The human body produces reactive oxygen species (ROS), such
as superoxide anion radical, hydroxyl radical, and hydrogen peroxide
by many enzymatic systems through oxygen consumption
. In small amounts, these ROS can be beneficial
as signal transducers and growth regulators . However, during oxidative stress, large amounts of
these ROS may favour some human disease conditions such as
cancer, cardiovascular diseases, ageing, and neurodegenerative diseases
.