Milk thistle is a flowering herb. Silymarin can be extracted from the seeds (fruit). The seeds are used to prepare
capsules containing powdered herb or seed; extracts; and infusions (strong teas).  Milk Thistle has been marketed as a
herbal supplement having a  protecting benefits on the liver, they claim milk thistle can even regenerate the liver cells in
most liver diseases such as cirrhosis (hardening of the liver), jaundice and hepatitis (inflammation of the liver),
cholangitis (inflammation of bile ducts resulting in decreased bile flow) or even liver intoxication.Traditionally, milk thistle
is commonly used for liver cirrhosis, alcoholic hepatitis, alcoholic fatty liver, liver poisoning, and viral hepatitis.

Milk thistle extracts are standardized to a concentration of 70-80% of flavone lignans including isosilybinin, silybinin,
silychristin, and silydianin, which are collectively called silymarin. Silymarin may play a role in displacing toxins binding to
the liver and causing the liver cells to regenerate at a faster rate.

Milk Thistle Benefits
Milk thistle silymarin has anti-inflammatory, cytoprotective, and anticarcinogenic effects. These effects are probably
related to inhibition of activation of NF-kappa B and the kinases. [7] Silymarin also has anti-oxidative effects. [9]

Milk thistle may have anti-microbial effects, as its ingredient silybin inhibited RNA and protein synthesis on gram-positive
bacteria. [8] Milk thistle and lecithin complex has anti-atherosclerotic activity in rabbits. [10] Thus, milk thistle may benefit
people at risk of cardiovascular issues. Milk thistle may also support patients suffered from cancers, as its ingredients
show anti-cancer activities. [11-36] Further, milk thistle may benefit people suffered from diabetes. [39, 40]

There are also some pieces of evidence that milk thistle have the protective effects for liver. A double blind study of 170
patients with cirrhosis demonstrated that a milk thistle extract treatment was effective on alcoholic cirrhosis. [44] Milk
thistle extracts retarded the development of alcohol-induced hepatic fibrosis in 12 baboons. [46] Milk thistle may have
injury healing effects, and these healing effects of milk thistle extracts on acute and chronic liver injury are probably
related to inhibition of leukotriene B (4) formation by silibinin. [47] For details, please, review
milk thistle benefits.
Milk Thistle Side Effects October 18, 2011
Milk Thistle Safety Issues

Milk Thistle Side Effects
Milk thistle appears to be safe and accepted by patients. Only a few cases of milk thistle side effect have been
reported. Citations about milk thistle side effects and safety issues from various scientific articles are summarized as

[1] Milk thistle extract has been safely used for centuries to treat liver ailments. [55]

[2] Milk thistle extract side effects include gastrointestinal disturbances and allergic skin rashes.[56]

[3] In a study of 170 patients with cirrhosis, researchers observed no milk thistle side effect.  [57]

[4] Silymarin exposure did not produce any signs of overt toxicity or any changes in relative organ weights. Johnson VJ
et al, Physiological responses of a natural antioxidant flavonoid mixture, silymarin, in BALB/c mice: III. [58]

[5] Treatment with milk thistle appears to be safe and well tolerated. No reduction in mortality, but improvements in
histology and in biochemical markers of liver function among patients with chronic liver disease were found with milk
thistle supplement. [59]

[6] Milk thistle was not associated with a significantly increased risk of adverse side effects. [60]

[7] High dose of milk thistle may stimulate inflammatory process (from a mice study). [61]

The common side effects of milk thistle include diarrhea, uterine and menstrual stimulation. Experience of intermittent
episodes of sweating, nausea, vomiting, diarrhea, abdominal pain, weakness and collapse after intake of milk thistle
has also been reported, but it is uncommon. At high doses, silibinin may elevate bilirubin and liver enzymes. [

According to WedMD [
WD], milk thistle sometimes causes mild side effect like laxative effect. While, nausea, diarrhea,
indigestion, intestinal gas, bloating, fullness or pain, and loss of appetite are less common milk thistle side effects.

