Comparative study of the effects of antitussive drugs in a canine acute cough model.

BACKGROUND: Cough is a common clinical complaint in small animal practice with limited treatment options for chronic underlying conditions. OBJECTIVES: The present study aimed to evaluate the efficacy of three antitussive drugs in a novel, minimally invasive canine acute cough model. METHODS: Five clinically healthy Beagles were used to create an acute cough model by administering sterile saline via a transtracheally placed central venous catheter. Single-dose antitussive effects of butorphanol, maropitant and Danpron were assessed. Cough frequency was measured before and at hourly intervals up to 3 h post-administration of each drug, with a linear mixed model used for statistical analysis. RESULTS: Butorphanol (0.3 m/kg, IM) significantly reduced cough frequency at 1 and 3 h post-administration. Danpron (0.1 mL/kg, IM) also significantly reduced cough frequency 1 h post-administration; however, this effect was not sustained at 3 h. Maropitant (1 mg/kg, IM) did not significantly reduce cough frequency. The cough induction method was effective and minimally invasive, with no adverse effects. CONCLUSION: The present study demonstrated that butorphanol has a potent and prolonged antitussive effect in an acute canine cough model, whereas Danpron shows a transient effect. These findings provide valuable insights into the comparative efficacy of commonly used antitussive drugs in dogs.

Anti-inflammatory, analgesic, antitussive and antipyretic activities of polyphenol-enriched fraction from Nymphaea candida.

ETHNOPHARMACOLOGICAL RELEVANCE: "Snow-white waterlily" (Nymphaea candida) dried flower possesses various efficacy in Uighur medicine such as reducing fever and nourishing the liver, anti-inflammatory and cough relieving, moistening the throat and quenching thirst. AIM OF THE STUDY: Polyphenols are characteristic component of N. candida as well as its quality markers, and the purpose of this study was to conduct investigations into anti-inflammatory, antitussive, antipyretic, and analgesic activities of the polyphenol-enriched fraction from N. candida (NCTP) in order to validate the traditional efficacy of this plant. MATERIALS AND METHODS: The polyphenols in NCTP were analyzed by HPLC, and an acute oral toxicity study was conducted for NCTP. The anti-inflammatory activities of NCTP were evaluated using xylene induced ear edema, capillary permeability, cotton pellet granuloma, and carrageenan-induced rat paw edema, of which multiple biochemical indices were measured in carrageenan-induced rat paw edema such as prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2),5-lipoxygenase (5-LOX), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) activities; the analgesic activities were investigated using acetic acid writhing, hot plate test, and formalin test; the anti-tussive and antipyretic effects were tested by ammonia induced cough in mice and yeast-induced fever respectively. RESULTS: NCTP with LD50 of 5222 mg/kg was low toxicity and safety. NCTP (200 mg/kg) could significantly reduce ear swelling and capillary permeability by 30.63% and 31.37%, respectively. NCTP revealed 15.76% inhibiting activities in cotton pellet granuloma in mice at a dosage of 200 mg/kg. Furthermore, NCTP (50, 100, and 200 mg/kg) substantially decreased carrageenin-induced paw edema in rats between 1 and 5 h, and NCTP could decrease PGE2, 5-LOX, COX-2 levels as well as IL-6, IL-1ß, TNF-α activities compared with the control group; NCTP could decrease MDA contents in carrageenin-induced rise, and increase SOD and GSH activities. Furthermore, the dose-dependent inhibition effect of NCTP on pain was revealed in the hot plate experiment. In addition to reducing the amount of writhes brought on by acetic acid, NCTP (50, 100, and 200 mg/kg) significantly inhibited pain latency against both stages of the formalin test. Moreover, NCTP (50, 100, 200 mg/kg) showed the better antitussive activities in mice in a dose-dependent manner. In the yeast-induced pyrexia test, dosages of 50, 100, and 200 mg/kg resulted in a statistically significant drop in rectal temperature. CONCLUSION: The experimental results proved the analgesic, anti-inflammatory, anti-tussive and antipyretic activities of the polyphenol-enriched fraction from N. candida, and supported the traditional use of this plant as well.

