Inhibitory Effect of Aqueuos Extracts of Avocado Pear (Persea americana) Leaf and Seed on Angiotensin 1- Converting Enzyme: A Possible Means in Treating/Managing Hypertension

Aim: This study sought to investigate the inhibitory effect of aqueous extract of Avocado pear leaf and seed on angiotensin 1 converting enzyme activity.

Place and Duration of Study: The work was carried out at The Neutraceutical and Pytomedicine Laboratory Unit of The Federal University of Technology Akure, Nigeria between October 2011 and February 2012.

Methodology: The aqueous extract of the samples were prepared (1:10 w/v) and were used for subsequent analysis. The total phenolic content and antioxidant properties of the leaf and seed of Avocado pear were evaluated. Thereafter, the inhibitory effect of the extracts on angiotensin 1 converting enzyme was determined in vitro.

Results: The results revealed that the leaf had significantly (P<0.05) higher total phenol (92.9 mg/g) and flavonoid content (51.0 mg/g) than the seed [total phenol (57.1 mg/g) and total flavonoid (19.48 mg/g) content]. Furthermore, the antioxidant properties of the leaf [as typified by ABTS] was also significantly (P<0.05) higher than that of the seed. Conversely, the seed had higher inhibitory effect on angiotensin 1 converting enzyme than the leaf extract.

Conclusion: The inhibitory effect of the avocado pear leaf and seed could be due to some phytochemicals present in the extracts. These antioxidant and enzyme inhibition of the leaf and seed of avocado pear could be part of the mechanism for their use in folklore medicine in the management/treatment of hypertension. However, the seed had a better antihypertensive property while the leaf had a better antioxidant property.