Cuprizone toxicity and Garcinia kola biflavonoid complex activity on hippocampal morphology and neurobehaviour.

Cuprizone-induced neurotoxicity has been employed to study the biology of remyelination in experimental models of multiple sclerosis. This study was aimed at determining the role of kolaviron, a biflavonoid from Garcinia kola, in mitigating the damaging effects of cuprizone on behaviour and the hippocampus. Twenty-four male albino mice aged 6-8 weeks were categorised into 4 equal groups: Group A (Control) received regular diet; Group B received 200 mg/kg/d of kolaviron in addition to their regular diet; Group C received 0.2% cuprizone diet only, while Group D received both kolaviron and cuprizone diet. The treatment lasted for 35 days after which behavioural tests (Morris water maze, Y maze and open field tests) were conducted and brain tissues were processed for histology, histochemistry (Nissl staining), immunohistochemistry (glial fibrillary acidic protein) and biochemistry (malondialdehyde, superoxide dismutase and glutathione peroxidase). Results showed that cuprizone toxicity led to weight loss, impairment in memory and exploratory drive, oxidative stress, chromatolysis and reactive astrocytosis; meanwhile administration of kolaviron prevented cuprizone-induced weight loss, memory decline, oxidative stress and neuromorphological alterations. In conclusion, administration of kolaviron might be useful in limiting the effects of cuprizone toxicity on the morphology and functions of the hippocampus.

Neuroanatomical and molecular correlates of cognitive and behavioural outcomes in hypogonadal males.

Robust epidemiological, clinical and laboratory evidence supports emerging roles for the sex steroids in such domains as neurodevelopment, behaviour, learning and cognition. Regions of the mammalian brain that are involved in cognitive development and memory do not only express the classical nuclear androgen receptor, but also the non-genomic membrane receptor, which is a G protein-coupled receptor that mediates some rapid effects of the androgens on neurogenesis and synaptic plasticity. Under physiological conditions, hippocampal neurons do express the enzyme aromatase, and therefore actively aromatize testosterone to oestradiol. Although glial expression of the aromatase enzyme is minimal, increased expression following injury suggests a role for sex steroids in neuroprotection. It is therefore plausible to deduce that low levels of circulating androgens in males would perturb neuronal functions in relation to cognition and memory, as well as neural repair following injury. The present review is an overview of some roles of the sex steroids on cognitive function in males, and the neuroanatomical and molecular underpinnings of some behavioural and cognitive deficits characteristic of such genetic disorders noted for low androgen levels, including Klinefelter syndrome, Bardet-Biedl syndrome, Kallman syndrome and Prader-Willi syndrome. Recent literature in relation to some behavioural and cognitive changes secondary to surgical and pharmacological castration are also appraised.

Effects of Unripe Musa Paradisiaca on the Histochemistry of the Testis and Testosterone Levels in Adult Albino Rats.

This study was aimed at determining the effects of the unripe fruit of Musa paradisiaca on the testis andtestosterone levels in male Wistar rats. The animals were grouped into three, comprising a control, and 2 treatment groupsadministered with different doses (500 mg/kg and 1000 mg/kg) daily of the fruit flour over 28 days. Histochemical evaluationof the testes was done using Haematoxylin and Eosin, Periodic acid Schiff's (PAS) and Feulgen staining techniques, whilethe serum and homogenised testicular tissue were evaluated for testosterone levels using Accu-Bind ELISA Kit. The testisof the treated groups showed more rapidly dividing cells and more population of sperm cells compared to the control group,and also showed more positivity for Feulgen staining and PAS reaction. Both serum and testicular testosterone levels werehowever reduced. Serum testosterone was significantly lowered in the animals given the low dose (0.67 ± 0.03 ng/ml),compared to those given high dose (0.85 ± 0.02 ng/ml) and the control animals (1.88 ± 0.15 ng/ml) (p < 0.05). Changes intesticular testosterone were not statistically significant. The study suggests that M. paradisiaca fruit has reproductiveenhancing potential when consumed moderately, but this benefit may not be related to testosterone levels.

Repeated Acute Oral Exposure to Cannabis sativa Impaired Neurocognitive Behaviours and Cortico-hippocampal Architectonics in Wistar Rats.

