Aqueous Extract of Ampelopsis Cantoniensis With the Addition of Curcuma Longa and Taraxacum Officinale: LD50 on Zebrafish (Danio Rerio) Embryos and Nanoformulations for Bacteria Inhibition

Herbal extracts are promising sources of bioactive compounds with potential antimicrobial and biomedical applications. However, their safety and bioavailability often limit their practical use. This study aimed to evaluate the acute toxicity and antibacterial activity of an aqueous extract of Ampelopsis cantoniensis combined with Curcuma longa and Taraxacum officinale (Am-CT extract), and to enhance its performance through nanoformulation. The Am-CT extract, containing 29.69% dihydromyricetin, was tested for toxicity in zebrafish embryos at concentrations ranging from 1.875 to 15 g L⁻¹. The results indicated that the extract was safe, with an LC₅₀ value of 7.81 g L⁻¹, showed weak teratogenicity (EC₅₀ = 7.422 g L⁻¹), and had a therapeutic index (TI) of 1.025. Three Am-CT nanoformulations were prepared using chitosan (CS) and carboxymethyl cellulose (CMC) and characterized by FESEM, DLS, and FTIR analyses. The nanoformulation with a CMC/CS ratio of 1/2 exhibited particle sizes of 80–100 nm and demonstrated stronger antibacterial activity against Escherichia coli and Staphylococcus aureus than the crude extract. Both the extract and its nanoformulation were more cytocompatible than dihydromyricetin, confirming their potential as safe and effective antibacterial agents.