NTP finds mice given black cohosh produce altered red blood cells
National Toxicology Program (NTP) researchers recently demonstrated that black cohosh dried ethanolic extract (BCE) resulted in dyserythropoiesis, or defective red blood cell (RBC) production, in mice. BCE is a dietary supplement frequently used as a remedy for menopausal symptoms and pain during menstruation. A 90-day subchronic study conducted by NTP showed a dose-dependent increase in macrocytic, or large size, RBCs in conjunction with a decrease in RBC counts, hemoglobin concentration, and hematocrit, indicative of megaloblastic-type anemia. In humans, megaloblastic anemia is often attributed to folate or cobalamin, also known as vitamin B12 deficiencies. This study investigated whether these deficiencies were related to the observed hematopoietic toxicity of BCE.
The researchers found that while circulating folate and cobalamin levels were not different between control and dosed B6C2F1/N female mice, homocysteine and methylmalonic acid (MMA) were both elevated in blood samples. In addition, significant increases in the number of Howell-Jolly bodies were present in RBCs, which suggested chromosomal damage and RBC basophilic stippling, which are often associated with abnormal production of erythrocytes. The authors concluded that BCE administration caused biochemical and hematological changes that were consistent with a functional, but not absolute, cobalamin deficiency. Future studies will evaluate hematological changes in bone marrow related to observed increases in homocysteine and MMA. (GK)
Citation: Cora MC, Gwinn W, Wilson R, King D, Waidyanatha S, Kissling GE, Brar SS, Olivera D, Blystone C, Travlos G. 2017. A black cohosh extract causes hematologic and biochemical changes consistent with a functional cobalamin deficiency in female B6C3F1/N mice. Toxicol Pathol; doi: 10.1177/0192623317714343 [Online 15 June 2017].