The Antihypertensive Property of Methanolic Extract of New Bouldia Laevis on Anaesthesized Cats

Abstract

Background: The plant Newbouldia laevis, commonly known as boundary tree, is a medium sized angiosperm which belongs to the family of Bignoniaceae. It is a native of trospical Africa. Extracts of all parts of Newbouldia laevis have been shown to exhibit antihypertensive property. Blood pressure is the optimal force needed to move blood through the body at rest and during physical activity while not exposing the arterial system to excessive force. An increase in blood pressure above the optimal level for an individual indicates that the cardiovascular system is abnormal in some way, and if this persists, damage to the heart and other vital organs will occur. Hypertension is not a threshold disease even though the current definition is commonly equated with blood pressure level above 140 / 90 mmHg. Objectives: To investigate the antihypertensive property of methanolic extract of Newbouldia Laevis on adult cats. This could be of relevance in the treatment of hypertension in clinical medicine in the near future. Methodology: An operating table was set up and ten adult cats of either sex were given pentobarbitone injection (40mg/kg) intraperitoneally. Little quantity of diethylether was given to the animals by inhalation so as to fully anaesthesize the animals. The animals were then made to lie on their back on the operating table with the fore and hind limbs tied firmly to the table. Incisions were made on their neck regions and the left hind limbs and cannulas were fixed on three points; the femoral vein, the ca rotid artery and the trachea. Heparin was injected through the femoral vein to aid free flow of blood. The carotid artery cannula was connected to a blood pressure transducer which was also linked to an electric recorder which made tracing showing the effect of the drugs on the blood pressure of the animals. The different doses of the extract were administered through the femoral vein until the end of the experiment. Results: The result showed that at the doses of 10-100ug, the extract gave a blood pressure lowering effect. When the control was administered, there was no effect on the blood pressure of the cats, while the standards showed expected effects. The acute toxicity test showed that proteins, alkaloids, oil, acidic compound, resins, carbohydrate, flavinoids, reducing sugar and tannin were present. Conclusion: The extract of Newbouldia Laevis exhibited anti-hypertensive action. This could find some relevance in the treatment of hypertension in clinical medicine. Clinicians and pharmacologists will find this study highly relevant with a view to actually formulating a medicament from the extract that could be effectively used in humans for the treatment of hypertension.