Chaparral (Larrea tridentata (DC) Coville, Larrea divaricata Cav) & Nordihydroguaiaretic acid (NDGA)

Chaparral (Larrea tridentata (DC) Coville, Larrea divaricata Cav) & Nordihydroguaiaretic acid (NDGA)

Background

Chaparral and its constituent nordihydroguaiaretic acid (NDGA) have been reported to possess antioxidant/free-radical scavenging properties. Although proposed as a treatment for cancer, effectiveness has not been demonstrated in clinical trials. Chaparral or NDGA has been associated with cases of hepatitis, cirrhosis, liver failure, renal cysts, and renal cell carcinoma. In response to these reports, the U.S. Food and Drug Administration removed chaparral from its "generally recognized as safe" (GRAS) list in 1970. Chaparral and NDGA are generally considered unsafe and are not recommended for use.

Synonyms

Chaparro, creosote bush, dwarf evergreen oak, el gobernadora, falsa alcaparra, geroop, obernadora, greasewood, guamis, gumis, hediondilla, hideonodo, jarillo, kovanau, kreosotstrauch, Larrea divaricata, Larrea glutiosa , Larrea mexicana Moric, palo ondo, shoegoi, sonora covillea, tasago, ya-tmep, yah-temp, zygophyllaceae.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*Cancer
Chaparral and one of its components called nordihydroguaiaretic acid (NDGA) have antioxidant ("free-radical scavenging") properties, and have been proposed as cancer treatments. However, chaparral and NDGA have been associated with cases of kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer in humans. In response to these reports, the U.S. Food and Drug Administration (FDA) removed chaparral from its "generally recognized as safe" (GRAS) list in 1970. Chaparral and NDGA are generally considered unsafe and are not recommended for use.

C

* Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Allergies, antibacterial, anti-inflammatory, anti-parasitic, antiviral, arthritis, immune system disorders, "blood purifier," bowel cramps, bruises, chicken pox, central nervous system disorders, colds, cough, chronic skin disorders, diabetes, diarrhea, diuretic (increasing urine flow), gas, gastrointestinal disorders, hair tonic, hallucinations (including due to "LSD" ingestion), heartburn, indigestion, influenza, menstrual cramps, pain, respiratory tract infections, rheumatic diseases, skin disorders, snakebite pain, stomach ulcer, tuberculosis, urinary tract infections, venereal disease, vomiting, wound healing.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. There is no widely accepted standardization for chaparral.

Adults (18 years and older)

Safety has not been established for any dose. Small doses of tea have been used, for example 1 teaspoon of chaparral leaves and flowers steeped in 1 pint of water for 15 minutes, 1-3 cups daily up to a maximum of several days. Tincture has also been used, for example 20 drops up to 3 times daily. These preparations may be associated with less toxicity, and possibly contain fewer allergenic compounds than capsules or tablets. Oil or powder forms of chaparral have also been suggested, applied to an affected area of skin several times daily.

Capsules or tablets may deliver large doses leading to toxicity, and are not recommended. Exposure to lignans, which may yield toxicity, appears to be greater from capsules or tablets than from chaparral tea.

Children (younger than 18 years)

Chaparral is not recommended for use in children, due to lack of scientific data and potential toxicity.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

People with allergy/hypersensitivity to chaparral or any of its components including nordihydroguaiaretic acid (NDGA), nor-isoguaiasin, dihydroguaiaretic acid, partially demethylated dihydroguaiaretic acid and demethoxyisoguaiasin may have allergic reactions to chaparral.

There are human case reports of allergic hypersensitivity (contact dermatitis) to chaparral and to its resin.

Side Effects and Warnings

Chaparral has been associated with multiple serious and potentially fatal adverse effects in animals and humans. Animals given the chaparral component nordihydroguaiaretic acid (NDGA) developed kidney or gastrointestinal cysts and liver cell death. In humans, chaparral has been associated with kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer. Human case reports note rash and fever with use of chaparral. Exposure to lignans, which may yield toxicity, appears to be greater from capsule or tablets than from decoctions of chaparral tea. The FDA removed chaparral from the "generally recognized as safe" (GRAS) list in 1970, and considers chaparral to be unsafe. Elevations of liver enzymes or kidney function tests (serum creatinine) may occur with chaparral.

Based on an animal study, chaparral may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels should be monitored closely and medication adjustments may be necessary.

Pregnancy & Breastfeeding

There is not enough scientific evidence to support the safe use of any dose of chaparral during pregnancy or breastfeeding.

