Table 1.
Antibacterial effects of some medicinal plants against uropathogenic Escherichia coli
| Plant material | Active phytochemicals | Type of assay | Antibacterial activity |
|---|---|---|---|
| Cinnamon oil | TC | In vitro | TC (560 and 750 µM) decreased the expression of major genes involved in UPEC attachment and invasion to urinary tract epithelial cellss[90] |
| TC (0.25% and 0.50% v/v) inhibited biofilm formation on plates and catheters[91] | |||
| Lock solution containing TC (1%, 1.25% and 1.5% v/v) inactivated UPEC biofilm on polystyrene plates and urinary catheters[91] | |||
| Oregano oil and thyme red oil | Carvacrol and thymol, respectively | In vitro | Carvacrol and thymol (0.01% v/v) inhibited biofilm formation, decreased the hemagglutination ability of UPEC and reduced fimbriae formation and swarming motility of UPEC[30] |
| In the presence of carvacrol and thymol (0.01% v/v), human whole blood was able to more easily kill UPEC[30] | |||
| Essential oils of O. majorana, T. zygis and R. officinalis |
O. majorana: Terpinene-4-ol T. zygis: Linalool R. officinalis: 1,8-cineole, camphor, α-Pinene and β-Pinene |
In vitro | Showed antibacterial and high antibiofilm activity against UPEC[31] |
| A. repens rhizomes | Coumaric acid ester | In vitro | Acetonic extract (>250 µg/mL) showed a significant antiadhesive activity against UPEC attachment to human T24 bladder cells[76] |
| Coumaric acid ester (1000 and 500 µg/mL) reduced the invasion of UPEC into the bladder cells[76] | |||
| Commercial plant secondary metabolites; asiatic acid and ursolic acid | Pentacyclic triterpenes (asiatic acid and ursolic acid) | In vitro | Asiatic and ursolic acid (40 and 50 μg/mL) showed antibacterial effects and significantly reduced the attachment of UPEC to urinary epithelial cells[92] |
| L. pumila var. Alata | N/A | In vivo | Induced apoptosis in bladder epithelial cells and significantly reduced the number of intracellular UPEC[37] |
| Garlic (A. sativum) | N/A | In vitro | Showed antibacterial activity against UPEC (MICs=62.5-100 mg/ml) and inhibited biofilm formation and dispersal[93] |
| O. aristatus leaves | N/A | In vivo (a mouse infection model) and in vitro | Reduced kidney and bladder colonization by UPEC[94] |
| Reduced the bacterial adhesion to T24 bladder cells[94] | |||
| Significantly inhibited bacterial quorum sensing[94] | |||
| Green tea | N/A | In vivo (a rat model) | Intravesical instillation of green tea attenuated the inflammatory response to UPEC-SR71-induced bacterial cystitis[36] |
| Nasturtium (Tropaeoli majoris herba) and horseradish (Armoraciae rusticanae radix) | ITC | In vitro | ITC showed a strong antimicrobial activity against clinical UPEC strains (MIC 90=0.17 mg/ml)[26] |
| ITC reduced bacterial internalization into human T-24 bladder cells[26] | |||
| C. bolivianum | N/A | In vitro | The extract (400 µg/ml) decreased the adhesion, invasion and biofilm formation of UPEC[95] |
| Rosemary (S. rosmarinus) | N/A | In vitro | Rosemary extract (1 and 10 μg/ml) showed a strong bacteriostatic effect against UPEC[57] |
| B. abyssinica | Picolinyl hydrazide | In vitro | The extract showed antibacterial activity against MDR-UPEC (MICs=12.5-50 mg/mL)[96] |
| Neem (A. indica) | N/A | In vitro | Showed inhibitory effect against UPEC[97] |
| A. nilotica | N/A | In vitro | The extract showed antibacterial activity against UPEC (MIC=11.7 mg/mL) and significantly reduced bacterial biofilm formation[98] |
TC: Trans-cinnamaldehyde, ITC: Isothiocyanates, N/A: Not applicable, UPEC: Uropathogenic Escherichia coli, R. officinalis: Rosmarinus officinalis, L. pumila: Labisia pumila, A. sativum: Allium sativum, A. repens: Agropyron repens, O. majorana: Origanum majorana, T. zygis: Thymus zygis, O. aristatus: Orthosiphon aristatus, C. bolivianum: Clinopodium bolivianum, S. rosmarinus: Salvia rosmarinus, B. abyssinica: Bersama abyssinica, A. indica: Azadirachta indica, A. nilotica: Acacia nilotica, MICs: Minimum inhibitory concentrations