Melatonin, widely known as the “sleep hormone,” may significantly enhance the effectiveness of glucocorticoids in treating allergic asthma and potentially open the door to a promising new combination therapy.
Chinese researchers revealed this promising therapy in their paper, “Synergistic Interactions of Melatonin and Glucocorticoids in Alleviating Allergic Airway Inflammation.” Their findings were recently published in Frontiers in Medicine.
Researchers outlined their case–control study and parallel animal experiments which found that melatonin not only reduces airway inflammation but also helps stabilize circadian rhythm–related gene expression — an effect that becomes even stronger when paired with corticosteroids such as dexamethasone.
In the clinical portion of the study, researchers compared 33 patients with allergic asthma to 25 healthy controls, analyzing lung function, blood markers, sleep quality and hormone levels. According to the study’s authors, there were significant differences between the two groups across all key indicators, including melatonin levels, cortisol, exhaled nitric oxide (FeNO) and sleep quality scores.
Study data revealed that lower melatonin levels were associated with worse asthma control, poorer sleep and higher inflammation markers. Researchers noted the intertwined relationship between asthma severity, sleep disruption and circadian rhythm disturbances.
To further test the biological mechanisms, researchers used a mouse model of allergic airway inflammation. When treating mice with melatonin, corticosteroids or both, their findings revealed:
- Melatonin alone reduced airway inflammation and helped stabilize key circadian genes (PER1 and CRY1).
- Corticosteroids reduced inflammation, consistent with standard asthma treatments.
- The combination of melatonin and glucocorticoids produced the strongest anti-inflammatory response, significantly lowering inflammatory cytokines, mucus production (MUC5AC) and inflammatory cell count.
According to the study’s authors, this enhanced effect suggests that melatonin may help restore circadian rhythm balance disrupted by chronic inflammation or long-term steroid use.
Although glucocorticoids remain central to asthma treatment, some patients respond poorly or experience sleep disturbances and hormonal side effects, researchers noted.
Additionally, the study’s authors emphasized that circadian rhythm appears to play a key role in asthma severity — and that targeting this biological system may represent a new therapeutic frontier.
Although the results are promising, researchers cautioned that their study included a relatively small sample size and short-term measurements. They said more extensive clinical trials were needed to determine:
- Optimal melatonin dosing
- Long-term safety
- Effects across diverse asthma populations
- True pharmacological synergy between melatonin and steroids
Still, they noted, the study’s results provided compelling early evidence that melatonin could become a valuable add-on therapy for millions living with allergic asthma.