The most abused illicit drug in both the developing and the developed world is Cannabis disposing users to varying forms of personality disorders. However, the effects of cannabis on cortico-hippocampal architecture and cognitive behaviours still remain elusive.  The present study investigated the neuro-cognitive implications of oral cannabis use in rats. Eighteen adult Wistar rats were randomly grouped to three. Saline was administered to the control rats, cannabis (20 mg/kg) to the experimental group I, while Scopolamine (1 mg/kg. ip) was administered to the last group as a standard measure for the cannabis induced cognitive impairment. All treatments lasted for seven consecutive days. Open Field Test (OFT) was used to assess locomotor activities, Elevated Plus Maze (EPM) for anxiety-like behaviour, and Y maze paradigm for spatial memory and data subjected to ANOVA and T test respectively. Thereafter, rats were sacrificed and brains removed for histopathological studies. Cannabis significantly reduced rearing frequencies in the OFT and EPM, and increased freezing period in the OFT. It also reduced percentage alternation similar to scopolamine in the Y maze, and these effects were coupled with alterations in the cortico-hippocampal neuronal architectures. These results point to the detrimental impacts of cannabis on cortico-hippocampal neuronal architecture and morphology, and consequently cognitive deficits.

Sweet old memories: a review of the experimental models of the association between diabetes, senility and dementia.

As the burden of Alzheimer's dementia rises, so does our understanding of the cellular and molecular basis of this neurodegenerative disease. Some of the recent advances in the aetiopathogenesis of neurodegeneration include the finding that insulin receptor signalling is key to neurogenesis and synaptogenesis in the brain, especially in areas related to memory formation and storage, including the hippocampus. This suggests an association between impaired insulin receptor signalling and neurodegenerative events. To decipher this association, several animal models are being employed. Such models include transgenic and non-transgenic animals that range from invertebrates (Drosophila melanogaster and Caenorhabditis elegans), to vertebrates (mouse, rats and primates). The current review is an account of such models and how they have contributed to our understanding of the relationship between type 2 diabetes mellitus, ageing and dementia.

Combined effects of chronic hyperglycaemia and oral aluminium intoxication on testicular tissue and some male reproductive parameters in Wistar rats.

Exposure to either environmental toxicants or chronic hyperglycaemia could impair male reproductive function. However, the extent to which exposure to such toxicants, in the presence of pre-existing metabolic dysfunction, could affect male reproduction is unclear. Streptozotocin-induced diabetic Wistar rats (12 weeks old) were exposed to oral aluminium chloride at 250 ppm for 30 days; followed by evaluation of caudal epididymal sperm count and motility, assay for serum follicle stimulating hormone (FSH), testosterone (T) and oestradiol; and assessment of testicular histology. Moreover, blood glucose was evaluated by the glucose oxidase method. In rats treated with streptozotocin (STZ) or aluminium (Al) alone, erosion of testicular parenchyma and stroma was observed. This effect was most severe in diabetic rats simultaneously exposed to Al; coupled with reduced caudal epididymal sperm count that was least in this (STZ+Al) group (18.75 × 10(6)  ml(-1) ) compared with controls (61.25 × 10(6)  ml(-1) ; P < 0.05), STZ group or Al group. Moreover, these reproductive perturbations (in the STZ+Al group) were associated with reduced sperm motility and significantly reduced serum FSH (P < 0.05); but elevated serum T and oestradiol (P < 0.05), compared with control. These suggest that diabetes-induced testicular lesion is exacerbated by simultaneous oral Al toxicity in Wistar rats.

Antimalarial Activity of Cocos nucifera Husk Fibre: Further Studies.

In this study, the antimalarial and toxicity potentials of husk fibre extracts of five Nigerian varieties of Cocos nucifera were evaluated in vitro. The only active extract fraction, West African Tall (WAT) ethyl acetate extract fraction, was then evaluated for its phytochemical constituents, antimalarial and toxicity potentials at varying doses (31.25-500 mg/kg body weight) using various organ function indices. The results revealed that WAT ethyl acetate extract fraction (WATEAEF) contained alkaloids, tannins, and flavonoids and was active against Plasmodium falciparum W2 strain maintained in continuous culture, with a selectivity index of 30.3. The same extract fraction was active in vivo against Plasmodium berghei NK65, causing more than 50% reduction in parasitaemia on days 4 and 6 after inoculation at various doses administered. WATEAEF did not significantly alter (P > 0.05) function indices of the liver and cardiovascular system at all doses administered but significantly increased (P < 0.05) plasma creatinine concentration at 250 and 500 mg/Kg body weight compared to controls. The results of this study suggest that WATEAEF possesses antimalarial activity and may not adversely affect normal liver function nor predispose subjects to cardiovascular diseases but may impair normal kidney function at higher doses. Further studies are underway to isolate the active principles.

Beneficial effects of low dose Musa paradisiaca on the semen quality of male Wistar rats.

