Preventive action of Ginkgo biloba in stress- and corticosterone-induced impairment of spatial memory in rats

In this study, we tested preventive effects of a natural medicine the extract of Ginkgo biloba (EGB 761) on post-stress cognitive dysfunction. Exposure to chronic restraint stress in rats and psychosocial stress in humans has been shown to alter cognitive functions such as learning and memory and have been linked to the pathophysiology of mood and anxiety disorders.Our findings indicate that chronic restraint stress impaired egocentric spatial memory as observed in the eight-arm radial maze but it did not alter the allocentric spatial memory in the Morris water maze. In control rats EGB 761 (100 mg/kg, orally) improved spatial memory in these two tests. Also, EGB 761 normalized cognitive deficits seen in rats chronically stressed or treated with an ‘equivalent’ dose of exogenous corticosterone (5 mg/kg, subcutaneously).We conclude that, in rats, repeated administration of EGB 761 prevents stress- and corticosterone-induced impairments of spatial memory.     

Middle Jurassic Ginkgo leaves from the Daohugou area,Inner Mongolia,China and their implication for palaeo-CO2 reconstruction

Well-preserved Ginkgo leaves with cuticle were collected from the Middle Jurassic Jiulongshan Formation in the Daohugou area, Inner Mongolia, China, which form the common elements in the Daohugou flora. Three new species of Ginkgo are recognized and their leaf morphology and cuticular structure are described for the first time. Two different pCO₂ proxy models were applied to reconstruct palaeo-atmospheric CO₂ concentration by using these new Ginkgo material. NLE (nearest living equivalent) suggests a semi-quantitative pCO₂ estimate as 839 ± 99 ppmv with Carboniferous standardization and 419 ± 49 ppmv with Recent standardization. While Barclay’s revised SI-pCO₂ regression suggests the estimates as 405 ± 71 ppmv. The results show that the pCO₂ estimate is higher than today’s atmospheric CO₂ concentration but lower than most of the other results on the Jurassic Period. Combined with the floristic composition, the climate at 165 Ma in the Daohugou area is inferred to be warm temperate.     

Synthesis and pharmacological evaluation of new arylpiperazines N-{4-[4-(aryl) piperazine-1-yl]-phenyl}-amine derivatives: Putative role of 5-HT1A receptors

In an attempt to design novel 5-HT_1A agonists/partial agonists, based on an arylpiperazine nucleus, a series of N-{4-[4-(aryl)piperazine-1-yl]-phenyl}-amine derivatives were synthesized and biologically tested. The anxiolytic effect of the compounds was investigated employing the Elevated plus Maze (EPM) task. On the basis of in vivo functional test, compound 1c (3 mg/kg) and 4c (3 mg/kg) induced significant increments in open arm entries and time on EPM as compared to Buspirone. The anxiolytic effects of compounds 1c and 4c were effectively antagonized by WAY-100635, a 5-HT_1A receptor antagonist (0.5 mg/kg). Furthermore, we have also evaluated the concentration of 5-HT in the brain tissue using HPLC with fluorescent detection. Our result showed that serotonin levels were significantly decreased by ～38% (p < 0.001) and ～32% (p < 0.001) after acute administration of compounds 1c and 4c, respectively. These findings suggest that the anxiolytic like activity of these new arylpiperazines is mediated via 5-HT_1A receptors in the brain.     

