Novel Biological Properties of Oenothera paradoxa Defatted Seed Extracts: Effects on Metallopeptidase Activity

• Published in: Journal of agricultural and food chemistry Vol. 56; no. 17; pp. 7845 - 7852
• Main Authors: Kiss, Anna K, Derwińska, Małgorzata, Dawidowska, Anna, Naruszewicz, Marek
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10.09.2008
• Subjects: aminopeptidase N; angiotensin-converting enzyme; Angiotensin-Converting Enzyme Inhibitors - pharmacology; Bioactive Constituents; biological activity; Biological and medical sciences; CD13 Antigens - antagonists & inhibitors; chemical constituents of plants; dosage; dose response; enzyme activity; enzyme inhibitors; Enzyme Inhibitors - pharmacology; epicatechin gallate; evening primrose; extraction; Food industries; Fundamental and applied biological sciences. Psychology; General pharmacology; Medical sciences; medicinal plants; metallopeptidases; Metalloproteases - antagonists & inhibitors; metalloproteinases; Neprilysin - antagonists & inhibitors; neutral endopeptidase; oenothein B; Oenothera; Oenothera - chemistry; Oenothera paradoxa; penta-O-gallosyl-beta-d-glucose; pentagalloylglucose; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Plant Extracts - pharmacology; polyphenols; proanthocyanidin B3; procyanidins; seed extracts; seeds; Seeds - chemistry; polyphenols; pentagalloylglucose; aminopeptidase N; biological activity; metallopeptidases; procyanidins; evening primrose; Oenothera paradoxa; neutral endopeptidase; angiotensin-converting enzyme; Biological properties; Seeds; Onagraceae; Extract; Flavonoid; Medicinal plant; Polyphenol; Dicotyledones; Oenothera; Angiospermae; Proanthocyanidin; Enzyme; Aminopeptidases; Biological activity; Peptidases; Renin angiotensin system; Endopeptidase; Angiotensin; Hydrolases; Spermatophyta
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf801372h

In this study, for the first time, we used the in vitro metallopeptidase model for the identification of a potential novel activity of defatted evening primrose seed extracts. Prepared extracts of different polarity (aqueous, 60% ethanolic, isopropanolic, and 30% isopropanolic) at concentrations of 1.5−100 μg/mL exhibited a significant and dose dependent inhibition of three tested enzymes. The 50% inhibition of enzymes activity showed that aminopeptidase N (APN) was the enzyme affected to the greatest extent with IC50 at the level of 2.8 μg/mL and 2.9 μg/mL for aqueous and 30% isopropanolic extracts, respectively. The activity of neutral endopeptidase (NEP) was quite strongly inhibited by the extracts as well. The HPLC-DAD analysis and bioguided fractionation led to the identification of four active compounds: (−)-epicatechin gallate, proanthocyanidin B3, oenothein B, and penta-O-galloyl-β-d-glucose (PGG). Oenothein B has been shown previously to inhibit metallopeptidases. The three other compounds are known to inhibit angiotensin-converting enzyme (ACE), but they have not been previouly reported to inhibit the NEP and APN activity. PGG and procyanidins with different degrees of polymerization, as the dominating compounds in O. paradoxa seeds, seemed to play a role in the crude extract activity.