Question: What is chaparral and what toxicities have been associate with this substance?
Answer: The cited reference notes: “Chaparral is an herbal preparation derived by grinding the leaves of the creosote bush (Larrea tridentata), an evergreen desert shrub. The ground leaves may be used for tea, placed in capsules, or formed into tablets. Chaparral has been recommended in nonscientific publications for use as an "antioxidant" or "free radical scavenger" to retard aging and to treat a variety of skin conditions (e.g., acne) and hepatitis. In addition, chaparral tea is used as a traditional American Indian medicine. The active ingredient in chaparral is a potent antioxidant, nordihydroguaiaretic acid (NDGA), which can act as a cyclooxygenase and lipoxygenase pathway inhibitor. Long-term studies in rats indicate that consumption of NDGA causes kidney cysts and mesenteric lymphadenopathy; however, there is no information on hepatotoxicity from animal studies.” There have been a limited number of cases of hepatic toxicity reported in individuals ingesting chaparral. (Chaparral-induced toxic hepatitis—California and Texas, 1992 MMWR 41(43):812-814)