Active components from Artemisia iwayomogi displaying ONOO(-) scavenging activity

Area of Science:

• Phytochemistry
• Pharmacology
• Biochemistry

Background:

• Peroxynitrite (ONOO(-)) is a cytotoxic species formed from superoxide (*O(2)(-)) and nitric oxide (NO).
• Oxidative stress mediated by ONOO(-) contributes to various pathologies.
• Identifying natural ONOO(-) scavengers is crucial for therapeutic development.

Purpose of the Study:

• To screen a diverse range of herbs for ONOO(-) scavenging constituents.
• To isolate and identify active compounds from the most potent herb, Artemisia iwayomogi.
• To evaluate the ONOO(-) scavenging efficacy of isolated compounds.

Main Methods:

• Screening of 138 methanolic herb extracts for ONOO(-) scavenging activity.
• Solvent fractionation of active extracts (Artemisia iwayomogi) using ethyl acetate, n-butanol, dichloromethane, and water.
• Purification of fractions using column chromatography.
• Identification of isolated compounds using spectroscopic methods.
• In vitro assay to determine ONOO(-) scavenging activity (IC50 values).

Main Results:

• Twenty out of 138 herbs exhibited significant ONOO(-) scavenging activity.
• Artemisia iwayomogi demonstrated the highest ONOO(-) scavenging capacity.
• The ethyl acetate and n-butanol fractions of Artemisia iwayomogi were rich in active compounds.
• Key compounds identified include chlorogenic acid, genkwanin, and scopoletin.
• Chlorogenic acid (IC50 = 0.52 microM), genkwanin (IC50 = 1.01 microM), and scopoletin (IC50 = 1.03 microM) showed potent ONOO(-) scavenging activity, comparable to penicillamine.

Conclusions:

• Artemisia iwayomogi contains potent natural ONOO(-) scavenging compounds.
• Chlorogenic acid, genkwanin, and scopoletin are promising candidates for developing therapeutics against ONOO(-)-mediated diseases.
• Further research into these compounds could lead to novel treatments for oxidative stress-related conditions.