Nigella sativa (NS) has been suggested to have neuroprotective and anti-seizures properties. The aim of current study was to investigate the effects of NS hydro-alcoholic extract on neural damage after pentylenetetrazole (PTZ) – induced repeated seizures. The rats were divided into five groups: (1) control (saline), (2) PTZ (50 mg/kg, i.p.), (3–5) PTZ-NS 100, PTZ-NS 200 and PTZ-NS 400 (100, 200 and 400 mg/kg of NS extract respectively, 30 min prior to each PTZ injection on 5 consecutive days). The passive avoidance (PA) test was done and the brains were then removed for histological measurements. The PTZ-NS 100, PTZ-NS 200 and PTZ-NS 400 groups had lower seizure scores than PTZ group (P < 0.01 and P < 0.001). The latency to enter the dark compartment by the animals of PTZ group was lower than control in PA test (P < 0.01). Pre-treatment by 400 mg/kg of the extract increased the latency to enter the dark compartment (P < 0.05). Meanwhile, different doses of the extract inhibited production of dark neurons in different regions of hippocampus (P < 0.001). The present study allows us to suggest that the NS possesses a potential ability to prevent hippocampal neural damage which is accompanied with improving effects on memory.

No abstract

No abstract

Adult neurogenesis is the production of new nerve cells in the adult brain. Neurogenesis is a clear example of the neuroplasticity phenomenon which can be observed in most of mammalian species, including human beings. This phenomenon occurs, at least, in two regions of the brain: the subgranular zone of the dentate gyrus in hippocampus and the ventricular zone of lateral ventricles. Numerous studies have investigated the relationship between sex steroid hormones and neurogenesis of adult brain; of which, mostly concentrated on the role of estradiol. It has been shown that estrogen plays a significant role in this process through both classic and non-classic mechanisms, including a variety of different growth factors. Therefore, the objective of this review is to investigate the role of female sex steroids with an emphasis on estradiol and also its potential implications for regulating the neurogenesis in the adult brain.

No abstract