CYP3A4 and MRP2 are predominant metabolic regulators attribute to the toxicity/efficacy of aconitine derived from Fuzi

Ethnopharmacological relevance

Aconitum carmichaelii Debx. exhibits overwhelming efficacy against heart failure, inflammation and pain, but its clinical application is limited by concomitant cardiotoxicity and neurotoxicity. Aconitine (AC), the most abundant bioactive alkaloid, has narrow therapeutic window, with well-defined toxic and therapeutic thresholds. However, the overlapping molecular targets mediating dual toxicity and efficacy of AC remain poorly characterized.

Aims of the study

This study aimed to evaluate dual pharmacological and toxicological roles of AC through integrative pharmacology and transgenic mouse models.

Materials and methods

The overlapping targets of AC-related toxicity/efficacy were identified based on integrative pharmacology. By generating Cyp3a^−/− transgenic mice expressing human CYP3A4 (hCYP3A4), Ugt1, P-gp, Mrp2, BCRP, and Nrf2 knockout mice, the effects of AC on toxicity, pain, inflammation, and heart failure were assessed.

Results

We identified 143 overlapping targets predominantly enriched in metabolic pathways. Symptom-based toxicity scores were strikingly elevated in AC-exposed hCYP3A4, Mrp2^−/−, P-gp^−/−, BCRP^−/−, and Nrf2^−/− mice compared to WT mice. Additionally, AC prolonged the latency of response by approximately 18s, 15s, 14s, and 5s, respectively, in hCYP3A4, Mrp2^−/−, P-gp^−/−, and Nrf2^−/− mice by hot plate assay. Interestingly, both toxicity score and analgesic latency initially increased and subsequently decreased, peaking at 60 min. AC obviously decreased the acetic acid-induced writhing and permeability by 45.7% and 22.2% in hCYP3A4 mice, whereas these changes were amplified in Mrp2^−/− mice compared to WT mice. Furthermore, AC attenuated DOX induced heart failure in hCYP3A4 mice, with an effective rate of 20.9%, with Septin4 implicated in AC-related metabolism.

Conclusions

Metabolic targets may elucidate the mechanistic overlap between the toxicity and efficacy of AC. Notably, hCYP3A4 exhibited heightened toxicity, alongside enhanced analgesic, anti-inflammatory, and cardioprotective effects. Our findings position metabolic pathways as critical nodes for AC-related dual effect, and establish Septin4 as a candidate mediator of its metabolic regulation.