PHARMACOLOGICAL ACTIVITIES:
Luteolin is a naturally occurring compound found in foods including parsley,
artichoke leaves, celery, peppers, olive oil, rosemary, lemons, peppermint, sage,
thyme, and many others. Luteolin has antioxidant, anti-inflammatory, anti-allergic,
anticancer, and immune-modulating properties to suppress hyperactive immune systems.
Luteolin is a potent hypoglycemic agent and improves insulin sensitivity. Luteolin
may help promote healthy blood glucose levels and help in weight management for
Syndrome X. Externally luteolin can be used for skin allergic/inflammatory disorders
and for skin cancer prevention. Luteolin is a promising agent for use in
ophthalmology: for prevention and treatment of cataract and of vascular eye
disorders. Luteolin is an active inhibitor of different hyaluronidases, which
modify hyaluronic acid. Hyaluronic acid, a heteropolysaccharide, is one the
polymers that accounts for the toughness and flexibility of cartilage and tendon.
Luteolin can helps the body withstand radiation and chemotherapy. In a study from
Japan, researchers went looking for the factor in rooibos tea that was protecting
DNA from radiation-induced free radicals. They discovered that the protective
factor is luteolin. They then treated mice with pure luteolin. The flavonoid gave
dramatic protection to the bone marrow and spleen against radiation. It was better
than any other plant derivative tested (see Free Radicals chart). They then tested
luteolin in conjunction with doxorubicin (Adriamycin), a common chemo-therapeutic
drug known for its cardiac and bone marrow toxicity. Doxorubicin caused lipid
peroxidation to rise in bone marrow to 5.9 times normal and cardiac rose to 1.5
times normal. Luteolin provided dramatic protection against this drug-induced free
radical damage. Bone marrow peroxidation decreased 91% and CPK levels
(an indication of heart damage) were normalized by luteolin. Importantly, luteolin
did not interfere with the therapeutic effects of doxorubicin.
Luteolin exhibits spasmolytic effects: Luteolin significantly antagonized
acetylcholine- and histamine-induced contraction of smooth muscle in the guinea
pig model of modified air overflow, and showed strong anti-histamine properties.
Luteolin displays anti-leishmanial activity. Luteolin displays strong
antinociceptive (against pain originating from peripheral nerves) action in mice.
This is in accordance with the fact that Luteolin is an active principle of
Brazilian plant Wedelia paludosa, traditionally used against the variety of
disorders, including painful conditions. Luteolin is a Super-Nutrient from a
class of naturally occurring molecules known as bioflavonoids. Luteolin
neutralizes free radicals such as superoxide, the hydroxyl radical, and other
reactive oxygen compounds to help reduce oxidative stress and may help reduce
inflammation, regulate hyperactive immune systems, and promote healthy
carbohydrate metabolism.
Luteolin is a flavonoid that has been shown to reduce proinflammatory molecule
expression in vitro. In the present study, we have tested the ability of luteolin
to inhibit lipopolysaccharide (LPS)- induced lethal toxicity and proinflammatory
molecule expression in vivo. Mice receiving LPS (Salmonella enteriditis LPS, 32
mg/kg, intraperitoneally) exhibited high mortality with only 4.1% of the animals
surviving seven days after the LPS challenge. On the contrary, mice that had
received luteolin (0.2 mg/kg, intraperitoneally) before LPS showed an increased
survival rate with 48% remaining alive on Day 7. To investigate the mechanism by
which luteolin affords protection against LPS toxicity we measured intercellular
adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha (TNF-alpha)
production in response to LPS in the presence or absence of luteolin pretreatment.
Treatment of animals with LPS increased serum TNF-alpha levels in a time-dependent
manner. The increase in peak serum TNF-alpha levels was sensitive to luteolin
pretreatment. Luteolin pretreatment also reduced LPS-stimulated ICAM-1 expression
in the liver and abolished leukocyte infiltration in the liver and lung. We
conclude that luteolin protects against LPS-induced lethal toxicity, possibly by
inhibiting proinflammatory molecule (TNF-alpha, ICAM-1) expression in vivo and
reducing leukocyte infiltration in tissues.
