Astragalus

Astragalus
Astragalus tragacantha ssp. vicentinus
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Tribe: Galegeae
Subtribe: Astragalinae
Genus: Astragalus
L.
Type species
Astragalus onobrychis
L.
Synonyms

Acanthophaca Nevski
Aragallus Neck. ex Greene
Astenolobium Nevski
Astracantha Podlech
Atelophragma Rydb.
Barnebyella Podlech
Batidophaca Rydb.
Biserrula L.[Note 1]
Brachyphragma Rydb.
Cnemidophacos Rydb.
Contortuplicata Medik.
Cryptorrhynchus Nevski
Ctenophyllum Rydb.
Cystium Steven
Didymopelta Regel & Schmalh.
Diholcos Rydb.
Diplotheca Hochst.
Erophaca Boiss.[Note 1]
Geoprumnon Rydb.
Gynophoraria Rydb.
Hamosa Medik.
Hedyphylla Steven
Hesperastragalus A. Heller
Hesperonix Rydb.
Holcophacos Rydb.
Homalobus Nutt.
Jonesiella Rydb.
Kentrophyta Nutt.
Kiapasia Woronow ex Grossh.
Lonchophaca Rydb.
Microphacos Rydb.
Mystirophora Nevski
Neodielsia Harms
Oedicephalus Nevski
Onix Medik.
Ophiocarpus (Bunge) Ikonn.
Orophaca (Torr. & A. Gray) Britton[Note 1]
Oxyglottis (Bunge) Nevski
Phaca L.
Phacomene Rydb.
Phacopsis Rydb.
Phyllolobium Fisch. ex Spreng.[Note 1]
Pisophaca Rydb.
Podlechiella Maassoumi & Kaz. Osaloo[Note 1]
Poecilocarpus Nevski
Pterophacos Rydb.
Sewerzowia Regel & Schmalh.
Thium Steud.
Tragacantha Mill.
Xylophacos Rydb.

Astragalus (As-trá-ga-lus) is a large genus of about 3,000 species[1] of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere. Common names include milk-vetch (most species), locoweed (in western US, some species; although most locoweeds are not genus Astragalus but in related genera)[2] and goat's-thorn (A. gummifer, A. tragacanthus). Some pale-flowered vetches are similar in appearance, but vetches are more vine-like.

Contents

Species

Astragalus species are used as food plants by the larvae of some Lepidoptera species including the following case-bearers of the genus Coleophora: C. astragalella (feeds exclusively on A. glycyphyllos), C. cartilaginella (feeds exclusively on Astragalus), C. colutella, C. euryaula (feeds exclusively on Astragalus), C. gallipennella (feeds exclusively on A. glycyphyllos), C. hippodromica (feeds exclusively on A. gombo), C. onobrychiella (feeds exclusively on Astragalus), C. polonicella (feeds exclusively on A. arenarius) and C. vicinella.

Traditional uses

Astragalus propinquus (also known as Astragalus membranaceus) has a history of use as a herbal medicine and is used in traditional Chinese medicine.[3]

Research

The biotechnology firms Geron Corporation and TA Therapeutics of Hong Kong have been working on deriving a telomerase activator from it. The chemical constituent cycloastragenol (also called TAT2) is being studied to help combat HIV, as well as infections associated with chronic diseases or aging.[4] However, the National Institutes of Health states: The evidence for using astragalus for any health condition is limited. High-quality clinical trials (studies in people) are generally lacking. There is some preliminary evidence to suggest that astragalus, either alone or in combination with other herbs, may have potential benefits for the immune system, heart, and liver, and as an adjunctive therapy for cancer.[5]

Supplement use

Extracts of Astragalus membranaceus are marketed as life prolonging extracts in humans. A proprietary extract of the dried root of Astragalus membranaceus, called TA-65, 'was associated with a significant age-reversal effect in the immune system, in that it led to declines in the percentage of senescent cytotoxic T cells and natural killer cells after six to twelve months of use.'[6] In October 2010, Intertek/AAC Labs, an ISO 17025 internationally recognized lab, found the largest component of TA-65 to be Cycloastragenol.[7] Telomerase activation was feared to pose an increased risk of cancer because telomere shortening is a mechanism that limits cell proliferation. However, short telomeres result in chromosome instability, hence there is also a potential mechanism for telomere lengthening to protect against cancer (as distinct from mutation-induced activation).[8]

Side effects

Astragalus may interact with medications that suppress the immune system, such as cyclophosphamide.[5] It may also affect blood sugar levels and blood pressure.[5] Some Astragalus species can be toxic. For example, several species that grow in the United States contain the neurotoxin swainsonine.[5]

Ornamental use

Several species, including A. alpinus (bluish-purple flowers), A. hypoglottis (purple flowers) and A. lotoides, are grown as ornamental plants in gardens.

Toxicology

The family of Astragalus has been reviewed by Rios and Waterman, indicating that the toxicities vary from one species to another.[9]

Selected species

(See external references)

See also

Notes

  1. ^ a b c d e This may actually be a valid genus.

References

  1. ^ David G. Frodin (2004). "History and concepts of big plant genera". Taxon 53 (3): 753–776. doi:10.2307/4135449. http://www.ingentaconnect.com/content/iapt/tax/2004/00000053/00000003/art00012. 
  2. ^ Astragalus (Locoweed) flowers
  3. ^ http://www.umm.edu/altmed/articles/astragalus-000223.htm
  4. ^ "Herbal chemical helps combat HIV". United Press International. January 1, 2009. http://www.upi.com/Health_News/2009/01/01/Herbal_chemical_helps_combat_HIV/UPI-75921230846928/. Retrieved January 28, 2011. 
  5. ^ a b c d Astragalus, NCCAM
  6. ^ Calvin B. Harley, Weimin Liu, Maria Blasco, Elsa Vera, William H. Andrews, Laura A. Briggs & Joseph M. Raffaele (2011). "A natural product telomerase activator as part of a health maintenance program". Rejuvenation Research 14 (1): 45–56. doi:10.1089/rej.2010.1085. PMC 3045570. PMID 20822369. http://www.liebertonline.com/doi/full/10.1089/rej.2010.1085. 
  7. ^ American Analytical Chemistry Laboratories Analysis Document #100710-236 of TA-65
  8. ^ Keiko Hiyama, Eiso Hiyama, Keiji Tanimoto & Masahiko Nishiyama (2009). "Role of telomeres and telomerase in cancer". In Keiko Hiyama. Telomeres and Telomerase in Cancer. Cancer Drug Discovery and Development. II. Humana Press. pp. 171–180. doi:10.1007/978-1-60327-879-9_7. ISBN 978-1-60327-879-9. http://www.springerlink.com/content/m8k8770876771t02/. 
  9. ^ Rios, J. L.; P. G. Waterman (1998). "A review of the pharmacology and toxicology of Astragalus". Phytotherapy Research 11 (6): 411–418. doi:10.1002/(SICI)1099-1573(199709)11:6<411::AID-PTR132>3.0.CO;2-6. 

External links