Ameliorative Effect of Berberine on Thiacloprid-Induced Hippocampal Oxidative Stress and Cognitive Deficits

Abstract

Background: Thiacloprid is a commonly used neonicotinoid insecticide that is used to control insects on farms. It has been found that thiacloprid causes neurotoxicity due to oxidative stress, mitochondrial dysfunction, inflammation, and neuronal damage. Berberine and Chlorogenic acid are effective antioxidants with neuroprotective potential. Thiacloprid (65 mg/kg), berberine (50 and 100 mg/kg), and chlorogenic acid (5 and 10 mg/kg) and their combinations were administered to Wistar albino rats randomly grouped into ten sets (n = 6) for 40 days. The behavioural activity of rats was determined using the open field test and Morris water maze test. Measurement of biochemical parameters such as malondialdehyde (MDA), glutathione (GSH), and acetylcholinesterase (AChE) was conducted on brain tissue homogenates. Activities of mitochondrial complex I, as well as pro-inflammatory cytokines like IL-6  were assessed. Histopathological evaluation of brain tissues was done by HE staining. Administration of thiacloprid led to a significant increase in MDA, nitric oxide, IL-6, and AChE, as well as significant decreases in GSH,  IL-6, and mitochondrial enzyme activities when compared to controls (P<0.05). Behavioural assessment showed a lack of locomotor activity and anxiety behaviour in the thiacloprid-exposed group, alongside memory impairment. There were findings of neuronal pyknosis and degeneration in the hippocampus following pathological assessment. The use of berberine and chlorogenic acid, individually or in combination, had a significant impact on all the biochemical, behavioral, inflammatory, mitochondrial, and histological findings in a dose dependent. Both berberine and chlorogenic acid showed strong neuroprotective properties against thiacloprid-induced neurotoxicity due to the presence of antioxidants, anti-inflammatory factors, and mitochondrial protection. In combination, they showed increased efficacy, indicating that they could be used as natural remedies to counteract oxidative neuronal damage and cognitive impairment caused by pesticides.