Alcalosis

Pharmacological studies document bronchodilatory and antitussive (cough-suppressing) activity for A. spectabilis extracts in preclinical models. The plant's leaves are recognized as expectorant in traditional medicine across Nepal and India. The 2021 pharmacological review confirms both activities as in vivo–evidenced.

Ajwain has documented bronchodilatory effects in human asthmatic patients, confirmed by a published clinical study comparing its extract to theophylline. In vitro and animal data additionally support antitussive and airway-relaxant properties. Traditional Ayurvedic use for bronchial complaints aligns with these findings.

Andrographis paniculata has meaningful clinical evidence for acute respiratory tract infections including acute bronchitis. A 2023 systematic literature review (Pharmaceuticals, Basel) classified Andrographis among four herbal medicines with moderate-to-high quality clinical evidence for acute uncomplicated respiratory tract infections, acting via immunomodulation, antiviral, and antipyretic mechanisms. Multiple clinical trials and systematic reviews support its use.

Astragalus (Astragalus membranaceus) has clinical evidence for bronchial asthma prevention in children, with a clinical study showing it reduced asthma recurrence and demonstrated superior effects when combined with conventional treatment. It is widely used in TCM for lung qi deficiency patterns associated with asthma and recurring bronchitis, and has immunomodulatory effects documented in multiple studies.

Black cumin (Nigella sativa) seed has clinical evidence for bronchial asthma, with multiple clinical trials and a dedicated literature review (PubMed 2018) confirming bronchodilatory and anti-inflammatory effects. A randomized controlled trial showed N. sativa supplementation improved lung function parameters and cytokine balance in partly controlled asthma patients. Its active constituent nigellone has demonstrated prophylactic effects in asthma and bronchitis.

Boswellia (Boswellia serrata) has clinical evidence specifically for bronchial asthma. A double-blind, placebo-controlled clinical trial published in the European Respiratory Journal found that 300 mg three times daily of Boswellia extract for 6 weeks significantly improved peak expiratory flow rate and reduced asthma symptoms and exacerbations compared to placebo. Its active boswellic acids inhibit 5-lipoxygenase, a key enzyme in leukotriene-driven bronchial inflammation.

Boswellic acids are the primary active constituents of Boswellia serrata, responsible for clinical evidence in bronchial asthma through potent inhibition of 5-lipoxygenase, the enzyme driving leukotriene synthesis in bronchial inflammation. Clinical trials using Boswellia extracts standardized to boswellic acids have shown significant improvements in peak expiratory flow, asthma attack frequency, and eosinophil counts versus placebo.

Caterpillar mushroom is a common name for Cordyceps sinensis, which has documented clinical evidence for bronchial conditions including chronic bronchitis, COPD, and asthma. A 2024 RCT in Frontiers in Pharmacology specifically studied this mushroom in chronic bronchitis patients. A meta-analysis confirmed improvements in FEV1 and FEV1/FVC ratios in COPD with adjunctive Cordyceps use.

Cineole (1,8-cineole/eucalyptol) has specific clinical trial evidence for acute bronchitis. A double-blind, placebo-controlled multicenter RCT in 242 patients with confirmed acute bronchitis found 3×200 mg/day cineole orally for 10 days significantly improved the Bronchitis Sum Score by day 4 (p=0.0383) and significantly reduced cough frequency (p=0.0001). It also reduces exacerbation rates in COPD and allows steroid reduction in asthma patients.

Forskolin has been studied in multiple clinical trials for asthma, demonstrating bronchodilatory effects via cAMP-mediated smooth muscle relaxation. One single-blinded RCT found oral forskolin reduced asthma attack frequency significantly more than sodium cromoglycate. Coleus forskohlii has also been used historically in Ayurveda for respiratory disorders.

Cordyceps sinensis has both traditional use in TCM for lung conditions and emerging clinical evidence for chronic bronchitis and COPD. A 2024 RCT published in Frontiers in Pharmacology examined Cordyceps sinensis (Hirsutella sinensis, Cs-C-Q80) in chronic bronchitis. A meta-analysis confirmed adjunctive Cordyceps use improved lung function parameters (FEV1% predicted, FEV1/FVC ratio) in COPD patients. Clinical studies also showed improved quality of life in moderate-to-severe asthma.