BACKGROUND: This study aimed at determining the effects of administration of mature green fruits of Musa paradisiaca on the semen quality of adult male Wistar rats. MATERIALS AND METHODS: THE ANIMALS USED FOR THE STUDY WERE GROUPED INTO THREE: the control group, given 2 ml of double distilled water, a low dose group given 500 mg/kg/day and a high dose group given 1000 mg/kg/day of the plantain fruits, which was made into flour, and dissolved in 2 ml of double distilled water for easy oral administration. RESULTS: Significant increment in the semen parameters was noticed in animals that received a lower dose of the plantain flour, but those animals who received the high dose had marked and very significant reduction in sperm cell concentration and percentage of morphologically normal spermatozoa. CONCLUSION: Musa paradisiaca should be consumed in moderate quantities in order to derive its beneficial effects of enhancing male reproductive functions.

Morphological and neurohistological changes in adolescent rats administered with nicotine during intrauterine life.

Tobacco smoking has been linked to many preventable diseases affecting various organs and systems of the body, including the brain. The current study was conducted to demonstrate the histological changes observable in the cerebral cortex of young Wistar rats exposed to nicotine during gestation. Vaginal smearing was conducted for the female Wistar rats to determine their oestrous cycle, after which they were exposed to male rats overnight, for mating. Pregnancy was confirmed and the pregnant rats were divided into 3 groups based on the 3 trimesters (A, B, C), with each group having a control and a treated subgroup. The Control Groups (A1, B1, C1) were given 0.1 ml of normal saline i. p., while the Treated Groups (A2, B2, C2) received 0.06 mg/kg/0.1 ml of nicotine intra-peritoneally. Treatment was for a period of 6 days only within each trimester for all subgroups. The pregnant animals were allowed to litter, and at postnatal day 35 they were sacrificed. The skull was dissected to expose and remove the brain; the temporal and parietal cortices were excised and fixed in 4% paraformaldehyde for histological tissue preparation, using cresyl fast violet staining techniques. Exposure of the developing brain to nicotine during gestation resulted in various degrees of abnormalities in the cytoarchitecture of the parietal and temporal cortices of young rats. The gestational period of nicotine exposure and specific cortical affectation are important factors to consider while investigating neurological abnormalities in offspring of tobacco smokers.

Evaluation of the histo - gastroprotective and antimicrobial activities of heliotropium indicum linn (boraginaceae).

Heliotropium indicum of the family Boraginaceae is used locally in Nigeria to treat ailments such as ulcer and fever. In this study, ulceration of the gastric mucosa in Wistar rats was induced via the oral administration of 80mg/kg/bodyweight of Indomethacin. Histological analyses of the stomach body wall in the rats of Groups 2 and 4 (which received 100mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin and 80mg/kg/bodyweight Indomethacin only respectively) showed erosion of the mucus-secreting cells, gastric pit, upper and middle parts of gastric glands and some of the parietal cells. Histological observations of the stomach body wall in rats of Group 5 (which received 200mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight of Indomethacin) showed erosion of the mucus-secreting cells, gastric pit and the upper most part of the gastric gland. Histological observations of the stomach body wall in rats of Groups 1, 6 and 3 (which received 50mg/kg/bodyweight of Ranitidine and 400mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin; and only 80mg/kg/bodyweight of Normal Saline respectively) showed normal morphological appearance of the different components of the mucosa layer. Thus, the aqueous extracts of the dried leaves of Heliotropium indicum have dose dependent histo-gastroprotective effects.

Evaluation of the histo-gastroprotective and antimicrobial activities of heliotropium indicum linn (BORAGINACEAE)

Heliotropium indicum of the family Boraginaceae is used locally in Nigeria to treat ailments such as ulcer and fever. In this study, ulceration of the gastric mucosa in Wistar rats was induced via the oral administration of 80mg/kg/bodyweight of Indomethacin. Histological analyses of the stomach body wall in the rats of Groups 2 and 4 (which received 100mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin and 80mg/kg/bodyweight Indomethacin only respectively) showed erosion of the mucus-secreting cells, gastric pit, upper and middle parts of gastric glands and some of the parietal cells. Histological observations of the stomach body wall in rats of Group 5 (which received 200mg/ kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight of Indomethacin) showed erosion of the mucus-secreting cells, gastric pit and the upper most part of the gastric gland. Histological observations of the stomach body wall in rats of Groups 1, 6 and 3 (which received 50mg/kg/bodyweight of Ranitidine and 400mg/kg/bodyweight of extract before oral administration of 80mg/ kg/bodyweight Indomethacin; and only 80mg/kg/bodyweight of Normal Saline respectively) showed normal morphological appearance of the different components of the mucosa layer. Thus, the aqueous extracts of the dried leaves of Heliotropium indicum have dose dependent histo-gastroprotective effects.

Spermatoprotective activity of the leaf extract of Psidium guajava Linn.

