Guayule

Scientific Name(s): Parthenium argentatum A. Gray. Family: Asteraceae (daisies)

Common Name(s): Guayule , Mexican rubber

Uses

There are no clinical studies using guayule. In vitro studies have shown that triterpene argentatins possess cytotoxic activity against some human cancer cell lines. Guayule provides an alternative source of rubber products for use in latex allergy.

Dosing

There are no clinical applications for guayule.

Contraindications

Contraindications have not been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Cross-reactivity with other members of the Asteraceae family is possible.

Toxicology

Information is lacking; 1 study demonstrated a lack of genotoxic effects for certain chemical constituents.

Botany

Guayule is a common shrub native to the deserts of northern Mexico and the adjacent region of Texas. The plant can be readily grown in the arid regions of the southwestern United States. The perennial shrub, which produces white to yellow flowers, grows to 1 m in 2 years, at which time it can be harvested by cutting off the whole plant just above the ground. Regrowth occurs after 12 to 18 months, allowing for further harvesting. The plant produces terpene resins, which are natural pesticides, making it resistant to many pests and diseases. 1 , 2 , 3

History

The use of guayule as a source of rubber for making balls for games has been attributed to the indigenous people of the Americas during the Mayan civilization. The plant was chewed to separate the fibrous material from the resin.

In the early 1900s, guayule accounted for almost 50% of all the natural rubber consumed in the United States and 10% of worldwide consumption; however, it later lost favor to the cheaper Hevea rubber. Interest in guayule as an alternative to latex in allergenic people has surged, and in 2008, the Food and Drug Administration (FDA) gave marketing approval to Yulex gloves, which conform to Category 4 American Society for Testing and Materials rubber standards. The US Agricultural Research Service is evaluating the energy-rich byproduct bagasse, which is produced after the resin has been extracted as a source of biofuel; its production is not likely to affect food crop areas because it is grown on agriculturally marginal land. 2 , 3 , 4 , 5

Chemistry

The physical and chemical properties of guayule rubber, which is composed of polymeric cisisoprenoid units, are essentially identical to those of Hevea rubber. Guayule rubber is found in parenchymatous cells of the stem and root tissue as latex.

Major components of the acetone extracts of woody guayule tissue are sesquiterpene esters (10% to 15% of the total), triterpenoids (7%), and fatty acid triglycerides (7% to 19%). The sesquiterpenes are, in part, artifacts of heat processing. The major triterpene compounds are C-30 argentatins, which may possess antifungal and antibacterial activity. Organic acid content varies, but the major aromatic acid is cinnamic acid and the major fatty acid is linoleic acid. The presence of unsaturated fatty acid triglycerides facilitates oxidative degradation of the latex product. 5 , 6 , 7

Uses and Pharmacology

There are no clinical studies using guayule.

Cancer

In vitro studies have shown triterpene argentatins to possess cytotoxic activity against some human cancer cell lines. In in vitro studies, argentatin B demonstrated noncompetitive inhibition at estradiol binding sites in hormone-dependent breast cancer. 7

Natural rubber latex

Clinical studies have routinely shown a lack of cross-reactivity to Hevea brasiliensis latex antibodies; thus, guayule provides an alternative source of rubber products for use in individuals with Hevea latex hypersensitivity. The FDA approved marketing of guayule-based Yulex gloves in 2008. 2 , 4 , 5 , 8 , 9 A study evaluating guayule latex gloves 4 years after storage found that the latex remained impermeable to 27 nm viruses (of the order of the smallest human viral pathogens). 8

Dosage

There are no clinical applications for guayule.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

The P. argentatum plant contains cinnamic acid, present in stems and leaves, that can elicit immune reactions. Cross sensitivity to the plant and its proteins is possible in people sensitized to other species of Asteraceae, such as ragweed and feverfew. 9 The processing of guayule for its rubber results in a low-protein–content product. 2 , 8

Toxicology

Information is lacking; 1 study demonstrated a lack of genotoxic effects via clastogenic or aneugenic mechanisms for the constituents argentatin A and B. 7

Bibliography

1. Parthenium argentatum . USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov, May, 2010). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
2. Wood M. Guayule! Go native with this promising biofuel and biomedical crop. Agricultural Research Magazine . 2009;57(2):18-19. Available at http://www.ars.usda.gov/is/AR/archive/feb09/biofuel0209.pdf . Accessed December 1, 2010.
3. Ray DT. Guayule: A source of natural rubber. In: Janick J, Simon JE, eds. New Crops . New York, NY: Wiley; 1993:338-343.
4. Mooibroek H, Cornish K. Alternative sources of natural rubber. Appl Microbiol Biotechnol . 2000;53(4):355-365.
5. van Beilen JB, Poirier Y. Guayule and Russian dandelion as alternative sources of natural rubber. Crit Rev Biotechnol . 2007;27(4):217-231.
6. Maatooq GT, el-Gamal AA, Furbacher TR, Cornuelle TL, Hoffmann JJ. Triterpenoids from Parthenium argentatum x P. tomentosa . Phytochemistry . 2002;60(8):755-760.
7. Parra-Delgado H, García-Pillado F, Sordo M, Ramírez-Apan T, Martínez-Vázquez M, Ostrosky-Wegman P. Evaluation of the cytotoxicity, cytostaticity and genotoxicity of argentatins A and B from Parthenium argentatum (Gray). Life Sci . 2005;77(22):2855-2865.
8. Cornish K, Lytle CD. Viral impermeability of hypoallergenic, low protein, guayule latex films. J Biomed Mater Res . 1999;47(3):434-437.
9. Siler DJ, Cornish K, Hamilton RG. Absence of cross-reactivity of IgE antibodies from subjects allergic to Hevea brasiliensis latex with a new source of natural rubber latex from guayule ( Parthenium argentatum ). J Allergy Clin Immunol . 1996;98(5 pt 1):895-902.

Copyright © 2009 Wolters Kluwer Health

Hide
(web3)