Vitamin C supplementation promotes locomotor and exploratory behaviors in male Wistar rats exposed to varying stress models.

Constant exposure to environmental stress has negative behavioral outcomes. Considering the inverse relationship between stress and Vitamin C intake, this study was aimed at investigating variable stress techniques and Vitamin C supplementation on exploratory/locomotor behaviors in male Wistar rats. Twenty-eight male Sprague-Dawley rats (100g-120g) were allotted into four groups (n=7). Control received 10ml/kg distilled water, group two received 100 mg/kg vitamin C, group three was exposed to different models of stress while group four was stressed alongside 100 mg/kg vitamin C. Vitamin C treatments were given orally for 2 weeks. Animals in groups 3 and 4 were stressed every other day with models such as multiple cage changes, exposure to noise, overnight strange objects, overnight wetting of beddings, and immobility. Explorative and locomotor activities were assessed with the open field test, novel object recognition test, and Y maze test using a Logitech camera and ANY-maze software to track the movement of the rats. Cortisol was assayed in the serum using Enzyme-linked Immuno Assay (ELISA) kit. Superoxide Dismutase, catalase, and lipid peroxidase; malondialdehyde (MDA) were also assayed in the serum. The results show that locomotor activities such as distance traveled, average speed, and time spent in the center square was significantly reduced by stress. These activities were improved with the intake of vitamin C compared with stress. Explorative activities such as locomoting around the environment, orientating towards novelty, and touching or sniffing novel objects were significantly increased in the rats on Vitamin C supplements and reduced in the stressed group. In the serum, cortisol level was significantly increased in rats exposed to stress and decreased with Vitamin C intake. Stress also significantly increased MDA and decreased SOD and CAT while vitamin C supplement decreased MDA and increased SOD and CAT. In conclusion, oral intake of vitamin C enhanced explorative/locomotor behavior and increased oxidative stress in rats exposed to different models of stress.

L-arginine supplementation lowers blood pressure, protein excretion and plasma lipid profile in experimental salt-induced hypertension in pregnancy: Relevance to preeclampsia.

This study aimed to investigate the effects of L-arginine supplementation on blood pressure, protein excretion, lipid profile in salt-induced hypertensive pregnant rats. Female Sprague-Dawley rats were divided into 4 groups. Control Preg (normal rat chow). Control Preg + L-ARG (normal rat chow and daily oral L-Arginine from 16th - 20th week). Salt Preg (high salt diet, 8%). Salt Preg + L-ARG (high salt diet, 8% and daily oral L-Arginine from 16th - 20th week. Non-invasive BP was recorded using a tail-cuff machine at 1 st and 2nd trimesters. On day 19 of pregnancy, invasive BP was obtained by carotid artery cannulation connected to LabChart-7 pro software. This was followed by blood samples collection for lipid profile analysis. L-arginine significantly reduced (P < 0.05) systolic, diastolic, MAP at 1 st, 2nd trimesters, day 19 of pregnancy, LDL, plasma and urinary creatinine and protein levels in Control Preg + L-ARG and Salt Preg + L-ARG groups compared to other groups. Urinary Na + and K + were significantly higher (P < 0.05) in Salt Preg + L-ARG group compared to other groups. Total cholesterol level was significantly higher (P < 0.05) in salt groups compared to control groups. Triglyceride level and urine volume were significantly higher (P < 0.05) in Salt Preg group compared to other groups. It also significantly increased (P < 0.05) HDL in Control Preg + L-ARG and Salt Preg + L-ARG groups compared to other groups. L-arginine supplementation ameliorates some deleterious effects in salt- induced hypertensive pregnant rats possibly through its known NO vasodilatory effect and might also mediate a diuretic like action.

L-Arginine Co-Administration with Carbamazepine Improves Cognition in Male Sprague-Dawley Rats.

Cognitive impairment is a common adverse effect associated with carbamazepine use. One of the proposedmechanisms for cognitive impairment may be attributed to the pro-oxidant properties of carbamazepine. This studyinvestigated the effects of L-Arginine supplementation with carbamazepine on cognition in adult male non-epileptic rats.Adult male Sprague-Dawley rats with average weight 200g to 220g were divided into 4 groups; (1) Control group treatedwith distilled water, (2) L-Arginine group treated with L-Arginine (100mg/kg BW) in distilled water, (3) Carbamazepinegroup treated with carbamazepine (25mg/kg BW twice daily) in distilled water, and (4) Carbamazepine + L-Arginine grouptreated with Carbamazepine and L-Arginine as above for two weeks to assess the acute changes in cognition and oxidativestress markers. Following two weeks of treatment, cognition was assessed using the Y-maze, after which the rats werehumanely sacrificed with the hippocampus and frontal lobes isolated from the brain and subsequently homogenized forassessment of oxidative stress markers [(Catalase, superoxide dismutase (SOD), malondialdehyde (MDA), and reducedGlutathione (GSH)]. Arm entry and correct alternation were significantly higher (p < 0.05) in the L-Arginine and L-Arginine+ Carbamazepine groups compared to carbamazepine group. In the frontal lobe, L-Arginine significantly increased (p < 0.05)catalase and GSH levels compared to other groups while in the hippocampus, it significantly (p < 0.05) reduced MDA withno change in other parameters. Likewise, SOD and MDA levels were significantly lower (p < 0.05) in the L-Arginine +Carbamazepine group compared to other groups. Oral L-Arginine supplementation with carbamazepine improved cognitiveperformance on Y maze.

