Oxidative stress plays a key role in the pathogenesis of various diseases.
Antioxidants protect the cells and tissues from oxidative stress by scavenging free
radicals and reactive oxygen species. These antioxidants may be endogenous or exogenous.
Plants are considered as potential and powerful exogenous source of antioxidants.
Astragalus species (spp.), especially Astragalus membranaceus, have a long
history of medicinal use in traditional Chinese medicine. Specifically, constituents of
the dried roots of Astragalus spp. (Radix Astragali) provide significant protection
against heart, brain, kidney, intestine, liver and lung injury in various models of oxidative
stress-related disease. Different isolated constituents of Astragalus spp., such as
astragalosides, flavonoids and polysaccharides also displayed significant prevention
of tissue injury via antioxidant mechanisms. In this article, the antioxidant benefits of Astragalus spp.
and its isolated components in protecting tissues from injury are reviewed, along with identification of
the various constituents that possess antioxidant activity.