Spicae aetheroleum in uncomplicated acute bronchitis: a double-blind, randomised clinical trial

Flower Power: An Overview on Chemistry and Biological Impact of Selected Essential Oils from Blossoms

Natural raw materials such as essential oils have received more and more attention in recent decades, whether in the food industry, as flavorings and preservatives, or as insecticides and insect repellents. They are, furthermore, very popular as fragrances in perfumes, cosmetics, and household products. In addition, aromatherapy is widely used to complement conventional medicine. This review summarizes investigations on the chemical composition and the most important biological impacts of essential oils and volatile compounds extracted from selected aromatic blossoms, including Lavandula angustifolia, Matricaria recutita, Rosa x damascena, Jasminum grandiflorum, Citrus x aurantium, Cananga odorata, and Michelia alba. The literature was collected from PubMed, Google Scholar, and Science Direct. Blossom essential oils discussed in this work are used in a wide variety of clinical issues. The application is consistently described as safe in studies and meta-analyses, although there are notes that using essential oils can also have side effects, especially dermatologically. However, it can be considered as confirmed that essential oils have positive influences on humans and can improve quality of life in patients with psychiatric disorders, critically ill patients, and patients in other exceptional situations. Although the positive effect of essential oils from blossoms has repeatedly been reported, evidence-based clinical investigations are still underrepresented, and the need for research is demanded.

Current state of research on the clinical benefits of herbal medicines for non-life-threatening ailments

Herbal medicines are becoming increasingly popular among patients because they are well tolerated and do not exert severe side effects. Nevertheless, they receive little consideration in therapeutic settings. The present article reviews the current state of research on the clinical benefits of herbal medicines on five indication groups, psychosomatic disorders, gynecological complaints, gastrointestinal disorders, urinary and upper respiratory tract infections. The study search was based on the database PubMed and concentrated on herbal medicines legally approved in Europe. After applying defined inclusion and exclusion criteria, 141 articles were selected: 59 for psychosomatic disorders (100% randomized controlled trials; RCTs), 20 for gynecological complaints (56% RCTs), 19 for gastrointestinal disorders (68% RCTs), 16 for urinary tract infections (UTI, 63% RCTs) and 24 for upper respiratory tract infections (URTI) (79% RCTs). For the majority of the studies, therapeutic benefits were evaluated by patient reported outcome measures (PROs). For psychosomatic disorders, gynecological complaints and URTI more than 80% of the study outcomes were positive, whereas the clinical benefit of herbal medicines for the treatment of UTI and gastrointestinal disorders was lower with 55%. The critical appraisal of the articles shows that there is a lack of high-quality studies and, with regard to gastrointestinal disorders, the clinical benefits of herbal medicines as a stand-alone form of therapy are unclear. According to the current state of knowledge, scientific evidence has still to be improved to allow integration of herbal medicines into guidelines and standard treatment regimens for the indications reviewed here. In addition to clinical data, real world data and outcome measures can add significant value to pave the way for herbal medicines into future therapeutic applications.

Lavender (Lavandula angustifolia) syrup as an adjunct to standard care in patients with mild to moderate COVID-19: An open-label, randomized, controlled clinical trial

Objective

ongoing COVID-19 pandemic has been associated with clinical signs characterized by fever, fatigue and cough. Our study aimed to assess the efficacy of a Persian medicine formulation, lavender syrup, as an add-on to standard care in patients with mild to moderate COVID-19.

Materials and Methods

In this clinical trial which was conducted in Gorgan (Iran), 84 male and female COVID-19 outpatients were randomly allocated to either lavender syrup receiving 9 ml/twice/day for 21 days with standard conventional care or control groups. The primary objectives were to assess the improvement of clinical symptoms, while the secondary objectives were treatment satisfaction and anxiety levels which were evaluated once a week for 3 weeks.