BACKGROUND: The leaves of Psidium guajava Linn. (guava) contain several natural antioxidants. We therefore designed the present study to evaluate the effect of ethanol extract of guava leaves on gossypol-associated sperm toxicity in Wistar rats. METHODS: Animal groups 1, 2, and 3 (n=6 each) were treated orally with crude cottonseed oil to provide 14 mg/kg/d of free gossypol for 53 d. Besides, groups 1 and 2 rats were supplemented orally with 250 mg/kg/d and 500 mg/kg/d respectively of guava leaf extract (GLE) for the same period. Group 4 animals (control, n=6) received normal saline. RESULTS: No significant difference (P>0.05) occurred in the sperm count of group 1 rats compared to control. In animal group 2, significant increase (P<0.05) in sperm count occurred, as opposed to group 3 animals, where this parameter decreased significantly (P<0.05). Besides, mean values of 78 %, 82 %, 30 %, and 65 % respectively were obtained for sperm motility in animal groups 1, 2, 3, and 4. CONCLUSION: Our findings suggest that ethanol extract of guava leaves possesses beneficial effect on gossypol-associated sperm toxicity, and may therefore enhance male fertility, possibly owing to its rich constituents of natural antioxidants.

Ethanol extract of the leaves of Psidium guajava Linn enhances sperm output in healthy Wistar rats.

Reactive oxygen species (ROS), among other factors, have been implicated in the aetiology of male infertility. Thus, the roles of antioxidants at improving sperm production and quality are being investigated. The present study was designed to assess the effect of the ethanol extract of fresh leaves of Psidium guajava Linn. on the sperm parameters of healthy male Wistar rats. A total of 18 rats, weighing between 108-124 g, were divided into 3 groups of 6 animals each. Animals in groups 1 and 2 were administered 250 mg/kg/d and 500 mg/kg/d of guava leaf extract (GLE) orally for 53 days respectively. Group 3 animals received normal saline. Sperm count increased from 56.2+/-0.3 (x10(6)) in the control to 57.1+/-0.2 (x10(6)) in group 1 animals, and from 56.2+/-0.3 (x10(6)) in the control to 72.3+/-0.4 (x10(6)) in group 2 animals. Similarly, dose-dependent increases in the percentages of motile spermatozoa were observed in GLE-treated animals compared to the control group. These findings suggest that the extracts of the leaves of Psidium guajava Linn. possess beneficial effects on sperm production and quality, and may thus improve the sperm parameters of infertile males with oligospermia and nonobstructive azoospermia.

Effect of cottonseed oil on oestrous cycle and ovulation in albino rats of Wistar strain.

OBJECTIVE: The antispermatogenic and contraceptive importance of gossypol had been established in male animals, including man; in the present work, adult female Wistar rats weighing 110 - 160g were used to study the effect of cottonseed oil (gossypol) on oestrous cycle and ovulation. MATERIALS AND METHODS: Forty-five cyclic female rats were sorted randomly into three experimental groups of fifteen animals each. Oral doses of 20 and 40 mg/kg/body weight were administered once a day at 0900 hr for a period of 15 days. Vaginal swab of animals were taken each day between 0700 hr- 0900 hr to study their oestrous cycle; at the end of each cycle (4-5 days), a batch of 5 animals was sacrificed in each group to evaluate the number of ova shed. RESULTS: The results showed that gossypol had no disruptive effects on oestrous cycle; ovulation was not adversely affected, neither was there any significant reduction (p > 0.05) in the number of oocytes released. CONCLUSION: Because gossypol did not alter the oestrous cycle and ovulation patterns in the study animals, we suggest that certain factors exist in female animals that abolish or limit gossypol toxicity; these were extensively discussed.

Proteinaceous diet inhibits gossypol-induced spermatotoxicity.

The present study was designed to investigate the effect of a proteinaceous dietary supplement, fishmeal, on gossypol-induced spermatotoxicity. Twenty-five adult male Wistar rats, averaging 205 g b.w., were randomly sorted into four experimental groups (I-IV) of 5 animals each, and a control group. Crude cottonseed oil was administered orally to each animal in groups I-IV at a rate that provided 14 mg/kg/d free gossypol; in addition, 3 g/d, 7 g/d, and 10 g/d of fishmeal was provided as meal supplement to each animal in groups I, II and III respectively. The control group received rat pellets and water freely. At the end of the 53-day treatment period, all animals were placed under chloroform anaesthesia; the caudal epididymides were removed, minced and placed in Ham's F10 solution for the evaluation of sperm count and motility. The testes were also processed for histological studies using the eosin and haematoxylin (H & E) method. Our findings revealed a dose-dependent inhibition of gossypol-induced spermatotoxicity by the supplemented fishmeal; this suggests that proteinaceous diets are protective against gossypol-induced male infertility.