Tripterygium wilfordii

Tripterygium wilfordii
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Celastrales
Family: Celastraceae
Genus: Tripterygium
Species: T. wilfordii
Binomial name
Tripterygium wilfordii
Hook.f.

Tripterygium wilfordii, or léi gōng téng (Mandarin) (Chinese:雷公藤, Japanese: raikōtō), sometimes called thunder god vine but more properly translated thunder duke vine, is a vine used in traditional Chinese medicine for treatment of fever, chills, edema and carbuncle.

Tripterygium wilfordii recently has been investigated as a treatment for a variety of disorders including rheumatoid arthritis, cancer, chronic hepatitis, chronic nephritis, ankylosing spondylitis, polycystic kidney disease as well as several skin disorders. It is also under investigation for its apparent antifertility effects, which, it is speculated, may provide a basis for a male oral contraceptive.[1]

Pharmacology

Triptolide, a diterpene triepoxide, is a major active component of extracts derived from Tripterygium wilfordii. Triptolide has multiple pharmacological activities including anti-inflammatory, immune modulation, antiproliferative and proapoptotic activity.[2]

Reduction of male fertility

The plant contains many active compounds, at least six of which have male anti-fertility effect (triptolide, tripdiolide, triptolidenol, tripchlorolide, 16-hydroxytriplide and a compound known as T7/19, whose structure is unpublished). The mechanism by which they affect fertility is not yet understood. What is known is that daily doses of these compounds reduce sperm counts and also severely affect the formation and maturation of sperm, causing them to be immotile.

Scientific research into medical effects

Contraception

Certain extracts from Tripterygium wilfordii, as well as from Tripterygium hypoglaucum (now considered identical to T. regelii) and Tripterygium regelii, were discovered in the 1980s to have temporary anti-fertility effects, which has led to research on its potential as a contraceptive.

"Tripterygium wilfordii Hook.f., known as Leigongteng (Thunder God Vine) in traditional Chinese medicine, has attracted much attention for its applications in relieving autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus, and for treating cancer. Molecular analyses of the ITS and 5S rDNA sequences indicate that T. hypoglaucum and T. doianum are not distinct from T. wilfordii, while T. regelii should be recognized as a separate species. The results also demonstrate potential value of rDNA sequence data in forensic detection of adulterants derived from Celastrus angulatus in commercial samples of Leigongteng."[3]

Not enough is known about T. wilfordii to actually test it as a contraceptive. Research thus far has dealt with establishing the mechanism by which the plant affects fertility, and investigating toxicity and side effects. What has been learned is encouraging, however: in both animals and humans, low doses of various Tripterygium extracts can produce significantly lowered sperm density and motility indices without major side effects. When the treatment was ended in the various trials, all indices returned to normal within months.

T. wilfordii could be an effective pharmaceutical alternative to contraceptives based on hormonal manipulation.

Immunosuppression

A small molecule Triptolide derived from T. wilfordii has been shown to disrupt mitochondrial function in cells and is under investigation as an anti-tumor agent or to suppress auto-immune disorders.

Rheumatoid arthritis

In China Tripterygium wilfordii has an established history of use in the treatment of rheumatoid arthritis. The herb shows immunosuppressive, cartilage protective, and anti-inflammatory effects.[4][5] The National Center for Complementary and Alternative Medicine has noted that one systematic review of the literature found that Tripterygium wilfordii may improve some RA symptoms, though another systematic review has stated that the serious side effects occur frequently enough to make the risks of taking this herbal supplement too high for the possible benefits.[6] A 2014 clinical trial with 207 RA patients compared the efficacy and safety of Tripterygium wilfordii Hook F (TwHF) with methotrexate (MTX) in the treatment of active rheumatoid arthritis (RA). This study concluded that "TwHF monotherapy was not inferior to, and MTX+TwHF was better than, MTX monotherapy in controlling disease activity in patients with active RA."[7]