Xingbei antitussive granules ameliorate cough hypersensitivity in post-infectious cough guinea pigs by regulating tryptase/PAR2/TRPV1 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Xingbei antitussive granules (XB) is a classic Chinese Medicine prescription for treating post-infectious cough(PIC), based on the Sanao Decoction from Formularies of the Bureau of People's Welfare Pharmacies in the Song Dynasty and Jiegeng decoction from Essentials of the Golden Chamber in the Han Dynasty. However, the therapeutic effects and pharmacological mechanisms are still ambiguous. In the present study, we endeavored to elucidate these underlying mechanisms. AIMS OF THE STUDY: This study aimed to explore the potential impact and mechanism of XB on PIC, and provide a scientific basis for its clinical application. MATERIALS AND METHODS: Cigarette smoking (CS) combined with lipopolysaccharide (LPS) nasal drops were administered to induce the PIC guinea pig with cough hypersensitivity status. Subsequently, the model guinea pigs were treated with XB and the cough frequency was observed by the capsaicin cough provocation test. The pathological changes of lung tissue were assessed by HE staining, and the levels of inflammatory mediators, mast cell degranulating substances, and neuropeptides were detected. The protein and mRNA expression of transient receptor potential vanilloid type 1(TRPV1), proteinase-activated receptor2(PAR2), and protein kinase C (PKC) were measured by Immunohistochemical staining, Western blot, and RT-qPCR. Changes in the abundance and composition of respiratory bacterial microbiota were determined by 16S rRNA sequencing. RESULTS: After XB treatment, the model guinea pigs showed a dose-dependent decrease in cough frequency, along with a significant alleviation in inflammatory infiltration of lung tissue and a reduction in inflammatory mediators. In addition, XB high-dose treatment significantly decreased the levels of mast cell Tryptase as well as ß-hexosaminidase (ß-Hex) and downregulated the expression of TRPV1, PAR2, and p-PKC. Simultaneously, levels of neuropeptides like substance P (SP), calcitonin gene-related peptide (CGRP), neurokinin A (NKA), and nerve growth factor (NGF) were improved. Besides, XB also can modulate the structure of respiratory bacterial microbiota and restore homeostasis. CONCLUSION: XB treatment alleviates cough hypersensitivity and inflammatory responses, inhibits the degranulation of mast cells, and ameliorates neurogenic inflammation in PIC guinea pigs whose mechanism may be associated with the inhibition of Tryptase/PAR2/PKC/TRPV1 and the recovery of respiratory bacterial microbiota.

Assessment and Management of Cough in Idiopathic Pulmonary Fibrosis: A Narrative Review.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal disease with an unknown cause. It is characterized by symptoms such as cough and breathlessness, which significantly impact patients' quality of life. Cough, in particular, has emerged as a burdensome symptom for individuals with IPF. The etiology of cough in IPF patients is believed to be complex, involving factors related to the disease itself, such as increased sensitivity of cough nerves, lung structural changes, inflammation, and genetic factors, as well as comorbidities and medication effects. Unfortunately, effective treatment options for cough in IPF remain limited, often relying on empirical approaches based on studies involving chronic cough patients in general and the personal experience of physicians. Medications such as opioids and neuromodulators are commonly prescribed but have shown suboptimal efficacy, imposing significant physical, psychological, and economic burdens on patients. However, there is hope on the horizon, as specific purinergic P2 receptor ligand-gated ion channel (P2X3) inhibitors have demonstrated promising antitussive effects in ongoing clinical trials. This review aims to provide a comprehensive overview of the evaluation and management of cough in IPF patients, as well as highlight emerging pharmacological and non-pharmacological approaches that target the cough reflex and are currently being investigated in clinical settings.

Efficacy of gefapixant, a P2X3 antagonist, for lung cancer-related cough: a case report.

