (i.v.) administration. After successive i.g. administration of verticinone, accumulation was observed in female rats but not in the male ones. The tissue distribution study showed that verticinone had a good tissue penetrability and a high tissue affinity in most studied tissues, except brain. After a 2 mg/kg oral dose, less than 4% of the dose was excreted as unchanged parent compound in male rats, and less than 1% in female rats, which indicated that verticinone was metabolized more extensively in female rats than in male rats.

Amino acid derivatives of ligustrazine-oleanolic acid as new cytotoxic agents

A series of novel ligustrazine-oleanolic acid (TOA) derivatives were designed, and synthesized by conjugating amino acids to the 3-hydroxy group of TOA by ester bonds. Their cytotoxicity was evaluated on four cancer cell lines (HepG2, HT-29, Hela and BGC-823) by standard MTT assays. The ClogP values were calculated by means of computer simulation, and logP values of both 3β-glycine ester olean-12-en-28-oic acid-3,5,6-trimethylpyrazin-2-methyl ester (6a) and TOA were determined using a shake flask-ultraviolet spectrophotometry method. It was found that 6a and the 3β-L-lysine ester-6g not only displayed good cytotoxicity (IC50<3.5 μM) but also possessed better hydrophilicity than TOA. Moreover, 6a (IC50=4.884 μM) had lower nephrotoxicity than both 6g (IC50=2.310 μM) and cisplatin (CDDP, IC50=3.691 μM) on MDCK cells. Combining Giemsa and DAPI staining, it was further verified that 6a could induce HepG2 apoptosis via nuclei fragmentation and had lower nephrotoxicity. In addition, the structure-activity relationships of these derivatives are briefly discussed.

Multi-component analysis of bile acids in natural Calculus bovis and its substitutes by ultrasound-assisted solid-liquid extraction and UPLC-ELSD

An ultrasound-assisted solid-liquid extraction (USLE) coupled to ultra-performance liquid chromatography-evaporative light scattering detection (UPLC-ELSD) method has been developed for the simultaneous extraction and determination of six bile acids (BAs) in natural Calculus bovis and its substitutes, collected from different origins. The USLE conditions, UPLC chromatographic and ELSD conditions for BAs were optimized. Under optimum conditions, the six target analytes were efficiently extracted and baseline separated within 10 min. The limits of detection (LODs) and quantification (LOQs) for six BAs were less than 7 ng and 22 ng, respectively. Average recoveries were within the range of 98.8-100.7% with relative standard deviations (RSDs) <2% for the six analytes. This method, due to its convenience, high selectivity, fast analysis efficiency and good reproducibility can be employed for analyzing the content differences of six BAs in 40 batches of natural C. bovis and its existing substitutes. The differences of the content of each BA in natural C. bovis and its substitutes were significant, and the total contents of six BAs in 13 batches of natural C. bovis were in the range of 7.96-160.17 mg g(-1), in 20 natural C. bovis of 0-245.89 mg g(-1), in 2 artificial cultivated C. bovis of 178.48-194.22 mg g(-1), in 3 cultured C. bovis of 41.01-107.3 mg g(-1), and in 2 counterfeit C. bovis of 144.9-340.25 mg g(-1). The significant differences of multi-component contents reflected the various inherent qualities of these samples, so, the use of these substitutes as the replacers of natural source in clinic should be paid more attention. Some substitutes could not be used as the replacers.

Antitussive, expectorant and bronchodilating effects of ethanol extract of Sorghum bicolor (L.) Moench roots

ETHNOPHARMACOLOGICAL RELEVANCE

Root of Sorghum bicolor (L.) Moench (RSB) is an herbal medicine in Traditional Chinese Medicine, still used in some rural areas in Central China as an alternative remedy to treat cough and asthma.

AIM OF THE STUDY

The study was aimed at evaluating the antitussive, expectorant and bronchodilating effects of ethanol extract of RSB, support its folk use with scientific evidence, and lay a foundation for its further researches.

MATERIALS AND METHODS

RSB was extracted with 80% ethanol aqueous in reflux conditions, solutions were concentrated in reduced pressure, and lyophilized in vacuum to yield the RSB extract. Antitussive evaluations were carried out with three different models including ammonia liquor induced mice cough, capsaicin induced mice cough, and citric acid induced guinea pigs cough; phenol red secretion experiments in mice were performed to evaluate the expectorant ability; bronchodilating effects were evaluated with a bronchoconstrictive challenge induced by acetylcholine chloride and histamine in guinea pigs.

RESULTS

In all the three antitussive tests, treatment of RSB significantly inhibited the frequency of cough, and prolonged the cough latent period in animals. And high dose of RSB (200mg/kg in mice and 100mg/kg in guinea pigs) created therapeutic activities as good as standard antitussive drug codeine phosphate (20mg/kg). In the expectorant evaluation, 50, 100 and 200mg/kg RSB treatment had significantly increased the amount of phenol red output for 0.39, 1.18, and 1.96 folds in mice tracheas. In the bronchodilating test, RSB treatment at 100mg/kg extended the preconvulsive time for 44.84% compared with that of before treatment in guinea pigs.

