Dendrobium officinale polysaccharides-chemical properties and pharmacodynamic effects on the airways in experimental conditions.

The study aimed to analyze the effects of Dendrobium polysaccharides on the cough and airway reactivity and compare them with the effects of clinically used antitussives (codeine phosphate and butamirate citrate) and bronchodilators (salbutamol), using the guinea pig test system. Dendrobium officinale polysaccharides contained proteins (4.0 wt%) and phenolic compounds (1.7 wt%) with a molecular weight of 25,000 g/mol. The sugar analysis revealed a dominance of glucose (93.7 wt%) and a lesser amount of mannose (5.1 wt%) while other sugar quantities were negligible. Methylation analysis indicated the presence of highly branched polysaccharides. Glucose was found mainly as terminal, 1,4- and 1,6-linked. Furthermore, some 1,4- and 1,6-linked glucose units were found branched at O2, O3, and O6/O4. Mannose was terminal and 1,4-linked. NMR spectra signals indicate the presence of the (1→4)-linked α-d-glucan, (1→4)-linked ß-d-glucan branched at position O6, (1→6)-linked ß-d-glucan branched at position O3 and (1→4)-linked glucomannan. Pharmacological studies showed statistically significant antitussive activity of Dendrobium polysaccharides, exceeding the effect of clinically used antitussives, which may be partially associated with confirmed bronchodilation and the ability of polysaccharides to increase the threshold of cough receptor activation. Dendrobium polysaccharides may increase the possibility of symptomatic treatment of cough, especially in asthmatics.

Chemical characteristics and significant antitussive effect of the Erigeron canadensis polyphenolic polysaccharide-protein complex.

ETHNOPHARMACOLOGICAL RELEVANCE: Erigeron canadensis has been used in traditional medicine to treat a variety of respiratory diseases, including acute upper and lower respiratory tract infections and cough-related asthma. There is as yet no relevant experimental or clinical study in the scientific literature evaluating the efficacy of plants in these disorders. AIM OF THE STUDY: To investigate the active ingredients in Erigeron canadensis, a complex isolated from flowering parts of a plant was tested for airway defense reflexes, in particular for cough reflexes and airway reactivity. Both were experimentally induced by a chemical irritant that simulated the inflammatory conditions of their formation. MATERIAL AND METHODS: The polyphenolic polysaccharide-protein (PPP) complex was isolated from the flowering parts of Erigeron canadensis by hot alkaline extraction and a multi-stage purification process. The antitussive activity was confirmed as a decrease in the number of citric acid-induced coughs and the bronchodilator effect was verified as a decrease in specific airway resistance (sRaw) in conscious guinea pigs. RESULTS: The dark brown Erigeron complex with a molecular weight of 38,000 g/mol contained phenolics (13.2% wt%), proteins (16.3% wt%), and uronic acids (6.3% wt%). The neutral carbohydrate part of Erigeron consisted mainly of xylose (12.1 wt%), glucose (13.3 wt%), arabinose (24.1 wt%), and galactose (41.0 wt%) residues. Arabinogalactan and 4-OMe-glucuronoxylan have been found to be the major polysaccharides in the Erigeron complex. Using a method of chemically-induced cough reflex and guinea pigs test system the Erigeron complex exhibited statistically significant, the dose-dependent antitussive activity, which was similar to that of the centrally-acting opioid agonist codeine. CONCLUSION: Pharmacological tests have revealed a new pharmacodynamic effect of the Erigeron complex, namely an antitussive effect. Its activity was most pronounced in comparison with all previously tested compounds from other medicinal plants and approached the effect of codeine, the most potent antitussive used in clinical practice. The results provide the scientific basis for the application of this herb in traditional medicine.

Structural characterization and anti-asthmatic effect of α-l-arabino(4-O-methyl-α-d-glucurono)-ß-d-xylan from the roots of Rudbeckia fulgida.

Many native plant biopolymers or derivatives thereof have interesting biological effects and therefore the search for additional biological activities is important to map their overall effects. A low molecular weight (Mw = 7600 g/mol) hemicellulose polymer α-L-arabino(4-O-methyl-α-D-glucurono)-ß-D-xylan (AGX) was isolated from the crushed roots of the Rudbeckia fulgida medicinal plant by alkaline extractions and anion-exchange chromatography. Analysis of neutral sugars revealed a predominance of xylose (82.3 wt%) and arabinose (6.8 wt%), while other neutral sugars were found only in small amounts as contaminants. The uronic acid content in Rudbeckia AGX was determined to be 8.8 wt%. Pharmacological tests showed that Rudbeckia AGX effectively suppressed cough and the initial amplitude of histamine/methacholine-induced bronchoconstriction in healthy OVA-sensitive guinea pigs. In addition, its effect at a dose of 100 mg/kg was similar to or greater than that of the positive control bronchodilator salbutamol and the antitussive codeine agent. These findings support the fact that Rudbeckia AGX could be a suitable candidate for alternative treatment of allergic asthma.