Echinacea species have documented clinical evidence for acute upper respiratory tract infections including bronchitis-associated conditions, primarily through immunomodulatory mechanisms. A 2023 Pharmaceuticals systematic review classified Echinacea among four herbal medicines with evidence of clinical effectiveness in treating acute uncomplicated respiratory infections. Multiple systematic reviews confirm modest but consistent reductions in cold and bronchitis duration and severity.

Echinacea purpurea is the most clinically studied of the Echinacea species for acute respiratory infections including bronchitis. A 2023 mechanistic systematic review in Pharmaceuticals confirmed its immunomodulatory mechanism in acute respiratory infections. Multiple RCTs and meta-analyses show reductions in respiratory illness incidence and duration when taken preventively or at illness onset.

Eucalyptus (Eucalyptus globulus) and its principal constituent 1,8-cineole (eucalyptol) have clinical evidence for bronchial conditions. A placebo-controlled double-blind trial in 242 patients with confirmed acute bronchitis found cineole (3×200 mg/day) significantly improved a composite Bronchitis Sum Score and reduced cough frequency within 4 days (p=0.0001). Additional double-blind studies support its use in asthma as a steroid-sparing agent.

Fritillary alkaloids demonstrably relax bronchial smooth muscle and inhibit MUC5AC mucin gene expression in human respiratory epithelium. Multiple preclinical studies and pharmacological reviews confirm antitussive and bronchodilatory activity. Clinical use in TCM for bronchial conditions is longstanding and supported by pharmacological evidence.

G. littoralis (Radix Glehniae) is documented in the Chinese Pharmacopoeia and clinical TCM practice for chronic bronchitis. Pharmacological studies confirm antitussive and anti-inflammatory activity. Extracts suppress key inflammatory mediators (NO, PGE2, TNF-α, IL-1β) via NF-κB/MAPK inhibition in cellular and animal models.

H. spicatum rhizome extracts demonstrate bronchodilator and antihistaminic activity in preclinical models, affirming traditional use for bronchial conditions. In guinea pig studies, both aqueous and ethanolic extracts attenuated histamine-induced bronchospasm in a dose-dependent fashion. The plant is classified in Ayurveda as 'Shwasahara mahakashaya dravya,' indicating a primary bronchial action.

Honey has documented efficacy for reducing cough and improving respiratory symptoms in upper respiratory tract infections, supported by a 2018 Cochrane systematic review of six RCTs (899 children). Honey probably reduces cough symptoms more than placebo and was more effective than salbutamol at relieving cough for up to three days. Traditional use of honey for bronchial complaints spans millennia across multiple cultures.

Indian Frankincense (Boswellia serrata) has clinical evidence for bronchial asthma from a double-blind, placebo-controlled trial showing significant improvement in peak expiratory flow rate, asthma symptoms, and eosinophil parameters versus placebo (70% vs 27% improvement). Its boswellic acids inhibit 5-lipoxygenase, blocking leukotriene synthesis that drives bronchial inflammation and smooth muscle contraction.

Ivy leaf (Hedera helix) extract has documented clinical evidence for acute bronchitis and upper respiratory tract infections, as well as bronchial asthma. Systematic reviews of randomized controlled trials support its secretolytic and spasmolytic effects on bronchial smooth muscle. A 2021 updated systematic review from NCBI covered RCTs in adults and children with bronchitis, confirming clinical improvements with ivy leaf preparations.

NAC (N-acetyl-L-cysteine), which is deacetylated to L-cysteine in the body, is a well-established mucolytic agent used globally to reduce mucus viscosity in bronchial diseases. It breaks disulfide bonds in mucoproteins and also exerts antioxidant and anti-inflammatory effects on bronchial epithelium. It is licensed as a mucolytic in numerous countries.

Licorice root (Glycyrrhiza glabra) has been used across traditional medical systems—including TCM, Ayurveda, and ancient Western herbalism—for respiratory conditions including bronchitis, cough, and asthma. Its principal constituent glycyrrhizin demonstrates anti-inflammatory effects, while saponins provide expectorant activity. A comprehensive 2021 MDPI/PubMed review confirmed its demulcent, expectorant, and anti-inflammatory properties relevant to obstructive respiratory diseases and COPD.