CONCLUSIONS

RSB is an effective alternative medicine for the treatment of cough with potent antitussive, expectorant and bronchodilating activities.

Synthesis and antitumor activity of N-sulfonyl-3,7-dioxo-5β-cholan-24-amides, ursodeoxycholic acid derivatives

A series of N-sulfonyl-3,7-dioxo-5β-cholan-24-amides, ursodeoxycholic acid derivatives, have been designed and synthesized in nine steps starting from ursodeoxycholic acid. The in vitro antitumor activity of the target compounds has been evaluated against HCT-116, MCF-7, K562, and SGC-7901 cell lines. The pharmacological results showed that most of the prepared compounds display excellent selective cytotoxicity toward HCT-116, MCF-7, and K562 cell lines. Particularly, compounds 10c, 10f and 10g show high inhibitory activity on these human cancer cell lines (IC50: 2.39-9.34 μM). Conversely, all compounds are generally inactive against SGC-7901, with only 10b having IC₅₀ below 50 μM.

A novel chenodeoxycholic acid-verticinone ester induces apoptosis and cell cycle arrest in HepG2 cells

In this study, the in vitro antitumor activity of chenodeoxycholic acid-verticinone ester (CDCA-Ver), a novel compound and its underlying mechanisms were evaluated. Results showed that CDCA-Ver significantly inhibited HepG2 cell viability in a both dose- and time-dependent manner, moreover CDCA-Ver induced apoptotic cell death and G(0)/G(1) cell cycle arrest in HepG2 cells. ROS generation, loss of balance of Bax/Bcl-2 ratio, loss of mitochondrial transmembrane potential, activation of caspases and elevation of intracellular free Ca(2+) concentration were involved in the CDCA-Ver induced apoptosis pathway in HepG2 cells. We concluded that CDCA-Ver may be a potential candidate for the therapy of cancer.

Synthesis and biological evaluation of new ligustrazine derivatives as anti-tumor agents

To discover new anti-cancer agents with multi-effect and low toxicity, a series of ligustrazine derivatives were synthesized using several effective anti-tumor ingredients of Shiquandabu Wan as starting materials. Our idea was enlightened by the “combination principle” in drug discovery. The ligustrazine derivatives’ anti-tumor activities were evaluated on the HCT-8, Bel-7402, BGC-823, A-549 and A2780 human cancer cell lines. In addition the angiogenesis activities were valued by the chick chorioallantoic membrane (CAM) assay. 1,7-bis(4-(3,5,6-Trimethylpyrazin-2-yl)-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (4) and 3 α,12 α-dihydroxy-5β-dholanic acid-3,5,6-trimethylpyrazin-2-methyl ester (5) not only displayed antiproliferative activities on these cancer cells, but also dramatically suppressed normal angiogenesis in CAM. The LD₅₀ value of the compound 5 exceeded 3.0 g/kg by oral administration in mice.

Antitussive, expectorant and anti-inflammatory activities of four alkaloids isolated from Bulbus of Fritillaria wabuensis

ETHNOPHARMACOLOGICAL RELEVANCE

Bulbus Fritillaria Cirrhosae (BFC), known by the Chinese name "Chuan-Bei-Mu", is used as an antitussive, antiasthmatic and expectorant drug for more than 2000 years in China, and Bulbus of Fritillaria wabuensis S. Y. Tang & S. C. Yueh (BFW) was recorded in the 2010 edition of China Pharmacopoeia as one of sources for BFC. The primary objective of this study was to evaluate the antitussive, expectorant and anti-inflammatory effects of alkaloids - imperialine, imperialine-β-N-oxide, isoverticine, and isoverticine-β-N-oxide, which were isolated from BFW, and to provide experimental evidence for its traditional use.

MATERIALS AND METHODS

The alkaloids were isolated using phytochemical methods, and their structures were determined by spectroscopic analysis. Their antitussive effects were measured using murine model of ammonia induced cough, the expectorant effects were evaluated by measuring mice's tracheal phenol red output, and the anti-inflammatory effects were assessed by using the murine model of xylene induced ear edema.

RESULTS

The structures of the four alkaloids - imperialine, imperialine-β-N-oxide, isoverticine, and isoverticine-β-N-oxide isolated from BFW were confirmed. The four alkaloids significantly inhibited cough frequency and increased latent period of cough in mice induced by ammonia. Imperialine and isoverticine showed obviously antitussive activities in a dose-dependent manner. Besides, the four alkaloids markedly enhanced mice's tracheal phenol red output in expectorant assessment and significantly inhibited the development of ear edema in anti-inflammatory evaluation assay. Moreover, significant differences were found between the structure-activity relationships of the four alkaloids.

CONCLUSIONS

The four alkaloids exhibited significant antitussive, expectorant and anti-inflammatory activities. We suggest that they may be the active ingredients of BFW. The results of the present study provided evidence for BFW to be used as an antitussive and expectorant Traditional Chinese Medicine (TCM).

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.