Pycnogenol, a compound isolated from the bark of pinus maritime mill, attenuates ventilator-induced lung injury through inhibiting NF-κB-mediated inflammatory response.

BACKGROUND: During mechanical ventilation, high end-inspiratory lung volume results in a permeability type pulmonary oedema, called ventilator-induced lung injury (VILI). The pathophysiology of ventilator-induced lung injury involves multiple mechanisms, such as excessive inflammation. And pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have anti-inflammatory activity.

OBJECTIVE: We investigated the effects of pyncogenol on ventilator-induced lung injury in rats.

METHODS: Rats were orally administrated with pycnogenol once (30 mg/kg) 2 days before lung injury induction with mechanical ventilation, then the rats were divided into three groups: lung-protective ventilation (LV group, n = 20), injurious ventilation (HV group, n = 20), HV + pycnogenol group (HV + Pyc group, n = 20). Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for histopathological examinations and biochemical analyses.

RESULTS: Pretreatment with pycnogenol could markedly decrease lung wet/dry ratio, lower myeloperoxidase (MPO) activity and total protein concentration and reduce the production of TNF-α, IL-6, IL-1β and MIP-2 in the BALF in ventilator-induced lung injury rats. Additionally, pycnogenol improved the histology of the lung and significantly inhibited the phosphorylation of NF-κB p65 and the degradation of IκB-α.

CONCLUSION: Pycnogenol treatment could attenuate ventilator-induced lung injury in rats, at least in part, through its ability to reduce the production of inflammatory cytokines via inhibiting the activation of NF-κB, indicating it as a potential therapeutic candidate for ventilator-induced lung injury.