Malabar nut (Adhatoda vasica/Justicia adhatoda) is one of the most important Ayurvedic and Unani respiratory herbs, with over 2,000 years of traditional use for bronchitis, asthma, and cough. Its primary alkaloid vasicine demonstrates bronchodilatory activity comparable to theophylline in preclinical studies. Limited clinical trials suggest benefits for bronchitis and asthma symptoms; its semi-synthetic derivative ambroxol is a globally-approved bronchitis mucolytic.

The antispasmodic and bronchodilator effects of A. vulgaris have been pharmacologically demonstrated to operate via dual blockade of muscarinic receptors and calcium influx on airway smooth muscle. This is one of the plant's better-characterized pharmacological mechanisms. The major constituent 1,8-cineole additionally provides mucolytic and broncholytic activity. Evidence is preclinical; no human clinical trials exist.

NAC is one of the most rigorously studied mucolytic agents for bronchial conditions. Multiple meta-analyses of randomized controlled trials demonstrate that oral NAC significantly reduces exacerbation frequency in chronic bronchitis and COPD. A 2019 meta-analysis of 11 RCTs (n=1,564) found NAC reduced chronic bronchitis exacerbations with RR=0.81 (95% CI 0.69–0.93, p=0.004). It acts as a mucolytic by cleaving disulfide bonds in mucin and as an antioxidant via glutathione replenishment.

Nigella seed (Nigella sativa) has both traditional and clinical evidence for bronchial asthma and bronchitis. Clinical studies showed bronchodilatory and lung function improvements in asthmatic patients, and a systematic review confirmed antitussive, antihistaminic, and bronchodilatory properties across preclinical and clinical research. Its active constituent nigellone has specific prophylactic action in asthma and bronchitis.

Omega-3 fatty acids reduce bronchial inflammation through leukotriene pathway modulation, producing less potent LTB5 in place of pro-inflammatory LTB4. Epidemiological studies associate omega-3 intake with reduced asthma incidence in children, and a Cochrane review found possible lung function improvement in cystic fibrosis at doses of 300–5,400 mg/day EPA/DHA.

Several early Indian clinical trials and controlled animal studies support P. kurroa's role in bronchial conditions. The compound androsin inhibits platelet-activating factor (PAF)-induced bronchial obstruction. One placebo-controlled RCT (Doshi et al., 1983) showed mixed results, and a Cochrane-referenced systematic review rated the evidence as weak but present.

Plantago lanceolata and P. major demonstrate bronchospasmolytic, expectorant, and anti-inflammatory effects on the bronchial mucosa. Commission E, ESCOP, and clinical studies support their use for bronchial catarrh. A clinical trial showed P. major syrup significantly reduced bronchitis severity scores.

Plantain herb has preclinical and clinical evidence relevant to bronchial health, including an RCT demonstrating reduction of bronchitis symptoms, sputum production, and bronchial irritation. In vitro studies confirm that P. lanceolata extract reduces bradykinin-mediated inflammatory responses in bronchial epithelial cells and modulates NF-κB signaling.

Platycodon root is one of the best-documented herbs for bronchial conditions in both traditional and modern pharmacological literature. Platycodin saponins enhance mucociliary clearance, reduce bronchial inflammation via TLR4/NF-κB pathways, and have been studied in chronic bronchitis models. Traditional use across Chinese, Korean, and Japanese medicine is extensive.

Purslane has documented bronchodilatory properties, confirmed in a clinical trial showing pulmonary function improvements in asthma patients and supported by in vitro evidence of smooth muscle relaxation via beta-adrenoceptor stimulation. Traditional use for cough, shortness of breath, and excess mucus is extensively documented globally.

Serratiopeptidase has clinical evidence for supporting bronchial health through its combined mucolytic and anti-inflammatory properties. It reduces sputum viscosity and elasticity in chronic airway disease (Nakamura et al., 2003) and inhibits elastase-driven bronchial injury. Clinical use in bronchial conditions has been documented in Japan and Europe for over 40 years.

Bronchodilatory and antitussive (anti-cough) activities are documented for S. indicus in multiple preclinical studies, and traditional use for cough and bronchial conditions is well-established in Ayurveda and Siddha medicine.

