An ethanolic extract of black cohosh causes hematological changes but not estrogenic effects in female rodents.
Black cohosh rhizome (Actaea racemosa) is used as a remedy for pain and gynecological ailments; modern preparations are commonly sold as ethanolic extracts available as dietary supplements. Black cohosh was nominated to the National Toxicology Program (NTP) for toxicity testing due to its widespread use and lack of safety data. Several commercially available black cohosh extracts (BCE) were characterized by the NTP, and one with chemical composition closest to formulations available to consumers was used for all studies. Female B6C3F1/N mice and Wistar Han rats were given 0, 15 (rats only), 62.5 (mice only), 125, 250, 500, or 1000 mg/kg/day BCE by gavage for 90 days starting at weaning. BCE induced dose-dependent hematological changes consistent with a non-regenerative macrocytic anemia and increased frequencies of peripheral micronucleated red blood cells (RBC) in both species. Effects were more severe in mice, which had decreased RBC counts in all treatment groups and increased micronucleated RBC at doses above 125 mg/kg. Dose-dependent thymus and liver toxicity was observed in rats but not mice. No biologically significant effects were observed in other organs. Puberty was delayed 2.9 days at the highest treatment dose in rats; a similar magnitude delay in mice occurred in the 125 and 250 mg/kg groups but not at the higher doses. An additional uterotrophic assay conducted in mice exposed for 3 days to 0.001, 0.01, 0.1, 1, 10, 100 and 500 mg/kg found no estrogenic or anti-estrogenic activity. These are the first studies to observe adverse effects of BCE in rodents.
National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, 111 Alexander Drive, Research Triangle Park, NC, USA.
Minerva
M
Mercado-Feliciano
Michelle C
MC
Cora
Kristine L
KL
Witt
Courtney A
CA
Granville
Milton R
MR
Hejtmancik
Laurene
L
Fomby
Katherine A
KA
Knostman
Michael J
MJ
Ryan
Retha
R
Newbold
Cynthia
C
Smith
Paul M
PM
Foster
Molly K
MK
Vallant
Matthew D
MD
Stout
D000748:Anemia, Macrocytic / Q000139:chemically induced; D000818:Animals; D031885:Cimicifuga / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects / Q000473:pathology; D004967:Estrogens / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry; D005260:Female; D006402:Hematologic Diseases / Q000139:chemically induced* / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D051379:Mice; D010936:Plant Extracts / Q000008:administration & dosage / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index; D012741:Sexual Maturation / Q000187:drug effects*; D013045:Species Specificity; D013950:Thymus Gland / Q000187:drug effects / Q000473:pathology; D018675:Toxicity Tests
D004967:Estrogens; D010936:Plant Extracts; D000431:Ethanol