I live in the beautiful Okanagan valley of southern British Columbia, which lies on the northeast edge of the North Cascade mountain range in Washington State. The environment resembles northern California’s Napa Valley. The climate is a complex tapestry of semi-arid desert mixed in with fertile soil for orchards and vineyards and temperate forests of pine, spruce, and fir trees. Okanagan Lake splits the valley and attracts tourists for sunshine, wine, and fruit. I am truly blessed to able to work and play in such a beautiful geographical region.

However, the drastic change in weather patterns is a sobering reality of the world we now live in. Climate change affects both air quality and purity everywhere. Wildfires have ravaged the Okanagan valley for two decades. The Okanagan Mountain Park fire of 2003 was a firestorm that devoured homes and habitat on a scale never seen before. The wildfire season of 2018 blanketed the valley with plumes of thick smoke that never left the area for over two months. The smoke was so thick and putrid that it resembled a foggy day in London. And to excuse the vernacular, but you could literally cut it with a knife. The air was hot and dry, and breathing was labored and difficult.

Few would argue that the quality of air we breathe is getting worse. Air pollution is a worldwide problem that affects millions of people. Air contaminants from human activity include industrial emissions, auto traffic, coal burning, home heating, shipping, construction, agricultural work, war and fire incidents. Also natural contributions to air pollution can be from earthquakes, volcanic activity, forest and wildfires, and extreme temperature fluctuations. Chemical air pollution can contain inorganic chemicals such as ozone, carbon monoxide, nitrogen dioxide, and sulfur dioxide and organic chemicals such as poly and mono-cyclic hydrocarbons, including benzene, toluene, industrial petrochemicals, other aliphatic chemicals, and toxic heavy metals including mercury, cadmium and asbestos The most harmful forms of particulate matter are less than 10 micrometers in diameters. These particles are inhaled and can affect the bronchi and bronchioles but the action of the mucociliary tract usually helps to expel them. Particles less than 2.5 micrometers in diameter pose a particular problem because they can be inhaled and lodged deep in lung tissue. Ultra-fine particles are less than 0.1 micrometer in diameter, and they can actually be absorbed into systemic circulation and lodged in tissues throughout the body.¹

Air pollution can contribute to airway and lung problems, including asthma, chronic obstructive pulmonary disease (COPD), emphysema, respiratory infections, chronic bronchitis and sinusitis, and lung cancer. Air pollution can also contribute to systemic disease, including cardiovascular disease with heart attacks and stroke. Air pollution can also be particular bothersome to the developing fetus in pregnant women, young children, and the frail elderly. Sometimes the effect of environmental exposure is latent on the body and will manifest as disease years and decades later.¹

As a naturopathic physician I am always looking for natural ways to improve lung and respiratory function. I have been using a lung formula that incorporates lobelia, peppermint, fenugreek, and wild cherry bark. It is a proprietary custom formula that I blend myself and get professionally encapsulated. I do not sell it commercially, but just dispense it in the office to patients. I have tinkered with the formula and have been happy with the current formulation. Most patients like the effects, and it seems to work well. At the very least it is a good, natural expectorant that helps to remove mucous and phlegm from the lungs. At its best it can improve lung function as well as a metered dose inhaler or mdi in asthmatics and those with chronic bronchitis.

Lobelia (Lobelia inflata) is an annual or biennial plant that grows up to one meter in height and is native to parts of North America. The small distinctive blue and purple petals and ease of growth make this a gardener’s favorite. Some native Indian cultures used to smoke the aerial parts of the plant and used it in indigenous medicine. Lobelia contains 0.48% piperidine alkaloids composed mainly as lobeline.² Other constituents include lobelanine, isobelanine, lobelandine, apigenin, quercetin, coumarins, glycosides and flavonoids.³ Lobeline shares some of the same chemical characteristics as nicotine and extracts of lobelia can even taste like a cigarette. As such, lobelia has been used as a smoking deterrent. Lobelia is a good expectorant and can help improve lung function. Lobeline may stimulate pulmonary sensory afferent nerves. Lobelia may stimulate chemoreceptors and mechano-receptors in juxtapulmonary capillaries as well as the carotid arteries. This may in turn stimulate the phrenic nerve and improve vascular tone to lung tissue. Lobeline can improve the cough reflex, promote expectoration, and relax bronchial smooth muscle.⁴ Other possible mechanisms suggest that lobeline decreases lung inflammation and edema through modulation of nuclear factor-kappa beta. This inhibits several pro-inflammatory pathways, including nitric oxide, cyclooxygenase-2, tumor necrosis factor and inteleukin-6.⁶ Lobeline has also demonstrated to decrease oxidative reactive species in lung tissue. It should be mentioned that high doses of lobelia and lobeline can cause nausea and vomiting. Excessive doses of lobelia and lobeline have been reported to cause respiratory suppression, heart arrhythmias, mental confusion, and stupor.^2,3

Fenugreek (Trigonella faenum-graecum) is an herb and culinary spice that has been used as a carminative and digestive aid, hormone balancer, hypoglycemic aid, and as a galactogogue. Fenugreek seeds contains alkaloids, including trigonelline, steroidal saponins, bitter principles, volatile oils and up to 30% mucilage. It is a good demulcent and vulnerary. Fenugreek has mild expectorant qualities and may help improve lung function.⁷ One study on mice showed that Trigonella foenum-graecum has a significant anti-inflammatory effect on lung tissue. Researchers concluded that it may prove to be an efficacious therapeutic regent on allergic asthma.⁸