SPMs are endogenously produced in airway tissue and reduce bronchial hyperreactivity, mucus hypersecretion, and inflammatory cell infiltration. Reduced SPM levels have been detected in human bronchial tissue and sputum in inflammatory airway diseases. SPMs act on bronchial epithelial cells and infiltrating leukocytes via specific surface receptors.

Sulforaphane induces antioxidant phase II enzymes in bronchial mucosa via Nrf2, attenuating pollutant- and allergen-driven bronchial inflammation. Human studies confirm airway mucosal enzyme induction. Animal data show reversal of bronchial remodeling and goblet cell metaplasia in chronic allergic airways disease.

Theophylline is a naturally occurring methylxanthine found in tea leaves, cacao, and other plants that has been used clinically as a bronchodilator for bronchial asthma and chronic bronchitis for decades. It acts by inhibiting phosphodiesterase and blocking adenosine receptors, relaxing bronchial smooth muscle. It is listed in pharmacopoeias and used worldwide as a standard pharmaceutical treatment for obstructive bronchial diseases.

Thyme (Thymus vulgaris) has both robust traditional use and meaningful clinical evidence for bronchial health. Clinical studies demonstrate that a combination of thyme and primrose root extract significantly reduced bronchitis symptoms in acute bronchitis patients. Thyme extract relaxes airway smooth muscle (bronchodilation) and its active constituent thymol provides antimicrobial and expectorant effects. A meta-analysis confirmed strong evidence for thyme/ivy/primrose combinations in cough and URTI.

Thymoquinone (TQ), the primary bioactive constituent of Nigella sativa, has demonstrated anti-asthmatic, anti-inflammatory, antihistaminic, and bronchodilatory effects in preclinical and some clinical studies. It suppresses NF-κB, reduces IL-4, augments IFN-γ, and inhibits mast cell histamine release, directly addressing the bronchial inflammatory cascade in asthma. Clinical trials of Nigella sativa (TQ's source) in asthma patients have shown improved lung function and cytokine balance.

Thymus vulgaris preparations have been evaluated in multiple prospective double-blind, placebo-controlled clinical trials for acute bronchitis with productive cough, showing significant reductions in cough frequency and severity. The German Commission E and EMA HMPC have recognised thyme-based preparations for bronchitis and upper respiratory catarrh. Thymol exerts direct secretolytic effects on respiratory tract cells, supporting mucus clearance.

Tylophora has been the subject of several controlled human trials specifically in bronchial asthma, making it one of the better-studied Ayurvedic plants for this indication. Studies show improvements in lung function parameters including FEV1, vital capacity, and peak expiratory flow rates. Urinary 17-ketosteroid levels increased and eosinophil counts declined following administration, suggesting a corticosteroid-like or adrenal-stimulating mechanism.

Vasicine is a quinazoline alkaloid from Adhatoda vasica (Malabar nut/Justicia adhatoda) with documented bronchodilatory activity both in vitro and in vivo comparable to theophylline. It has antispasmodic, expectorant, and anti-inflammatory effects demonstrated in preclinical studies. The semi-synthetic derivative ambroxol, developed from vasicine, is a globally-approved mucolytic/secretolytic agent used in bronchitis treatment. Vasicine has been used in Ayurvedic and Unani medicine for over 2,000 years for bronchitis and asthma.

Vasicinone is the principal metabolite of vasicine from Adhatoda vasica, demonstrating bronchodilating activity in vitro and contributing to the plant's established bronchial pharmacology. It and vasicine together define the bronchospasmolytic profile of Adhatoda vasica preparations used in Ayurvedic bronchitis and asthma treatment. The semi-synthetic mucolytic ambroxol, derived from vasicine/vasicinone chemistry, has extensively documented clinical use in bronchitis.

Vitamin A is essential for maintaining the integrity of bronchial epithelium. Deficiency leads to squamous metaplasia of the respiratory epithelium, including necrotizing tracheobronchiolitis, which reverses upon repletion. Observational data from NHANES associate higher vitamin A intake with better spirometric lung function parameters in populations without chronic respiratory disease.