According to National Cancer Institute [
NCI] (October 20, 2011), human studies of silymarin have shown minimal
adverse effects in multiple large, blinded, placebo-controlled, randomized studies. Silymarin is well tolerated, with only
rare reports of a mild laxative effect. Mild allergic reactions have been seen at high doses (>1,500 mg /day), although
the details of these allergic reactions were not reported.[1] A recent case report from Australia described a reaction to
a milk thistle extract that included intermittent episodes of sweating, abdominal cramping, nausea, vomiting, diarrhea,
and weakness.[2] All symptoms resolved when the silymarin was discontinued. The authors suggested that the
capsules were contaminated; the type of contamination was unknown.

According to the German Commission E, there are no reported side effects with milk thistle within the recommended
doses. Rare cases of milk thistle having a laxative effect have been reported. Human studies have reported stomach
upset, heartburn, and transient headaches; however, none of these symptoms were attributed to supplementation with
milk thistle, and supplementation was not discontinued.[3] One human dosing study reported nausea, heartburn, and
dyspepsia in patients treated with 160 mg/day, dyspepsia in patients treated with 240 mg/day, and postprandial
nausea and meteorism in patients treated with 360 mg/day. None of these side effects were dose related.

Milk Thistle Toxicity
Silymarin has been well tolerated in high doses. Silymarin has been used in pregnant women with intrahepatic
cholestasis at doses of 560 mg/day for 16 days, with no toxicity to the patient or the fetus. The published data on
silymarin use in children focuses on intravenous doses of 20 to 50 mg/kg body weight for mushroom poisoning.
Silymarin has also proved nontoxic in rats and mice when administered in doses as high as 5,000 mg/kg body weight.
Rats and dogs have received silymarin at doses of 50 to 2,500 mg/kg body weight for a 12-month period.
Investigations, including postmortem analyses, showed no evidence of toxicity. [NCI]

Milk Thistle Drug Interaction
Milk thistle inhibits cytochrome P-450 3A4, it may alter certain the oral absorption of certain drugs.

University of Maryland suggests not to use milk thistle if you are taking: antipsychotics, phenytoin(Dilantin), halothane,
and birth control pills or hormone replacement therapy. Milk thistle may interact with allergy drugs -- such as
fexofenadine (Allegra), statins, anti-anxiety drugs, anti-platelets, anti-coagulants, some cancer drugs and drugs borken
down by liver. [

It is not known whether milk thistle may reduce, enhance, or have no effect on the effectiveness of chemotherapy.
Silymarin decreases the activity of the cytochrome P450 enzyme system, which is involved in the clearance of certain
chemotherapy drugs.[NCI] However, the dose at which inhibition is observed is high and not achieved with oral intake
of silymarin.[NCI] One study investigated the effects of silymarin on the pharmacokinetics of irinotecan. Oral
administration of milk thistle (200 mg, a clinically relevant dose, 3 times per day) had no significant effects on the
pharmacokinetics of irinotecan. The authors concluded that the recommended doses of milk thistle are too low to affect
activity of CYP3A4 or UGT1A1 enzyme pathways.[NCI]

Theoretically, milk thistle may also interact adversely with chemotherapy drugs that exert their cytotoxic effects through
the generation of free radicals. Silymarin and its metabolite inhibit P-glycoprotein–mediated cellular efflux, leading to
the potentiation of doxorubicin cytotoxicity. No trials have been performed to support or negate these theoretical
considerations. No effects on indinavir and alcohol pharmacokinetics have been observed. Enhancement of
antiarrhythmic effects of amiodarone in rats has been observed. [NCI]

Milk thistle PLANT extract might act like estrogen. People with breast cancer, uterine cancer, ovarian cancer,
endometriosis, or uterine fibroids or other hormonal sensitive conditions must discuss with their doctors before taking
milk thistle. [WD]

Milk thistle can produce allergic reactions, which tend to be more common among people who are allergic to plants in
the same family (e.g. ragweed, chrysanthemium, marigold, and daisy}.
Different people may experience different side effects and benefits of a product. You are encouraged to
report adverse side effects to FDA, its website is, or report the adverse side effects to the
manufacturer, you should be able to find the contact information on the label.

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