Reproductive and developmental toxicity of the Ginkgo biloba special extract EGb 761® in mice

Extracts from leaves of Ginkgo biloba are among the most widely used and best investigated phytopharmaceuticals worldwide. Almost all clinical trials and the majority of preclinical studies have been performed with a specifically defined extract (EGb 761^®) standardized to contain confined concentrations of active ingredients and limited quantities of potentially harmful substances. Besides pharmaceutical grade extracts poorly characterized Ginkgo preparations are now increasingly appearing on the market as nutraceuticals. While the safety of EGb 761^® has been evaluated in an extensive set of toxicology studies, adverse effects of Ginkgo extracts of non-pharmaceutical quality on reproductive functions in mice have been reported in several publications in recent years. As this species has not previously been used in reproductive toxicity studies with EGb 761^®, the present investigation was conducted to examine the influence of EGb 761^® (100, 350 and 1225 mg/kg/day) on embryo-fetal development in mice during the critical period of organogenesis. During external and internal inspection of the fetuses as well as examination of skeletal and soft tissues no embryotoxic properties were noted. In particular, the incidence of malformations, variations or retardations was not increased and the general condition of dams was not influenced. Thus, the no-observed-effect level (NOEL) was above 1225 mg/kg/day for the dams and the fetuses.     

Reading paleoenvironmental information from Middle Jurassic ginkgoalean fossils in the Yaojie and Baojishan basins,Gansu Province,China

A new method for reconstructing paleoenvironments using the pavement cell characteristics of Middle Jurassic ginkgoalean fossils from the Yaojie and Baojishan basins, Gansu Province, China, is presented. Specifically, we use present-day relationships between the length-to-width (L/W) ratio of leaf pavement cells of Ginkgo biloba and mean annual temperature (MAT), mean annual precipitation (MAP), and relative humidity (RH). Primary analyses indicate that the L/W ratio of Ginkgo biloba pavement cells is negatively correlated with MAT, MAP, and RH, and linear regression equations can be established. Based on these equations, paleoclimatic parameters were inferred using the ginkgoalean fossil data. The estimated paleotemperatures in the Yaojie and Baojishan basins during the Middle Jurassic are approximately 6 °C higher than those of the present day, which is consistent with the results of the currently used stomata ratio method and the global CO₂ prediction model. We deduce that paleoprecipitation in the basins was approximately 460 mm higher and paleohumidity approximately 20% higher than current conditions and thus the two basins exhibited humid subtropical conditions during the Middle Jurassic. Fossil flora and spore-pollen assemblage data from the study areas corroborate the new observations.     

Cytotoxic azaphilone alkaloids from Chaetomium globosum TY1

Three novel azaphilone alkaloids, namely chaetomugilides A–C (1–3), together with three related compounds (4–6) were isolated from the methanol extract of Chaetomium globosum TY1, an endophytic fungus isolated from Ginkgo biloba. Their structures were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic data analysis. The isolated compounds exhibited highly cytotoxic activities against human cancer cell line HePG2 with the IC₅₀ values range from 1.7 to 53.4 μM.     

Anosmia does not impair the anxiolytic-like effect of lavender essential oil inhalation in mice

AimThe inhalation of Lavandula angustifolia (lavender) essential oil has anxiolytic-like effects in animal models and humans, but its mechanism of action is still not fully understood. The inhalation of essential oils can induce anxiolytic effects through the central nervous system (e.g., lung absorption and bloodstream transport) or stimulation of the olfactory system and secondary activation of brain regions. Thus, the main objective of the present study was to evaluate whether the perception of lavender essential oil aroma, when inhaled, is necessary to obtain its anxiolytic-like effects in mice tested in the marble-burying test.Main methodsAnosmia was induced by irrigating the nasal cavity with zinc gluconate + zinc acetate so that the mice could not detect odors in the olfactory discrimination test. The marble-burying test was used to evaluate the anxiolytic-like effects of inhaled lavender essential oil.Key findingsAnosmia did not interfere with the anxiolytic-like effect of lavender essential oil inhalation in the marble-burying test at concentrations of 2.5% (number of marbles buried: vehicle, 4.7 ± 1.0; zinc, 6.2 ± 2.2; p > 0.10) and 5% (number of marbles buried: vehicle, 3.4 ± 0.8; zinc, 4.3 ± 0.9; p > 0.10). Lavender essential oil at a concentration of 0.5% was ineffective.SignificanceThese results suggest that olfactory system activation is unlikely to participate in the anxiolytic-like effect of lavender essential oil inhalation.     

