ABSTRACT
The contraceptive effect of oral administration of ethanolic extract of Dioscorea villosa tuber for thirty days on reproductive hormones of female albino rats was investigated. Twenty four female albino rats weighing 150-220g were completely randomized into four groups (A-D) comprising six rats each. Animals in Group A (control) were administered 0.5ml of distilled water. Animals in groups B, C and D received 100, 200 and 400mg/kg body weight of ethanolic extract of Dioscorea villosa tuber respectively for 30 consecutive days. Preliminary phytochemical screening of ethanolic extract of Dioscorea villosa tuber revealed the presence of alkaloids, saponins, flavonoids and cardiac glycosides. The extract at all tested doses decreased serum luteinizing hormone (LH) levels, although this effect was statistically significant only at 100mg/kg body weight (p<0.05). The extract at all doses significantly (p<0.05) decreased the concentration of progesterone in the serum of the animals. A decrease in serum estradiol levels was observed only in animals that received 100 and 200mg/kg body weight of the extract while the 400mg/kg body weight of the extract did not significantly (p>0.05) affect the serum estradiol concentration when compared with the distilled water treated control animals. Serum levels of follicle stimulating hormone (FSH) increased following treatment in a dose-dependent manner, and this effect was statistically significant only at 400mg/kg body weight (p<0.05). These alterations in female rat reproductive hormones by the extract are hormonal imbalance and would have adverse effect on maturation and ovulation of follicles. Consequently, the extract may impair fertility and pregnancy in female rats. Therefore, the ethanolic extract of Dioscorea villosa tuber may be explored as a female contraceptive.
ABSTRACT
Aim: This study was carried out to investigate the role of coconut oil on pentylenetetrazole (PTZ) induced convulsant activity in Wistar rats using the laboratory model. Convulsant activity was achieved by injection of PTZ. Study Design: The rats were divided into five groups. Group 1 served as control and received distilled water orally. Group2 was a reference group and received only PTZ. The remaining three groups (3, 4 and 5) were test groups and rats were given oral administration of coconut oil at doses of 2, 4 and 5.3 ml/kg for 21 days. Methodology: 25 rats weighing between 125 and 200g were used. 30 minutes after the last administration of coconut oil after 21 days, a convulsive dose of PTZ was given intraperitoneally. Electroencephalogram (EEG) readings of the rats were then taken using an EEG machine and electrodes placed on the head of the rats recorded the waves produced on the scalp of the rats. The frequencies of the waves recorded were analyzed and compared for all groups. Result: The frequency of EEG readings produced during convulsion that was caused by the PTZ in the rats were reduced for the rats that received coconut oil. There was a significant decrease in the mean frequency of EEG of rats that received 2, 4 and 5.3 ml/kg coconut oil ( which had frequencies of 13Hz, 14.6Hz and 14. 4Hz, respectively) when compared with the reference group that received only PTZ which had a mean frequency of 16Hz. Coconut oil significantly reduced the frequency produced by PTZ. The result also shows that the lower dose group had the most appreciable decline in convulsive activity returning the frequency of electroencephalogram waves recorded to 13Hz same as the control group. Conclusion: The result suggests that coconut oil given at a moderate dose has anticonvulsant effect and will cause an increase in weight. These findings supports reports that ketogenic diet could help reduce convulsant activities and epileptic seizures.