Cough is a frequent symptom accompanied by lung cancer. More potent antitussive treatment for this complex and distressing symptom is required, but anti-cancer chemotherapy cannot fully manage the cough. Inhibition of vagal nerves might control coughing in patients with troublesome lung cancer-related cough and P2X3 inhibitory therapy may be useful for targeting neuronal function. We report the case of a woman in her late 70s who never smoked and had advanced lung cancer. She visited our hospital complaining of serious deterioration of a non-productive cough. She was diagnosed with relapse of lung cancer, but she requested 2-week anti-tussive therapy before second-line chemotherapy. Gefapixant (P2X3 antagonist) add-on at a dose of 90 mg/day (45 mg twice daily as the usual dosage in Japan) improved her cough as indicated by an improvement in the visual analog scale for cough from 70 to 20 mm and in the Japanese version of the Leicester Cough Questionnaire from 8.2 to 16.3, despite a deterioration in lung cancer after 2 weeks. There are no current guidelines for cough accompanied by lung cancer; however, our findings suggest that P2X3 inhibition is a potent therapeutic option for lung cancer-related cough.

[Efficacy of compound pholcodine syrup and compound codeine phosphate oral solution on lung cancer-related cough].

Objective: To assess the clinical efficacy of compound pholcodine syrup and compound codeine phosphate oral solution on lung cancer-related cough. Methods: A total of 60 patients diagnosed with middle-advanced stage lung cancer and had lung cancer-related cough in the Department of Geriatric Oncology of Chongqing University Cancer Hospital from January to May 2022 were prospectively enrolled. According to the random number table method, the patients were divided into two groups: observation group and control group. The observation group [n=30, with 21 males and 9 females, and aged (62.3±10.4) years] received compound pholcodine syrup treatment, while the control group [n=30, with 21 males and 9 females, and aged (62.0±8.1) years] received compound codeine phosphate oral solution treatment. The dosage of the two drugs was 15 ml each time, 3 times a day, and the treatment course was 5 days. The antitussive effectiveness, cough severity and quality of life (Leicester Cough Questionnaire in Mandarin-Chinese scale) were observed and compared between the two groups 3 days and 5 days after the treatment. Results: All 60 patients completed the study. Both regimens were effective in controlling lung cancer-related cough. After 3 days treatment, the antitussive effective rate of the observation group and the control group was 83.3% (25/30) and 73.3% (22/30), respectively, with no statistically significant difference (P=0.347). Likewise, after 5 days treatment, the antitussive effective rate of observation group and control group was 90.0% (27/30) and 86.6% (26/30), respectively, with no statistically significant difference (P=0.687). There was no statistically significant difference in the cough severity between observation group [moderate and severe cough: 56.7% (17/30)] and control group [moderate and severe cough: 67.7% (20/30)] (P=0.414). After 3 days treatment, cough symptoms were relieved in both groups. Patients with mild cough accounted for 73.3% (22/30) in the observation group and 56.7% (17/30) in the control group, and the difference was not statistically significant (P=0.331). Moreover, after 5 days treatment, there was also no significant difference in mild cough between observation group [86.7% (26/30)] and control group [66.7% (20/30)] (P=0.067). Meanwhile, there were no significant differences in the physiological score, psychological score, social score and total score of the Leicester Cough Questionnaire in Mandarin-Chinese scale before the treatment, after 3 days and 5 days treatment between the two groups (all P>0.05). The incidence of both xerostomia and constipation in the observation group was 0, which was lower than those of the control group [20.0% (6/30) and 20.0% (6/30)] (both P<0.05). Conclusions: Both compound pholcodine syrup and compound codeine phosphate oral solution are effective in treating lung cancer-related cough with similar antitussive effectiveness. Compound pholcodine syrup has a lower incidence of xerostomia and constipation than control group, with a better safety profile.

Managing Chronic Cough Associated with Idiopathic Pulmonary Fibrosis - Will Nalbuphine Fill an Unmet Need?

