Utilization of selected natural products as complementary therapeutic approach for Obstructive Sleep Apnea (OSA) management: a literature review

Obstructive sleep apnea (OSA) is one of the foremost potential severe disorders, with frequent episodes of complete or partial obstructions of the upper airway during sleep. Therefore, several attempts to find an effective pharmacotherapy by repurposing several drugs such as serotonin reuptake inhibitors (SRIs) and norepinephrine and dopamine reuptake inhibitors (NDRIs) were recently considered as alternative therapeutic strategy. So, in this review, we will present non-conventional pharmacological approaches for managing OSA via either repurposing selected natural products or traditional medicine. Scientific databases and literature reviewed in the last twenty years were screened using different keywords related to OSA; exclusion criteria were applied based on the accessibility and the ability of the sources to follow evidence-based approaches. The eligible resources were classified into two main categories: clinical-based studies and preclinical studies. The findings of these studies were analyzed and discussed in light of current evidence derived from recent studies. Several natural components and traditional formulas were found to regulate several molecular targets involved in OSA pathogenesis, supported by several in-vitro and in-vivo studies. Also, natural products subjected to clinical trials give promising results. Still, there are some limitations, such as involving a small number of patients depending on subjective yet acceptable scores rather than objective scores, a lack of positive control groups, or a small number of patients. Therapeutic protocols should consider non-conventional polypharmacological strategies targeting all OSA aspects. Hence, there is an opportunity to reposition some well-defined natural products, such as cinnamic acid derivatives, isoflavones, and lignans, as several evidences from in-vitro, in-vivo, and clinical trials support their potential efficacy in the management of OSA.