In vitro bactericidal activity of Berberis aristata extract against clinical isolates of carbapenem-resistant Escherichia coli.

BACKGROUND

Berberis aristata is known to contain a variety of phenolic compounds, flavonoids such as quercetin attributing towards its holistic capability of mitigating multidrug resistance.

METHODS

B. aristata stem bark extract was prepared and characterized using phytochemical and bioactivity-based fingerprinting. Anti-oxidant and anti-lipid peroxidation profiling was also done in conjunction with in vitro anti-microbial efficacy testing against the test microorganism i. e., New Delhi Metallo-β-lactamase-1 (NDM-1) Escherichia coli.

RESULTS

Aquo-alcoholic (1:1) extract of B. aristata (PTRC-2111-A), containing 3.0±0.02 µg of QUERCETIN/mg of dried extract, exhibited [flavonoid/polyphenol: F/P (quercetin %) ~ 0.16(0.06 %)]. The bioactivity fingerprint profile of PTRC-2111-A included IC50 ratio [DPPH/NOS]=0.064 as functional standardized value having IC50 (DPPH Scavenging)=16±0.5 µg/mL and IC50 (Nitric Oxide Scavenging)=250±0.5 µg/mL respectively. The reducing ability and anti-lipid peroxidation equivalent (extract: standard) of PTRC-2111-A with respect to standard was estimated to be 3.44 (ascorbic acid) and 0.78 (quercetin) respectively. In vitro anti-microbial activity evaluated against sts-09 multidrug-resistant strain of carbapenem-resistant E. coli was found to be 25 µg/mL.

CONCLUSIONS

B. aristata was found to contain a number of phytoconstituents, which acts in a synergistic manner to provide significant bactericidal potential against carbapenem-resistant E. coli.