Rhynchophylline attenuates allergic bronchial asthma by inhibiting transforming growth factor-β1-mediated Smad and mitogen-activated protein kinase signaling transductions in vivo and in vitro

Corilagin attenuates airway inflammation and collagen deposition in ovalbumin-induced asthmatic mice

OBJECTIVE

To investigate the effects of corilagin on inflammation and collagen deposition in ovalbumin (OVA)-induced asthma mouse model and uncover the mechanism.

METHODS

We constructed a mouse model of OVA-induced asthma. Enzyme-linked-immunosorbent serologic assays were conducted to detect the effects of corilagin on cytokines and Immunoglobulin E (IgE) production. Hematoxylin and eosin staining was used to show pathological features in lung tissues. Masson trichrome assay was used to examine collagen deposition. In addition, the lung function was detected by mouse lung function apparatus. Immunoblot was used to confirm the mechanism.

RESULTS

Corilagin alleviates OVA-induced cytokine and IgE production. In addition, corilagin alleviates OVA-induced pathological changes and collagen deposition in lung tissues. Corilagin also suppressed airway resistance and lung function in mice. Mechanically, corilagin activated the adenosine monophosphate-activated protein kinase (AMPK) pathway in lung tissues.

CONCLUSION

Corilagin attenuates airway inflammation and collagen deposition in OVA-induced asthmatic mice via AMPK pathway.

Effect of the BMPR-II-SMAD3/MRTF pathway on proliferation and migration of ASMCs and the mechanism in asthma

Background

A variety of smooth muscle-specific genes and proteins, including SMAD3, BMPR-II, and MRTF, are involved in airway remodeling in asthma. As a receptor of bone morphogenetic protein (BMP) signaling, BMPR-II has important roles in airway remodeling in asthma. However, the underlying mechanism of BMPR-II in airway smooth muscle cells (ASMCs) in asthma remains incomplete.

Methods

Wistar rats were intraperitoneally injected with ovalbumin antigen suspension and aluminium hydroxide and, stimulated with ovalbumin nebulized inhalation to constructed asthma model. Primary ASMCs were isolated with collagenase I and identified by testing the α-SMA expression. Quantitative polymerase chain reaction (qPCR) and western blot assay were employed to detect the gene expression. CCK8, Transwell and Fluo-4 A assays were introduced to measure the cell viability, migration and intracellular Ca²⁺. Co-Immunoprecipitation (Co-IP) assay was applied to test the interaction among proteins.

Results

First, we observed significant increases in BMPR-II in asthmatic rat model and ASMCs at both the mRNA and protein levels. Second, we observed that silencing of siBMPR-II inhibited proliferation, migratory capacity and intracellular Ca²⁺ concentration in ASMCs. Furthermore, our study demonstrated that siBMPR-II inhibited the Smad3 expression and overexpression promoted the bioactivity of ASMCs. In addition, this study showed that p-Smad3 could interacted with MRTF and siMRTF inhibits the bioactivity of ASMCs. Finally, our results revealed BMPR-II-SMAD3/MRTF pathway affected the bioactivity of ASMCs.

Conclusions

This study indicates that the BMPR-II-SMAD3/MRTF signaling pathway is involved in the process of ASMCs remodeling, providing novel avenues for the identification of new therapeutic modalities.

Recent Advances in the Anti-Inflammatory Activity of Plant-Derived Alkaloid Rhynchophylline in Neurological and Cardiovascular Diseases

Rhynchophylline (Rhy) is a plant-derived indole alkaloid isolated from Uncaria species. Both the plant and the alkaloid possess numerous protective properties such as anti-inflammatory, neuroprotective, anti-hypertensive, anti-rhythmic, and sedative effects. Several studies support the significance of the anti-inflammatory activity of the plant as an underlying mechanism for most of the pharmacological activities of the alkaloid. Rhy is effective in protecting both the central nervous system and cardiovascular system. Cerebro-cardiovascular disease primarily occurs due to changes in lifestyle habits. Many previous studies have highlighted the significance of Rhy in modulating calcium channels and potassium channels, thereby protecting the brain from neurodegenerative diseases and related effects. Rhy also has anticoagulation and anti-platelet aggregation activity. Although Rhy has displayed its role in protecting the cardiovascular system, very little is explored about its intervention in early atherosclerosis. Extensive studies are required to understand the cardioprotective effects of Rhye. This review summarized and discussed the various pharmacological effects of Rhy in neuro- and cardioprotection and in particular the relevance of Rhy in preventing early atherosclerosis using Rhy-loaded nanoparticles.

