Augmenting the potency of third-line antibiotics with Berberis aristata: In vitro synergistic activity against carbapenem-resistant Escherichia coli

- An aquoethanolic extract of stem bark of Berberis aristata (PTRC-2111-A) was characterised using FTIR- and LC-MS analyses.
- FTIR analysis of PTRC-2111-A revealed the presence of seven characteristic functional groups similar to quercetin.
- LC-MS analysis revealed the presence of isoquinoline alkaloids as the predominant phytoconstituents, further validated by quantitative alkaloid estimation (ca. 25.44% alkaloids).
- Bioactivity fingerprinting of PTRC-2111-A revealed its superoxide ion and hydroxyl radical scavenging activities, comparable with the known synthetic standards.
- PTRC-2111-A exhibited synergistic behaviour with colistin, tigecycline and Augmentin® against carbapenem-resistant Escherichia coli.