In vitro serotonergic activity of black cohosh and identification of N(omega)-methylserotonin as a potential active constituent.
Level 5 - mechanism / opinion, no new human data
In vitro laboratory study evaluating receptor binding, signaling, and reuptake inhibition without human subjects.
PubMed 19049296 · doi:10.1021/jf803298z
What was done
Researchers evaluated crude extracts and isolated constituents of black cohosh (Cimicifuga racemosa) using in vitro 5-HT7 receptor binding, cAMP induction, and serotonin selective re-uptake inhibitor (SSRI) assays. Methanol extracts were fractionated, and constituents were identified using LC-MS/MS.
What was found
Crude extracts displayed 5-HT7 receptor binding and cAMP induction. Triterpenoids and phenolic acids bound weakly to the 5-HT7 receptor with no cAMP or SSRI activity. In contrast, N(omega)-methylserotonin bound to the 5-HT7 receptor with an IC50 of 23 pM, induced cAMP with an EC50 of 22 nM, and blocked serotonin re-uptake with an IC50 of 490 nM.
Why it matters
This identifies a specific serotonergic compound in black cohosh, providing a plausible mechanism of action for its effects on thermoregulation and menopausal hot flashes.
Limits
The study is entirely in vitro. It does not measure human bioavailability, blood-brain barrier penetration, in vivo efficacy, or clinical symptom relief.
Cited by
- context Clinical studies show black cohosh acts on serotonin and dopamine pathways in the hypothalamus to aid in temperature regulation and mood.