Studies on Bronchodilator Activity of Salvia officinalis (Sage): Possible Involvement of K+ Channel Activation and Phosphodiesterase Inhibition

Dose-dependent Spasmolytic, Bronchodilator, and Hypotensive Activities of Panicum miliaceum L

Panicum miliaceum L. is a medicinally effective plant used in indigenous system of medicine for a variety of ailments. However, there is no comprehensive study explaining its effectiveness in gastrointestinal tract, respiratory, and cardiovascular system ailments. This study was designed to validate the pharmacological basis for the folkloric use of Panicum miliaceum L. in diarrhea, asthma, and hypertension. Panicum miliaceum extract was analyzed to detect the presence of bioactive compounds by HPLC. The isolated rabbit jejunum, trachea, and aorta were used for in vitro experiments using tissue bath assembly coupled with Power Lab data acquisition system to explore their relative effects. In-vivo experiments were performed for anti-diarrheal activity. HPLC analysis revealed the presence of gallic acid, butylated hydroxytoluene, catechin, and quercetin. Concentration dependent activities were observed by relaxing K+ (low) induced contractions having spasmolytic effect with EC50 = .358 ± .052, bronchodilator (EC50 = 2.483 ± .05793), and vasorelaxant (EC50 = .383 ± .063), probably due to the ATP dependent potassium channel activation. It was confirmed through pre-exposure of glibenclamide (specific ATP-dependent K+ channel blocker) having similarities with cromakalim. Pm.Cr revealed its antidiarrheal via in vivo experiments on rats. This study indicates that Panicum miliaceum has antidiarrheal, spasmolytic, bronchodilator, and vasorelaxant activities probably due to the ATP dependent K+ channel activation.

Inhibitors of phosphodiesterases in the treatment of cough

A group of 11 enzyme families of metalophosphohydrolases called phosphodiesterases (PDEs) is responsible for a hydrolysis of intracellular cAMP and cGMP. Xanthine derivatives (methylxanthines) inhibit PDEs without selective action on their single isoforms and lead to many pharmacological effects, e.g. bronchodilation, anti-inflammatory and immunomodulating effects, and thus they can modulate the cough reflex. Contrary, selective PDE inhibitors have been developed to inhibit PDE isoforms with different pharmacological effects based on their tissue expression. In this paper, effects of non-selective PDE inhibitors (e.g. theophylline) are discussed, with a description of other putative mechanisms in their effects on cough. Antitussive effects of selective inhibitors of several PDE isoforms are reviewed, focusing on PDE1, PDE3, PDE4, PDE5 and PDE7. The inhibition of PDEs suggests participation of bronchodilation, suppression of TRPV channels and anti-inflammatory action in cough suppression. Selective PDE3, PDE4 and PDE5 inhibitors have demonstrated the most significant cough suppressive effects, confirming their benefits in chronic inflammatory airway diseases associated with bronchoconstriction and cough.

Therapeutic efficacy of a combined sage and bitter apple phytopharmaceutical in chronic DSS-induced colitis

Inflammatory bowel diseases are multifactorial disorders of the gastrointestinal tract with rising incidence worldwide. Current standard therapies are only partially effective and often show severe adverse effects. Thus, novel, more efficient and well-tolerated therapeutic options are urgently needed. We have studied the therapeutic potential of a phytopharmaceutical combining sage and bitter apple (SBA) in the mouse model of chronic dextran sulfate sodium (DSS) colitis. SBA represents a traditional medicine against diarrhea and was shown to exhibit anti-inflammatory effects in vitro. In the chronic DSS colitis model SBA treatment significantly reduced clinical symptoms in a dose-dependent manner. The positive therapeutic effect of SBA was characterized by a decreased histopathological score indicating tissue healing. Moreover, the number of neutrophils as well as the expression of the neutrophil-recruiting chemokine CXCL-1/KC in the colon tissue was significantly reduced, whereas the recruitment of macrophages was induced. Also, the expression of inflammatory markers was significantly suppressed, while the expression of the anti-inflammatory cytokine interleukin-10 was induced in colon tissue following treatment with SBA. Phytopharmaceuticals are increasingly recognized as potential therapeutics in IBD. Thus, based on the results from this study, SBA can be considered as an alternative or supplementary option for IBD therapy.

Natural Products Useful in Respiratory Disorders: Focus on Side-Effect Neutralizing Combinations

This review summarizes literature related to medicinal plants reputed in traditional medical systems for treatment of asthma and coughs. The plants that are pharmacologically investigated for their effectiveness in such conditions, along with respective experimental protocol details, are also discussed. Some of plant origin compounds, which are considered useful as antitussive and antiasthmatic agents, are described as well. Chrysoeriol, a constituent of Aspalathus linearis (Fabaceae) was observed to be selective for relaxant effect in airways (through K⁺ channel activation), compared with other smooth muscles. We reported that Hypericum perforatum (Hyperieaceae), Andropogon muricatus (Poaceae), Juniper excelsa (Coniferae) and Nepeta cataria (Lamiaceae) exhibit bronchodilatory action, mediated through combination of Ca⁺⁺ antagonist and phospohodiesrase inhibitory mechanisms, which scientifically explains their medicinal use in asthma. Hyocyamus niger (Solanaceae), Artemisia vulgaris (Compositae), Fumaria parviflora (Fumariaceae) and Terminalia bellerica (Combretaceae) caused bronchodilation via dual blockade of muscarinic receptors and Ca⁺⁺ influx. Acorus calamus (Araceae), Carum roxburghianum (Apiaceae), Lens culinaris (Fabaceae) and Lepidium sativum (Cruciferae) mediate bronchodilatation through multiple pathways: anticholinergic and inhibition of Ca⁺⁺ channels and PDE enzyme(s). In conclusion, this review presents an analysis of different novel combinations of pharmacological activities in medicinal plants with side effect-neutralizing/synergistic potential, setting new trends in the therapeutic options for hyperactive respiratory disorders such as asthma and cough. Copyright © 2015 John Wiley & Sons, Ltd.