Bronchodilatory, antitussive and anti-inflammatory effect of morin in the setting of experimentally induced allergic asthma.

OBJECTIVE: Using an experimental model of allergic asthma, we evaluated the anti-asthmatic potential of polyphenol flavonol derivate morin after either acute or long-term treatment of male OVA-sensitised guinea pigs. METHODS: The following methods were used in experiments: the in-vitro tracheal smooth muscle contraction induced by histamine; the changes in specific airway resistance (sRaw) to histamine and the sensitivity of a chemically induced cough reflex both via an in-vivo method; the serum and BALF concentrations' analysis of the inflammatory cytokines interleukin IL-4, IL-5, IL-13; and lung tissue infiltration by eosinophils and mastocytes. KEY FINDINGS: Our data show that acute morin (30 mg/kg) and chronic 21-day morin (30 mg/kg/day) administration had a comparable antitussive efficiency with opioid antitussive codeine. Acute morin bronchodilatory activity defined by in-vivo sRaw decline did not reach SABA salbutamol effect. However, bronchodilatory efficiency of morin after long-term administration was by 34% higher as effect of LABA salmeterol. The 21-day morin treatment of OVA-sensitised guinea pigs reduced the serum, BALF levels of IL-4 and IL-13, lung tissue eosinophil and mastocyte infiltration comparable with corticosteroid budesonide. CONCLUSIONS: In summary, morin represents very rational target for additional studies as potential substance for control as well as prevention of asthma inflammation and symptoms.

Echinacea complex--chemical view and anti-asthmatic profile.

ETHNOPHARMACOLOGICAL RELEVANCE: Echinacea purpurea (L.) Moench is one of the mostly used herbs in the traditional medicine for the treatment of respiratory diseases. Modern interest in Echinacea is directed to its immunomodulatory activity. Recent studies have shown that secretion of asthma-related cytokines in the bronchial epithelial cells can be reversed by Echinacea preparations. AIM OF THE STUDY: To examine the pharmacodynamics profile of Echinacea active principles, a complex has been isolated from its flowers by alkaline extraction and has been tested using an animal model of allergic asthma. MATERIAL AND METHODS: The structural features of Echinacea purpurea complex was determined using chemical and spectroscopic methods. Allergic inflammation of the airways was induced by repetitive exposure of guinea pigs to ovalbumin. Echinacea complex was then administered 14 days in 50mg/kg b.w. daily dose perorally. Bronchodilatory effect was verified as decrease in the specific airway resistance (sRaw) in vivo and by reduced contraction amplitude (mN) of tracheal and pulmonary smooth muscle to cumulative concentrations of acetylcholine and histamine in vitro. The impact on mucociliary clearance evaluated measurement of ciliary beat frequency (CBF) in vitro using LabVIEW™ Software. Anti-inflammatory effect of Echinacea complex was verified by changes in exhaled NO levels and by Bio-Plex® assay of Th2 cytokine concentrations (IL-4, IL-5, IL-13 and TNF-alpha) in serum and bronchoalveolar lavage fluid (BALF). RESULTS: Chemical and spectroscopic studies confirmed the presence of carbohydrates, phenolic compounds and proteins, as well as the dominance of rhamnogalacturonan and arabinogalactan moieties in Echinacea complex. The significant decrease in sRaw values and suppressed histamine and acetylcholine-induced contractile amplitude of isolated airways smooth muscle that were similar to effects of control drug salbutamol confirmed Echinacea complex bronchodilatory activity. The anti-inflammatory effect was comparable with that of control agent budesonide and was verified as significantly reduced exhaled NO levels and concentration of Th2 cytokines in serum and BALF. The values of CBF were changed only insignificantly on long-term administration of Echinacea complex suggested its minimal negative impact on mucociliary clearance. CONCLUSION: Pharmacodynamic studies have confirmed significant bronchodilatory and anti-inflammatory effects of Echinacea complex that was similar to effects of classic synthetic drugs. Thus, results provide a scientific basis for the application of this herb in traditional medicine as a supplementary treatment of allergic disorders of the airways, such as asthma.

Chemical and pharmacological profiles of Echinacea complex.

Echinacea purpurea has a long history in traditional medicine. To verify the pharmacological efficacy of active principles, a polysaccharide-phenolic-protein complex has been isolated from flowering parts of herb by alkaline extraction. It showed on GPC and HPLC one peak of molecular mass around 10 kDa. Chemical and spectroscopic analyses revealed carbohydrate, phenolic and protein contents in Echinacea complex. Pharmacological tests have shown its marked cough suppressing and bronchodilatory effects. The antitussive effect of Echinacea was similar to the narcotic drug codeine and the bronchodilatory effect was more significant than salbutamol, the antiasthmatic drug used in a clinical practice. Pharmacodynamic study shows the beneficial effects of Echinacea complex on the respiratory system and highlights the great potential for development of antitussive and bronchodilatory drugs from natural sources.