Results

Out of 84 participants, 81 were analyzed (41 in the add-on group). The comparison between groups for cough severity and anosmia showed a higher reduction in the lavender group. The effect size was 0.6 for cough relief. Other symptoms and the Hamilton total score decreased in both groups with no statistically significant differences between the groups. The lavender group showed greater patients' satisfaction score.

Conclusion

Adjunctive therapy with lavender syrup could reduce cough and improve the quality of life in patients with COVID-19 patients.

Pharmacologic effects approach of essential oils and their components on respiratory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oils (EOs) are concentrated hydrophobic liquids with volatility and a unique aroma. Formed by aromatic plants as secondary metabolites, EOs have been used as traditional medicines to treat various health problems worldwide. Historical records show that herbs rich in EOs have been widely used to treat respiratory diseases in China, Europe, and many other regions.

AIM OF THE REVIEW

This review summarizes the traditional applications and modern pharmacological mechanisms of EOs derived from aromatic herbs and their active ingredients in respiratory diseases in preclinical and clinical trials through multitarget synergy.

MATERIALS AND METHODS

Information about EOs and respiratory diseases was collected from electronic databases, such as ScienceDirect, Web of Science, PubMed, Google Scholar, Baidu Scholar, and the China National Knowledge Infrastructure (CNKI).

RESULTS

This review presents the preventive and therapeutic effects of EOs on respiratory diseases, including chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, pulmonary infection, and pulmonary fibrosis. The molecular mechanisms of EOs in treating different lung diseases are summarized, including anti-inflammation, anti-oxidation, mucolytic, and immune regulatory mechanisms.

CONCLUSIONS

EOs show potential as supplements or substitutes for treating lung diseases.

Appropriate use of essential oils and their components in the management of upper respiratory tract symptoms in patients with COVID-19

Introduction

The involvement of the upper respiratory tract is common in COVID-19, and the majority of patients are treated at home with a mild-to-moderate form of the disease. Many approaches based on essential oils have been proposed for the symptomatic treatment of COVID-19. This work aims to outline the potential and safe evidence-based uses of essential oils and their major components for the clinical management of mild respiratory symptoms caused by uncomplicated coronavirus infections, including SARS-CoV-2. Due to their wide use, a focus on the constituents eucalyptol and menthol has been provided.

Methods

An overview of the scientific literature with a critical discussion of retrieved evidence and clinical recommendations.

Results

In general, eucalyptol and essential oils or blends whose content is rich in it, may be used as an integrative remedy for the symptomatic improvement of patients with mild and uncomplicated infections caused by coronaviruses. Menthol is not recommended in patients with COVID-19, due to a potential reduction of the self-perception of dyspnea, which can lead infected patients to underestimate the actual disease severity and to delay medical attention.

Discussion

Based on available evidence, symptomatic remedies for COVID-19, such as essential oils and their isolated compounds, can be useful, but are not an alternative to standard medical therapy and do not exempt patients from following precautionary measures issued by health authorities. Clinical recommendations on the appropriate use of essential oils for the management of upper airway symptoms of COVID-19 are provided. Further studies on the topic are advised.

Effects of essential oils on symptoms and course (duration and severity) of viral respiratory infections in humans: A rapid review

Oral doses of certain essential oils may reduce symptoms of acute respiratory infections of viral origin. It is likely that the commercially available essential oil capsules Myrtol® (a mixture of essential oils of eucalyptus Eucalyptus globulus, sweet orange Citrus sinensis, myrtle Myrtus communis and lemon Citrus limonum) and Tavipec® (spike lavender Lavandula latifolia) could also provide mild to moderate symptom relief in patients with viral respiratory diseases. Myrtol® may also improve the course (duration and severity) of acute bronchitis of viral origin, in humans. Both products were well tolerated, with most of the mild to moderate side-effects affecting the gastrointestinal tract. This review found no research evidence describing the clinical effect of inhalation of essential oils for acute respiratory viral infections.