Bone development: The effect of short-term alpha-ketoglutarate administration on long-term mechanical properties of ribs in ram lambs

The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram lambs were randomly assigned to two weight-matched groups at birth. During the first 14 days of life AKG was administered orally to the experimental group (n = 12) at the dosage of 0.1 g/kg body weight per day, while the control group (n = 11) received an equal dose of the vehicle. Lambs were slaughtered at 146 days of life and five left and right ribs (fourth to eighth) were removed for analysis. The influence of AKG on skeletal system development was evaluated in relation to both geometrical and mechanical properties, as well as quantitative computed tomography (QCT). No significant differences between the groups were recorded in terms of: (1) growth rate, (2) body weight at days 14, 28 and 130 of age or (3) final body weight. The weight and length of ribs were, however, significantly increased in the lambs given AKG for the first 14 days of neonatal life by 8.2% and 3.2%, respectively (P < 0.01). Furthermore, AKG administration induced significantly higher bone mineral density of the cortical bone by 7.1% (P < 0.01) and improved the mechanical endurance of ribs in terms of the moments of maximum elastic strength and ultimate strength by 10% and 8%, respectively (P < 0.05). It could be concluded that AKG has a long-term effect on skeletal development when given early in neonatal life, and that changes in rib properties serve to improve chest mechanics and functioning in young animals. Moreover, neonatal administration of AKG may be considered as an effective factor enhancing proper development and function of the skeleton during growth and later life.     

Morphogenesis of leaves and cones of male short-shoots of Ginkgo biloba L.

Although the subject of several studies, the phylogeny of Ginkgo biloba is still ambiguous. Most of the morphological and some palaeontological studies assume a close relationship to conifers, but other palaeontological studies regard the origin of Ginkgo biloba in groups that exhibit a pinnate bauplan like Peltaspermales or Dicranophyllales. This divergence has led to controversial interpretations of male sporangiophores and leaves. Attempting to resolve this, here we have investigated the male cones and leaves of short-shoots by SEM and light-microscopy. Our results indicate that the male sporangiophores are simple structures, and the observed formation of thickened cell walls at the sterile adaxial side of the sporangiophores, similar to the endothecium of the sporangia, gives weak support for a precursor of Ginkgo-sporangiophores that displayed simple male sporangiophores with radial arrangement of the sporangia. Thus, our interpretations of the male sporangiophores of Ginkgo biloba allude to a relationship with Coniferales, Gnetales and Cordaitales and reject a close relationship of Ginkgo biloba with pinnate groups like Cycadaceae, as assumed by some molecular studies. In contrast to previous studies on long-shoot leaves, our results on short-shoot leaves give no indication for a compound character of Ginkgo leaves. Moreover, we infer that Ginkgo leaves could be derived from a simple bauplan, by two modifications of the basic growth pattern of conifer leaves, assuming that the dissection of Ginkgo leaves is secondary. Although more comparative investigations are necessary, our results support a coniferophyte origin of the Ginkgoales.     

Estradiol modulates the anorexic response to central glucagon-like peptide 1

Estrogens suppress feeding in part by enhancing the response to satiation signals. Glucagon-like peptide 1 (GLP-1) acts on receptor populations both peripherally and centrally to affect food intake. We hypothesized that modulation of the central GLP-1 system is one of the mechanisms underlying the effects of estrogens on feeding. We assessed the anorexic effect of 0, 1, and 10 μg doses of GLP-1 administered into the lateral ventricle of bilaterally ovariectomized (OVX) female rats on a cyclic regimen of either 2 μg β-estradiol-3-benzoate (EB) or oil vehicle 30 min prior to dark onset on the day following hormone treatment. Central GLP-1 treatment significantly suppressed food intake in EB-treated rats at both doses compared to vehicle, whereas only the 10 μg GLP-1 dose was effective in oil-treated rats. To follow up, we examined whether physiologic-dose cyclic estradiol treatment influences GLP-1-induced c-Fos in feeding-relevant brain areas of OVX females. GLP-1 significantly increased c-Fos expression in the area postrema (AP) and nucleus of the solitary tract (NTS), and the presence of estrogens may be required for this effect in the paraventricular nucleus of the hypothalamus (PVN). Together, these data suggest that modulation of the central GLP-1 system may be one of the mechanisms by which estrogens suppress food intake, and highlight the PVN as a region of interest for future investigation.     

