Study the effect of olive extracts on chromium (VI) induced neuro-histo-toxicological defects in adult male albino rats

Many industries are based on chromium, leading to an increase in its environmental residue percentage, especially hexavalent chromium, which increases the risk for several types of cancers and is recognized as a neurotoxicant. Olive oil is a major component of the Mediterranean diet because of its high antioxidant and anti-inflammatory effects. The present study aimed to investigate the adverse effects of hexavalent chromium intoxication (2 mg/b.wt) on several neurophysiological parameters in the cortex and cerebellum and to demonstrate the ameliorating effects of 200 mg/b.wt olive extract on the resulting chromium effect via biochemical, histopathological, and immunohistochemical investigations. The animals were grouped into four groups (control, chromium (Cr), olive extract (OE) and Cr + OE). The results revealed that chromium hexavalent significantly increased the levels of three monoamines, norepinephrine (NE), dopamine (DA), serotonin (5-HT) and both sodium and calcium ions, in addition to increasing the levels of oxidative stress biomarkers, interleukin-1β (IL-1β), interferon (INF-γ), malondialdehyde and nitric oxide. Additionally, chromium caused a significant decrease in potassium ion and glutathione (GSH) levels. Additionally, chromium administration caused intensive necrosis with shrinking in the neural cell while olive extract could mitigate this effect. The coadministration of chromium and olive extract had an ameliorating effect on all the tested parameters. Finally, the ameliorative effect of olive extract may be attributed to its high antioxidant activity and ability to scavenge free radicals.