Simultaneous Exposure to Noise and Toluene Induces Oxidative and Inflammatory Damage in the Heart of Wistar Rats: Therapeutic Potential of Olea europaea L. Leaf Extract.

Workers in occupational settings often face simultaneous exposure to multiple risk factors, including noise and chemicals. This study aimed to investigate the effects of combined exposure to noise and toluene on the cardiac health of rats, with a focus on assessing the potential mitigating effects of Olea europaea L. (OLE) leaf extract (40 mg/kg/day). The evaluation involved scrutinizing biochemical and hematological markers, quantifying oxidative stress levels, determining proinflammatory cytokines in the serum, and conducting an in silico Docking studies. Forty-two male Wistar rats were divided into eight groups-(n = 6/group):-Control-group-(C),-OLE-group-(Rats administered OLE), NT-group (rats co-exposed to noise and toluene), NT-4 group-(rats co-exposed to noise and toluene four weeks after the exposure period), NT + OLE1-group (rats co-exposed to noise and toluene treated with OLE for one week), NT + OLE2-group-(rats co-exposed to noise and toluene treated with OLE for two weeks), NT + OLE3-group-(rats co-exposed to noise and toluene treated with OLE for three weeks), and NT + OLE4-group (rats co-exposed to noise and toluene treated with OLE for four weeks). The results revealed that combined exposure to noise and toluene led to oxidative damage and increased serum levels of proinflammatory cytokines. However, OLE treatment attenuated these effects by reducing lipid peroxidation and enhancing catalase and superoxide dismutase activities. Additionally, OLE treatment significantly decreased proinflammatory cytokine levels compared to the noise and toluene co-exposed group. The study highlighted the potential of OLE to attenuate the adverse effects of combined exposure to noise and toluene, attributed to its anti-inflammatory and antioxidant properties.

Olea europaea L. leaf extract mitigates pulmonary inflammation and tissue destruction in Wistar rats induced by concurrent exposure to noise and toluene.

This study aimed to investigate the effects of combined exposure to noise (85 dB(A)) and inhaled Toluene (300 ± 10 ppm) on rat lung health. It also aimed to assess the potential therapeutic effects of Olea europaea L. leaves extract (OLE) (40 mg/kg/day) using biochemical, histopathological, and immunohistochemical (IHC) analyses, as well as determination of pro-inflammatory cytokines (TNF-α and IL-1ß), and in silico Docking studies. The experiment involved forty-two male Wistar rats divided into seven groups, each exposed to a 6-week/6-hour/day regimen of noise and Toluene. The groups included a control group, rats co-exposed to noise and Toluene, and rats co-exposed to noise and Toluene treated with OLE for different durations. The results indicated that noise and Toluene exposure led to structural damage in lung tissue, oxidative harm, and increased levels of pro-inflammatory cytokines (TNF-α and IL-1ß). However, the administration of OLE extract demonstrated positive effects in mitigating these adverse outcomes. OLE treatment reduced lipid peroxidation and enhanced the activities of catalase and superoxide dismutase, indicating its anti-oxidant properties. Furthermore, OLE significantly decreased the levels of pro-inflammatory cytokines compared to the groups exposed to noise and Toluene without OLE treatment. Moreover, the in silico investigation substantiated a robust affinity between COX-2 and OLE components, affirming the anti-inflammatory activity. Overall, our findings suggest that OLE possesses anti-inflammatory and anti-oxidative properties that mitigate the adverse effects of concurrent exposure to noise and Toluene.

Olea europaea L. leaf extract mitigates oxidative and histological damage in rat heart tissue exposed to combined noise and toluene: An experimental study.

In many occupational settings, workers are frequently exposed to toluene and noise. However, the individual and combined effects of these exposures on the cardiovascular system have not been fully elucidated. Therefore, this study aimed to investigate the impact of simultaneous exposure to toluene and noise on the rat heart, while also evaluating the potential preventive effect of olive leaf extract (OLE). Forty-eight male Wistar rats were randomly assigned to eight groups (n = 6/group): control group (C), control group that received OLE (C + OLE), group exposed to noise (N), group exposed to noise and receiving OLE (N + OLE), group exposed to toluene (T), group exposed to toluene and receiving OLE (T + OLE), group co-exposed to noise and toluene (NT), and group co-exposed to noise and toluene and receiving OLE (NT + OLE). The rats in this study were subjected to simultaneous exposure to toluene and noise for a duration of six weeks, within a custom-built plexiglass chamber. Toluene was administered at a concentration of 300 ppm, while the noise level was set to 85 dB(A). The exposure chamber was equipped with a generation system, an exposure system, and a monitoring system, ensuring precise and accurate exposure conditions. After the six-week period, heart and blood samples were collected from the rats for subsequent analysis. Plasma levels of cholesterol (CHOL), triglycerides (TG), lactate dehydrogenase (LDH), and creatine kinase (CK) were measured, and histopathological investigation was conducted using HE staining. Additionally, superoxide dismutase (SOD) and catalase (CAT) activities, as well as malondialdehyde (MDA) levels in heart tissue were measured. Our results showed that simultaneous exposure to noise and toluene altered CHOL, TG, LDH, and CK levels, and also caused an increase in lipid peroxidation levels and superoxide dismutase activity, along with a decrease in catalase activity in the heart. A significant alteration in the myocardium was also observed. However, treatment with OLE was found to modulate these oxidative and histological changes, ultimately correcting the deleterious effects induced by the combined exposure to noise and toluene. Therefore, our study suggests that OLE could be a potential preventive measure for individuals exposed to toluene and noise in industrial settings.

Cochlear neuropathy in the rat exposed for a long period to moderate-intensity noises.