Kaempferol from the leaves of Apocynum venetum possesses anxiolytic activities in the elevated plus maze test in mice

The present work evaluated the anxiolytic activity of an aqueous extract of Apocynum venetum L. (Apocynaceae) and bioguided its fractionation using the elevated plus maze (EPM) in mice as a model of anxiety. A single treatment of AV extract markedly increased the percentage time spent on the open arms of the EPM in two distinct concentration ranges of 22.5–30 and 100–125 mg/kg p.o., respectively, indicating a putative anxiolytic-like activity. Fractions showing anxiolytic effects in concentrations equal to 30 or 125 mg/kg of whole extract were antagonized using the benzodiazepine antagonist flumazenil (3 mg/kg i.p.) or the 5-HT_1A receptor antagonist WAY-100635 (0.5 mg/kg i.p.). All active fractions in a concentration equal to 125 mg/kg were effectively blocked by the benzodiazepine antagonist flumazenil, while the anxiolytic activities of fractions in the lower dose equivalent to 30 mg/kg of whole extract were inhibited by the 5-HT_1A receptor antagonist WAY-100635. Through further separation of AV fractions it was possible to isolate and characterize the flavonol kaempferol which showed an anxiolytic-like activity in concentrations from 0.02 to 1.0 mg/kg p.o. The anxiolytic activity of kaempferol was partially antagonized by concomitant administration of flumazenil, but not by WAY-100635. In conclusion, our study clearly demonstrates that AV extract possesses anxiolytic-like activity and that at least one of its flavonoids, kaempferol, can elicit the same kind of neuropharmacological activity.     

Effects of Panax ginseng on the nerve growth factor expression in testosterone induced benign prostatic hyperplasia

The prostatic hyperplasia in benign prostatic hyperplasia (BPH) leads to obstructive micturition symptoms. Previous studies showed that pontine micturition center (PMC), ventrolateral periaqueductal gray (vlPAG), and medial preopticnucleus (MPA) regions in the brain have been known to regulate the urinary bladder function. The present study shows the influences of Panax ginseng on nerve growth factor (NGF) expressions in PMC, vlPAG, and MPA regions in the brain. Wistar rats were used for the present study. The rats split into four groups; 4 groups (n = 6) in control group, BPH-induced group, BPH-induced and P. ginseng-treated group, and BPH-induced and finasteride-treated group. BPH in rats was induced by testosterone and the animals were evaluated for NGF expression in PMC, vlPAG, and MPA regions in the brain. The NGF expression was identified using immunohistochemistry (IHC). The NGF expression by IHC showed spots with dark brown color. In our results, NGF expressions in PMC, vlPAG, and MPA regions in the brainstem of the BPH-induced group showed increase than the control animal. These increased NGF expressions in three regions were decreased using treatment with P. ginseng (200 mg/kg). These results suggest that P. ginseng has therapeutic effects on the symptoms of BPH and is associated with the regulation of NGF expression in the brain. In conclusion, the administration of P. ginseng helps nerve growth factor activation.     

773. GINKGO BILOBA – Connections with people and art across a thousand years

We review the representation of Ginkgo biloba L., a quintessentially Chinese plant, in the art of those Western botanists who first encountered it in China and Japan. We also show how several later representations of Ginkgo, in both the West and the East, were inspired and made possible by specimens of Ginkgo in cultivation.     

