No abstract

Lead poisoning is one of the most significant health problem of environmental origin. It is known to cause different damages in the central and peripheral nervous system which could be represented by several neurophysiological and behavioral symptoms. In this study we firstly investigated the effect of lead prenatal exposure in rats to (3g/L), from neonatal to young age, on the motor/sensory performances, excitability of the spinal cord and gaits during development. Then we evaluated neuroprotective effects of curcumin I (Cur I) against lead neurotoxicity, by means of grasping and cliff avoidance tests to reveal the impairment of the sensorimotor functions in neonatal rats exposed prenatally to lead. In addition, extracellular recordings of motor output in spinal cord revealed an hyper-excitability of spinal networks in lead treated rats. The frequency of induced fictive locomotion was also increased in treated rats. At the young age, rats exhibited an impaired locomotor gait. All those abnormalities were attenuated by Cur I treatment at a dose of 16g/kg. Based on our finding, Cur I has shown features of a potent chemical compound able to restore the neuronal and the relative locomotor behaviors disturbances induced by lead intoxication. Therefore, this chemical can be recommended as a new therapeutic trial against lead induced neurotoxicity.

Substantial evidence supports the neurochemical vulnerability to lead (Pb) as one of the most potent neurotoxic heavy metals. In the present study, we aimed to assess: (i) The subcommissural organ (SCO) responsiveness as a secretory circumventricular organ to chronic and acute Pb intoxication together with its serotoninergic innervation. (ii) The possible restorative effect of curcumin against Pb intoxication under the same pathological conditions. We used immunohistochemistry with antibodies against Reissner's fiber and serotonin [5-hydroxytryptophan (5-HT)] in Wistar rats following chronic as well as acute Pb administration, respectively, at 25 mg/kg intraperitoneally for 3 days and 0.3% in drinking water from the intrauterine stage until 2 months of adult age. Our data showed a significant decrease in Reissner's fiber material immunoreactivity concomitant with an overall increased 5-HT innervation of the SCO and the ventricular borders. Coadministration of curcumin (50 mg/kg body weight) restores this impairment by reversing the effect of chronic and acute Pb on the secretory activity and the 5-HTergic innervation of the SCO. The investigation showed, on the one hand, the involvement of the SCO in the response to heavy metals, especially Pb, and on the other, the beneficial corrector role of curcumin. As a part of the circumventricular organ, known as a privileged area of brain-blood exchanges, the SCO may play a key role in the mechanism of brain defense against heavy metal neurotoxicity in rats.

Depression and anxiety are among the most serious disorders spread-out all over the world. In most cases, patients with depression present features of anxiety. Interestingly and inversely, patients with anxiety also present depression. Thus, both disorders may occur together, with one meeting criteria of the other. The extent of the two disorders has been shown through the high rates of their prevalence. They are, furthermore, associated with significant morbidity which shows how important is to identify and treat both illnesses. However, several epidemiological studies have reported such illnesses to be intensified with the influence of environmental factors such as the toxic effect of heavy metals. Furthermore, the influence of climate change exacerbates the negative effect of these elements. Biological and preclinical investigations have reconciled the mechanism of action by which heavy metals set off emotional disorders. Though its potential harms are important, more studies are needed to understand heavy metals' influence on the evoked pathways.

Climate change has an important impact on the environment. As it degrades the quality of water, soil, and area, it also spreads the distribution of many toxic elements, specifically heavy metals and pesticides. The impact of climate change on contamination with heavy metals and pesticides has been well investigated and discussed. The influence of these elements on human health is obviously exacerbated following their extended distribution. Moreover, a wide range of health problems have been associated to such intoxication, among which impairment and dysfunction of the nervous system are prominent. In this chapter, the authors will shed light on two most common neurological diseases such as epilepsy and stroke affecting people worldwide arising from food and water contaminations, mainly with heavy metals and pesticides.