An in silico and in vitro integrated analysis method to reveal the curative mechanisms and pharmacodynamic substances of Bufei granule on chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with high disability and mortality. Clinical studies have shown that the Traditional Chinese Medicine Bufei Granule (BFG) has conspicuous effects on relieving cough and improving lung function in patients with COPD and has a reliable effect on the treatment of COPD, whereas the therapeutic mechanism is vague. In the present study, the latent bronchodilators and mechanism of BFG in the treatment of COPD were discussed through the method of network pharmacology. Then, the molecular docking and molecular dynamics simulation were performed to calculate the binding efficacy of corresponding compounds in BFG to muscarinic receptor. Finally, the effects of BFG on bronchial smooth muscle were validated by in vitro experiments. The network pharmacology results manifested the anti-COPD effect of BFG was mainly realized via restraining airway smooth muscle contraction, activating cAMP pathways and relieving oxidative stress. The results of molecular docking and molecular dynamics simulation showed alpinetin could bind to cholinergic receptor muscarinic 3. The in vitro experiment verified both BFG and alpinetin could inhibit the levels of CHRM3 and acetylcholine and could be potential bronchodilators for treating COPD. This study provides an integrating network pharmacology method for understanding the therapeutic mechanisms of traditional Chinese medicine, as well as a new strategy for developing natural medicines for treating COPD.

Folium Sennae and emodin reverse airway smooth muscle contraction.

The objective of this project was to find a bronchodilatory compound from herbs and clarify the mechanism. We found that the ethanol extract of Folium Sennae (EEFS) can relax airway smooth muscle (ASM). EEFS inhibited ASM contraction, induced by acetylcholine, in mouse tracheal rings and lung slices. High-performance liquid chromatography assay showed that EEFS contained emodin. Emodin had a similar reversal action. Acetylcholine-evoked contraction was also partially reduced by nifedipine (a selective inhibitor of L-type voltage-dependent Ca2+ channels, LVDCCs), YM-58483 (a selective inhibitor of store-operated Ca2+ entry, SOCE), as well as Y-27632 (an inhibitor of Rho-associated protein kinase). In addition, LVDCC- and SOCE-mediated currents and cytosolic Ca2+ elevations were inhibited by emodin. Emodin reversed acetylcholine-caused increases in phosphorylation of myosin phosphatase target subunit 1. Furthermore, emodin, in vivo, inhibited acetylcholine-induced respiratory system resistance in mice. These results indicate that EEFS-induced relaxation results from emodin inhibiting LVDCC, SOCE, and Ca2+ sensitization. These findings suggest that Folium Sennae and emodin may be new sources of bronchodilators.

CYP1A1 specificity of Verlukast epoxidation in mice, rats, rhesus monkeys, and humans.

It has previously been shown that Verlukast is converted to Verlukast dihydrodiol in microsomes from beta-naphthoflavone (BNF)-treated, but not uninduced Swiss Webster mice and Sprague-Dawley rats. We have examined the involvement of CYP1A1 in this reaction in more detail. It is concluded that this reaction is catalyzed exclusively by CYP1A1 in rats, mice, and humans based on the following criteria: 1) the epoxidation of Verlukast is negligible in uninduced rats, which express CYP1A2 but not CYP1A1; 2) Verlukast epoxidation is highly inducible by BNF treatment (60- to 200-fold); 3) Verlukast epoxidation in BNF-treated rat microsomes was inhibited by alpha-naphthoflavone (ANF) treatment, indicating that this activity was mediated by the CYP1A subfamily; 4) > 95% of Verlukast epoxidation in BNF-treated rat microsomes was inhibited by antibodies raised against CYP1A1; and 5) Verlukast was epoxidized by human CYP1A1 but not CYP1A2. Thus, Verlukast epoxidation appears to be specific for rat, mouse, and human CYP1A1. Additional studies showed that Verlukast was metabolized to Verlukast dihydrodiol in microsomes from uninduced rhesus monkeys. This reaction was inhibited by nanomolar concentrations of ANF in rhesus monkey microsomes implicating the involvement of the CYP1A subfamily. In addition, the 8-hydroxylation of R-warfarin, a pathway that is selective for rodent and human CYP1A1 activity, was also catalyzed at significant rates by rhesus monkey microsomes. These findings indicate that, unlike rats, mice, and humans, which have very low constitutive levels of hepatic CYP1A1 activity, the uninduced rhesus monkey is able to catalyze reactions specific to CYP1A1 in rodents and humans.(ABSTRACT TRUNCATED AT 250 WORDS)