Vitamin C is actively transported into the bronchial epithelium via SVCT2 and GLUT2 transporters, where it acts as an antioxidant against reactive oxygen species generated in the airways. Clinical evidence shows supplementation at ≥400 mg/day can improve FEV1% in patients with chronic obstructive pulmonary disease. Evidence in exercise-induced bronchoconstriction is suggestive but limited by small trial sizes.

Animal studies demonstrate that A. millefolium extract inhibits carbachol and potassium-induced bronchoconstriction in guinea pig tracheal preparations, producing bronchodilatory effects. Traditional use for respiratory conditions is widespread, and the plant has expectorant properties attributed to its essential oil.

In TCM, Anemarrhena is classified as moistening the lungs and relieving cough, with documented use for dry cough, bronchitis, and lung heat conditions. The rhizome's expectorant, antitussive, and antibacterial properties support its traditional bronchial indications.

Aster root (Zi Wan) has over 2,000 years of documented use in TCM as an expectorant and antitussive targeting the bronchi. It is a classic ingredient in formulas such as Zhi Sou San, which address bronchial congestion and cough. Modern pharmacological work has focused primarily on animal models rather than controlled human bronchial trials.

Bamboo preparations are used in TCM and Ayurveda for bronchial conditions including cough, bronchitis, and phlegm obstructing the bronchi. Tianzhuhuang (tabasheer) is used clinically in TCM for acute bronchitis and pneumonia. Bamboo sap enters the lung meridian and is prescribed for bronchial phlegm-heat.

Black spruce resin has been traditionally smeared on the chest and its needles used in teas and inhalations to address bronchial diseases and coughs. The essential oil is rich in camphene and bornyl acetate, which are considered expectorant and mucolytic. The British Herbal Pharmacopoeia and aromatherapy traditions cite it for bronchial congestion.

Boneset is traditionally used to support bronchial health through its expectorant and anti-inflammatory properties, particularly during acute infections with fever. Historical medical literature including Lockwood (1847) describes it as valuable in bronchitis and catarrhal conditions. Its bitter sesquiterpene lactones and diaphoretic action are proposed to relieve bronchial congestion and inflammation. No clinical evidence specifically for bronchial health exists.

Cardamom is used in Ayurvedic and traditional medicine for bronchial conditions including congestion, bronchial irritation, and respiratory clearance. The volatile oil component 1,8-cineole has pharmacologically documented bronchodilatory and mucolytic properties. No human clinical trials targeting bronchial health as a primary endpoint have been published for cardamom specifically.

Chen Pi is one of the most historically important TCM herbs for bronchial conditions, used to 'dry dampness and transform phlegm' in the Lungs. It is traditionally combined with pinellia and poria for cough with phlegm congestion and chest tightness.

Clove has longstanding traditional use as an expectorant and bronchial soothing agent in Ayurvedic, Chinese, and folk medicine. Eugenol exhibits anti-inflammatory properties relevant to bronchial tissue, and a PMC pharmacological review documents eugenol's use in upper respiratory tract mucosa inflammation.

Coltsfoot (Tussilago farfara) has centuries of traditional use across European herbal medicine as a demulcent and antitussive for bronchitis, coughs, and bronchial congestion, with its mucilage content soothing airway mucosa. Pharmacological studies confirm anti-inflammatory (tussilagone) and antitussive properties. However, clinical trials are severely limited, and the plant contains pyrrolizidine alkaloids (PAs) with hepatotoxic potential that limit modern clinical use.

Elecampane (Inula helenium) has been used in European and Asian herbal traditions for centuries to treat coughs associated with bronchitis, asthma, and whooping cough, classified as an expectorant and mild bronchospasmolytic. Its active constituent inulin and sesquiterpene lactones (including alantolactone) contribute to its mucus-clearing and antimicrobial properties. Evidence is primarily traditional, with limited clinical study data.

Fennel has documented traditional use across multiple pharmacopeial systems as a bronchodilatory and expectorant herb for respiratory complaints. Its volatile oil, especially anethole, is attributed with antispasmodic and mucolytic properties in the bronchi. Clinical human trial evidence for bronchial-specific effects remains absent.

Forsythia is traditionally used in TCM for conditions of the lung meridian including bronchiolitis and upper respiratory infections. It is incorporated into combination preparations used intravenously or orally for bronchiolitis in clinical TCM settings. The evidence base for standalone bronchial use is primarily from traditional practice and preclinical studies.

