Ziziphus spina-christi Leaf Extract Mitigates Mercuric Chloride-induced Cortical Damage in Rats

Background: Mercuric chloride (HgCl2) severely impairs the central nervous system when humans are exposed to it. Aims: We investigated the neuroprotective efficiency of Ziziphus spina-christi leaf extract (ZSCLE) on HgCl2-mediated cortical deficits. Methods: Twenty-eight rats were distributed equally into four groups: the control, ZSCLE-treated (300 mg/kg), HgCl2-treated (0.4 mg/kg), and ZSCLE+HgCl2-treated groups. Animals received their treatments for 28 days. Results: Supplementation with ZSCLE after HgCl2 exposure prevented the deposition of mercury in the cortical slices. It also lowered malondialdehyde levels and nitrite and nitrate formation, elevated glutathione levels, activated its associated-antioxidant enzymes, glutathione reductase, and glutathione peroxidase, and upregulated the transcription of catalase and superoxide dismutase and their activities were accordingly increased. Moreover, ZSCLE activated the expression of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 when compared with the HgCl2 group. Notably, post-treatment with ZSCLE increased the activity of acetylcholinesterase and ameliorated the histopathological changes associated with HgCl2 exposure. Furthermore, ZSCLE blocked cortical inflammation, as observed by the lowered mRNA expression and protein levels of interleukin-1 beta and tumor necrosis factor-alpha, as well as decreased mRNA expression of inducible nitric oxide synthase. In addition, ZSCLE decreased neuron loss by preventing apoptosis in the cortical tissue upon HgCl2 intoxication. Conclusion: Based on the obtained findings, we suggest that ZSCLE supplementation could be applied as a neuroprotective agent to decrease neuron damage following HgCl2 toxicity.