Famous toxic herb smoothes arthritis pain
| |
|
CM NEWS - Triptolide, an extract of the famous toxic Chinese herb lei gong teng, has the ability to suppress inflammation and cartilage destruction in collagen-induced arthritis mice, a Beijing study reveals.
The study was completed at the Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences in Beijing.
Chinese herb lei gong teng (雷公藤, Tripterygium wilfordii Hook. f., Radix Tripterygium wilfordii, three-wing-nut) has captured a lot of scientific interests in recent years. Lei gong teng has been reported to be therapeutically efficacious in the treatment of rheumatoid arthritis. In another study, lei gong teng showed potential to stop cyst formation in polycystic kidney disease, which could mean a hope for the first treatment for the disease other than kidney transplant or frequent dialysis. Scientists have also indicated that lei gong teng may limit tumour growth.
What is lei gong teng? Lei gong teng is a traditional Chinese medicine which can be used for anti-inflammation, kills worms, resolves toxins, treating proteinuric renal disease, used as immunosuppressive agent on autoimmune diseases. Modern applications include proliferative arthritis, inflammation of spinal cord, lupus, purpura, kidney inflammation, asthma, tuberculosis of the lungs, psoriasis, dermatitis and Reiter syndrome.
However, lei gong teng is highly toxic and and large consumption could be toxic to the liver. Toxic reactions include: dizziness, palpitation, weakness, nausea, vomiting, stomach ache, diarrhea, pain in liver and kidney areas, bleeding in the digestive tract, even respiration and circulation exhaustion and death.
Lei gong teng has a very romantic nickname: “Heartbreaking Grass” (斷腸草), for its high toxicity. “Heartbreaking Grass” was rumoured to be the plant that killed the king of traditional Chinese medicine Shen Nong (神農) thousands of years ago. It has another nickname “Seven Steps to Death” (七步死), again implying its high toxicity.
Because of its toxicity, the daily dose should be kept between five and 12 grams, with a maximum of 15 grams. Classic texts specifically instructed users to peel and discard the root bark of this herb before decocting. In addition, lei gong teng should be cooked for at least 60 minutes before the addition of other herbs, then cooked for another 15 minutes. Prolonged (between one and two hours) is recommended to decrease its toxicity. Side-effects are minimal when this herb is prescribed following the proper dosage and preparation.
The researchers induced arthritis in mice by manipulating their collagen levels. As a result, histological examination demonstrated that triptolide significantly reduced the inflammatory responses and cartilage damage in the joint tissues.
What is the relationship between collagen and arthritis? When people suffer from arthritis, there is a selective destruction of collagen type II in the joint cartilage itself.
Scientists know that this particular component of cartilage is being attacked by white blood cells and somehow this activates the immune system in the rheumatoid arthritic patient to develop antibodies to collagen type II.
This then sets up an immune response to all of the cartilage that is degenerating in the body. Thus, both wrists hurt, both knees hurt, the hips, the back, etc. In osteoarthritis, we have a wear and tear type of destruction of the cartilage with the release of soluble collagen type II, but without the immune response. The end result is the same. Pain, more pain, and loss of quality of life.
Interestingly, the Beijing study showed that triptolide interfered with the expression of matrix metalloproteinases-13 and -3, which are considered to be key enzymes in the pathological destruction of cartilage.
What are matrix metalloproteinases (MMPs)? MMPs are capable of degrading all kinds of extracellular matrix proteins. MMPs are also thought to play a major role on cell behaviours such as cell proliferation, migration (adhesion/dispersion), differentiation, angiogenesis, apoptosis and host defense.
Collagens are the major components of bone and cartilage, and MMPs are the only known mammalian enzymes capable of degrading them.
Triptolide also showed the ability to inhibit the expression of a particular enzyme which can provide relief from the symptoms of inflammation and pain; this is the method of action of well-known drugs such as aspirin and ibuprofen.
In addition, triptolide treatment in vivo was able to reduce an abundance of nuclear factor-kappaB, the transcriptional factor closely related to the inflammatory process.
The researchers conclude that these results suggest that triptolide exerts novel chondroprotective and anti-inflammatory effects on rhematoid arthritis. The study has proved that the therapeutic action of lei gong teng rhematoid arthritis is, in part, due to the triptolide activities.
[Biochem Pharmacol. 2007 Jan 1;73(1):136-46]
