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WHO monographs on medicinal plants commonly used in the Newly Independent States (NIS)
rylhydrazyl radical (DPPH) free radical-scavenging and β-carotene/linoleic
acid). In the first test system, the extracts showed no antioxidant
activity. In the second test system, inhibition rates of the oxidation of
linoleic acid were comparable to those of the synthetic antioxidant butylated
hydroxytoluene (96%). It could be useful to consider use of the extract
as an alternative antioxidant for the food processing industries (37).
The antioxidant properties of lyophilized water extracts from the dried
inflorescences of Helichrysum arenarium with different polyphenol and
flavonoid contents were examined in microsomal fractions of rat liver.
Enzymatically-induced lipid peroxidation and nicotinamide adenine dinucleotide
phosphate (NADPH) cytochrome C-reductase activity in
liver microsomes were measured by a spectrophotometric method. The
extracts have weak DPPH free radical scavenging activity in microsomal
fractions of rat liver at a concentration of 1 µg/ml measured by a chemiluminometric
method. The activity was comparable to that of the flavonoid
silibinin, the main constituent of Silybium marianum (31). Lyophilized
water extracts of Flos Helichrysi diminished the enzymatically
induced lipid peroxidation and reduced cytochrome C in a concentration-dependent
manner. The same extracts inhibited NADPH-induced
lipid peroxide formation at a concentration of 20 µg/ml and stimulated
NADPH cytochrome C reductase in rat liver microsomes at a concentration
of 100 µg/ml. The extracts were observed to be more effective than
silibinin at the concentrations tested (38).
A methanolic extract obtained from inflorescences of Helichrysum arenarium
was evaporated and the dry residue was dissolved in hot water. The
solution was stored at 4 ºC and the precipitate discarded. The remaining
solution was divided into three aliquots a, b and c. Part a was extracted with
ethyl acetate to obtain extract A, part b was extracted with diethyl ether to
obtain extract B and part c was subjected to alkaline hydrolysis and then
extracted with diethyl ether to obtain extract C. After evaporation, the dry
residues A, B and C were further investigated for phenolic compound content
by thin-layer chromatography and high-performance liquid chromatography
(HPLC), as well as for 2,2-diphenyl-1-picrylhydrazyl-antiradical
activity. Residue C exhibited stronger antiradical properties than non-hydrolysed
residues A and B. HPLC analysis showed a greater increase in the
strong antioxidant, caffeic acid, in residue C, resulting in an increase in the
antiradical activity observed with residue C (39).
Antimicrobial activity
A 95% ethanol extract of the dried flowers and leaves of the plant was
found to have weak antibacterial activity against Pseudomonas aerugi-
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