In this issue of NEJM Evidence, Maher et al.1 report the results of a randomized, controlled, 22-day treatment crossover trial comparing the antitussive effect of extended-release nalbuphine, an opioid agonist-antagonist, with placebo in a cohort of patients with definite or probable idiopathic pulmonary fibrosis (IPF). In this small, short-term trial of 38 evaluable patients, the active drug was associated with a 75.1% reduction in daytime objective cough frequency (the primary outcome) compared with a 22.6% reduction in placebo-treated patients, yielding a substantial and statistically significant 52.5 percentage point placebo-adjusted change from baseline.

Effects of treatment with montelukast alone, budesonide/formoterol alone and a combination of both in cough variant asthma.

BACKGROUND: Whether cysteinyl-leukotriene receptor antagonists (LTRAs) have a similar antitussive effect to inhaled corticosteroids and long-acting ß2-agonist (ICS/LABA), and that LTRA plus ICS/LABA is superior to LTRAs alone or ICS/LABA alone in treating cough variant asthma (CVA) remain unclear. This study aimed to investigate and compare the efficacy of montelukast alone, budesonide/formoterol alone and the combination of both in the treatment of CVA. METHODS: Ninety-nine CVA patients were assigned randomly in a 1:1:1 ratio to receive montelukast (M group: 10 mg, once daily), budesonide/formoterol (BF group: 160/4.5 µg, one puff, twice daily), or montelukast plus budesonide/formoterol (MBF group) for 8 weeks. The primary outcomes were changes in the cough visual analogue scale (VAS) score, daytime cough symptom score (CSS) and night-time CSS, and the secondary outcomes comprised changes in cough reflex sensitivity (CRS), the percentage of sputum eosinophils (sputum Eos%) and fractional exhaled nitric oxide (FeNO). CRS was presented with the lowest concentration of capsaicin that induced at least 5 coughs (C5). The repeated measure was used in data analysis. RESULTS: The median cough VAS score (median from 6.0 to 2.0 in the M group, 5.0 to 1.0 in the BF group and 6.0 to 1.0 in the MBF group, all p < 0.001), daytime CSS (all p < 0.01) and night-time CSS (all p < 0.001) decreased significantly in all three groups after treatment for 8 weeks. Meanwhile, the LogC5 and sputum Eos% improved significantly in all three groups after 8 weeks treatment (all p < 0.05). No significant differences were found in the changes of the VAS score, daytime and night-time CSSs, LogC5 and sputum Eos% among the three groups from baseline to week 8 (all p > 0.05). The BF and MBF groups also showed significant decreases in FeNO after 8 weeks treatment (p = 0.001 and p = 0.008, respectively), while no significant change was found in the M group (p = 0.457). Treatment with MBF for 8 weeks significantly improved the FEV1/FVC as well as the MMEF% pred and decreased the blood Eos% (all p < 0.05). CONCLUSIONS: Montelukast alone, budesonide/formoterol alone and a combination of both were effective in improving cough symptom, decreasing cough reflex sensitivity and alleviating eosinophilic airway inflammation in patients with CVA, and the antitussive effect and anti-eosinophilic airway inflammation were similar. Trial registration ClinicalTrials.gov, number NCT01404013.

The Effect of Ramosetron on Remifentanil in Preventing Emergence Cough from Sevoflurane Anesthesia in Female Patients.

