The effect of pterostilbene and its active ingredients on experimental pulmonary fibrosis in asthma; a meta-analysis

Introduction
Pulmonary fibrosis (PF) is a chronic progressive interstitial lung disease caused by a variety of factors. Aim: To systematically evaluate the therapeutic effect of pterostilbene (PTE) on experimental PF in asthma and other oxidative damage pathway-related diseases, and to provide evidence for clinical treatment.

Material and methods
Chinese and English databases such as CNKI, Wanfang, VIP, PubMed, Embase, Cochrane Library, and CBM were searched by computer. The Chinese literature on pterostilbene for the treatment of asthma by evaluating experimental pulmonary fibrosis, diabetes, and myocardial infarction was collected from the establishment of a randomized controlled trial until May 2021.Outcome indicators include related physical and chemical indicators such as MDA and SOD. Data were analysed using Review Manager 5.4 software after screening by 2 researchers.

Results
Seven randomized controlled animal experiments were included, with a total sample size of 62 cases. Meta-analysis results showed the following: 1) compared with pulmonary fibrosis, diabetes and other model groups, the pterostilbene intervention group were able to up-regulate SOD, and the effect was better than that of the model group (MD = 20.87, 95% CI: 19.41–22.33; n = 7, I2 = 96%); the pterostilbene intervention group could also up-regulate the expression of GSH, and its effect was better than that of the model group (MD = 9.37, 95% CI: 8.67–10.07; n = 2, I2 = 98%). The MDA level of the intervention group was significantly down regulated, and the intervention group was also better than the model group. Pterostilbene can prevent experimental PF by lowering the level of MDA.

Conclusions
Pterostilbene can effectively improve experimental pulmonary fibrosis, diabetes, myocardial infarction, and other oxidative damage pathway-related diseases have certain guiding significance for clinical trials on asthma.