Current status of herbal medicine research for respiratory diseases induced by particulate matter: a protocol for a scoping review.

Background: Particulate matter (PM) is an important environmental risk factor for the initiation and exacerbation of respiratory disease. Various herbal medicines have exhibited a reduction in symptoms of respiratory diseases induced by PM in animal models. However, the types and characteristics of studies on herbal medicine for respiratory diseases by PM have not been reviewed. This scoping review will focus on the currents status and research gap of herbal medicines for respiratory diseases caused by PM.

Methods: We will follow the scoping review framework developed by Arksey and O'Malley. MEDLINE (via PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials will be searched for relevant English-language publications, and only peer-reviewed, controlled comparative in vivo/in-vitro/human studies examining the effects of herbs on respiratory disease induced by PM will be included. The basic characteristics, research methods, detailed regimens, possible mechanisms, outcomes, and results will be extracted using a predefined standardized data extraction form. Outcomes will be presented in the following categories: pulmonary function, inflammatory markers, reactive oxygen species, histology and mechanisms, and adverse events. Two researchers will independently perform the study selection, data extraction, and quality assessment. We will also present the research map and implications for further study.

Ethics And Dissemination: Ethical approval is not required because individual patient data will not be included. The findings will be disseminated through peer-reviewed publications or conference presentations.

Systematic Review Registration: This review protocol has been registered with the Open Science Framework on February 12, 2021 ( https://osf.io/s7uvk/ ).