PEQUI FRUIT (CARYOCAR BRASILIENSE CAMB) PULP OIL, A NATURAL SOURCE OF ANTIOXIDANTS, REDUCE THE OXIDATIVE STRESS STATUS AND DNA DAMAGE IN EXPERIMENTAL LUNG CANCER

Abstract

Background: It is well known that the endogenous antioxidant enzyme defense as well as an adequate ingestion of exogenous sources of antioxidants prevents the oxidative damage caused by reactive species (ROS),including DNA damage, and can reduce the risk of cancer, atherosclerosis and other degenerative diseases. The pulp of Caryocar brasiliense Camb, most known as pequi, is a Brazilian fruit that has high levels of antioxidants properties, such as vitamin C, carotenoids, phenolic compounds like flavonoids, saponins and tannins, and essential oils. The aim of this study was to estimate and to evaluate the antioxidant enzyme activities of catalase (CAT) and superoxide dismutase (SOD), as well as the ratio between then, and the antioxidant activity of the pequi oil, measuring lipid peroxidation and DNA damage in experimental model of lung cancer induced by urethane. Methods: The study was performed in 18 male BALB/c mice: 14 animals received by gavage 0,5μL/mg/day of pequi oil (PI0601631-6) (Control+CBCoil = 4) during 75 days. After 15 days of the beginning of the gavage, 10 of these mices received two doses of 1,5g/kg intraperitoneal of urethane (Urethane+CBC oil=10). The other 4 animals were only submitted to two doses of 1,5g/kg intraperitoneal of urethane (Urethane group=4). After 75 days, the three groups were sacrificed. The antioxidant activity of pequi oil was evaluated in the lung tissues by the biochemical TBARS (Thiobarbituric acidreactive substances), CAT and SOD test. The DNA damage was estimated by the comet test method. Results and Conclusion: The lung parenchyma from the Urethane groups without oil and with oil showed neoplasic formations induced by the chemical carcinogenesis in contrast with Control + CBC oil group. The results of the TBARS test showed a significant decreased of the lipid peroxidation in the Urethane + CBC oil, similar as values of the Control+CBC oil, when compared with Urethane group. The CAT and SOD test, as well as the ratio between then, didn’t show a significant difference. The image analysis of the comet assay showed a statistical significant decreased of the DNA damage cells in the Urethane + CBC oil group when compared with urethane group (p=0.001). The decreased DNA damage was very similar that we obtained in the Control + CBC oil group. We conclude that the different natural antioxidant components found in the pequi oil are efficient to diminish the oxidative stress status and the DNA damage in chemical carcinogenesis induced by urethane experimental lung cancer, suggesting that this type of strategies may have a greater impact in lung cancer treatment.