Protective effect of combined therapy with dithiothreitol,zinc and selenium protects acute mercury induced oxidative injury in rats

The present study was undertaken to establish mode of action, comparative therapeutic efficacy and safety evaluation of dithiothreitol (DTT) supplemented with Zn and Se against dimethylmercury in rats. Adult male albino rats of Sprague-Dawley strain (150 ± 10 g, n = 6 per group) were exposed a bolus dose of dimethylmercury (10 mg/kg, p.o.) for once only followed by DTT (15.4 mg/kg, i.p.) along with the combination of antioxidants Zn and Se (2 mmol/kg and 0.5 mg/kg, p.o.) after 72 h of toxicant administration for three days. The results showed a significant (P ≤ 0.05) increase in the activities of AST, ALT, alkaline phosphatase, lactate dehydrogenase, in serum after toxicant administration. This was accompanied by histopathological observations. A significant rise was observed in lipid peroxidation level and mercury ion concentration however reduced glutathione content decreased in liver, kidney and brain. A significant (P ≤ 0.05) decrease in the activity of acetyl cholinesterase was also seen in different regions of brain. Combined treatment of DTT along with Zn and Se significantly (P ≤ 0.05) recouped the alterations in the enzymatic activities of serum and reversed the tissue biochemical and histopathological changes of liver, kidney and brain. Our results demonstrate that combined treatment of thiol chelator (DTT) along with antioxidants (Zn and Se) plays an important role against dimethylmercury induced tissue damage and hepatic, nephro and neurotoxicity.     

Effect of total flavonoids of Radix Ilicis pubescentis on cerebral ischemia reperfusion model

This paper aims to observe the effects of total flavonoids of Radix Ilicis pubescentis on mouse model of cerebral ischemia reperfusion. Mice were orally given different doses of total flavonoids of Radix Ilicis pubescentis 10 d, and were administered once daily. On the tenth day after the administration of 1 h in mice after anesthesia, we used needle to hook the bilateral common carotid artery (CCA) for 10 min, with 10 min ischemia reperfusion, 10 min ischemia. Then we restored their blood supply, copy the model of cerebral ischemia reperfusion; We then had all mice reperfused for 24 h, and then took their orbital blood samples and measured blood rheology. We quickly removed the brain, with half of the brain having sagittal incision. Then we fixed the brains and sectioned them to observe the pathological changes of brain cells in the hippocampus and cortex. We also measured the other half sample which was made of brain homogenate of NO, NOS, Na⁺-K⁺-, ATP enzyme Mg²⁺-ATPase and Ca²⁺-ATPase. Acupuncture needle hook occlusion of bilateral common carotid arteries can successfully establish the model of cerebral ischemia reperfusion. After comparing with the model mice, we concluded that Ilex pubescens flavonoids not only reduce damage to the brain nerve cells in the hippocampus and cortex, but also significantly reduce the content of NO in brain homogenate, the activity of nitric oxide synthase (NOS) and increases ATP enzyme activity (P < 0.05, P < 0.01). In this way, cerebral ischemia reperfusion injury is improved. Different dosages of Ilex pubescens flavonoids on mouse cerebral ischemia reperfusion model have good effects.     

Acute flesinoxan treatment produces a different effect on rat brain serotonin synthesis than chronic treatment: An α-methyl-l-tryptophan autoradiographic study