Damaging effects on the cochlea of high-intensity acoustic overexposures have been extensively documented, but only few works have focused on the danger of moderate noise levels. Using scanning and transmission electron microscopy, we explored the noise-induced neuroepithelial changes that occur in the cochlea of rats subjected to moderate intensities, 70 and 85 dB SPL, for an extended period of time (6 hr/day over 3 months). Although the full quota of outer and inner sensory hair cells remained present, we detected discrete abnormalities, likely resulting from metabolic impairment, in both types of hair cell within the basal region of the cochlea. In contrast, important noise-dependent losses of spiral ganglion neurons had occurred. In addition, we found cytoplasmic accumulations of lipofuscin-like aggregates in most of the surviving cochlear neurons. These results strongly suggest that noise levels comparable to those of certain working environments, with sufficient exposure duration, pose a severe risk to the cochlea. Moreover, our data support the notion that long-duration exposure to moderate noise is a causative factor of presbycusis.

Assessment of cochlear effects and extra-auditory disorders in male rats exposed repetitively to low noise.

BACKGROUND: The noise is considered as a factor of environmental stress, causing a wide range of health effects such as acoustic, cardiovascular, nervous and endocrine systems. PURPOSE: The present study was conducted to examine the affects of repeated exposure to noise on the peripheral auditory system, adrenal gland and heart tissue. METHOD: The White strain rats "Wistar" were exposed to chronic and repetitive exposure noise at two different intensity levels of 70 and 85dB (A). The noise level was generated by the Audacity® software to an octave-band noise (8616 kHz). The sound exposure duration was 6 hr/day, 5 days per week for 3 months. Quantitative and qualitative investigations were performed by using electron microscopy. The ganglion neuron counting was examined via light microscopy. RESULTS: The results show that exposure to sound intensities 70 and 85 dB (A) for long periods, lead to changes in the morphological structure of the cochlea (inner ear), adrenal cortex and cardiac tissue which involve cell disruption which over time can lead to pathological effects. CONCLUSION: This study provides morphological evidence that repetitive exposure noise at moderate sound levels to 70 and 85 dB (A) induces changes in the peripheral auditory system, the adrenal cortex and heart tissue.

Morphological changes of adrenal gland and heart tissue after varying duration of noise exposure in adult rat.

Noise was considered an environmental stressor causing a wide range of health effects such as acoustic, cardiovascular, nervous, and endocrine systems. The present study was performed to examine the effects of a repeated noise exposure on adrenal gland and heart tissue. The results showed that exposure to moderate intensity sound (70 dB[A]) causes time-dependent changes in the morphological structure of the adrenal cortex that involve disarrangement of cells and modification in thickness of the different layers of the adrenal gland. The experiment revealed important changes depending on exposure duration in the morphological structure of heart tissue that causes irreversible cell damage leading to cell death or necrosis.

Qualitative and quantitative assessment of noise at moderate intensities on extra-auditory system in adult rats.

Noise has long been realized as an environmental stress causing physiological, psychological and behavioral changes in humans. The aim of the present study was to determinate the effect of chronic noise at moderate intensities on both glandular and cardiac function and oxidative status. Our problem comes from working conditions in call centers where operators are responsible for making simple and repetitive tasks. One wishes to ascertain the effects of moderate sound levels on rats exposed to the same noise levels during similar periods to those experienced by call center operators. Male Wistar rats were exposed to 70 and 85 dB(A) to an octave-band noise (8-16 kHz) 6 h/day for 3 month. Corticosterone levels, oxidative status and functional exploration of adrenal and thyroid glands and cardiac tissue were determined. Exposure to long-term noise for different intensities (70 and 85 dB(A)) resulted in increased corticosterone levels, affected various parameters of the endocrine glands and cardiac function. Markers of oxidative stress (catalase, superoxide dismutase and lipid peroxidation) were increased. These results imply that long-term exposure to noise even at moderate levels may enhance physiological function related to neuroendocrine modulation and oxidative imbalance. In these data, the physiological changes occur during the different sounds suggests the concept of allostatic load or homeostatic response of the body.

[Occupational low back pain in Tunisia]. / La lombalgie post-traumatique professionnelle en Tunisie.

BACKGROUND: In Tunisia, eight researches works, dealing with low back trauma (LBT), have been achieved in some occupational sector activities and only 2 of them have been published. AIM: To synthesize data provided by these 8 works realized between 1998 and 2007, in order to estimate the disorder magnitude and to describe LBT victims profile in Tunisia. METHODS: The global population of study is made of 1357 LBT victims (977 belonging to the private sector and 380 to the public sector). The data collection was carried out according to an uniformed model for the 8 studies. RESULTS: In the public sector, Commission Médicale Centrale data show that LBT account for 4 to 5% of occupational accidents (OA) and that their annual incidence is from 32 to 36/100000. In the private sector, Caisse Nationale d'Assurance Maladie data reveal that LBT account for 7.7% to 9.5% of OA. LBT victim is a male (83%), with an age ranging between 36 and 43.5 years, married (84%), educated up to the secondary educational (91%) with a vertebral disorders history (34%). He belongs to the general-purpose workmen category in 1/2 of cases with an average seniority ranging between 7.8 and 16.2 years. LBT almost subjects, get at least of a sick leave. Work days lost is around 210 days for the private sector and 18 days for the public. The per annum amount versed for each LBT case, within the framework of the Total Temporary incapacity, is of 1449.319 DT and 45% of the subjects profit from a professional reclassification. CONCLUSION: Our results join those of international studies having dealt with LBD in professional environment. In spite of some limiting methodological issues, they allowed us to provide to professionals in occupational health useful data for this occupational risk management.