Study on the embryotoxic effects and potential mechanisms of Aconitum diterpenoid alkaloids in rat whole embryo culture through morphological and transcriptomic analysis.

Ethnopharmacological Relevance: The lateral root of Aconitum carmichaelii Debeaux, or Fuzi, is recognized in Asia for its anti-inflammatory, analgesic, and cardiotonic effects. Its main active compounds are diester diterpenoid alkaloids (DDAs) such as aconitine (AC), mesoacitine (MA), and hypoaconitine (HA), which are also toxic and have a narrow therapeutic window, limiting their clinical use. Although Aconitum DDAs are known for cardiotoxic and neurotoxic effects, their impact on embryonic development remains unclear.

Aim Of The Study: The embryotoxicity of three representative Aconitum DDAs (AC, MA, and HA) and their metabolites were systematically assessed, and the mechanisms underlying AC-induced embryotoxicity was explored.

Materials And Methods: The embryotoxicity of these DDAs was assessed by indicators such as morphological scores in a whole embryo culture (WEC) system. Immunofluorescence analysis was conducted to detect DNA damage and apoptosis in embryos, and transcriptomic analysis and western blotting were performed to explore the underlying mechanisms.

Results: DDAs, particularly AC, induced dose-dependent developmental retardation and malformation in rat embryos. Notably, the embryotoxicity of AC metabolites such as benzoyltrypine (BAC) and aconine, was significantly reduced. AC treatment caused substantial DNA damage and apoptosis in embryos. Transcriptomic analysis indicate that AC treatment may impair DNA replication and histone synthesis by activating the p53/p21/CDK2/NPAT pathway, ultimately affecting embryonic development.

Conclusion: Among these Aconitum DDAs, AC exhibited the strongest embryotoxicity, mainly through DNA damage and regulation of histone genes via the p53/p21/CDK2/NPAT pathway.