Antioxidative and chelating activities of phenylpropanoid glycosides from Pedicularis striata
Abstract
AIM: To study the antioxidative and iron chelating activities of phenylpropanoid
glycosides (PPG) isolated from a Chinese herb Pedicularis striata.
METHODS: Antioxidative effects of PPG on lipid peroxidation induced by
FeSO4-edetic acid in linoleic acid were measured by thiobarbituric acid method.
Chelating activities of PPG for Fe2+ were tested by differential spectrum method.
RESULTS: The reaction rates (A532.min-1) of lipid peroxidation were 0.0046 in the
control, 0.0021 in verbascoside group, and 0.0008 in isoverbascoside group. The
chelating activity of isoverbascoside was 2-fold stronger than that of
verbascoside. Permethyl verbascoside showed neither antioxidative nor chelating
activities.
CONCLUSION: The inhibitory effects of PPG with phenolic hydroxy groups on lipid
peroxidation are owing to their chelating properties. Under physiological
condition PPG-Fe2+ chelates are sufficiently stable. Thus PPG are able to inhibit
the Fe(2+)-dependent lipid peroxidation in vivo through chelating Fe2+ and
exhibit their therapeutic potential by the same mechanism in vitro.
Keywords:
glycosides (PPG) isolated from a Chinese herb Pedicularis striata.
METHODS: Antioxidative effects of PPG on lipid peroxidation induced by
FeSO4-edetic acid in linoleic acid were measured by thiobarbituric acid method.
Chelating activities of PPG for Fe2+ were tested by differential spectrum method.
RESULTS: The reaction rates (A532.min-1) of lipid peroxidation were 0.0046 in the
control, 0.0021 in verbascoside group, and 0.0008 in isoverbascoside group. The
chelating activity of isoverbascoside was 2-fold stronger than that of
verbascoside. Permethyl verbascoside showed neither antioxidative nor chelating
activities.
CONCLUSION: The inhibitory effects of PPG with phenolic hydroxy groups on lipid
peroxidation are owing to their chelating properties. Under physiological
condition PPG-Fe2+ chelates are sufficiently stable. Thus PPG are able to inhibit
the Fe(2+)-dependent lipid peroxidation in vivo through chelating Fe2+ and
exhibit their therapeutic potential by the same mechanism in vitro.