Protective Effect of Thai Perilla frutescens Seed Oil Against Chronic Obstructive Pulmonary Disease Induced by Cigarette Smoke Extract in a Mouse Model.

Abstract

<p>Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory lung disorder primarily caused by exposure to cigarette smoke. This leads to oxidative stress and alveolar damage. Current treatment strategies are largely palliative, focusing on symptom relief rather than halting disease progression. Perilla frutescens seed oil (PSO), which is rich in alpha-linolenic acid, possesses notable antioxidant and anti-inflammatory properties. However, its therapeutic potential in COPD remains inadequately explored. This study aimed to investigate the protective effects of Thai PSO on lung inflammation, oxidative stress, and histopathological changes in a mouse model of COPD induced by cigarette smoke extract (CSE). C57BL/6J mice were administered PSO orally at low (123 mg/day) or high (246 mg/day) doses via gavage, either for 14 days (short-term) or 28 days (long-term). COPD was induced by intraperitoneal injection of CSE once weekly for four consecutive weeks. Lung histopathology was evaluated using hematoxylin and eosin staining, and alveolar enlargement was quantified by measuring the mean linear intercepts (MLI). Bronchoalveolar lavage fluid (BALF) was collected to determine total and differential white blood cell counts. Oxidative stress was assessed by measuring total antioxidant activity and malondialdehyde (MDA) levels as indicators of lipid peroxidation. CSE exposure resulted in marked airspace enlargement, increased MLI values, and elevated macrophage and eosinophil counts in BALF. PSO treatment, particularly short-term administration at a low dose, significantly reduced MLI values and attenuated overall inflammatory cell infiltration. Notably, PSO consistently decreased eosinophil counts across both short- and long-term treatment groups. Furthermore, long-term PSO administration led to a significant reduction in serum MDA levels, indicating enhanced antioxidant activity. PSO exhibited protective effects against CSE-induced pulmonary inflammation, alveolar destruction, and oxidative stress in a murine COPD model. These findings support the potential role as a dietary supplement for the prevention or attenuation of COPD progression.</p>