Silymarin milk thistle
Research on milk thistle and it's components appears to be growing. The current theory regarding mode of activity is that silymarin supports liver health in two major ways. First, it alters the outer cell membrane of hepatocytes (liver cells) in such a way as to prevent penetration of harmful substances into the interior of cells. Second, it stimulates the action of nucleolar polymerase A (an enzyme involved in chromosome replication) resulting in an increase in ribosomal protein synthesis, which stimulates the regenerative ability of the liver and the formation of new hepatocytes. Silymarin may also stimulate an increase in bile flow from the gall bladder to the intestine. Silymarin is being investigated as an agent to support healthy cholesterol levels by exerting an effect on the liver cholesterol metabolism. Silymarin also possesses antioxident properties. Studies have indicated that oxidative stress plays a role in the pathogenisis of toxic liver disease and other liver problems, and silymarin may reduce oxidative stress in the liver. Therefore, any liver subjected to chemical or chronic illness stresses may benefit from the additional nutritional support that silymarin provides. In an article for Prevention magazine, Varro Tyler, Ph.D., Sc.D, states that milk thistle may help support the liver in people taking prescription medication that may adversely affect the liver.
Milk thistle, known in Latin as Silybum marianum, is one of the most effective herbs for detoxifying and regenerating the liver. The liver is responsible for breaking down and eliminating most toxic substances. These include drugs, antibiotics, cortisone, chemotherapy, anti-seizure medications, anti-inflammatory, preservatives in food, artificial flavoring and coloring agents, shampoos, environmental chemicals, foods fried in certain oils, chemicals found in tap water, household cleansers, air pollution, tobacco smoke and distillates. Hundreds of scientific studies have demonstrated that milk thistle can protect the liver from potent toxins such as poisonous mushrooms, heavy metals and alcohol.
The herb has several mechanisms of action. It stimulates protein synthesis, which contributes to regeneration and replacement of liver cells. It helps protect the liver against poisoning by blocking the absorption of toxins into liver cells. It inhibits the formation of inflammatory substances that contribute to liver degeneration. It helps the liver break down toxins. Milk thistle is a potent anti-oxidant (more potent than Vitamins C and E). This means it can counteract free radical damage that can cause degenerative diseases including cancer. It increases intracellular levels of glutathione, a substance necessary for detoxicating reactions.
Clinical studies have confirmed milk thistle's benefits. Trials in more than 2,000 patients showed benefits in alcohol and chemical induced fatty liver, cirrhosis, chronic hepatitis, bile duct inflammation and non specific changes in liver tissue. Elevated liver enzymes (blood tests for liver function) also improve with milk thistle therapy. Silymarin may also help prevent or treat gallstones by increasing the solubility of the bile. The best-known active compound in milk thistle is silybin. It is important to remember that there are many other naturally occurring ingredients that are vital for optimum activity.
Recent studies have shown that Milk thistle extract may also be beneficial for reducing the chance for certain cancers. With almost no known side effects (Milk thistle is a food!) and well-known hepatoprotective efficacy, it is said that Milk thistle can't be beat as a liver protector.
Yucca Schidegera (Saponins)Saponins are natural detergents that are found in certain desert plants and are also present in small amounts within some pod family foods. The major commercial sources of saponins are Yucca Schidigera, which grows in the arid Mexican desert country of Baja California.
Yucca Saponins, and other components of yucca as well, have ammonia-binding activity. When ammonia is processed by the liver, uric acid is created. When added to the diet, Yucca Saponins pass the ammonia through the digestive tract unabsorbed and are then excreted in the feces. Yucca is also used in some dog foods to reduce the odor in their urine and bowel movements.
Saponins bind with cholesterol, which has many important considerations including cholesterol-lowering activity in humans. Saponins react with cholesterol in the protozoal cell membrane by causing the cell to rupture. Research currently in progress at Agriculture Canada in Lethbridge, Alberta has shown yucca extract to be very effective in killing Giardia trophozoites, which are the infective stages released in the gut when the oocytes, or eggs, sporulate. Yucca saponins are also effective in killing rumen protozoa (helps breed Salmonella bacteria) when ingested.
The blood cholesterol-lowering properties of dietary saponins are of interest in human nutrition. One research program on this subject was that of Dr. Rene Malinow at the Oregon Regional Primate Center, whose research (published in the American Journal of Clinical Nutrition in 1997) demonstrated unequivocally the cholesterol-lowering properties of saponins. This desirable effect is achieved by the binding of bile acids and cholesterol by saponins. Bile acids form mixed micelles (molecular aggregates) with cholesterol further increasing its absorption. Cholesterol is continually secreted into the intestine via the bile, with much of it subsequently reabsorbed. Saponins cause a depletion of body cholesterol by preventing its reabsorption, thus increasing its excretion in much the same way as other cholesterol-lowering drugs do.
Although there are reports of the development of synthetic saponins as drugs for treating high blood cholesterol, yucca / saponins are natural phytochemicals currently used in foods and beverages and herbal products and are safer. Recent research conducted in Canada and Africa have suggested that the very low serum cholesterol levels of tribes in East Africa, who consume a diet very high in animal products, cholesterol, and saturated fat, are likely due to the consumption of saponin-rich herbs like Yucca.
The binding of bile acids by saponins has other important factors. Bile acids excreted in the bile are metabolized by bacteria in the colon, producing secondary bile acids. Some of the secondary bile acids are promoters of colon cancer. Saponins binding to primary bile acids reduce the formation of these secondary bile acids thus helping to prevent colon cancer. The University of Toronto has shown that feeding saponins to laboratory animals reduced the number of pre-cancer colon lesions in mice. The Canadian researchers also found that saponins had a dose-dependent inhibitory effect on growth of human carcinoma cells in culture. Major current interest in saponins concerns their effects on the immune system.
Yucca is a rich storehouse of phytochemicals with many useful and important functions in human and animal nutrition.
Written by Holly Wagner,