Effects of selected Taiwanese endemic plants on anti-lipid peroxidation and antibacterial activities against clinically isolated extended-spectrum-β-lactamase producing Klebsiella pneumoniae and Escherichia coli
Abstract It has been a challenge for many clinicians to treat a complicated extended-spectrum-β-lactamase (ESBL) producing Klebsiella Pneumoniae (Kp) and Escherichia coli (E. coli) infection due to widespread antibiotic abuse with renal damage as one of its common side effects. Therefore, this study aimed to assess the antibacterial activity of extracts from several Taiwanese folk medicinal plants against ESBL- Kp and E. coli. with renal protecting ability against lipid peroxidation (LPO) on mice kidney mitochondria. Preliminary antibacterial activities of ethanol extracts from twenty (20) Taiwanese folk medicinal plants were measured by agar-dilution method against standard ESBL strains of E. coli (ATCC 25922, ATCC 35218) and Kp (ATCC 23856, ATCC 700603). Rhus semialata var. roxburghiana DC. (RSR) exerted the most inhibitory effect and then further extracted with n-hexane, ethyl acetate, acetone, ethanol, and water, respectively. Each extract also evaluated against the four standard ATCC microorganisms. Their MIC50, MIC90, and time kill assay were adapted with detecting the maximum inhibitory activities and the antibacterial spectrum range of each extract was measured against twenty-four (24) kinds of microbes. Which were used including gram-positive, gram-negative bacteria and fungus by agar dilution method. Finally, renal protective ability was detected inhibitory effect of ferrous induced lipid peroxidation on mice mitochondria. Among 20 Taiwanese folk medicinal plants tested, Rhus semialata var. roxburghiana DC. (RSR) exhibited maximum inhibition against clinical ESBL-producing Kp and E. coli strains with acetone extracts showing MIC50/MIC90 values at 1000 µg/mL, the course of antimicrobial action was bacteriostatic and with inhibitions to all 24 kinds of microbial including Gram positive and negative bacteria and fungi. Furthermore, result of thiobarbituric acid reactive substances (TBARS) assay from this extract showed high lipid peroxidative (LPO) protective capability on mice kidney mitochondria (IC50: 29.29 ± 0.35µg/mL). RSR acetone extract, with its maximum activity against clinical isolated ESBL-producing Kp and E. coli, antimicrobial effect against other wide spectral range bacteria and relatively high LPO protective ability on mice kidney mitochondria, is a potential source, albeit further studies have yet to be conducted, to develop an antimicrobial drug against ESBL-Kp and E. coli.