Olea Europaea L. leaf extract attenuates histological alterations and oxidative stress in the rat heart induced by combined exposure to noise and toluene.

Abstract Toluene is a solvent widely produced and used by the industrial sector. Noise is a nuisance present in many professional sectors. We aimed to investigate in the present study the impact of exposure to toluene (300 ppm) and/or noise 85 dB(A) on rat heart and to assess the preventive effect of olive leaf extract OLE (40 mg/Kg/day) administrated for six weeks (5 days/week). Forty-eight male Wistar rats were divided into 8 groups (n = 6/group): C: control group, C+OLE: control group received OLE, N: group exposed to noise, N+OLE: group exposed to noise and received OLE, T: group exposed to toluene, T+OLE: group exposed to toluene and received OLE, NT: group co-exposed to noise and toluene, NT+OLE: group co-exposed to noise and toluene received. At the end of the experimental period, heart and blood samples were collected. Plasma cholesterol (CHOL), triglycerides (TG), lactate dehydrogenase (LDH) and creatine kinase (CK) levels were determined. Histopathological investigation was determined by HE staining. Superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) level in heart tissue were also measured. Our results showed that Simultaneous exposure to noise and toluene altered CHOL, TG, LDH and CK levels. In parallel, an increase in lipid peroxidation levels and Superoxide dismutase activity with a decrease in catalase activity in the heart were shown. A significant alteration in the myocardium was also recorded. OLE treatment modulated theses oxidative and histological changes. In conclusion, OLE was found to correct the deleterious effects induced by combined exposure to noise and toluene.