Mechanistic insight into the synergistic antimicrobial potential of Fagonia indica Burm.f. extracts with cefixime

• Published in: Saudi pharmaceutical journal Vol. 32; no. 1; p. 101893
• Main Authors: Abrar, Anum, Zafar, Aroosa, Fatima, Mahvish, Muntaqua, Durdana, Naz, Iffat, Fatima, Humaira, Ul Haq, Ihsan
• Format: Journal Article
• Language: English
• Published: Saudi Arabia Elsevier B.V 01.01.2024; Elsevier
• Subjects: Antibiotic; Antimicrobial potential; Bacteria; Biocompatibility profile; Cefixime-resistant strains; Eescherichia coli; Fagonia indica; Plant extract; Scanning electron microscopy; Synergism potential; Scanning electron microscopy; Cefixime-resistant strains; Eescherichia coli; Antibiotic; Fagonia indica; Synergism potential; Antimicrobial potential; Plant extract; Biocompatibility profile; Bacteria
• ISSN: 1319-0164; 2213-7475
• DOI: 10.1016/j.jsps.2023.101893

Fagonia indica Burm.f. is known for its anti-infective character and has been studied in the present work as a synergistic remedy against resistant bacterial strains. Initially, phytochemicals were quantified in n-Hexane (n-Hex), ethyl acetate (E.A), methanol (MeOH), and aqueous (Aq.) extracts by Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis. Later, after establishing an antibacterial resistance profile for extracts and antibiotics against gram-positive and gram-negative strains, synergism was evaluated in combination with cefixime through time-kill kinetics and bacterial protein estimation studies. Topographic images depicting synergism were obtained by scanning electron microscopy for Methicilin-resistant Staphylococcus aureus (MRSA) and Resistant Escherichia coli (R.E. coli). Results showed the presence of maximum phenolic (28.4 ± 0.67 μg GAE/mg extract) and flavonoid (11 ± 0.42 μg QE/mg extract) contents in MeOH extract. RP-HPLC results also displayed maximum polyphenols in MeOH extract followed by E.A extract. Clinical strains were resistant to cefixime whereas these were moderately inhibited by all extracts (MIC 150–300 µg/ml) except Aq. extract. E.A and n-Hex extracts demonstrated maximum synergism (Fractional inhibitory concentration index (FICI) 0.31) against R.E. coli. The n-Hex extract displayed total synergism against R.P. a with a 4-fold reduction in cefixime dose. Time-kill kinetics showed maximum inhibition of gram-negative bacterial growth from 3 to 12 h when treated at FICI and 2FICI values with > 10-fold reduction of the extracts’ dose. All combinations demonstrate > 70 % protein content inhibition with bacterial cell wall disruption in SEM images. Fortunately, FICI concentrations have low hemolytic potential (<5%). Conclusively, F. indica extracts can mitigate antimicrobial resistance against cefixime and can be investigated in detail by in vivo and mechanistic studies.