Upper Respiratory Tract Infections: Support With Aromatic Herbs

Herbal medicine has been practiced in regions of the world for generations, and continues to emerge in Westernized societies as an alternative to conventional approaches.¹ Interestingly, aromatic herbs are known to exhibit a wide spectrum of pharmacological properties used both in culinary herbs and traditional remedies.¹⁽¹⁾ One particular use for such herbs could be for the management of upper respiratory tract infections (URTIs). As such, the following will consider the implementation of herbal blends (Eucalyptus citriodora, Eucalyptus globulus, Mentha piperita, Origanum syriacum, and Rosmarinus officinalis) for the management of common symptoms related to such a condition.

As mentioned in the introduction, several aromatic herbs exist which are thought to help control symptoms of URTIs (sore throat, cough, fatigue, pain when talking, hoarseness or loss of voice, and difficulty in breathing). For example, Mentha piperita (peppermint) contains menthol which exhibits antiviral and antibacterial properties as well as an antitussive effect (reduces coughing).¹⁽¹⁾ Origanum syriacum (from the mint family) contains the active ingredients of carvacrol and thymol which induces antimicrobial as well as antifungal effects.^1(1-2) Rosmarinus officinalis is a herb which causes the tracheal smooth muscle to relax (i.e., relaxant) while Eucalyptus globulus oil contains cineole which has an anti-inflammatory effect upon chronic bronchitis.¹⁽²⁾ Finally, Eucalyptus citriodora which contains citronellal as its active constituent and induces peripheral and central analgesic (pain-reducing) effects in addition to anti-inflammatory properties.¹⁽²⁾ Although the utility of each herb has been explored individually, Ben-Arye  et al¹⁽²⁾ considered the potential synergistic benefits of combining said aromatic herbs in a single delivery system (spray). As such, the following will consider the same in greater detail.

The researchers recruited 60 participants (ages 21-66 years) who were diagnosed with having viral tracheitis, pharyngotonsillitis, or viral laryngitis. Participants were excluded if they were pregnant or diagnosed with a sensitivity to aromatic essential oils, immunosuppressive drugs, coumadin, antibiotic treatment or had asthma, peritonsillar abscess, or acute follicular tonsillitis.¹⁽²⁾ The study was constructed as a double-blind randomized controlled trial of a spray containing aromatic oils to include: Eucalyptus citriodora, Eucalyptus globulus, Mentha piperita, Origanum syriacum, and Rosmarinus officinalis.¹⁽²⁾ Participants were self-assessed the severity of 6 symptoms over a 4-degree scale (0: no symptoms, 1: mild, 2: moderate, and 3: severe). Said symptoms included difficulty breathing, pain when talking, loss of voice, cough, sore throat, and fatigue.¹⁽²⁾ Finally, the severity of was based on a score combining said 6 symptoms assessed by patients and 4 signs assessed by the physician (systemic fever >38◦C, mucous secretion, dyspnea, stridor). Each sign was graded as 0 (none) or 1 (positive sign).¹⁽²⁾

Once participants completed baseline measures, they were randomly assigned to either the experimental group (26 subjects received an aromatic spray blend of 20% Rosmarinus officinalis, 10% Eucalyptus citriodora, 20% Mentha piperita, 20% Eucalyptus globulus, and 30% Origanum syriacum ) or a placebo (34 subjects received a spray with no aromatic herbs) while investigators and participants were blinded to the constituents of each spray bottle.¹⁽²⁾ All participants were requested to spray bottle contents into their mouths 4 times every 5 minutes. After 20 minutes passed, all participants were asked to evaluate 3 main symptoms (cough, hoarseness, sore throat). Following said self-evaluation, participants were instructed to continue use of sprays at home (4 sprays x 5 times a day) for 3 more consecutive days.¹⁽²⁾ Each spray (experimental and placebo) released 0.1 ml of atomized liquid (3 mcg per spray of active ingredients in the experimental group).¹⁽⁴⁾ Upon completion of home use of spray, participants revisited their physicians’ offices to evaluate compliance, sensations caused by sprays, and the participants’ evaluation of symptoms.¹⁽²⁾

Results suggested that participants in the experimental group reported better improvements in reduction of severity of symptoms within 20 minutes of administering spray, especially when compared to placebo groups; reduction of symptoms was defined as an improvement of scores in at least one symptom i.e., cough, hoarseness, sore throat.¹⁽⁴⁾ Furthermore, participants who reported severe symptoms experienced higher degrees of improvement from the herbal spray when compared to placebo participants with similar scores in (severity of symptoms).¹⁽³⁾ However, no differences in severity of symptoms were noted between groups after 3 days (an expected outcome form the researchers as such symptoms naturally resolve by said time frame). Although such findings are promising and do show local effects upon the upper respiratory tract, one should note that said study had several limitations: (1) a small sample size making it difficult to fully interpret the results, (2) more participants were smokers in the control group limiting taste and smell, (3) difficulty making the placebo spray smell and taste similar to the experimental spray, (4) a lack of conclusively and/or certainty that combining all herbs was essential.¹⁽⁶⁾

In conclusion, herbal medicine has been practiced in regions of the world for generations, and continues to emerge in Westernized societies as an alternative to conventional approaches. Several aromatic herbs are known to exhibit a wide spectrum of pharmacological properties to include antiviral, antifungal, anti-inflammatory, and antitussive agents; qualities likely to help manage URTI symptoms. Though the research study of Ben-Arye et al¹⁽⁶⁾ had limitations, results remin encouraging as participants still experienced positive changes from safe, accessible, and cost-effective aromatic herbal interventions.

References

1. Ben-Arye E, Dudai N, Eini A, et al. Treatment of upper respiratory tract infections in primary care: A randomized study using aromatic herbs. Evid Based Compliment Alternat Med. 2011;2011:1-8. doi:10.1155/2011/690346.

-Michael McIsaac