5-HT_1A receptor agonists display anxiolytic and anti-depressant properties in clinical studies. In this study, we used the α-[¹⁴C]methyl-l-tryptophan (α-MTrp) autoradiographic method to evaluate the effects of the 5-HT_1A agonist, flesinoxan, on regional 5-HT synthesis in the rat brain, following acute or a 14-day continuous treatment. In the first series of experiments, flesinoxan (5 mg/kg; i.p.) was administered 40 min before the α-MTrp. It resulted in a significant increase of the arterial blood oxygen partial pressure (pO₂) and a reduction of the regional rate of 5-HT synthesis throughout the brain, with the exception of a few regions (medial geniculate body and thalamus). In the second series of experiments, flesinoxan (5 mg/kg day) was administered for 14 days, using an osmotic minipump implanted subcutaneously. When compared to rats treated with saline, there was an overall significant (p < 0.05) reduction in the synthesis (one-sample two-tailed t-test). However, there was no significant influence on the 5-HT synthesis rate in the dorsal and median raphe nuclei and the majority of their projection areas. A significant (p < 0.05) reduction was observed in the nucleus raphe magnus, medial caudate, ventral thalamus, amygdala, ventral tegmental area, medial forebrain bundle, nucleus accumbens, medial anterior olfactory nucleus and superior olive. The unaltered 5-HT synthesis rates in a large majority of regions following the 14-day treatment of flesinoxan may reflect the normalization (implies to not be different from salne treated control) of synthesis due to a desensitization of 5-HT_1A autoreceptors on the cell body of 5-HT neurons as well as at postsynaptic sites, which is known to occur following long-term treatment with 5-HT_1A agonists. It is of some importance to note that the normalization of the synthesis occurred in the majority of the brain limbic structures, the brain areas implicated in affective disorders and the corresponding successful treatments, as well as in the cortical regions, which are implicated in mood. However, there were some terminal regions (e.g., accumbens, anterior olfactory, lateral thalamus, raphe magnus and obscurus) in which the chronic flesinoxan treatment resulted in a significant reduction of synthesis, suggesting that there was not a full desensitization across the brain of the receptors controlling 5-HT synthesis.     

Effect of group size on feed intake,aggressive behaviour and growth rate in goat kids and lambs

The effects of different group sizes on feed intake, growth and behaviour in penned kids and lambs were studied in an experiment (Exp. 1) with 30 kids and 30 lambs used in 3 periods. In each period, animals were divided into five group sizes. The group sizes were one, two, three, four or five animals per pen. In a second experiment (Exp. 2) 36 kids and 36 lambs were allotted to two groups of one and five animals per group. The diet consisted of Jackfruit (Artocarpus heterophyllus) and Acacia (Acacia mangium) foliages, sugar-cane (Saccharum officinarum) and concentrate. The foliages were given ad libitum, equal to 130% of intake of fresh matter of the group the previous day, and concentrate and sugar-cane were given at a level of 10 g dry matter (DM)/kg initial body weight. The time for each period in Exp. 1 was 21 days, with the last 7 days for data collection. The behaviour observations were done during the last 4 days of each data collection period. The time for Exp. 2 was 84 days.In Exp. 1, the kids had a higher total DM intake (DMI) (P = 0.011) and DMI of Jackfruit (P < 0.001) than the lambs. Total intake increased linearly as group size increased (P = 0.03). When feeding Jackfruit or sugar-cane aggressive behaviours recorded per pen or per animal increased linearly with group size. In Exp. 2, there was no difference in total DMI between kids and lambs, but kids had a significantly higher DMI of Jackfruit and a lower DMI of sugar-cane. Total DMI and DMI of Jackfruit and sugar-cane were similar for the group sizes of five animals and one animal, but kids showed a higher total intake and intake of Jackfruit in the group sizes of five animals, while a higher intake was obtained in single pens for lambs. The weight gain was higher (P < 0.05) for the lambs compared to the kids, but similar for the animals in the group size of one or five animals. The feed conversion ratio (FCR) was significantly lower for the lambs compared to the kids, but not different between group sizes. The water intake of the lambs was higher (P < 0.05) than that of the kids in both experiments and the animals in the pens with high density drank more water than the animals in individual pens only in Exp. 2. In conclusion, increasing the number of animals in the pens increased feed and water intake and also aggressive behaviours and did not improve growth rate or feed conversion ratio.     

