Antioxidant Properties of Sutherlandia frutescens
Fernandes a, Cromarty D, Albrecht C, Jansen van Rensburg
C. The antioxidant potential of Sutherlandia frutescens. Journal
of Ethnopharmacology. 2004;95:1-5.
The use of botanical and herbal medicines as a
complementary approach for the treatment of inflammatory diseases
has been steadily increasing, possibly because of the adverse effects
associated with the use of non-steroidal anti-inflammatory drugs.
However, little is known about the mechanisms of action, appropriates
doses, and toxicity of these herbal medicines. Sutherlandia frutescens
is one of the best known multipurpose medicinal plants in Southern
Africa, and it is used for a wide range of conditions (e.g., cancer,
viral disease, and inflammation). This plant is indigenous to the
Western Cape and Karoo regions of Southern Africa and is known there
as "cancer bush." S. frutescens is rich in amino acids
and pinitol, contains small amounts of saponins, and contains canavine,
which is a non-protein alpha-amino acid with anti-tumor properties.
Because the anti-inflammatory properties of various medicinal plants
are thought to be due to their antioxidant activities, the authors
of this study investigated the effects of a hot water extract of
S. frutescens on lucigenin- and luminol-enhanced chemiluminescence
on neutrophils stimulated by L-formyl-L-methionyl-L-leucyl-L-phenylalanine
(FMLP). In addition, the superoxide- and hydrogen peroxide–scavenging
activities of this plant were tested in cell-free systems.
Hot water extracts of S. frutescens subsp. microphylla
were prepared by combining 1.0 g dessicated plant material and 20
mL of boiling water. Neutrophils were isolated from venous blood
collected from healthy subjects. Oxidant production by FMLP-stimulated
neutrophils was measured with the use of either luminol-dependent
(for 150 seconds) or lucigenin-dependent (for 125 seconds) chemiluminescence.
The oxidant-scavenging potential of the hot water extract was measured
in cell-free systems: the superoxide anion and horseradish peroxidase/hydrogen
peroxide systems. Cell viability in neutrophil suspensions incubated
for 30 minutes at 37 degrees Celsius in various concentrations of
the plant extract was also evaluated.
The luminol- and lucigenin-enhanced chemiluminescence
responses of neutrophils stimulated by FMLP decreased significantly
in a dose-dependent manner in hot water extracts of S. frutescens
at concentrations as low as 10 mcg/mL. Hot water extracts of this
plant inhibited superoxide-induced chemiluminescence at concentrations
as low as 10 mcg/mL and inhibited horseradish peroxidase/hydrogen
peroxide–induced chemiluminescence at concentrations as low
as 0.62 mcg/mL. Furthermore, the hot water extract of S. frutescens—up
to concentrations of 40 mcg/mL—had no adverse effects on the
cell viability of the neutrophil suspensions tested.
The results indicate that the hot water extract
of Sutherlandia frutescens studied exhibited significant
superoxide- and hydrogen peroxide–scavenging activities at
concentrations as low as 10 mcg/mL in cell-free and in stimulated
neutrophil systems. These scavenging properties may have accounted
for the observed anti-inflammatory properties of the plant extract.
The observed antioxidant activity may be related to the plant's
constituent phenolic compounds (e.g., tannins and flavonoids). However,
a better understanding of the extract's antioxidant activity requires
further analysis to identify its active compounds. The authors conclude
that both the reactive oxygen species–scavenging properties
of the extract and the extract's low toxicity "suggest that
this plant may be developed as an effective immunomodulator for
the treatment of diseases associated with an overproduction of reactive
oxidants by human phagocytes."
- Inflammatory Diseases
- Sutherlandia frutescens
Date: November 30, 2004 HC# 110343-269