References

1. Alderman S, Kailas S, Goldfarb S, et al. Cholestatic hepatitis after ingestion of chaparral leaf: confirmation by endoscopic retrograde cholangiopancreatography and liver biopsy. J Clin Gastroenterol 1994;19(3):242-247.

2. Anonymous. From the Centers for Disease Control and Prevention. Chaparral-induced toxic hepatitis--California and Texas, 1992. JAMA. 1992 Dec 16;268 (23) :3295, 3298.

3. Anonymous. Chaparral-induced toxic hepatitis--California and Texas, 1992. MMWR Morb Mortal Wkly Rep. 1992 Oct 30;41(43):812-4.

4. Batchelor WB, Heathcote J, Wanless IR. Chaparral-induced hepatic injury. Am J Gastroenterol. 1995 May;90(5):831-3.

5. Chitturi S, Farrell GC. Drug-induced cholestasis. Semin Gastrointest Dis. 2001 Apr;12(2):113-24.

6. Fleiss PM. Chaparral and liver toxicity. JAMA. 1995 Sep 20;274(11):871; author reply 871-2. Comment on: JAMA. 1995 Feb 8;273(6):489-90.

7. Gordon DW, Rosenthal G, Hart J, Sirota R, Baker AL. Chaparral ingestion. The broadening spectrum of liver injury caused by herbal medications. JAMA. 1995 Feb 8;273(6):489-90. Comment in: JAMA. 1995 Feb 8;273(6):502. JAMA. 1995 Sep 20;274(11):871; author reply 871-2.

8. Heron S, Yarnell E. The safety of low-dose Larrea tridentata (DC) Coville (creosote bush or chaparral): a retrospective clinical study. J Altern Complement Med. 2001 Apr;7(2):175-85.

9. Ippen H. Chaparral and liver toxicity. JAMA. 1995 Sep 20;274(11):871; author reply 871-2. Erratum in: JAMA 1995 Dec 20;274(23):1838. Comment on: JAMA. 1995 Feb 8;273(6):489-90.

10. Katz M, Saibil F. Herbal hepatitis: subacute hepatic necrosis secondary to chaparral leaf. J Clin Gastroenterol. 1990 Apr;12(2):203-6.

11. Luo J, Chuang T, Cheung J, et al. Masoprocol (nordihydroguaiaretic acid): a new antihyperglycemic agent isolated from the creosote bush (Larrea tridentata). Eur J Pharmacol 1998;346(1):77-79.

12. Obermeyer WR, Musser SM, Betz JM, et al. Chemical studies of phytoestrogens and related compounds in dietary supplements: flax and chaparral. Proc Soc Exp Biol Med 1995;208(1):6-12.

13. Shad JA, Chinn CG, Brann OS. Acute hepatitis after ingestion of herbs. South Med J. 1999 Nov;92(11):1095-7.

14. Sheikh NM, Philen RM, Love LA. Chaparral-associated hepatotoxicity. Arch Intern Med. 1997 Apr 28;157(8):913-9.

15. Smart CR, Hogle HH, Vogel H, et al. Clinical experience with nordihydroguaiaretic acid--"chaparral tea" in the treatment of cancer. Rocky Mt Med J 1970;67(11):39-43.

16. Smith AY, Feddersen RM, Gardner KD, Jr., et al. Cystic renal cell carcinoma and acquired renal cystic disease associated with consumption of chaparral tea: a case report. J Urol 1994;152(6 Pt 1):2089-2091.

17. Smith BC, Desmond PV. Acute hepatitis induced by ingestion of the herbal medication chaparral. Aust N Z J Med. 1993 Oct;23(5):526.

18. Stashower ME, Torres RZ. Chaparral and liver toxicity. JAMA. 1995 Sep 20;274(11):871; author reply 871-2. Comment on: JAMA. 1995 Feb 8;273(6):489-90.

19. Stickel F, Egerer G, Seitz HK. Hepatotoxicity of botanicals. Public Health Nutr. 2000 Jun;3(2):113-24. Comment in: Public Health Nutr. 2000 Jun;3(2):111.

20. Stickel F, Seitz HK, Hahn EG, Schuppan D. Liver toxicity of drugs of plant origin [Article in German] Z Gastroenterol. 2001 Mar;39(3):225-32, 234-7.

21. Zang LY, Cosma G, Gardner H, Starks K, Shi X, Vallyathan V. Scavenging of superoxide anion radical by chaparral. Mol Cell Biochem. 1999 Jun;196(1-2):157-61.

January 01, 2004