Ginger (Zingiber officinale) has long-standing traditional use in Ayurveda, TCM, and folk medicine for bronchial conditions including cough, bronchitis, and asthma, attributed to its expectorant, anti-inflammatory, and immunostimulatory properties. Active compounds—gingerols, shogaols, and zingiberene—have demonstrated anti-inflammatory effects relevant to bronchial conditions in preclinical studies. Multiple herbal medicine reviews identify ginger as a respiratory supportive herb.

Glehnia root has a long history of use in TCM for bronchial complaints, particularly chronic bronchitis and cough. It is listed in the Korean, Chinese, and Japanese Pharmacopoeias for such indications. No controlled human trials have been conducted to verify these effects.

Green chiretta has a long tradition of use for bronchial complaints including cough and bronchitis. In TCM it is described as clearing heat from the lungs; Ayurvedic texts indicate its use for cough, tonsillitis, and throat complaints. Modern preclinical data show bronchodilatory and anti-inflammatory activity relevant to bronchial health, but robust human RCT data specific to bronchial disease remain limited.

Grindelia (Gumweed) has traditional use in North American Indigenous medicine and 19th-century American botanical medicine as a bronchospasmolytic and expectorant for bronchitis, asthma, and whooping cough. It is listed in EBSCO's Natural Treatments for Asthma among herbs used by herbalists for bronchial conditions. Its resinous exudate and saponin content are attributed to antispasmodic and mucus-clearing effects.

Gumweed is a common name for Grindelia species, used in North American Indigenous and 19th-century botanical medicine as a bronchospasmolytic and expectorant for bronchitis and asthma. EBSCO's natural medicine database lists it among traditional herbal treatments for asthma. Its resinous diterpene acids and saponins are attributed to antispasmodic and mucus-clearing bronchial effects.

Ho wood is traditionally used in aromatherapy for bronchitis and respiratory tract support. It is described as clearing and purifying for the respiratory tract when diffused or applied topically to the chest. This use is documented in French aromatherapy tradition.

Holly leaves have a documented tradition in European herbalism as an expectorant and for treating catarrh (mucous membrane inflammation of the airways) and chest congestion. The plant contains trace methylxanthines (theobromine, theophylline) that may provide mild bronchodilatory effects.

White horehound (Marrubium vulgare) has been used since antiquity in European herbal medicine as an expectorant and bronchospasmolytic for bronchitis, coughs, and bronchial mucus congestion. Its active compound marrubiin is documented to have expectorant and antispasmodic effects on bronchial smooth muscle. EBSCO's natural medicine database lists it among herbs with traditional support for bronchitis treatment.

Hyssop (Hyssopus officinalis) has extensive traditional use in European and Middle Eastern herbal medicine as an expectorant and bronchial tonic for bronchitis, chronic mucus congestion, and respiratory infections. It is commonly classified as an expectorant and mild antispasmodic for bronchial smooth muscle in traditional herbalism. Evidence is primarily traditional; clinical trials are limited.

H. italicum is traditionally used as an expectorant and for bronchial conditions including bronchitis and cough. Its EO has demonstrated in vitro antibacterial activity against respiratory pathogens relevant to bronchial health. Traditional use across Mediterranean Europe is well-documented.

Lily bulb has been used for centuries across Asia to treat bronchitis, pertussis, and cough. The Chinese Pharmacopoeia lists it for moistening the lungs and relieving cough. Saponin-enriched fractions demonstrate mild expectorant activity in animal airway preparations. In vitro anti-inflammatory data in cigarette-smoke models support a plausible mechanism, but no human bronchial trials have been conducted.

Lobelia (Lobelia inflata) has traditional use in Native American medicine and 19th-century American botanical medicine as a respiratory stimulant and expectorant for asthma and bronchitis. Its active alkaloid lobeline stimulates breathing, supports the cough reflex, and promotes mucus clearance from bronchial tubes. Clinical trial evidence is limited; use requires careful dosing due to narrow therapeutic window.

Marshmallow root (Althaea officinalis) has extensive traditional use across European and Middle Eastern herbalism as a demulcent and emollient for bronchial mucosa, employed for dry irritating coughs, bronchitis, and bronchial irritation. Its high mucilage content physically coats and soothes inflamed respiratory mucous membranes. EBSCO and multiple herbal medicine reviews list it among bronchitis supportive remedies. German Commission E has approved it for irritation of oral and pharyngeal mucosa and dry cough.