Pancreatic cancer

Two compounds, the diterpenoid epoxide triptolide and the quinone triterpene celastrol found in the plant may have potential as antitumor drugs.[8]

Drugs derived from the plant also show potential for reduction and elimination of pancreatic tumors in mice. Clinical trials may soon begin for the development of a drug for use in humans.[9]

Side effects

At medicinal doses, T. wilfordii extract does have significant side effects, including immunosuppression. However, this may not apply to contraceptive use. Many of the side effects are caused by the other active compounds found in the plant, and do not appear when a pure extraction of its compounds with anti-fertility effect is used. In addition, the dose required to lower fertility is significantly lower than the standard medicinal dose.

In August 2011, the UK Medicines and Healthcare Products Regulatory Agency (MHRA) published a drug safety bulletin advising consumers not to use medicines containing Lei Gong Teng. This was due to concerns over potentially serious side effects.

China State Food and Drug Administration issued a warning in April 2012 about this medicine, urging caution.[10]

However, a recent review stated that although Tripterygium wilfordii has toxic potential, careful extraction gives an acceptable frequency of adverse reactions, which are largely related to the gastrointestinal tract and amenorrhea. The review found that T. wilfordii extract is useful remedy for postmenopausal rheumatoid arthritis.[11]

The Beijing TV series of China Medicine has shown people being treated successfully with the herb in a formula for rheumatoid arthritis. and outlined some practice to alleviate problems of using the herb. As often the case of TCM, formulations need to be adjusted for individual's physiology for best result.

See also

Footnotes

  1. ↑ Zhen QS, Ye X, Wei ZJ (February 1995). "Recent progress in research on Tripterygium: a male antifertility plant". Contraception 51 (2): 121–9. doi:10.1016/0010-7824(94)00018-R. PMID 7750290.
  2. ↑ Liu Q. (2011). "Triptolide and its expanding multiple pharmacological functions". International Immunopharmacology 11 (3): 377–383. doi:10.1016/j.intimp.2011.01.012. PMID 21255694.
  3. ↑ Sue Ka-Yee Law et al. (2011). "Molecular analyses of the Chinese herb Leigongteng (Tripterygium wilfordii Hook.f.)" (PDF). Phytochemistry (Elsevier) 72: 21.
  4. ↑ Bao J., Dai S.-M. "A Chinese herb Tripterygium wilfordii Hook F in the treatment of rheumatoid arthritis: mechanism, efficacy, and safety" Rheumatology International 2011 (1-7)
  5. ↑ Moudgil K.D., Venkatesha S.H., Rajaiah R., Berman B.M. "Immunomodulation of autoimmune arthritis by herbal CAM" Evidence-based Complementary and Alternative Medicine 2011 2011 Article Number 986797
  6. ↑ "Rheumatoid Arthritis and Complementary Health Approaches". National Center for Complementary and Alternative Medicine. Retrieved 21 April 2013.
  7. ↑ Trial Registration Number: NCT01613079. Ann Rheum Dis. 14 April 2014, doi: 10.1136/annrheumdis-2013-204807.
  8. ↑ Liu Z, Ma L, Zhou GB. (2011). "The main anticancer bullets of the Chinese medicinal herb, thunder god vine.". Molecules 16 (6): 5283–97. doi:10.3390/molecules16065283. PMID 21701438.
  9. ↑ Drug From Chinese ‘Thunder God Vine’ Slays Tumors in Mice. 17 Oct 2012
  10. ↑ 中医・我が愛しの上海へ／理想の中医学・漢方を求めて-
  11. ↑ Bao J., Dai S.-M., (September 2011). "A Chinese herb Tripterygium wilfordii Hook F in the treatment of rheumatoid arthritis: Mechanism, efficacy, and safety.". Rheumatology International 31 (9): 1123–1129. doi:10.1007/s00296-011-1841-y. PMID 21365177.

References