BACKGROUND: Remifentanil reduces cough during extubation. Ramosetron, a 5-HT3 receptor antagonist, is a potent antiemetic. Regarding the antitussive property of 5-HT receptor agonists, ramosetron can mediate the cough reflex by increasing the remifentanil requirement. This study evaluated the effect of ramosetron on the optimal effect-site concentration (Ce) of remifentanil for preventing emergence cough from sevoflurane anesthesia in female patients. METHODS: Forty-seven randomly selected female patients undergoing laparoscopic cholecystectomy received either ramosetron 0.3 mg (n = 23) or the same volume of normal saline (n = 24) intravenously at the end of surgery. The remifentanil Ce using target-controlled infusion in 50% of patients (EC50) and 95% of patients (EC95) were assessed using Dixon's up-and-down or isotonic regression method with a bootstrapping approach. RESULTS: Using Dixon's up-and-down method, the EC50 of remifentanil in the control group (1.33 ± 0.38 ng/mL) was comparable to that of ramosetron group (1.50 ± 0.69 ng/mL) (P = 0.615). Using isotonic regression analysis, the EC50 (83% confidence interval) did not differ between the two groups (1.17 [0.86-1.43] ng/mL and 1.13 [0.68-1.56] ng/mL in control and ramosetron groups). However, the EC95 (95% confidence interval) was significantly lower in the control group than in the ramosetron group (1.90 [1.45-1.96] ng/mL and 2.92 [2.35-2.97] ng/mL). CONCLUSION: Remifentanil Ce for preventing emergence cough was higher in the ramosetron group than in the control group. It may indicate the lowering effect of ramosetron on the antitussive activity of remifentanil.

Evidence for Alpha7 Nicotinic Receptor Activation During the Cough Suppressing Effects Induced by Nicotine and Identification of ATA-101 as a Potential Novel Therapy for the Treatment of Chronic Cough.

Studies performed in healthy smokers have documented a diminished responsiveness to tussive challenges, and several lines of experimental evidence implicate nicotine as an antitussive component in both cigarette smoke and the vapors generated by electronic cigarettes (eCigs). We set out to identify the nicotinic receptor subtype involved in the antitussive actions of nicotine and to further evaluate the potential of nicotinic receptor-selective agonists as cough-suppressing therapeutics. We confirmed an antitussive effect of nicotine in guinea pigs. We additionally observed that the alpha-4 beta-2 (α 4 ß 2)-selective agonist Tc-6683 was without effect on evoked cough responses in guinea pigs, while the α 7-selective agonist PHA 543613 dose-dependently inhibited evoked coughing. We subsequently describe the preclinical evidence in support of ATA-101, a potent and highly selective (α 7) selective nicotinic receptor agonist, as a potential candidate for antitussive therapy in humans. ATA-101, formerly known as Tc-5619, was orally bioavailable and moderately central nervous system (CNS) penetrant and dose-dependently inhibited coughing in guinea pigs evoked by citric acid and bradykinin. Comparing the effects of airway targeted administration versus systemic dosing and the effects of repeated dosing at various times prior to tussive challenge, our data suggest that the antitussive actions of ATA-101 require continued engagement of α 7 nicotinic receptors, likely in the CNS. Collectively, the data provide the preclinical rationale for α 7 nicotinic receptor engagement as a novel therapeutic strategy for cough suppression. The data also suggest that α 7 nicotinic acetylcholine receptor (nAChR) activation by nicotine may be permissive to nicotine delivery in a way that may promote addiction. SIGNIFICANCE STATEMENT: This study documents the antitussive actions of nicotine and identifies the α7 nicotinic receptor subtype as the target for nicotine during cough suppression described in humans. We additionally present evidence suggesting that ATA-101 and other α7 nicotinic receptor-selective agonists may be promising candidates for the treatment of chronic refractory cough.

[Study on mechanism of Qinbaohong Oral Liquid in anti-inflammation, stopping cough, eliminating phlegm and relieving asthma based on network pharmacology].