Monk fruit has a long-documented history of use in TCM for bronchial conditions including cough, bronchial irritation, and congestion. Historical texts describe it as clearing heat and phlegm from the lungs. Preliminary pharmacological evidence shows anti-inflammatory and antioxidant properties in mogrosides, but no human clinical trials specific to bronchial health have been conducted.

Mulberry root bark (Sang Bai Pi) is documented in the Chinese Pharmacopoeia specifically for cough, wheezing, and phlegm obstruction in the Lungs, corresponding to bronchial conditions. Mulberry leaf addresses dry cough and early respiratory infection. Both are formally listed TCM indications.

Mullein (Verbascum thapsus) has a centuries-long history in European and Native American herbal medicine as an expectorant and demulcent for bronchial conditions including bronchitis, coughs, and bronchial congestion. Its mucilaginous constituents coat and soothe irritated bronchial membranes, while saponins act as natural expectorants to loosen mucus. Laboratory studies confirm anti-inflammatory and antimicrobial properties, but large human clinical trials are lacking.

C. rotundus is used in Ayurveda and Unani medicine for bronchitis and cough (antitussive use). Its antispasmodic, anti-inflammatory, and antimicrobial properties provide mechanistic support for bronchial health applications. Traditional documentation is consistent across multiple ethnomedicinal systems.

Orange peel and its essential oil have extensive traditional use across Chinese, Ayurvedic, and European medicine for bronchial health, cough relief, and respiratory congestion. Vitamin C from orange also supports mucosal immunity relevant to bronchial protection. Some clinical evidence for vitamin C in reducing severity of respiratory infections is relevant.

P. foetida is used across northeastern India and in Chinese traditional medicine for respiratory disorders including bronchitis, asthma, and coughs. The plant has an expectorant action aiding phlegm elimination. Antitussive activity has been demonstrated preclinically in cats.

Pear has long-standing use in East Asian traditional medicine for bronchial conditions, including cough and bronchial irritation. Pear syrup is a documented traditional remedy across China for bronchial complaints. Pear's flavonoids (quercetin, rutin) show some potential for reducing allergic airway responses in mechanistic research.

Pennycress has been used in traditional herbal medicine as an expectorant to help clear mucus from the respiratory tract. The seeds were particularly used in Tibetan medicine for conditions involving pus in the lungs. The plant has occasionally appeared in herbal formulas for bronchial irritation and coughs.

Peppermint (Mentha × piperita) and its principal constituent menthol have traditional use for bronchial complaints including coughs and bronchitis through topical and inhalation routes, with menthol acting as a counterirritant and mild expectorant that reduces cough reflex sensitivity. Multiple respiratory herbal medicine reviews include peppermint as a bronchial supportive herb. Its volatile oil provides antimicrobial activity against respiratory pathogens.

Perilla leaf and seed have documented traditional use in TCM for bronchial conditions including chronic bronchitis, bronchial asthma, and excessive phlegm. A described clinical study of chronic bronchitis used perilla leaf-ginger infusion over 10-day courses. The herb is a constituent of saiboku-to, the classic Japanese Kampo formula for bronchial asthma.

Pine has been used traditionally across Native American cultures, ancient Greek medicine (Hippocrates), and medieval European herbalism for bronchial conditions including bronchitis. Pine steam inhalation and pine resin-based preparations were historically used to clear bronchial congestion and fight respiratory infections.

Polygala root has longstanding traditional use in TCM for bronchial conditions including productive cough and bronchitis. Animal studies using validated bronchitis models confirm antitussive, expectorant, and anti-inflammatory effects. The Chinese Pharmacopoeia formally includes bronchial/respiratory indications.

In Traditional Chinese Medicine, dried pomelo peel (Huajuhong) is a canonical remedy for dissolving phlegm, relieving cough, and regulating lung Qi. It features in classical TCM formulas for respiratory congestion. The peel's essential oils and flavonoids have antimicrobial and anti-inflammatory properties consistent with bronchial support.

