C Nosiri, I Hussaini, I Abdu-Aguye, E Abdurahaman
acetylcholine, atropine, blood pressure, irvingia gabonensis, muscarinic
C Nosiri, I Hussaini, I Abdu-Aguye, E Abdurahaman. Pharmacological Effect of Irvingia gabonensis Leaf Extracts on Cat Blood Pressure. The Internet Journal of Pharmacology. 2009 Volume 9 Number 1.
The effect of ethanol extract of the leaves of
For many years, hypertension has been globally recognised as the most prevalent cardiovascular disease with paramount complications such as coronary heart disease, stroke, sudden cardiac death, congestive heart disease, renal insufficiency and dissecting aortic aneurysm1,2 The campaign to reduce cardiovascular disease has been aimed at treating hypertension since it a major tool in cardiovascular diseases3 . It has been estimated that approximately 25% of all prescribed medications today are of natural plant sources4. Rural dwellers in developing countries have attempted to control hypertension and its complications in the face of scarce socioeconomic resources by opting for herbal remedies5,6,7. More scientific researches are needed to be done to verify the effectiveness and elucidate the safety profile of such herbal remedies.
Materials And Methods
Collection and preparation of plant material
The leaves of
Screening the effect of the extract on the blood pressure of anaesthetized cat.
Adult cats weighing 2.3 -2.7kg were used for the study. They were maintained in the animal house of the Faculty of pharmaceutical Sciences of Ahmadu Bello University, Zaria, Nigeria, fed and allowed access to clean water
All values were expressed as mean ±sem and results analyzed using student’s t-test. P values < 0.05 were considered statistically significant.
The results of evaluating the effect of ethanol extract on cat blood pressure are shown in table 1 and 2. Different doses of the extract produced a fall in mean arterial blood pressure (MABP). This vasodepressor effect of ethanol extract was compared with that of acetylcholine using cat blood pressure. The mean arterial blood pressure (MABP) was 100mmHg. Intravenous administration of the ethanol extract produced a dose-related decrease in MABP with an EC50 of 1.08mg/kg and maximum fall (85.7mmHg) was obtained with 5mg/kg of the extract. There was a significant fall in MABP with the 5mg/kg extract (P<0.002).
Value represent mean ± SEM (n = 5), MABP before each injection was 100mmHg, *(P< 0.002)
Acetylcholine produced a maximum fall in MABP (71.4mmHg) when 0.2µg/kg was injected. Pre-treatment of the cat with atropine reduced the effects of both acetylcholine and ethanol extract on MABP (Table 2)
A low dose (2.5µg/kg) of atropine reduced the effect of the extract by 5mmHg and that of acetylcholine by 23mmHg, respectively. Atropine (5µg/kg) reduced the effect of acetylcholine and ethanol extract by 61mmHg and 76mmHg respectively. Propanalol injected before Ach or Ethanol extract did not reduce their depressor effects.
The result of screening the effect of the ethanol extract of