Red yeast rice promotes bone formation

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CM NEWS – Red yeast rice, rice fermented with a special purple-red mold, has been known for its abilities to lower cholesterol and blood lipid levels. A recent study opens up the possible use of red yeast rice to stimulate bone formation, which might be good news for patients with osteoporosis.

Rice yeast rice is fermented with a mold called Monascus purpureus (hongqu, 紅曲) and has been used in Chinese medicine for centuries. Scientists have long established that red yeast rice contains a natural form of statin.

What are statins? Statins are a group of drugs that are commonly used to reduce the level of cholesterol in the blood. They include atorvastatin, fluvastatin, pravastatin, rosuvastatin, and simvastatin. They each have different brand names. Statins work by blocking the action of a certain enzyme (chemical) in the liver which is needed to make cholesterol.

Statins, which control the first step in the biosynthesis of cholesterol, have been shown to stimulate bone formation in rodents both in vitro and in vivo. The effect is associated with an increased expression of the bone morphogenetic protein-2 (BMP-2) gene in bone cells.

What are bone morphogenetic proteins? One of the most critical components of building, healing and remodeling bone in humans is a process called osteoinduction. Bone Morphogenetic Proteins (BMPs), found in human blood and bones, are a group of growth factors and cytokines known for their ability to induce the formation of bone and cartilage.

BMPs have been used to stimulate the production of bone in animals and humans with great success.

FDA has approved the use of BMPs for anterior spinal fusion in the lumbar spine, and many other clinical trials have found these proteins to be effective in generating bone in other areas of the spine.

The spine research community is encouraged by BMPs and hopes they may someday be the standard for fusion procedures, reducing postsurgical pain and improve the effectiveness of spinal surgeries.

In the present study done at the University of Hong Kong, rabbits with bone defects created to their parietal bones were grafted with collagen matrix mixed with red yeast rice extract. In the control animal, two defects were grafted with collagen matrix alone.

In the control group, cells were cultured for three durations (24 hours, 48 hours and 72 hours) without any intervention. In the red yeast rice group, cells were cultured for the same durations with various concentrations of red yeast rice extract. Total protein, mitochondrial activity and bone cell formation were measured.

As a result, the test animal showed more formation of new bone in the defects than the control animal. The red yeast rice extract stimulated new bone formation in bone defects on the animals and increased bone cell formation in vitro.

The researchers explained that red yeast rice contains monacolins which are a family of HMG-CoA reductase inhibitors. Moreover, monacolin K is equivalent to the statin known as mevinolin or lovastatin. It is the function of the statin in red yeast rice that promotes bone formation.

Other active ingredients in red yeast rice include sterols (β-sitosterol, campesterol, stigmasterol, sapogenin), isoflavones and monounsaturated fatty acids.

The researchers induced that red yeast rice is a natural product with potential in treating bone defects and probably also osteoporosis.

[Chinese Medicine 2008, 3:4]