Cellular Effects of Rhynchophylline and Relevance to Sleep Regulation

Uncaria rhynchophylla is a plant highly used in the traditional Chinese and Japanese medicines. It has numerous health benefits, which are often attributed to its alkaloid components. Recent studies in humans show that drugs containing Uncaria ameliorate sleep quality and increase sleep time, both in physiological and pathological conditions. Rhynchophylline (Rhy) is one of the principal alkaloids in Uncaria species. Although treatment with Rhy alone has not been tested in humans, observations in rodents show that Rhy increases sleep time. However, the mechanisms by which Rhy could modulate sleep have not been comprehensively described. In this review, we are highlighting cellular pathways that are shown to be targeted by Rhy and which are also known for their implications in the regulation of wakefulness and sleep. We conclude that Rhy can impact sleep through mechanisms involving ion channels, N-methyl-d-aspartate (NMDA) receptors, tyrosine kinase receptors, extracellular signal-regulated kinases (ERK)/mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K)/RAC serine/threonine-protein kinase (AKT), and nuclear factor-kappa B (NF-κB) pathways. In modulating multiple cellular responses, Rhy impacts neuronal communication in a way that could have substantial effects on sleep phenotypes. Thus, understanding the mechanisms of action of Rhy will have implications for sleep pharmacology.

Suppression of autophagy through JAK2/STAT3 contributes to the therapeutic action of rhynchophylline on asthma

Background

Asthma is a chronic inflammatory disease characterized by airway remodeling and inflammation. Rhynchophylline is a kind of indole alkaloid isolated from Uncaria rhynchophylla. Here we investigated the effect of rhynchophylline on autophagy in asthma.

Methods

A mice model of asthma was established by ovalbumin challenge. Histopathological changes were assessed by hematoxylin-eosin staining, periodic acid-schiff staining and Masson staining. The levels of IgE in serum, interleukin-6 and interleukin-13 in bronchoalveolar lavage fluid, as well as the activities of superoxide dismutase and catalase in lung tissues were detected. The expression of autophagy-related genes and Janus kinase (JAK) 2/ signal transducer and activator of transcription (STAT) 3 signal was detected by western blot and immunofluorescence. Airway smooth muscle cells (ASMCs) were isolated, and the effect rhynchophylline on autophagy in ASMCs was explored.

Results

Our data showed that rhynchophylline treatment alleviated inflammation, airway remodeling, and oxidative stress in asthma. In addition, autophagy, which was implicated in asthma, was suppressed by rhynchophylline with decreased level of autophagy-related proteins. Furthermore, rhynchophylline suppressed the JAK2/STAT3 signaling pathway, which was activated in asthma. In vitro study showed that rhynchophylline suppressed ASMC autophagy through suppressing the activation of JAK2/STAT3 signal.

Conclusions

Our study demonstrated that rhynchophylline can alleviate asthma through suppressing autophagy in asthma, and that JAK2/STAT3 signal was involved in this effect of rhynchophylline. This study indicates that rhynchophylline may become a promising drug for the treatment of asthma.

Rhynchophylline attenuates migraine in trigeminal nucleus caudalis in nitroglycerin-induced rat model by inhibiting MAPK/NF-кB signaling

Migraine causes severe health and social issues worldwide. Rhynchophylline (Rhy) is one of the major active components of Uncaria rhynchophylla that is used for the treatment of headache in Traditional Chinese Medicine. In the current study, the effect of Rhy on nitroglycerin (NTG)-induced migraine was assessed and the associated mechanism was also explored to explain its function. Rats were pre-treated with Rhy of two doses (10 mg/kg and 30 mg/kg) and then subjected to NTG to induce migraine symptoms. Thereafter, the electroencephalogram (EEG) signaling, spontaneous behaviors, levels of indicators related to oxidative stress, and expression of calcitonin gene-related peptide (CGRP) were measured to assess the anti-migraine function of Rhy. Moreover, the activities of MAPK/NF-κB pathway under the administrations of Rhy were also detected. The results showed that NTG induced EEG and behavior disorders in rats, which was associated with the initiation of oxidative stress and increased expression of CGRP. Nevertheless, the pre-treatments with Rhy attenuated the damages induced by NTG by reversing the levels of all the above indicators. The results of western blotting demonstrated that the anti-migraine effect of Rhy was accompanied by the inhibition of MAPK/NF-кB pathway. The findings outlined in the current study revealed an alternative mechanism of Rhy in protecting brain tissues against migraine: the agent exerted its effect by suppressing MAPK/NF-кB pathway, which would ameliorate impairments associated with migraine.