Angiotensin converting enzyme (ACE) inhibitory flavonoids from Erythroxylum laurifolium

Area of Science:

• Phytochemistry
• Pharmacology
• Cardiovascular Research

Background:

• Hypertension is a global health concern requiring novel therapeutic strategies.
• Plant-derived compounds are a rich source of potential antihypertensive agents.
• Traditional medicine often holds untapped potential for drug discovery.

Purpose of the Study:

• To investigate the antihypertensive properties of Erythroxylum laurifolium leaf extract.
• To identify the specific compounds responsible for angiotensin converting enzyme (ACE) inhibition.
• To evaluate the synergistic effects of identified compounds on ACE activity.

Main Methods:

• Screening of plant extracts for biological activity.
• Chemical isolation and identification of active compounds from Erythroxylum laurifolium.
• In vitro assays to determine angiotensin converting enzyme (ACE) inhibitory activity.
• Analysis of synergistic effects between isolated compounds.

Main Results:

• The 99% ethanol extract of Erythroxylum laurifolium exhibited significant ACE inhibitory activity.
• Proanthocyanidins (condensed tannins) and flavonoids, specifically quercitrin and afzelin, were identified as active components.
• Quercitrin (IC50 = 0.67 mM) and afzelin (IC50 = 2.8 mM) demonstrated potent ACE inhibition.
• Quercitrin and afzelin showed in vitro synergistic ACE inhibitory activity.

Conclusions:

• Erythroxylum laurifolium is a potential source of natural antihypertensive compounds.
• Flavonoids quercitrin and afzelin are key contributors to the ACE inhibitory activity of the plant extract.
• The synergistic interaction between quercitrin and afzelin offers a promising avenue for developing novel ACE inhibitors.