Protective effects of piperlongumin in the prevention of inflammatory damage caused by pulmonary exposure to benzopyrene carcinogen.

Benzopyrene is one of the main polycyclic aromatic hydrocarbons with carcinogenic capacity. Research has shown that anti-inflammatory drugs can reduce the incidence of lung cancer. In this scenario, we highlight piperlongumin (PL), an alkaloid from Piper longum with anti-inflammatory properties. Therefore, our aim was to study the effect of PL administration in a model of pulmonary carcinogenesis induced by benzopyrene in Balb/c mice. Animals were divided into 3 groups (n = 10/group): sham (10% DMSO), induced by benzopyrene (100 mg/kg, diluted in DMSO) without treatment (BaP) for 12 weeks and induced by benzopyrene and treated with PL (BaP/PL) (2 mg/kg in 10% DMSO) from the eighth week post-induction. Animals were weighed daily and pletsmography was performed in the 12th week. Genotoxicity and hemoglobin levels were analyzed in blood and quantification of leukocytes in bronchoalveolar lavage (BAL). Lungs were collected for histopathological evaluation, immunohistochemical studies of annexin A1 (AnxA1), cyclooxygenase 2 (COX-2), anti-apoptotic protein Bcl-2 and nuclear transcription factor (NF-kB) and also the measurement of interleukin cytokines (IL)-1β, IL-17 and tumor necrosis factor (TNF) -α. Treatment with PL reduced the pulmonary parameters (p < 0,001) of frequency, volume and pulmonary ventilation, decreased lymphocytes, monocytes and neutrophils in BAL (p < 0,05) as well as blood hemoglobin levels (p < 0,01). PL administration also reduced DNA damage and preserved the pulmonary architecture compared to the BaP group. Moreover, the anti-inflammatory effect of PL was evidenced by the maintenance of AnxA1 levels, reduction of COX-2 (p < 0,05), Bcl-2 (p < 0,01) and NF-kB (p < 0,001) expressions and decreased IL-1β, IL-17 (p < 0,01) and TNF-α (p < 0,05) levels. The results show the therapeutic potential of PL in the treatment of pulmonary anti-inflammatory and anti-tumor diseases with promising therapeutic implications.