Comparative In Vitro Antibacterial, Ciprofloxacin-Combination, and Antioxidant Activities of Aqueous and Alcoholic Extracts of Cymbopogon citratus
Department of Biology, College of Education for Pure Science, Tikrit University, Tikrit 34001, Iraq.
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Research Article
Open Access Research Journal of Life Sciences, 2026, 12(01), 042–051.
Article DOI: 10.53022/oarjls.2026.12.1.0029
Publication history:
Received on 18 July 2026; revised on 26 August 2026; accepted on 28 August 2026
Abstract:
Lemongrass (Cymbopogon citratus) is widely used for traditional medicine and potential antimicrobial and antioxidant properties. This study evaluated the antibacterial activity of aqueous and alcoholic extracts of lemongrass against Staphylococcus aureus and Escherichia coli, the combined effects with ciprofloxacin and free-radical scavenging capacity by DPPH assay. The antibacterial activity was evaluated by the agar disc diffusion method using ciprofloxacin as a positive control and 15% DMSO as a negative control. Antioxidant activity was determined at 10, 20, 40, 80 and 100 mg/mL of extract concentrations with ascorbic acid as the reference antioxidant. The alcoholic extract showed an inhibition zones of 14 mm for S. aureus and 11 mm for E. coli. No antibacterial activity was detected for the aqueous extract. Ciprofloxacin alone showed inhibition zones of 26 and 25 mm against S. aureus and E. coli respectively. The combination of aqueous extract-ciprofloxacin gave zones of 24 and 23 mm while the combination of alcoholic extract-ciprofloxacin gave 25 mm against both organisms indicating no clear synergistic enhancement. In DPPH assay, alcoholic extract showed higher antioxidant activity than aqueous extract with 62.50% radical scavenging activity at 100 mg/mL, while aqueous extract showed 18.75% and ascorbic acid showed 87.50%. To summarize, alcoholic extract showed better antibacterial and antioxidant activities. Further phytochemical characterisation and MIC-, MBC-, checkerboard- and time-kill-based studies are needed to confirm its bioactive constituents and antimicrobial interaction profile. The results suggest that alcoholic extraction is more efficient in recovering active constituents from lemongrass under these conditions.
Keywords:
Cymbopogon Citratus; Lemongrass; Antibacterial Activity; Antioxidant Activity; DPPH; Ciprofloxacin; Plant Extract.
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