NEW YORK (Reuters Health) - Berberine, an herb used in traditional Chinese medicine, lowers LDL ("bad") cholesterol and works in a way that is distinct from statin drugs like Lipitor or Zocor, a new study shows.
Because the herb works in a different way, it could potentially be combined with a statin to reduce cholesterol levels even further.
Dr. Jian-Dong Jiang of the Mount Sinai School of Medicine in New York City and colleagues describe their animal and human studies of berberine in the journal Nature Medicine. The drug is traditionally used as an over-the-counter remedy for diarrhea caused by bacterial infection.
Statins work by blocking cholesterol formation in liver cells. This cholesterol shortage causes more cholesterol receptors -- hook-like molecules -- to appear on the cell surface in an effort to pull cholesterol from the blood to make up for the deficit. As a result, blood cholesterol levels drop.
In contrast, berberine works in a way that doesn't depend on how much cholesterol is in the cell, Jiang told Reuters Health. Like statins, the herb increases the number of cholesterol receptors on the cell surface, but it does this by stabilizing and improving the process by which the receptors are formed.
Jiang and colleagues screened 700 Chinese remedies in lab tests and found that berberine had the greatest effect in increasing cholesterol receptors. Further testing showed that receptor levels were increased further when the herb was used together with a statin.
The researchers then assessed cholesterol levels in 91 patients with high cholesterol who were treated with berberine or inactive "placebo" for 3 months. The herb was well-tolerated, and lowered total cholesterol by 18 percent and LDL cholesterol by 20 percent.
No effect on levels of HDL ("good") cholesterol was seen.
Jiang and colleagues then analyzed berberine's effect in a subset of patients who were not taking any other medications or herbs before or during the study. Among these individuals, berberine lowered total cholesterol by 29 percent and LDL cholesterol by 25 percent.
Berberine appears to be safe and is extremely cheap, according to Jiang, costing about 70 cents per day.
"The next step is to have more clinical studies for this drug to see what is the best dose and what is the effect of the combination with statins," Jiang said. While the effect of berberine was small compared with that seen with statins, the authors note that the dose used in the current study was "moderate." Larger effects may be seen with larger doses, they add.
SOURCE: Nature Medicine 2004.