When temperatures cool, we are reminded how important and yet, how vulnerable our lungs are. Both Ayurvedic and Traditional Chinese medical philosophies dedicate scrolls and scrolls of text about this organ and its relationship to the heart, which it surrounds. Likewise, in conventional medical models, the respiratory and cardiovascular systems are often taught side by side or at least in sequence. As the world continues to face the pandemic while juggling its regular cold and flu season, it seems essential to review some of the herbal answers to strengthening the lung for both prevention, and for convalescence.
In Ayurveda, lung health is very closely discussed with the term Bala which literally translates as strength, but also has a connotation of resistance. Similarly in Chinese medicine, the Lung is the governor of Wei qi, the name for the aspect of the body that protects the exterior from invasion, and helps resolve disharmony within the system. In the West, we call this complex system the immune system, and indeed we too link it directly with the lung’s overall health. Therefore, when discussing herbs that are most useful for supporting the respiratory system, we must also include a discussion on herbs that influence the immune system. Luckily for the practitioner, many botanicals serve to influence both these systems, and the research supports that herbal medicines influence respiratory health, decrease severity of common symptoms such as sore throat and cough, while also exerting immunomodulatory effects.
One such herb Phyllanthus emblica (formerly: Emblica officinalis), better known as amla, demonstrates antiviral[i], anti-inflammatory[ii], and anti-tussive[iii] activity. The antioxidant capability of amla has been demonstrated repeatedly. It contains high amounts of polyphenols such as the hydrolysable tannins phyllemblin, emlicol, and emblicanin that have all been studied for their effects as potent dietary antioxidants[iv]. Also adding to the antioxidant power of amla is its content of vitamin C (ascorbic acid). After acerola, amla is second richest natural source of vitamin C having approximately 600 to 700 mg per fruit.
Amla is also part of a famous Ayurvedic formula known as Triphala. Triphala is a combination of Phyllanthus emblica, Terminalia bellerica (bibhitaki), and Terminalia chebula (haritaki). The uses for Triphala are robust in the Ayurvedic materia medica due to its classification as tridoshic making it appropriate for all types of patients. This designation plays a role in how it has become a staple of supporting immune function as well as illness prevention. While it is less common to see classic formulations used in clinical research than individual herbs, Triphala has been studied and shown to be safe in doses up to 2500mg per day[v], and also has demonstrated direct anti-streptococcus activity in human subjects[vi]. The other herbs in Triphala, bibhitaki and haritaki, have also been studied individually and found to have immunomodulating or anti-viral capabilities. Haritaki, along with amla, is currently being included in a study to assess restoring lung health after COVID-19 infection[vii]. Meanwhile, bibhitaki demonstrates a bronchodilatory effect and supports lung health during inflammation. In an effort to elucidate the mechanism of how this herb exerts its effects, a rat study indicated that bronchodilation and anti-tussive actions occur in a dose dependent manner and act at the level of the calcium channel and functionally mimicked anticholinergic medications[viii]. The authors conclude this mechanism should be further studied and clinical trials are warranted to explore the extent of bibhitaki’s respiratory effects. As with many traditional medicines, we see Triphala both as a formulation, and when taken in its individual parts, continue to pass the stages of evidence informed medicine with positive results.
Similarly, Trikatu, another commonly prescribed Ayurvedic combination of Piper longum (long pepper), Piper nigrum (black pepper), and Zinigiber officinalis (ginger) show mucolytic properties. In a unique study utilizing Ayurvedic diagnosis and treatment for chronic sinusitis, 37 individuals were randomized into three groups, with one group receiving Trikatu as part of their treatment plan. The results demonstrated resolution of the chronic sinusitis. An additional study of mice also found anti-inflammatory, anti-microbial and analgesic properties[ix]. Additional in vivo studies have taken this work a step further to establish Trikatu’s action in suppressing the production of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and monocyte chemoattractant protein (MCP)-1). Furthermore, COX-2 inhibition was recorded[x]. Given these molecules’ role in cytokine storms, more research is warranted regarding the potential therapeutic effects in acute respiratory conditions, especially given the tradition of use.
An exploration of the lung would not be complete without a discussion of cough, the lung’s central means of alerting us to its distress which can persist far beyond acute illness. The most researched natural remedy for cough is honey. The Cochrane review database included a review of the pediatric use of honey for acute cough and they found honey relieves cough symptoms to a greater extent than no treatment, diphenhydramine, and placebo. Additionally the authors conclude that honey not only relieves cough symptoms, but also reduces cough duration better than placebo and salbutamol[xi]. Between its soothing flavor, pancultural historic use, and robust scientific validation, it seems fitting that a substance from delicate insects would be so nourishing to such a delicate organ.
Another consideration for honey’s utility in treating cough is what herbs it is paired with. A study looking at antioxidant potential of various honeys found that honey combined with dried herbs has a stronger antioxidant potential than either alone[xii]. For instance, honey combined with ginger has shown to increase glutathione levels and thus provide higher antioxidant capability than honey or ginger given alone[xiii]. So the research validates this classic kitchen medicine of combining herbs and honey for a stronger effect. Like honey, an herb that has been studied for its effects on cough is Adhatoda vasica (vasaka). In a trial combined with Echniacea purpurea and Eleutherococcus senticosis, the blend improved respiratory comfort and decreased cough similarly to the mucolytic Bromhexine. Interestingly, they also included an arm that did not include Adhatoda vasica, and cough symptoms became unaffected, suggesting this herb was instrumental in cough relief[xiv]. Another trial demonstrated the immediate effects of Adhatoda vasica. Sixty six participants with diagnosed cold symptoms were randomized to receive vasaka vs placebo. On days 2, 4, and 6 those utilizing the herb reported better sinus comfort, ability to sleep, and decreased cough compared to placebo.
