DIURETIC AND TOXICITY STUDIES OF METHANOL STEM BARK EXTRACT OF SPONDIAS MOMBIN LINN (ANACARDIACEAE) IN RATS

DIURETIC AND TOXICITY STUDIES OF METHANOL STEM BARK EXTRACT OF SPONDIAS MOMBIN LINN (ANACARDIACEAE) IN RATS

Abstract:

Spondias mombin belongs to the family Anacardiacae. All parts of the tree are reported to be medicinally useful. The fruit juice is drunk as a diuretic and febrifuge. The main aim of the study is to determine the diuretic activity and toxicity of methanol stem bark extract of Spondias mombin. The plant was collected, authenticated, and studied in Department of Pharmacology and Therapeutics, Ahmadu Bello University, Zaria. Adult albino rats of Wistar strain of either sex were used for the experiments. Phytochemical screening of the methanolic extract of stem bark of Spondias mombin was carried out according to the methods described by Trease and Evans. The oral median lethal dose (LD50) of the extract was determined in rats according to Lorke’s method. The sub-chronic study was carried out in accordance with WHO and OECD 407 guidelines. Twenty four adult rats (Wistar strain) were randomly divided into four groups of six rats each. The rats in group I were administered with normal saline orally and served as the control. Groups II – IV were administered 250mg/kg, 500mg/kg, and 750mg/kg of the extract daily for twenty eight days.At the end of the study, the animals were euthanized and relative organ weight ratio (ROW) was determined.Histological examination of heart, liver and kidneys were also performed. Complete blood count, liver and kidney function tests were also determined. For diuretic screening, test animals were placed into metabolic cages with total withdrawal of food and water for 12 hours. They were then randomly divided into five groups of five animals each. Each animal was rehydrated with 25 ml/kg of normal saline just before the experiment. Group-I animals were provided only with 25ml/kg of Normal saline to serve as control. Group-II animals were provided with frusemide at a dose of 5 mg/kg body weight. Group- vii III, IV and V animals were given 250mg/kg, 500mg/kg and 750mg/kg of the extract respectively. These preparations were all given by the oral route. After administration of test samples, the urinary excretion was recorded at 3rd, 6th and 24th hour, from the graduated urine chamber of metabolic cage. Urine was also analyzed for electrolytes. The phytochemical screening of methanolic stem bark extract of S. mombin revealed the presence of flavonoids, alkaloids, tannins, saponins, cardiac glycosides, phenols, and carbohydrates,but anthraquinones were absent. The median oral lethal dose was found to be greater than 5000mg/kg. Sub-chronic toxicity studies revealed there was no significant statistical difference in the animal body weights at all weeks compared to week zero and in relation to different doses of extract compared to the control.A significant statistical reduction of bicarbonate was noted at the dose of 500mg/kg compared with control (p< 0.05).There was no statistically significant difference observed in the liver function test, haematological indices, and relative organ weight (ROW) ratio of the groups administered with the extract compared with control.Vascular congestion was noted in the heart at 500mg/kg and the kidneys at 250mg/kg. Vacuolar changes seen at 750mg/kg dose are most likely due to fatty liver.No significant statistical differences were observed in urine output between the test groups given the extract and the control groups during the first 6 hours and after 24 hours. There was significant excretion of potassium at 500mg/kg dose compared with the negative control. No other significant statistical differences were observed between the other test groups given the extract and the control groups. In conclusion methanolic extract of the stem bark of S.mombin has shown structural toxicity on the some organs, but has not been shown to have diuretic property.

DIURETIC AND TOXICITY STUDIES OF METHANOL STEM BARK EXTRACT OF SPONDIAS MOMBIN LINN (ANACARDIACEAE) IN RATS