This study aimed to investigate the anti-inflammatory, antitussive, expectorant, and anti-asthmatic effects of Qinbaohong Oral Liquid in mouse experiments and explore its action mechanism based on network pharmacology. The mouse auricle swelling was induced by xylene for detecting the anti-inflammatory effect of Qinbaohong Oral Liquid, whose antitussive effect was then examined in mice with cough after exposure to ammonium hydroxide. The expectorant effect was determined based on the excretion of phenol red into the mouse trachea. The mouse model of asthma induced by histamine phosphate and acetylcholine chloride was used to observe the anti-asthmatic effect. The chemical components of Qinbaohong Oral Liquid were retrieved from TCMSP and literature, followed by target prediction based on BATMAN-TCM. The targets of inflammation, cough, expectoration, and asthma collected from GeneCards were intersected with drug targets for GO and KEGG enrichment analysis using Metascape. The results were imported into STRING for exploring protein-protein interactions and screening the key targets. As demonstrated by our findings, Qinbaohong Oral Liquid at 4.5 and 9.0 mL·kg~(-1) obviously decreased the weight(P<0.05) and thickness(P<0.01) of the right swelling ear and also the weight diffe-rence(swelling degree) between the two ears(P<0.05), prolonged the incubation period of cough(P<0.05), reduced the frequency of cough within 3 min(P<0.05), and increased the excretion of phenol red into the mouse trachea(P<0.01). Qinbaohong Oral Li-quid at 2.3, 4.5, and 9.0 mL·kg~(-1) dramatically prolonged the incubation period of asthma(P<0.05). A total of 324 chemical components and 1 245 targets were harvested for the Qinbaohong Oral Liquid, together with 10 272 inflammation targets, 4 400 cough targets, 192 expectoration targets, and 7 533 asthma targets. Their intersection revealed that the anti-inflammatory, antitussive, expectorant and anti-asthmatic effects of Qinbaohong Oral Liquid were correlated with such GO biological processes as the regulation of ion transport and blood circulation and such KEGG pathways as cancer-related signaling pathways and neuroactive ligand-receptor interaction. Qinbaohong Oral Liquid has been confirmed by both experiments and network pharmacology analysis to be efficient in anti-inflammation, stopping cough, eliminating phlegm, and relieving asthma.

[Investigation on status of lung cancer cough management and concept and practice of lung cancer cough management in Chinese medical providers].

Objective: Investigate the current situation of lung cancer cough diagnosis and treatment and the awareness of related issues among Chinese medical providers. Methods: Doctors, nurses, pharmacists from the oncology department, respiratory department, or general department were investigated using an electronic questionnaire from January 29 to March 29, 2021. There were 25 questions about lung cancer in the questionnaire. The questionnaire was including the most common accompanying symptoms in patients with lung cancer, the incidence of lung cancer-related cough, the assessment of the proportion of central antitussive drugs, and the commonly used central antitussives. Results: Questionnaires from 2 424 medical providers were collected from 402 hospitals in 21 provincial administrative units. Cough was the most common symptom in lung cancer. Most physicians believed that the incidence of lung cancer-related cough was 51%~75%, while the proportion of patients satisfied with the treatment was only 11%~20%. The evaluation of lung cancer-related cough was seriously insufficient. The leading cause of lung cancer-related cough was tumors. And the main problem was the inadequate antitussive effect of drugs in lung cancer-related cough management. The proportion of central antitussive medication usage in the secondary and tertiary hospitals was 93.9% and 92.0%, significantly higher than 75.0% in Primary hospitals (χ²=8.390, P=0.015). The proportion of the physicians who underhanded that codeine is at risk of addiction was 76.6% and 72.0% in the secondary and tertiary hospitals, which were significantly higher than 53.9% in Primary hospitals (χ²=9.240, P=0.010). In different occupations, the proportions of doctors and pharmacists who knew the risk of addicting to codeine were 73.0% and 82.6%, which were significantly higher than the 66.4% of nurses (χ²=21.200, P<0.001). The Chinese medical providers were lack of training about the basic knowledge of using central antitussive medication. Conclusions: The proportion of patients who were satisfied with the effect of cough treatment is low. The medical staff did not have enough awareness of this. There was an urgent need to develop a consensus and standardize lung cancer cough diagnosis and treatment in China.

Aprepitant for Cough in Lung Cancer. A Randomized Placebo-controlled Trial and Mechanistic Insights.

