Pretreatment with a grape seed proanthocyanidin extract downregulates proinflammatory cytokine expression in airway epithelial cells infected with respiratory syncytial virus.

Respiratory syncytial virus (RSV) infections are associated with significant morbidity and mortality. Inflammation is mediated by cytokine secretion from RSV‑infected airway epithelial cells. Grape seed proanthocyanidin extract (GSPE) exhibits potent antioxidant capacity, as well as anti‑bacterial, anti‑viral, anti‑carcinogenic, anti‑inflammatory and anti‑allergic actions. However, few studies have explored the anti‑inflammatory effects of GSPE on airway epithelial cells infected with RSV. Airway epithelial A549 cells were pretreated with GSPE and its effects on cytokine production during RSV infection were investigated. A549 cells were infected with RSV, with or without GSPE pretreatment, and cultured for 24, 48 and 72 h. The expression of interleukin (IL)‑1β, IL‑6 and IL‑8, were measured by reverse transcription‑quantitative polymerase chain reaction, ELISA and western blotting. RSV infection induced significant increases in proinflammatory cytokine expression. However, GSPE pretreatment decreased the mRNA and protein expression levels of IL‑1ß, IL‑6 and IL‑8. GSPE regulated the immune response by reducing the RSV‑induced transcription of proinflammatory cytokines in airway epithelial cells, suggesting that GSPE helps to prevent RSV‑induced airway disease.