Abeer M. Waggas

Neurophysiological study on possible protective and therapeutic effects of Sidr (Zizyphus spina-christi L.) leaf extract in male albino rats treated with pentylenetetrazol.

In this study, anti-convulsant effect of Sidr leaf extract was examined by using pentylenetetrazol (PTZ) model on male albino rat by evaluating the changes in norepinephrine (NE), dopamine (DA) and serotonin (5-HT) contents in different brain regions (cerebellum, brainstem, striatum, cerebral cortex, hypothalamus and hippocampus). The administration of subconvulsive dose of PTZ (40 mg/kg i.p.) every other day for 9 days caused a significant decrease in monoamine content in different brain areas, this is may be due to the increase in nitric oxide levels, although antagonized the GABAA receptors which led to neurotransmitter release so the content is decreased. Administration of PTZ after treatment with Sidr (50 mg/kg i.p.) leaf extract for 3 weeks as a protective group and administration of Sidr leaf extract for 3 weeks after treatment of PTZ as a therapeutic group caused significant increase in NE, DA, and 5-HT contents in all tested brain regions at most of the time intervals studied. This may be due to the presence of peptide and cyclopeptide alkaloids in the extract which inhibit neurotransmitter activity which led to the inhibition of neurotransmitter release. From these results, we can say that the Sidr leaf extract has neuroprotective and therapeutic roles against pentylenetetrazol convulsant effect.

Neurophysiological and behavioral effects of mycotoxin deoxynivalenol and fumonisin

Two experiments were conducted to compare the effects of feeding blends of wheat grains naturally contaminated with deoxynivalenol (DON) and maize products contaminated with Fusarium (FUM) mycotoxins on brain regional concentration of brain dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in hippocampus, mid brain, cortex, striatum, pons and medulla and cerebellum of male albino mice. Daily feeding of wheat or maize grains contaminated with deoxynivalenol in a dose level (803 μg/kg) or fumonisin in a dose level (1330 ppb) for six weeks caused highly significant increase in dopamine (DA), norepinephrine (NE) and serotonin (5-HT ) contents, in most of the studied mice brain areas. When all the studied brain areas were compared, it can be concluded that hypothalamusdopamine concentration was more sensitive towards the studied toxicants. On the other hand, except for norepinephrine in pons and medulla oblongata, there was a significant increase in epinipherine and serotonin levels at all the studied brain areas. Maximal concentration, however, was attained in the cortex for both neurotransmitters. Additionally, rearing behavior was found to increase following feed intake of the test feed and deoxynivalenol was found to modulate more behavioral disturbances as compared with fuminisin. The data recorded also showed a highly significant increase in the aggressive and locomotor behavior of the intoxicated albino mice.