Rationale: Effective cough treatments are a significant unmet need in patients with lung cancer. Aprepitant is a licensed treatment for nausea and vomiting, which blocks substance P activation of NK-1 (neurokinin 1) receptors, a mechanism also implicated in cough.Objectives: To assess aprepitant in patients with lung cancer with cough and evaluate mechanisms in vagal nerve tissue.Methods: Randomized double-blind crossover trial of patients with lung cancer and bothersome cough. They received 3 days of aprepitant or matched placebo; after a 3-day washout, patients crossed to the alternative treatment. The primary endpoint was awake cough frequency measured at screening and Day 3 of each treatment; secondary endpoints included patient-reported outcomes. In vitro, the depolarization of isolated guinea pig and human vagus nerve sections in grease-gap recording chambers, indicative of sensory nerve activation, was measured to evaluate the mechanism.Measurements and Main Results: Twenty patients with lung cancer enrolled, with a mean age 66 years (±7.7); 60% were female and 80% had non-small cell cancer, 50% had advanced stage, and 55% had World Health Organization performance status 1. Cough frequency improved with aprepitant, reducing by 22.2% (95% confidence interval [CI], 2.8-37.7%) over placebo while awake (P = 0.03), 30.3% (95% CI, 12.7-44.3) over 24 hours (P = 0.002), and 59.8% (95% CI, 15.1-86.0) during sleep (P = 0.081). Patient-reported outcomes all significantly improved. Substance P depolarized both guinea pig and human vagus nerve. Aprepitant significantly inhibited substance P-induced depolarization by 78% in guinea pig (P = 0.0145) and 94% in human vagus (P = 0.0145).Conclusions: Substance P activation of NK-1 receptors appears to be an important mechanism driving cough in lung cancer, and NK-1 antagonists show promise as antitussive therapies.

Therapeutic effects and mechanisms study of Hanchuan Zupa Granule in a Guinea pig model of cough variant asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Hanchuan Zupa Granule (HCZP), a traditional Chinese ethnodrug, has the functions of supressing a cough, resolving phlegm, warming the lungs, and relieving asthma. In clinical practice employing traditional Chinese medicine (TCM), HCZP is commonly used to treat acute colds, cough and abnormal mucous asthma caused by a cold, or "Nai-Zi-Lai" in the Uygur language. Studies have confirmed the use of HCZP to treat cough variant asthma (CVA) and other respiratory diseases. However, the pharmacological mechanisms of HCZP remain unrevealed. AIM OF THE STUDY: To investigate the anti-tussive and anti-asthmatic effects and the possible pharmacological mechanisms of HCZP in the treatment of CVA. MATERIALS AND METHODS: A guinea pig CVA animal model was established by intraperitoneal injection of ovalbumin (OVA) combined with intraperitoneal injection of aluminium hydroxide adjuvant and atomized OVA. Meanwhile, guinea pigs with CVA received oral HCZP (at dosages of 0.571, 0.285 and 0.143 g/kg bodyweight). The number of coughs induced by aerosol capsaicin was recorded, and the airway hyperresponsiveness (AHR) of CVA guinea pigs was detected with the FinePointe series RC system. H&E staining of lung tissues was performed to observe pathological changes. ELISA was used to detect inflammatory cytokines. qRT-PCR and western blotting analyses were used to detect the expression of Th1-specific transcription factor (T-bet), Th2-specific transcription factor (GATA3), and Toll-like receptor 4 (TLR4) signal transduction elements. These methods were performed to assess the protective effects and the potential mechanisms of HCZP on CVA. RESULTS: Great changes were found in the CVA guinea pig model after HCZP treatment. The number of coughs induced by capsaicin in guinea pigs decreased, the body weights of guinea pigs increased, and inflammation of the eosinophilic airway and AHR were reduced simultaneously. These results indicate that HCZP has a significant protective effect on CVA. A pharmacological study of HCZP showed that the levels of interleukin-4 (IL-4) and IL-5 and tumour necrosis factor-α (TNF-α) in serum decreased. The amount of interferon-γ (IFN-γ) increased, mRNA and protein expression of TLR4 and GATA3 weakened, and mRNA and protein expression of T-bet increased. CONCLUSIONS: HCZP ameliorated the symptoms of guinea pigs with CVA induced by OVA by regulating the Th1/Th2 imbalance and TLR4 receptors.