Peppermint (Mentha piperta) is a common aromatic herb that is widely used as an herb in cooking and teas and also a wide variety of over-the-counter cosmetics and analgesic counter-irritant medicines. The plant contains up to 2.0% volatile oil in all part, including the stalks, stems and leaves, in addition to tannins and bitter principles. Menthol makes up to 50% of the content of the volatile oil along with jasmone and menthone and minor esters.⁹ Mint and menthol can improve lung function. In one small study, supplementation of peppermint oil in twelve male volunteers improved exercise tolerance and lung function parameters.¹⁰ In another small study with 23 patients, nebulized menthol helped to reduce airway hyper-responsiveness in cases of mild asthma without improving lung parameters on spirometry measurement of forced expiratory volume. The patients that consumed menthol had less wheezing episodes and consumed less bronchodilator medicine than the control group.¹¹ It should also be mentioned that large dose of menthol can cause airway irritation and asthma in some individuals.

Wild cherry bark (Prunus serotina) has been popular in folk medicine as an expectorant, antitussive, antispasmodic and anti-inflammatory. It was a popular ingredient in cough syrups and bronchial formulas.² The active ingredients in wild cherry bark include cyanogenic glycosides like prunasin, amygdalin, maldelonitrile and hydrocyanic acid, benzaldehyde, volatile oils, tannins, coumarin, a resin mainly as scopletin, and trace minerals. The hydrocyanic acid content varies from 0.23 to 0.32% of the dry bark. Wild cherry bark has demonstrated a sedative effect on the cough reflex.¹²

The combination of herbs in Resperex is a good expectorant that helps to expel mucous and phlegm from the broncho-pulmonary tract and sinuses. It can help to relax the bronchi smooth muscles and improve air flow. In some patients I have measured an approximate 25% to 30% increase in office based spirometry as measured by FEV (forced expiratory volume). It can be a good adjunct to the use of bronchodilator medicine. For some patients it seems to work as well as mdi inhaler. I have used it with patients on beta-agonist inhalers as well as inhaled corticosteroids. I have modified with the formula by adding licorice (Glycyrrhiza glabra), mullein (Verbascum Thapsus), magnesium, potassium iodide, and guaifenesin or glyceryl guaiacolate to the formula with no appreciable change in benefits. I seem to like the formulation that has a small amount of guaifenesin and potassium iodide. I have additionally recommended patients to take supplemental magnesium and N-acetyl cysteine.

No one can deny that the quality of the air we breathe is important for human health. As climate change and air pollution increases the quality of the air we breathe decreases. In true ecological fashion, we can understand the inter-relatedness of environmental disasters in one region of the planet affecting the air quality in another region. As climate change and air pollution worsens, lung disease increases. The quest to find some natural based supplements to improve lung function has been an interesting forethought. Resperex, a mixture of the herbs lobelia, fenugreek, peppermint, and wild cherry bark is an attempt to help clear the airways and improve lung function.

References

1. Kim D et al. Air pollutants and early origins of respiratory diseases. Chronic Dis Transl Med. 2018 Jun; 4(2):75-94.
2. Leung A. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, John Wiley and Sons. New York, NY, 1980.
3. Yang S et al. Chemical constituents of Lobelia chinensis, Fitoterapia. 2014; 93:168–74.
4. Stansbury J et al. The Use of Lobelia in the Treatment of Asthma and Respiratory Illness. Journal of Restorative Medicine. 2013 October 2(1):94-100.
5. Li KC et al. Lobeline Improves Injury via Nuclear factor-kB-signaling Pathway and Oxidative Stress. Respir Physiol NeuroBiol. 2016 225:19-30.
6. Li KC et al. Anti-oxidative and Anti-Inflammatory Effects of Lobelia Chinensis in Vitro and in Vivo. Am J Chin Med. 2015; 43(2): 269-87.
7. Yadav Umesh CS and Baquer NZ. Pharmacogical Effects of Trigonella Foenum-Graecum L. In Health and Disease. Pharm Biol. 2014 Feb; 52 (2):243-54.
8. Piao CH et al. Trigonella Foenum-Graecum Alleviates Airway Inflammation of Allergic Asthma in Ovalbumin-Induced Mouse Model. Biochem Biophys Res Commun. 2017 Jan 22, 482(4); 1284-1288.
9. Sun Z. Chemical Composition and Anti-Inflammatory, Cytotoxic and Antoxidant Activities of Essential Oil from Leaves of Mentha piperita Grown in China. PLoS One. 2014; 9(12): e114767.
10. Meamarbashi A. Instant effects of peppermint essential oil the physiological parameters of exercise performance. Avicenna J Phytomed. 2014 Jan-Feb; 4(1): 72–78.
11. Tamaki J et al. Effect of menthol vapour on airway hyperresponsiveness in patients with mild asthma. Respiratory Medicine. 1995; 89:503-504.
12. Tyler VE et al. Pharmacognosy 9^th edition. Lea and Febiger. Philadelphia, Pennsylvania., 1988.