Evaluation of Combination Effects of Ethanolic Extract of Ziziphus mucronata Willd. subsp. mucronata Willd. and Antibiotics against Clinically Important Bacteria

Abstract

A pragmatic approach to the treatment of infectious diseases with multicausal agents and prevention of the development of resistant isolates is the combination of herbal remedies with the first-line antimicrobial agents to which most of them have become resistant. This study evaluated the interactions between the ethanolic bark extract of Ziziphus mucronata with known antimicrobial agents in vitro. In this study, the results showed that varied zones of inhibitions (ZME—chloramphenicol (17–42 mm), ZME—amoxicillin (17–35 mm), ZME—tetracycline (17–36 mm), ZME—ciprofloxacin (20–41 mm), ZME—nalidixic acid (17–34 mm), and ZME—kanamycin (17–38 mm)) were produced by the antibacterial combinations. At the highest combined concentrations, 12 isolates (ZME—ciprofloxacin) > 10 isolates (ZME—chloramphenicol) = (ZME—kanamycin) > 6 isolates (ZME—amoxicillin) = (ZME—nalidixic acid) and 5 isolates (ZME—tetracycline) were inhibited with zones of inhibition greater than 20 ± 1.0 mm. Although the agar diffusion assay suggested that the interactions between the ethanolic extract of Z. mucronata and the antibiotics were both synergistic and additive in nature, the fractional inhibitory concentration indices (FICI) showed that the interactions were synergistic (54.17%), additive (27.78%), indifferent (16.67%), and antagonistic (1.39%). While the fractional inhibitory concentration indices (FICIs) for synergism ranged between 0.00391 and 0.5, that of additivity ranged between 0.516 and 1.0, indifferences ranged between 1.062 and 3.0 and antagonistic interaction was 5.0. The synergistic effects implied that the antibacterial combinations would be more effective and useful in the treatment of multicausal and multidrug-resistant bacteria than a single monotherapy of either antibacterial agent.

Comparative in vitro cytotoxic, anti-inflammatory and anti-microbiological activities of two indigenous Venda medicinal plants

“…The percentage for plant extract inhibition was not calculated as there was no observable microbial growth comparing the test and control wells. The results observed contradict the findings by Olajuyigbe and Afolayan [26]. The bacterial isolates (E. faecalis, E. coli, K. pneumoniae) exhibited varied degree of susceptibility with zones of inhibition ranging between 17 and 27 ± 1.0 mm, though the difference in results can be attributed to the extraction solvent they used.…”

Antimicrobial potential of Rothmannia longiflora Salisb and Canna indica Linn extracts against selected strains of fungi and bacteria

“…With this increased incidence of antimicrobial resistance and appearance of new infectious for their antimicrobial activity and resistance modifying ability (Gibbon, 2004;Coutinho et al, 2009). While the natural products are known to play significant roles in the development of novel drugs and served as leads for the treatment and prevention of diseases (Belini et al, 2008), plant-derived antimicrobials provide the much needed therapeutics (Olajuyigbe and Afolayan, 2013) . The leaves of C. indica showed antimicrobial activity (Abdullah et al, 2012), analgesic activity, and the rhizomes showed a good anthelmintic activity against Pheritima posthuma (Nirmal et al, 2007).…”

Nimbolide from Azadirachta indica and its derivatives plus first-generation cephalosporin antibiotics: a novel drug combination for wound-infecting pathogens

“…With the increase in the prevalence of multidrug resistant wound pathogens, synergism testing using various combinations of plant compound and their corresponding synthetic derivatives with antimicrobial drugs could be a more powerful tool in helping to select appropriate antimicrobial therapy to control pathogens. [51][52][53] The indiscriminate use of various antibiotics in the treatment of bacterial infections especially against wound pathogens has led to the emergence and spread of resistant bacterial strains, and this in turn resulted in a great loss of clinical efficacy of previously effective first-generation antibiotics which results in shifting of antimicrobial treatment regimen to second-generation or third-generation antibiotics that are often more expensive with many unwanted side effects to human beings. 54 In fact, studies have shown that crude extracts of plants possess the ability to enhance the activity of antimicrobial agents without causing any unwanted side effects.…”