Effect of orally administered l-carnitine on selected biochemical indicators of lactating Tuj-ewes

The effect of orally administered l-carnitine on biochemical parameters was examined in lactating Tuj-ewes. Ewes were orally given 500 mg of l-carnitine daily for 3 weeks. To evaluate the changes on selected blood indicators (total protein, albumin, glucose, triglyceride, cholesterol, urea, aspartate amino transferase, alanine amino transferase, lipase, triiodothyronine and thyroxine), blood samples were collected at the beginning of the study, and at the end of 1st, 2nd and 3rd week of study. Oral administration of supplemental carnitine significantly decreased serum triglyceride (P < 0.05), glucose (P < 0.05), cholesterol (P < 0.05) and triiodothyronine (P < 0.05) concentrations. In addition, serum thyroxine (P < 0.001) and albumin (P < 0.01) concentrations were significantly elevated as a result of oral carnitine treatment. These results suggest that supplemental l-carnitine improves selected biochemical indicators in Tuj-ewes.     

Neurobehavioral effect of essential oil of Cymbopogon citratus in mice

Tea obtained from leaves of Cymbopogon citratus (DC) Stapf is used for its anxiolytic, hypnotic and anticonvulsant properties in Brazilian folk medicine. Essential oil (EO) from fresh leaves was obtained by hydrodistillation and orally administered to Swiss male mice 30 min before experimental procedures. EO at 0.5 or 1.0 g/kg was evaluated for sedative/hypnotic activity through pentobarbital sleeping time, anxiolytic activity by elevated plus maze and light/dark box procedures and anticonvulsant activity through seizures induced by pentylenetetrazole and maximal electroshock. EO was effective in increasing the sleeping time, the percentage of entries and time spent in the open arms of the elevated plus maze as well as the time spent in the light compartment of light/dark box. In addition, EO delayed clonic seizures induced by pentylenetetrazole and blocked tonic extensions induced by maximal electroshock, indicating the elevation of the seizure threshold and/or blockage of seizures spread. These effects were observed in the absence of motor impairment evaluated on the rotarod and open field test. Our results are in accord with the ethnopharmacological use of Cymbopogon citratus, and after complementary toxicological studies it can support investigations assessing their use as anxiolytic, sedative or anticonvulsive agent.     

Comparative study on the influence of fluoride on lipid peroxidation and antioxidants levels in the different brain regions of well-fed and protein undernourished rats

Effects of fluoride on the levels of Lipid peroxidation (LP) and antioxidant enzymes in the brain regions of protein undernourished (PU) and well-fed rats (WF) rats exposed to 100 ppm fluoride in drinking water were investigated. The results indicate that the mean body weights and the total brain weights of PU rats as well as those given fluoride (both WF and PU) were significantly (P < 0.05) lower than their respective controls. The weights of different brain regions were also significantly reduced (P < 0.05) in PU rats compared to WF rats except in the brain stem. Fluoride ingestion diminished the weights of WF and PU rats affecting the cerebrum only (in the case of PU rats) and the cerebellum of both WF and PU rats without an effect on the brain stem of both WF and PU. Additionally, increased LP was observed in the cerebrum and cerebellum of PU rats but after fluoride ingestion, 30% increase in LP was observed only in the cerebrum. In the brain stem however, protein undernutrition was accompanied with a significant reduction in LP but the region seems insensitive to fluoride. There were significant reductions (P < 0.05) in CAT, SOD and GSH in all the brain regions (except the GSH level in the brain stem only) of PU rats. Fluoride induced reduction in the activity of CAT in the three brain regions and on SOD activity in cerebrum only for WF rats but no effect of fluoride on all the antioxidants studied in the three brain regions for PU rats. It is concluded that WF and PU rats responded differently to fluoride toxicity. However, it seems that at the dosage used, fluoride toxicity may be a direct effect on the antioxidant enzymes.