Reduction of hippocampal CA 1 neurons in Wistar rats following the administration of phenytoin for seven days.

This study evaluated the neurotoxic effect of parenteral Phenytoin on the Cornu Ammonis 1 (CA 1) region of the Hippocampus in Wistar rats.Twenty wistar rats were randomized into two groups of ten animals each with the experimental group receiving intraperitoneal Phenytoin at a dose of 25 mg/kg body weight per day for seven days while the control group had sham injection of normal saline at equivalent volume for the same period. Hippocampal sections were processed for histology using routine paraffin sectioning followed by Heamatoxylin and Eosin staining. There was a statistically significant reduction in the mean body weight of the experimental group compared to the control group. The cell density in the stratum pyramidale (per 0.11 mm2 area of the CA 1 region of the Hippocampus) was reduced in the experimental group when compared to the control group. (P<0.05). The mean brain weight in both groups did not differ significantly. Our findings reveal that the administration of parenteral phenytoin at a dose of 25mg/kg body weight per day for seven days in Wistar rats resulted in reduction of the cell density in the stratum pyramidale of the CA 1 subfield of the Hippocampus in Wistar rats and a reduction in the mean body weight.

Gross morphological studies on the effect of cyanide on the developing cerebellum of wistar rat (rattus novegicus).

The teratogenic effect of maternal cyanide consumption on the gross morphology of the post-natal phase of the developing rat cerebellum was studied. Twenty pregnant female rats weighing between 170 g and 190 g were separated into control and experimental groups. The control animals were fed a standard diet of mice cubes, while the experimental animals were fed 500 ppm potassium cyanide, mixed with the standard diet. The diets were fed to the animals and their litters in separate cages and water provided ad libitum during gestation and to the offspring after birth. After birth, the offspring (five per group) of days 1, 9, 14, 21, 28 and 50 were weighed, killed by cervical dislocation and the gross parameters studied. In the experimental animals, no significant differences were observed in the studied parameters between the control and experimental animals on day 1. A significant reduction in body weight was observed on day 14 (P < 0.05). The brain weight was significantly reduced on day 9 (P < 0.05). Similarly, the cerebellar weight was significantly reduced on days 14,21 and 28 (P < 0.05). The maximum vermal length was significantly reduced on day 50 (P < 0.05), and the maximum side-to-side dimension of the cerebellum was also reduced on day 28 (P < 0.05). There was no reduction in the thickness (anteroposterior dimension) of the cerebellum in the experimental group (P > 0.05). From the result, it is inferred that maternal consumption of 500 ppm cyanide causes reduction in the cerebellar weight, vermal length and side-to-side dimension of the developing cerebellum in postnatal life in rats.

Wound healing activities of methanolic extracts Ocimum gratissimum leaf in Wistar rats - a preliminary study.

The wound healing effect of leaf extracts of Ocimum gratissimum was investigated in adult male Wistar rats. Two groups of adult male Wistar rats, average body weight 170g, had a 2cm by 2cm square wound inflicted on the dorsolateral aspect of their trunk with Paniculus Carnosus removed. Experimental group had their wound dressed with methanolic leaf extracts of Ocimum gratissimum while control group had their wounds dressed with normal saline dressing. All animals had wound dressing done every five days; wound dimension measured and, wound morphometry assessed. Wound biopsy was done by random selection in each group on day 10 and the day of complete re-epithelisation. Routine paraffin wax processing was done, slides stained with haematoxylene and eosin for histological assessment of fibroblast count, neovascularisation and granulation tissue profile. The result revealed significant wound contraction (P<0.05) on day 10 in the experimental group (mean 73.40 +/- 3.30)cm2 compared with the control group (mean 53.50 +/- 4.32)cm2. Histology of the healed scar showed non-significant (P>0.05) decrease in the mean fibroblast count forthe experimental group (83.80 +/- 5.70) relative to fibroblast count of 90.20 +/- 17.90 in the control group. The mean blood vessel count was also non-significantly lowered (P>0.05) in the experimental group (9.20 +/- 1.20) relative to the control group (13.40 +/- 2.40). Granulation tissue histology on day 10 showed denser inflammatory infiltrate as reflected by increased cellularity in the control group relative to that of the experimental group which though appeared adequate was not as dense as the control group. Thus we suggest that the methanolic extracts of O. gratissimum could be a potential wound healing agent due to its ability to enhance wound contraction.

