Urinary tract infections (UTIs) are among the most prevalent bacterial infections worldwide, posing a significant health burden, particularly in the context of rising antimicrobial resistance. The increasing ineffectiveness of conventional antibiotics has necessitated the exploration of alternative therapeutic approaches, especially those derived from natural plant-based sources. This study aimed to evaluate the antimicrobial efficacy of Cymbopogon citratus (lemongrass) leaf extracts against multidrug-resistant uropathogens. Extracts were prepared using three solvents: methanol, ethanol, and n-hexane, and tested against three clinically relevant bacterial strains: Escherichia coli, Bacillus subtilis, and Enterobacter hormaechei subsp. xiangfangensis. Phytochemical screening revealed that extracts contained a wide variety of bioactive compounds, including alkaloids, flavonoids, saponins, tannins, terpenoids, phenols, coumarins, and volatile oils. Further analysis using Fourier-transform infrared spectroscopy identified characteristic functional groups, including O–H, C–H, C = O, C = C, and N–H, indicating the presence of alcohols, aldehydes, ketones, alkenes, and amines, which are often associated with antimicrobial activity. Antibacterial assays showed that the methanolic extract exhibited the strongest inhibitory activity. In disc diffusion tests, it produced the largest zones of inhibition: 14 mm against Escherichia coli, 14 mm against Bacillus subtilis, and 13 mm against Enterobacter hormaechei subsp. xiangfangensis. Minimum inhibitory concentration values further confirmed its superior potency, with results of 3.12 mg/mL for Escherichia coli, 6.25 mg/mL for Bacillus subtilis, and 12.5 mg/mL for Enterobacter hormaechei subsp. xiangfangensis. The extract also showed bactericidal activity, with minimum bactericidal concentrations of 12.5 mg/mL for Escherichia coli and 25 mg/mL for the other two strains. In summary, this study provides strong evidence that Cymbopogon citratus, particularly when extracted with methanol, possesses significant antibacterial and antioxidant properties against multidrug-resistant uropathogens. These findings support its potential use as a complementary or alternative therapeutic agent in managing resistant urinary tract infections, offering a promising natural strategy to address the growing challenge of antimicrobial resistance. IMPACT STATEMENT. Methanolic extracts of Cymbopogon citratus demonstrated strong antibacterial and bactericidal activity against multidrug-resistant uropathogens, including Escherichia coli and Enterobacter hormaechei subsp. xiangfangensis. Phytochemical and FTIR analyses confirmed the presence of bioactive functional groups associated with antimicrobial effects. These findings highlight lemongrass as a promising plant-based candidate for developing complementary therapies to address antimicrobial resistance in urinary tract infections and support further pharmacological standardization and clinical investigation. Graphical Abstract

Phytochemical characterization, antioxidant, and antibacterial activities of Cymbopogon citratus extracts against multidrug-resistant uropathogens

期刊论文
发表日期：

2026年5月7日

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Kainnat Khalid,
Shumaila Naz,
Azka Javaid,
Anas Rashid

摘要

Urinary tract infections (UTIs) are among the most prevalent bacterial infections worldwide, posing a significant health burden, particularly in the context of rising antimicrobial resistance. The increasing ineffectiveness of conventional antibiotics has necessitated the exploration of alternative therapeutic approaches, especially those derived from natural plant-based sources. This study aimed to evaluate the antimicrobial efficacy of Cymbopogon citratus (lemongrass) leaf extracts against multidrug-resistant uropathogens. Extracts were prepared using three solvents: methanol, ethanol, and n-hexane, and tested against three clinically relevant bacterial strains: Escherichia coli, Bacillus subtilis, and Enterobacter hormaechei subsp. xiangfangensis. Phytochemical screening revealed that extracts contained a wide variety of bioactive compounds, including alkaloids, flavonoids, saponins, tannins, terpenoids, phenols, coumarins, and volatile oils. Further analysis using Fourier-transform infrared spectroscopy identified characteristic functional groups, including O–H, C–H, C = O, C = C, and N–H, indicating the presence of alcohols, aldehydes, ketones, alkenes, and amines, which are often associated with antimicrobial activity. Antibacterial assays showed that the methanolic extract exhibited the strongest inhibitory activity. In disc diffusion tests, it produced the largest zones of inhibition: 14 mm against Escherichia coli, 14 mm against Bacillus subtilis, and 13 mm against Enterobacter hormaechei subsp. xiangfangensis. Minimum inhibitory concentration values further confirmed its superior potency, with results of 3.12 mg/mL for Escherichia coli, 6.25 mg/mL for Bacillus subtilis, and 12.5 mg/mL for Enterobacter hormaechei subsp. xiangfangensis. The extract also showed bactericidal activity, with minimum bactericidal concentrations of 12.5 mg/mL for Escherichia coli and 25 mg/mL for the other two strains. In summary, this study provides strong evidence that Cymbopogon citratus, particularly when extracted with methanol, possesses significant antibacterial and antioxidant properties against multidrug-resistant uropathogens. These findings support its potential use as a complementary or alternative therapeutic agent in managing resistant urinary tract infections, offering a promising natural strategy to address the growing challenge of antimicrobial resistance. IMPACT STATEMENT. Methanolic extracts of Cymbopogon citratus demonstrated strong antibacterial and bactericidal activity against multidrug-resistant uropathogens, including Escherichia coli and Enterobacter hormaechei subsp. xiangfangensis. Phytochemical and FTIR analyses confirmed the presence of bioactive functional groups associated with antimicrobial effects. These findings highlight lemongrass as a promising plant-based candidate for developing complementary therapies to address antimicrobial resistance in urinary tract infections and support further pharmacological standardization and clinical investigation.

Graphical Abstract