Study hints at milk thistle's heart health benefits

Tag : Milk Thistle Extract


The in vitro study found that the milk thistle extract protected LDL cholesterol against oxidation in adose-dependent manner, a result with potentially importantimplications since the oxidative modification of LDL has beenreported to be a major part of the pathogenesis of atherosclerosis,and subsequently cardiovascular disease.

Cardiovascular disease (CVD), the cause of almost 50 per cent of deaths in Europe, andreported to cost the EU economy an estimated €169bn ($202bn)per year.

"Thus, it is possible that the extract prepared from the fruits ofan easily accessible plant could be useful to prevent theprogression of atherosclerotic events," wrote lead author Sunny Wallace from the University of Arkansas.

"However, before important conclusions that could lead toprevention strategies are drawn, it would be of interest todetermine the atheroprotective effect of silymarin in vivo using an atherosclerosis-prone apolipoprotein E or LDLreceptor knockout mouse model."

The results are reported in the Journal of Agricultural and Food Chemistry.

Study details

Wallace and co-workers tested both the crude extract and purifiedforms of the major flavonolignans compounds that make up silymarin,the key flavanone in milk thistle, including silichristin (SC),silidianin (SD), silibinin (SBN), and isosilibinin (IS).

At doses of the milk thistle extract of 38, 75, 150, and 300micromoles, LDL oxidation was inhibited by 18, 73, 82, and 86 percent, respectively, said the researchers.

The individual flavonolignans were also associated with reductionsin LDL oxidation with 300 micromole doses of SC, SD, SBN, and ISreducing LDL oxidation by 60, 28.1, 60, and 30.1 per cent,respectively, report Wallace and co-workers.

"These results showed that silymarin and SBN, likely throughantioxidant and free radical scavenging mechanisms of action,inhibit the generation of oxidised LDL," concluded the researchers.

Significant further research is necessary if milk thistle and itsextracts can be seen as providing a benefit to cardiovascularhealth. Indeed, the researchers identified animal studies with miceas the next step.

Milk thistle (Silybum marianum) has been used for a long time as afood in Europe. Young leaves are used in salads, the stalks eatenlike asparagus, and the heads boiled like artichoke.

According to the Manitoba Agriculture, Food and Rural Initiatives(Canada) milk thistle ranked 12th among the top selling herbsupplements in the US mass market, with sales of over $3m in 1997.