Growth-Inhibiting, Bactericidal, Antibiofilm, and Urease Inhibitory Activities of Hibiscus rosa sinensis L. Flower Constituents toward Antibiotic Sensitive- and Resistant-Strains of Helicobacter pylori

Abstract

The aim of the present study was to assess antimicrobial effects of naringenin (NRG), luteolin (LUT), myricetin (MCT), and protocatechuic acid (PCA) identified in a Hibiscus rosa sinensis flower against two reference strains and five clinical isolates of Helicobacter pylori . NRG displayed the most growth inhibitory and bactericidal activities to seven bacterial strains including six strains resistant to one or several antibiotics, azithromycin (MIC, 16–32 mg/L), erythromycin (MIC, 32 mg/L), levofloxacin (MIC, 32 mg/L), and/or metronidazole (24–64 mg/L), followed by LUT and MCT, while PCA showed weak activities toward the strains. These constituents had similar antibacterial activities toward the seven tested strains suggesting that these constituents and the antibiotics do not have a common mechanism of anti- H. pylori activity. NRG, LUT, and MCT resulted in a high percentage of coccoid forms of H. pylori . NRG exhibited the highest anti-biofilm formation activity. MCT produced the strongest inhibition of urease activity followed by LUT and PCA, whereas the activity of NRG was similar to standard inhibitor thiourea. The four constituents had no significant toxicity to human cell lines. A global attempt to decrease utilization of antibiotics justifies the need for further research on H. rosa sinensis derived materials containing NRG, LUT, MCT, and PCA as potential products or lead compounds for the prevention or treatment of diseases caused by H. pylori infection.

Multi-Therapeutic Potential of Naringenin (4′,5,7-Trihydroxyflavonone): Experimental Evidence and Mechanisms

“…Naringenin possesses a wide spectrum of antimicrobial activities, including antifungal and antibacterial [ 169 ]. Naringenin is found to possess potent activity against Methicillin-resistant Staphylococcus aureus [ 170 ] and resistant strains of Helicobacter pylori [ 171 ]. Naringenin exhibits its antibacterial action by inhibiting the autoinducer-mediated cell signaling pathway [ 172 ].…”

Antibacterial activity of Hibiscus rosa-sinensis L. red flower against antibiotic-resistant strains of Helicobacter pylori and identification of the flower constituents

“…In our present study, the EtOAc fraction exerted lower inhibitory activity than the positive control thiourea against H. pylori urease. However, myricetin and luteolin were found to exhibit stronger inhibitory activity than the positive control (14). It was reported that plant flavonoids may contribute to several antimicrobial mechanisms, such as inhibition of nucleic acid synthesis (by inhibiting helicase, gyrase, and topoisomerase activity), disruption of membrane function (by inhibiting efflux pumps, porins, fatty acid synthase, and peptidoglycan synthesis), inhibition of energy metabolism, quorum sensing and biofilm formation, and thereby attenuation of the pathogenicity (40).…”

“…The cytotoxicity of the EtOH extract and fractions to HeLa, Jurkat, and MCF7 cells was evaluated using a sulforhodamine (SRB) assay described previously (14). In brief, cells were seeded onto 96-well plates at a density of 5 Â 10 3 cells/well (HeLa), 5 Â 10 4 cells/well (Jurkat), and 10 4 cells/well (MCF7) for 24 h. The culture medium was then removed from the wells and replaced with a medium containing various concentrations of the extract and fractions (0 À 1 mg/mL) in DMSO.…”

“…The phytochemical constituents, pharmacological effects, and medicinal uses of the plant have been well described ( 13 ). In our previous study, the ethanol extract and ethyl acetate fraction derived from the H. rosa-sinensis flower were found to have antibacterial activity against H. pylori ATCC 43504 and four isolated compounds (naringenin, luteolin, myricetin, and protocatechuic acid) from the fraction were also proven to possess potent antibacterial properties against seven antibiotic-sensitive and -resistant strains of H. pylori ( 14 ).…”

Green and Facile Synthesis and Antioxidant and Antibacterial Evaluation of Dietary Myricetin-Mediated Silver Nanoparticles

“…Myricetin (MY) or 3,3,4,5,5,7-hexahydroxy-flavone belongs to a class of natural dietary flavonoids that can be extracted from the bark and leaves of bayberry, beyond that, it is also widely found in vegetables, fruit, tea, and medicinal herbs. 7 MY has a variety of biological functions including antibacterial, 8 antiviral and antioxidant, 9 − 11 anti-inflammatory and anticancer, 12 inhibition of urease, 13 and so forth. At present, MY has been widely used in medicine, food, healthcare products, cosmetics, and other fields.…”