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

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.

Artemisia brevifolia Wall. Ex DC Enhances Cefixime Susceptibility by Reforming Antimicrobial Resistance.

(1) Background: A possible solution to antimicrobial resistance (AMR) is synergism with plants like Artemisia brevifolia Wall. ex DC. (2) Methods: Phytochemical quantification of extracts (n-hexane (NH), ethyl acetate (EA), methanol (M), and aqueous (Aq)) was performed using RP-HPLC and chromogenic assays. Extracts were screened against resistant clinical isolates via disc diffusion, broth dilution, the checkerboard method, time-kill, and protein quantification assays. (3) Results: M extract had the maximum phenolic (15.98 ± 0.1 µg GAE/mgE) and flavonoid contents (9.93 ± 0.5 µg QE/mgE). RP-HPLC displayed the maximum polyphenols in the M extract. Secondary metabolite determination showed M extract to have the highest glycosides, alkaloids, and tannins. Preliminary resistance profiling indicated that selected isolates were resistant to cefixime (MIC 20-40 µg/mL). Extracts showed moderate antibacterial activity (MIC 60-100 µg/mL). The checkerboard method revealed a total synergy between EA extract and cefixime with 10-fold reductions in cefixime dose against resistant P. aeruginosa and MRSA. Moreover, A. brevifolia extracts potentiated the antibacterial effect of cefixime after 6 and 9 h. The synergistic combination was non- to slightly hemolytic and could inhibit bacterial protein in addition to cefixime disrupting the cell wall, thus making it difficult for bacteria to survive. (4) Conclusion: A. brevifolia in combination with cefixime has the potential to inhibit AMR.

Quercus floribunda Lindl. Ex A. Camus; a tremendous remedy against inflammation and associated symptoms.

Crude extracts prepared from aerial parts and nut galls of Quercus floribunda Lindl. Ex. A. Camus were evaluated for phytochemical screening, in vitro antioxidant, and in vivo analgesic, anti-inflammatory and antipyretic activities. Various solvents including methanol (M), acetone (A), distilled water (DW), distilled water + methanol (DWM) were used for extraction. Highest total phenolic (66.9 ± 0.05 µg GAE/mgE) and flavonoid content (38.4 ± 0.72 µg QE/mgE) were measured in QFAA extract by colorimetric methods. Cumulative maximum concentrations of polyphenols were quantified in QFMG, QFAA, and QFMA extracts i.e. 19.036, 15. 574 and 11.647 µg/mg of extract by RP-HPLC analysis. From aerial parts extracts, apentacyclic tritepenoid, glutinol was isolated using column chromatography techniques and structure was elucidated using spectroscopic techniques. QFDWMA (205.5 ± 0.56 µg AAE/mg of extract) showed highest total reducing power while highest total antioxidant capacity (207.1 ± 0.49 AAE/mg of extract) and free radical scavenging potential (96.1 ± 0.42%) were observed in QFAA extract. QFAA extract showed significant (p ≤ 0.001) analgesic potential in different pain models i.e. hot plate method, cold plate method, Haffner's tail clip method and acetic acid induced writhing assay having 50.20%, 62.07%, 57.26% and 70.49% analgesia respectively at 300 mg/kg. QFAA extract showed maximum anti-inflammatory activity in croton oil induced edema (68.83%) and in carrageenan induced paw edema models (72.32%) at 300 mg/kg concentration. QFAA extract markedly reduced the rectal temperature at 300 mg/kg concentration, in brewer's yeast induced pyrexia model. Detailed investigations can be executed in future to determine the molecular mechanisms of these pharmacological attributes.

Characterization and comparative evaluation of wound healing potential of Ajugarin I and Ajuga bracteosa Wall. ex Benth.

Ajuga bracteosa (family: Lamiaceae), commonly known as kauri booti, is an important ethnomedicinal plant. The current research was conducted to appraise and compare the in vitro antioxidant and antibacterial profiles as well as in vivo wound healing potentials of Ajugarin I and A. bracteosa extract. Ajugarin I and polyphenols in A. bracteosa were enumerated by reversed-phase high-performance liquid chromatography analysis that confirmed significant amounts of Ajugarin I (2.2 ± 0.02 µg/mg DW) and other phenolic compounds (14 out of 17 standards). A. bracteosa (374.4 ± 0.20 µg AAE/mg of DW, 201.9 ± 0.20 µg AAE/mg of DW, 87 ± 0.30%) showed a higher antioxidant profile compared to Ajugarin I (221.8 ± 0.50 µg AAE/mg of DW, 51.8 ± 0.40 µg AAE/mg of DW, 27.65 ± 0.80%) with 1.86-, 3.89-, and 3.15-fold greater activity in ferric reducing antioxidant power, total antioxidant capacity, and free radical scavenging assays, respectively. Likewise, A. bracteosa showed antibacterial activity against 3/5 strains (MIC 25-200 µg/ml) than Ajugarin I (2/5 strains; MIC 50-200 µg/ml). Hemolytic (<2% hemolysis) and dermal toxicity tests rendered both samples non-toxic. Additionally, A. bracteosa (100 ± 2.34% at day 12; 9.33 ± 0.47 days) demonstrated 1.11- and 1.24-fold higher percent wound contraction and epithelization time, respectively, than Ajugarin I (95.6 ± 1.52% at day 12; 11.6 ± 0.47 days) as assessed by an excision wound model in mice. Histopathological examination further reinforced the better wound healing potential of A. bracteosa with good epithelization, collagen synthesis, fibroblast proliferation, and revascularization. Briefly, we endorse the significant comparative antioxidant, antibacterial, and wound healing activities of A. bracteosa and Ajugarin I and present these as prospective candidates for wound healing drugs.