With so many therapies for acute respiratory conditions, at what point must the clinician also consider care after the pathogen has been defeated? When discussing post illness recovery, a classic herb for convalescence in the Ayurvedic materia medica is Tinospora cordifolia (guduchi). It was traditionally used from the point a fever emerges until recovery was complete and is considered supportive to the tridosha, which means it is used for the largest cross section of individuals. Today, human trials are beginning to validate this use. A study of post-surgical patients found that phagocytic and cytotoxic capacities of neutrophils normalized faster than the placebo group. Additionally, improved hepatic function testing was observed[xv].
As we continue to navigate a world with increasing respiratory assaults, it is likely we will need to utilize the multi-target capabilities of herbal medicines to prevent disease, manage symptoms, and support convalescence. As the title of this article suggests, the lungs are indeed a delicate system, being arguably the most exposed internal organ of the body. As such, we must consider all options for support and protection at this time, and these herbs may prove to be a frontline participant in stemming the tide of disease.
[i] Arjin, C., Pringproa, K., Hongsibsong, S., Ruksiriwanich, W., Seel-Audom, M., Mekchay, S., & Sringarm, K. (2020). In vitro screening antiviral activity of Thai medicinal plants against porcine reproductive and respiratory syndrome virus. BMC veterinary research, 16(1), 102. https://doi.org/10.1186/s12917-020-02320-8
[ii] Yadav, S. S., Singh, M. K., Singh, P. K., & Kumar, V. (2017). Traditional knowledge to clinical trials: A review on therapeutic actions of Emblica officinalis. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 93, 1292–1302. https://doi.org/10.1016/j.biopha.2017.07.065
[iii] Nosál'ová, G., Mokrý, J., & Hassan, K. M. (2003). Antitussive activity of the fruit extract of Emblica officinalis Gaertn. (Euphorbiaceae). Phytomedicine : international journal of phytotherapy and phytopharmacology, 10(6-7), 583–589. https://doi.org/10.1078/094471103322331872
[iv] Krishnaveni, M., & Mirunalini, S. (2010). Therapeutic potential of Phyllanthus emblica (amla): the ayurvedic wonder. Journal of basic and clinical physiology and pharmacology, 21(1), 93–105.
[v] Phetkate, P., Kummalue, T., Rinthong, P. O., Kietinun, S., & Sriyakul, K. (2020). Study of the safety of oral Triphala aqueous extract on healthy volunteers. Journal of integrative medicine, 18(1), 35–40. https://doi.org/10.1016/j.joim.2019.10.002
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[vii] Shokoohi, R., Kianbakht, S., Faramarzi, M., Rahmanian, M., Nabati, F., Mehrzadi, S., & Huseini, H. F. (2017). Effects of an Herbal Combination on Glycemic Control and Lipid Profile in Diabetic Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. Journal of evidence-based complementary & alternative medicine, 22(4), 798–804. https://doi.org/10.1177/2156587217737683
[viii] Gilani, A. H., Khan, A. U., Ali, T., & Ajmal, S. (2008). Mechanisms underlying the antispasmodic and bronchodilatory properties of Terminalia bellerica fruit. Journal of ethnopharmacology, 116(3), 528–538. https://doi.org/10.1016/j.jep.2008.01.006
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[x] Doss, H. M., Ganesan, R., & Rasool, M. (2016). Trikatu, an herbal compound ameliorates rheumatoid arthritis by the suppression of inflammatory immune responses in rats with adjuvant-induced arthritis and on cultured fibroblast like synoviocytes via the inhibition of the NFκB signaling pathway. Chemico-biological interactions, 258, 175–186. https://doi.org/10.1016/j.cbi.2016.09.003
[xi] Oduwole, O., Udoh, E. E., Oyo-Ita, A., & Meremikwu, M. M. (2018). Honey for acute cough in children. The Cochrane database of systematic reviews, 4(4), CD007094.
[xii] Dżugan, M., Sowa, P., Kwaśniewska, M., Wesołowska, M., & Czernicka, M. (2017). Physicochemical Parameters and Antioxidant Activity of Bee Honey Enriched With Herbs. Plant foods for human nutrition (Dordrecht, Netherlands), 72(1), 74–81. https://doi.org/10.1007/s11130-016-0593-y
[xiii] Sani NF, Belani LK, Sin CP, et al. Effect of the combination of gelam honey and ginger on oxidative stress and metabolic profile in streptozotocin-induced diabetic Sprague-Dawley rats. Biomed Res Int. 2014;2014:160695.
[xiv] Narimanian, M., Badalyan, M., Panosyan, V., Gabrielyan, E., Panossian, A., Wikman, G., & Wagner, H. (2005). Randomized trial of a fixed combination (KanJang) of herbal extracts containing Adhatoda vasica, Echinacea purpurea and Eleutherococcus senticosus in patients with upper respiratory tract infections. Phytomedicine : international journal of phytotherapy and phytopharmacology, 12(8), 539–547. https://doi.org/10.1016/j.phymed.2004.10.001
[xv] Rege, N., Bapat, R. D., Koti, R., Desai, N. K., & Dahanukar, S. (1993). Immunotherapy with Tinospora cordifolia: a new lead in the management of obstructive jaundice. Indian journal of gastroenterology : official journal of the Indian Society of Gastroenterology, 12(1), 5–8.