Searsia chirindensis reverses the potentiating effect of prenatal stress on the development of febrile seizures and decreased plasma interleukin-1β levels

Acute hypoxia exposure following prenatal stress impairs hippocampus and novelty-seeking behavior in adolescent rats

OBJECTIVES

The present study aimed to investigate the effects of acute hypoxia exposure following prenatal stress on the novelty-seeking behavior and hippocampus of adolescent rats.

METHODS

The offspring were divided into prenatal stress (PS) and non-stress (NS) groups. Both groups were exposed to hypoxia on postnatal day 10 (P10) while control groups were undisturbed. Novel object recognition task was performed in each group. Next, brains were collected to examine hippocampus via immunohistochemical and biochemical studies on postnatal day 35 (P35).

RESULTS

PS decreased novelty discrimination and synaptophysin (SYN) expressions in both CA1 and CA3 of the hypoxia group prominently (p < 0.05). Nestin-expressing cells were reduced while vascular endothelial growth factor (VEGF) expression was enhanced in the subgranular zone (SGZ) of PS-hypoxia group (p < 0.05). VEGF enhancement triggered angiogenesis in the CA1 and CA3 significantly (p < 0.05). PS also increased thiobarbituric acid reactive substances (TBARS) levels in the hypoxia group as a result of oxidative stress (p < 0.05).

CONCLUSION

These findings demonstrated that PS exacerbates neurodevelopmental deficits in the hippocampus of acute hypoxia-induced offspring in adolescence.

The Pathogenesis of Fever-Induced Febrile Seizures and Its Current State

Febrile seizures, commonly in children between the ages of 3 months to 5 years, are a neurological abnormality characterized by neuronal hyper-excitability, that occur as a result of an increased core body temperature during a fever, which was caused by an underlying systemic infection. Such infections cause the immune system to elicit an inflammatory response resulting in the release of cytokines from macrophages. The cytokines such as interleukin (IL)- 1β, IL-6, and tumour necrosis factor-α (TNF-α) combat the infection in the localized area ultimately spilling over into circulation resulting in elevated cytokine levels. The cytokines, along with pathogen-associated molecular patterns (PAMPs) expressed on pathogens for example, lipopolysaccharide (LPS), interact with the blood brain barrier (BBB) causing a ‘leaky’ BBB which facilitates cytokines and LPS entry into the central nervous system. The cytokines activate the microglia which release their own cytokines, specifically IL1β. IL-β interacts with the brain endothelium resulting in the activation of cyclooxygenase 2 which catalyzes the production of prostaglandin 2 (PGE2). PGE2 enters the hypothalamic region and induces a fever. Abnormally increased IL-1β levels also progressively increases excitatory (glutamatergic) neurotransmission, and decreases inhibitory (GABAergic) neurotransmission, thus mediating the pathogenesis of convulsions. Current treatments for febrile seizures present with side effects that are detrimental to health, which fosters the need for an alternative, more affordable treatment with fewer adverse side effects, and 1 that is easily accessible, especially in low income areas that are also affected by other underlying socio-economic factors, in which febrile seizures are of growing concern.

Notes on the Recent History of Neuroscience in Africa

Neuroscience began with neuroanatomy and neurosurgery in Egypt more than 5000 years ago. Knowledge grew over time and specialized neurosurgery centers were established in north Africa in the eleventh century. However, it was not until the twentieth century that neuroscience research became established in sub-Saharan Africa. In most African countries, clinical research focused on understanding the rationale and improving treatment of epilepsy, infections, nutritional neuropathies, stroke and tumors. Significant advances were made. In the twenty-first century, African knowledge expanded to include all branches of neuroscience, contributing to genetic, biochemical and inflammatory determinants of brain disorders. A major focus of basic neuroscience research has been, and is, investigation of plant extracts, drugs and stress in animal models, providing insight and identifying potential novel therapies. A significant event in the history of African neuroscience was the founding of the Society of Neuroscientists of Africa (SONA) in 1993. The International Brain Research Organization (IBRO) supported SONA conferences, as well as workshops and neuroscience training schools in Africa. Thanks to their investment, as well as that of funding agencies, such as the National Institutes of Health (NIH), International Society for Neurochemistry (ISN), World Federation of Neurosurgical Societies (WFNS), World Federation of Neurology (WFN) and the International League Against Epilepsy (ILAE), neuroscience research is well-established in Africa today. However, in order to continue to develop, African neuroscience needs continued international support and African neuroscientists need to engage in policy and decision-making to persuade governments to fund studies that address the unique regional needs in Africa.

The Effect of Quercetin on Pro- and Anti-Inflammatory Cytokines in a Prenatally Stressed Rat Model of Febrile Seizures

Febrile seizures are childhood convulsions resulting from an infection that leads to an inflammatory response and subsequent convulsions. Prenatal stress has been shown to heighten the progression and intensity of febrile seizures. Current medications are costly and have adverse effects associated with prolonged use. Quercetin flavonoid exhibits anti-inflammatory, anti-convulsant, and anti-stress effects. This study was aimed to investigate the therapeutic effect of quercetin in a prenatally stressed rat model of febrile seizures. We hypothesized that quercetin will alleviate the effects of prenatal stress in a febrile seizure rat model. On gestational day 13, Sprague-Dawley rat dams were subjected to restraint stress for 1 hour/d for 7 days. Febrile seizures were induced on postnatal day 14 on rat pups by intraperitoneally injecting lipopolysaccharide followed by kainic acid and quercetin on seizure onset. Hippocampal tissue was harvested to profile cytokine concentrations. Our results show that quercetin suppresses prenatal stress–induced pro-inflammatory marker (interleukin 1 beta) levels, subsequently attenuating febrile seizures. This shows that quercetin can be therapeutic for febrile seizures in prenatally stressed individuals.

Hepatoprotective activity of Rhus oxyacantha root cortex extract against DDT-induced liver injury in rats

The present investigation aimed to study the antioxidant activity and hepatoprotective effects of ethyl acetate extract of R. oxyacantha root cortex (RE) against DDT-induced liver injury in male rats. The RE exhibited high total phenolic, flavonoid and condensed tannins contents. The antioxidant activity in vitro systems showed a significant potent free radical scavenging activity of the extract. The HPLC finger print of R. oxyacantha active extract showed the presence of five phenolic compounds with higher amounts of catechol and gallic acid. The in vivo results showed that a single intraperitoneal administration of DDT enhanced levels of hepatic markers (ALT, AST and LDH) in serum of experimental animals. It also increased the oxidative stress markers resulting in increased levels of the lipid peroxidation with a significant induction of SOD and GPx, metallothioneins (MTs) and a concomitant decrease of non protein thiols (NPSH) in liver. However, pretreatment of rats with RE at a dose of 150 and 300mg/kg body weight significantly lowered serum transaminases and LDH in treated rats. A significant reduction in hepatic thiobarbituric reactive substances and a decrease in antioxidant enzymes activities and hepatic MTs levels by treatment with plant extract against DDT, were observed. These biochemical changes were consistent with histopathological observations, suggesting marked hepatoprotective effect of RE with the two doses used. These results strongly suggest that treatment with ethyl acetate extract normalizes various biochemical parameters and protects the liver against DDT-induced oxidative damage in rats and thus help in evaluation of traditional claim on this plant.