Thymoquinone ameliorate oxidative stress, GABAergic neuronal depletion and memory impairment through Nrf2/ARE signaling pathway in the dentate gyrus following cypermethrin administration.

BACKGROUND: Exposure to chemical toxins, including insecticides, harms bodily organs like the brain. This study examined the neuroprotective of thymoquinone on the cypermethrin's harmful effects on the histoarchitecture of the dentate gyrus and motor deficit in the dentate gyrus. METHODS: Forty adult male rats (180-200 g) were randomly divided into 5 groups (n = 8 per group). Groups I, II, III, IV, and V received oral administration of 0.5 ml of phosphate-buffered saline, cypermethrin (20 mg/kg), thymoquinone (10 mg/kg), cypermethrin (20 mg/kg) + thymoquinone (5 mg/kg), and cypermethrin (20 mg/kg) + thymoquinone (10 mg/kg) for 14 days respectively. The novel object recognition test that assesses intermediate-term memory was done on days 14 and 21 of the experiment. At the end of these treatments, the animals were euthanized and taken for cytoarchitectural (hematoxylin and eosin; Cresyl violet) and immunohistochemical studies (Nuclear factor erythroid 2-related factor 2 (Nrf2), Parvalbumin, and B-cell lymphoma 2 (Bcl2). RESULT: The study shows that thymoquinone at 5 and 10 mg/kg improved Novelty preference and discrimination index. Thymoquinone enhanced Nissl body integrity, increased GABBAergic interneuron expression, nuclear factor erythroid 2-derived factor 2, and enhanced Bcl-2 expression in the dentate gyrus. It also improved the concentration of nuclear factor erythroid 2-derived factor 2, increased the activities of superoxide dismutase and glutathione, and decreased the concentration of malondialdehyde level against cypermethrin-induced neurotoxicity. CONCLUSION: thymoquinone could be a therapeutic agent against cypermethrin poisoning.

Honey and levodopa comparably preserved substantia nigra pars compacta neurons through the modulation of nuclear factor erythroid 2-related factor 2 signaling pathway in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease model.

Parkinson's disease (PD) affects about 8.5 million individuals worldwide. Oxidative and inflammatory cascades are implicated in the neurological sequels, that are mostly unresolved in PD treatments. However, proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors. Moreover, prevention may be the best response to the progressive nature of PD, thus, the therapeutic novelty of honey and levodopa may be prospective. This study aimed to investigate the neuroprotective role of honey and levodopa against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced oxidative stress. Fifty-four adult male Swiss mice were divided into control and PD model groups of 27 mice. Each third of the control mice either received phosphate buffered saline, honey, or levodopa for 21 days. However, each third of the PD models was either pretreated with honey and levodopa or not pretreated. Behavioral studies and euthanasia were conducted 2 and 8 days after MPTP administration respectively. The result showed that there were significantly (P<0.05) higher motor activities in the PD models pretreated with the honey as well as levodopa. furthermore, the pretreatments protected the midbrain against the chromatolysis and astrogliosis induced by MPTP. The expression of antioxidant markers (glutathione [GSH] and nuclear factor erythroid 2-related factor 2 [Nrf2]) was also significantly upregulated in the pretreated PD models. It is thus concluded that honey and levodopa comparably protected the substantia nigra pars compacta neurons against oxidative stress by modulating the Nrf2 signaling molecule thereby increasing GSH level to prevent MPTP-induced oxidative stress.

Frequent exposure to varied home cage sizes alters pain sensitivity and some key inflammation-related biomarkers.

BACKGROUND: Nature and size of rodent cages vary from one laboratory or country to another. Little is however known about the physiological implications of exposure to diverse cage sizes in animal-based experiments. METHOD: Here, two groups of male Swiss mice (Control group - Cage stationed, and Test group - Cage migrated) were used for this study. The cage-migrated mice were exposed daily to various cage sizes used across laboratories in Nigeria while the cage-stationed mice exposed daily to different but the same cage size and shape. At the end of the 30 days exposure, top-rated paradigms were used to profile changes in physiological behaviours, and this was followed by evaluation of histological and biochemical metrics. RESULTS: The study showed a significant (p < 0.05) decrease in blood glucose levels (at 60 and 120 min of oral glucose tolerance test) in the cage-migrated mice compared to cage-stationed mice. Strikingly, peripheral oxidative stress (plasma malondialdehyde) and pain sensitivity (formalin test, hot-and-cold plate test, and von Frey test) decreased significantly in cage-migrated mice compared to cage-stationed animals. Also, the pro-inflammation mediators (IL-6 and NF-κB) increased significantly in cage-migrated mice compared to cage-stationed mice. However, emotion-linked behaviours, neurotransmitters (serotonin, noradrenaline and GABA), brain and plasma electrolytes were not significantly difference in cage-migrated animals compared to cage-stationed mice. CONCLUSION: Taken together, these results suggest that varied size cage-to-cage exposure of experimental mice could affect targeted behavioural and biomolecular parameters of pain and inflammation, thus diminishing research reproducibility, precipitating false negative/positive results and leading to poor translational outcomes.