Poppy—especially P. rhoeas and P. somniferum—has extensive traditional use across Middle Eastern, Turkish, European, and Ayurvedic medicine for bronchial conditions including bronchitis and chest congestion. Antitussive alkaloids (codeine, noscapine) from P. somniferum are pharmaceutically validated cough suppressants.

Quillaja bark has a long history of traditional use in Chilean and Andean folk medicine for respiratory complaints, including cough and bronchitis. The saponin content is thought to stimulate the production of more watery mucus in the airways, facilitating expectoration. No controlled human clinical trials have confirmed this effect specifically for bronchial health.

Red clover flowers have a centuries-old traditional use across European, Chinese, and North American herbal medicine as a remedy for bronchial conditions including bronchitis, whooping cough, and asthma. It was used as an expectorant and antispasmodic to relax bronchial smooth muscle and promote mucus clearance. No clinical trial evidence for bronchial health exists.

Red root's classification as an expectorant, antispasmodic, and mucolytic herb places it in longstanding use for general bronchial conditions including mucus congestion, bronchospasm, and inflammatory airway states. This is recorded in Eclectic, Native American, and modern herbal traditions.

Saw palmetto has a well-documented traditional and 19th-century eclectic medical history as an expectorant and mucous membrane tonic for bronchial and respiratory complaints. Native Americans used the berries for respiratory infections, and 19th-century physicians prescribed it for chronic bronchial coughs, laryngitis, and asthma. No modern clinical trials exist for respiratory indications.

In TCM, schisandra is a primary herb used to 'inhibit the leakage of Lung qi,' stop cough and wheeze, and address chronic bronchial insufficiency. Traditional Chinese texts and the Shen Nong Ben Cao Jing list it for cough, asthma, and phlegm. The MSKCC monograph confirms its traditional TCM use for lung conditions, though clinical trials have not been conducted.

Slippery elm has a documented traditional role in soothing the respiratory mucosa, particularly for dry, unproductive coughs and throat irritation. Its mucilage is thought to coat and soothe inflamed bronchial and pharyngeal membranes. Clinical evidence is limited and mostly confined to sore throat lozenges; no bronchial-specific trials have been conducted.

Fresh spruce shoots and spruce needle oil have been used by medical herbalists and in registered herbal medicines to soothe bronchial irritation and coughs. The volatile oil is rich in terpenes including bornyl acetate and camphene, which have mucolytic and antiseptic properties. UK registered herbal medicines containing Norway spruce are used for cough relief based on traditional use.

Stillingia has an established traditional role supporting bronchial health, used as an expectorant and mucosal stimulant for chronic bronchial complaints by Eclectic physicians and Native American healers. No human clinical studies have been conducted.

Sunflower seeds have a long-documented traditional use for bronchial, laryngeal, and pulmonary affections. The seeds and oil have been classified as expectorants in historical herbal monographs (including A Modern Herbal). Traditional preparations include seed decoctions and tinctures used specifically for bronchial conditions.

Swertia chirayita is documented across Ayurvedic, Siddha, and Tibetan traditional medicine systems as a treatment for bronchial asthma and cough. The plant's airways-modulatory effects have been noted in pharmacological reviews. However, robust human clinical trials for bronchial indications are lacking.

Aster tataricus root is classified in TCM and Japanese Kampo medicine as a primary stimulant expectorant for the bronchial system, documented for over 2,000 years. Triterpene saponins and shionone are the mechanistically active bronchial constituents. Smooth muscle relaxation in the bronchi has been demonstrated in preclinical models. No human bronchial health trials exist.

Watercress is traditionally used across multiple cultures and medical systems as an expectorant and bronchial remedy, with documented use for bronchial conditions dating to ancient Greek medicine. The botanical medicine compendium and RxList cite use for swollen breathing passages. Mechanistic support comes from its isothiocyanate and vitamin C content.

Yerba santa (Eriodictyon californicum) has traditional use among Indigenous California peoples and in 19th-century American botanical medicine as an expectorant, bronchospasmolytic, and bronchial tonic for coughs, bronchitis, and asthma. EBSCO's Natural Treatments for Bronchitis lists yerba santa among herbs with traditional support for bronchial conditions. Its active flavonoids including eriodictyol provide anti-inflammatory and expectorant effects.