Calcium and Magnesium Metabolism in Pre-Eclampsia.

BACKGROUND: Preeclampsia is a multisystem disorder associated with high maternal and perinatal mortality and morbidity. The cause of the disorder is largely unknown and its pathogenesis is complex and poorly understood. Calcium and magnesium are divalent ions which may have roles to play in the manifestations of the disease. An understanding of their metabolism in preeclampsia may aid our management of pregnant women who develop the disease. OBJECTIVE: To determine the plasma and urinary concentrations of calcium, magnesium and parathyroid hormone in women with mild, severe preeclampsia and in normal pregnancy. METHODS: This is was a case control study of fifty women with mild preeclampsia, fifty women with severe preeclampsia and fifty women with normal pregnancy as controls, drawn from The Antenatal Clinic at the Lagos University Teaching Hospital, Lagos, Nigeria. The women were consecutively recruited after signing an informed consent form. Ethical approval was obtained from the medical ethics committee of the hospital. RESULTS: The three groups of women were similar in their socio demographic characteristics. Plasma calcium was low in mild and severe preeclampsia compared to normal pregnancy controls (p=0.021). Urine calcium/creatinine ratio was lower in mild and severe preeclampsia compared to normal pregnancy controls (p= 0.030). Fractional excretion of calcium and levels of parathyroid hormone were similar across all three subgroups of women. Plasma magnesium was higher in mild and severe preeclampsia compared to normal pregnancy controls (p=0.011) and showed a positive correlation with plasma creatinine (r=0.48, p=0.045). Parathyroid hormone levels were similar across the study groups. CONCLUSION: Preeclampsia is associated with significant changes in calcium and magnesium metabolism. This study noted significant hypocalcaemia in mild and severe preeclampsia with significantly low urine calcium/creatinine levels. Calcium supplementation may have a place in patient's management. Hypermagnesemia was observed in mild and severe preeclampsia and appeared related to renal function.

Streptozotocin diabetes and insulin resistance impairment of spermatogenesis in adult rat testis: central vs. local mechanism.

Mammalian reproduction is dynamically regulated by the pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones are synthesized in the pituitary gland following stimulation by the gonadotropin-releasing hormone (GnRH) and act by stimulating steroid production and gametogenesis in both males and females. Male adult Sprague-Dawley rats (120 - 140 g) were randomly divided into 7 groups. Group 1 > Control group; fed on normal rat pellets. Group 2 > Streptozotocin group; received a single dose IP injection of streptozotocin 45 mg/kg BW in Na+ citrate buffer pH 4.5. Group 3 > Streptozotocin-insulin treated group; received a single dose IP injection of streptozotocin as in group 2 above and treated with insulin sub-cutaneously. Group 4 > Streptozotocin-ginger treated group; received a single dose IP injection of streptozotocin as in group 2 above and treated with 500 mg/Kg Ginger extract orally. Group 5 > Insulin resistant group; fed ad libitum on a special diet containing 25% fructose mixed with 75% normal rat chow (w/w). Group 6 > Insulin resistant-pioglitazone treated group; fed ad libitum on a special diet as in group 5 above and treated with Pioglitazone 15 mg/kg orally. Group 7 > Insulin resistant-ginger treated group; fed ad libitum on a special diet as in group 4 above, and also treated with 500 mg/Kg Ginger extract orally. Hormonal and tissue biochemistry analyses revealed that both central and local mechanisms are implicated in the impairment of spermatogenesis by diabetes but the hypothalamo-pituitary testicular axis alteration might not likely have a major impact as the local defect on steroidogenesis in the testis. This local defect could also predispose to male hypogonadism, i.e. failure of gonadal function.

Anti-diabetic and anti-oxidant effects of Zingiber officinale on alloxan-induced and insulin-resistant diabetic male rats.

This study was designed to investigate the hypoglycaemic and anti-oxidant effects of Zingiber officinale on experimentally induced diabetes mellitus using alloxan and insulin resistance. Aqueous extracts of raw ginger was administered orally at a chosen dose of 500mg/ml for a period of 4 weeks to alloxan-induced diabetic and insulin resistant diabetic rats. The experimental rats exhibited hyperglycaemia accompanied with weight loss to confirm their diabetic state. Ginger effectively reduced fasting blood glucose and malonydealdehyde levels in alloxan-induced diabetic and insulin resistant diabetic rats compared to control and ginger only treated rats. Furthermore, ginger increased serum insulin level and also enhanced insulin sensitivity in alloxan-induced diabetic and insulin resistant diabetic rats compared to control and ginger only treated rats. The results of the study clearly show that dietary ginger has hypoglycaemic effect, enhances insulin synthesis in male rats and has high antioxidant activity. One of the likely mechanisms is the action of malonydealdehyde, which acts as a scavenger of oxygen radicals.