Abstract

The effect of the aqueous extract of sudachi (Citrus sudachi) peels on Angiotensin-I Converting Enzyme (ACE) activity was examined in vitro to assess its potential ability to improve high blood pressure. The obtained results indicated that the extract caused the concentration-dependent inhibition of the enzyme activity in a competitive manner and suggested that putative active substances might be heat-stable with dialyzable molecular size. By comparison with the extracts prepared from lemon and orange peels, the extract of sudachi peels was shown to have the most potent inhibitory activity, which might be closely related to the amounts of total polyphenolic compounds in these extracts. The contents of phenolic acids and flavonoid compounds in the extract of sudachi peels were also shown to be higher than those of two other extracts. Thus, it seems possible to consider that the aqueous extract of sudachi peels may contain substantial amounts of water soluble polyphenolic compounds responsible for its inhibitory action on the enzyme.

Keywords:

Angiotensin-I Converting Enzyme (ACE), hypotensive action, polyphenolic compounds, sudachi peel extract,

References

Competing interests

The authors have no competing interests.

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