Enhanced wound contraction in fresh wounds dressed with honey in Wistar rats (Rattus Novergicus).

BACKGROUND: Due to reports that honey accelerates wound healing, an investigation on its role in wound contraction in fresh wounds inflicted on wistar rats was carried out. METHOD: Twenty adult male wistar rats had 2cm by 2cm square wound inflicted on their right dorsolateral trunk. They were divided into two groups. The experimental group had their wounds dressed with honey while the control group had normal saline dressing. Wound dressing was done every five days and measurements taken at each dressing. Wound morphology was also assessed. RESULTS: Dressing with honey significantly enhanced percentage wound contraction on day 10 with value of 79.20+/-2.94 compared to control value of 53.50+/-4.32. p=0.0. The mean wound measurement on day 10 reduced significantly in honey group, 1.15+/-0.18 compared to control group 2.38+/-0.28. p=0.002. However, there was no significant difference in fibroblast count per high power field in honey group 68.0+/-2.59 compared to control 90.2+/-17.40, p=0.242. Honey dressing increased mean blood vessel count per high power field, 18.8+/-3.77 albeit non significantly when compared to control value of 13.4+/-2.44, p=0.264. Also honey dressing caused increased granulation tissue formation in wounds dressed with honey compared to control group. CONCLUSION: Our study suggests that honey dressing enhances wound contraction in fresh wounds which is one of the key features of wound healing.

Histomorphometric studies on the effect of cyanide consumption of the developing cerebellum of wistar rat (Rattus Novergicus).

OBJECTIVE: To investigate the microscopic effect of maternal cyanide consumption on the developing cerebellum of Wistar rats. MATERIALS AND METHODS: Twenty pregnant female rats weighing between 160 g and 180 g were used in this study. The rats were separated into two groups comprising ten control and ten experimental animals. The control animals were fed a standard diet of mice cubes, while the experimental animals were fed 500 ppm potassium cyanide, mixed with the standard diet. The diets were fed to the animals and their litters in separate cages and water provided ad libitum during pre and postnatal life. After birth, the offspring (five per group) of days 1,9,14,21,28 and 50 were weighed and killed by cervical dislocation. The cerebellar tissues were processed and microscopic parameters studied. RESULTS: A thicker external granular layer (EGL) was seen in the control group on day 1(39+/-9.2microm) compared with the experimental group (29+/-5.8microm) and on day 9(83+/-7.1microm) compared with the experimental group (78+/-13microm). However, these were not significantly different statistically. A thicker and persistent EGL was observed in the experimental group on days 14 and 21. A significant (P<0.05) reduction in the thickness of molecular layer (ML) was observed on days 28 and 50 in the experimental group. The density and size of the Purkinje cells were the same in both the control and experimental groups (P>0.05). CONCLUSION: Maternal consumption of 500 ppm cyanide in rats does not significantly affect light microscopic prenatal cerebellar development, but causes mild changes in the post-natal life. Maternal cyanide consumption causes delayed maturation of the cerebellum, as evidenced by the thicker EGL, and reduction in the ML in the experimental group which become noticeable only at about 28th day of postnatal life.

A comparative study of the wound healing properties of honey and Ageratum conyzoides.

The present study investigates the wound healing properties of methanolic extracts of Ageratum conyzoides leaves compared with those of honey. Thirty Wistar rats were randomized into 3 groups of 10 animals each. They were fed with standard rat cubes and Tap water weighed and acclimatized to laboratory conditions for one week. Under anesthesia, each animal had the skin of its dorsolateral flank shaved after which an area of the skin was excised. On achieving haemostasis, the wounds were packed with gauze soaked in the appropriate dressing for each group. Measurement of wound size, and wound biopsies were taken on the 10th day post-wound creation. Together with healed wound samples, these were processed for histology. Fibroblast and blood vessel densities per unit area of wound were determined for the healed wound samples. Histologically, the day 10 Ageratum sections showed fewer inflammatory cells compared with similar honey and Control sections. Also, healed scar sections of wounds dressed with the herb extract showed more fibrosis. Honey and Ageratum caused significant greater wound contraction than controls (p = 0.001 and 0.005 respectively). Healed wounds from the Ageratum group had significantly fewer fibroblasts than honey and controls (p = 0.012 and 0.036 respectively).