In vitro bactericidal activity of promising nutraceuticals for targeting multidrug resistant Pseudomonas aeruginosa

Three Licorice Extracts' Impact on the Quality of Fresh-Cut Sweet Potato (Ipomoea batatas (L.) Lam) Slices

The quality of fresh-cut produce, particularly sweet potatoes, is crucial for their value. Licorice extract is an optional additive in fresh-cut sweet potatoes. This study examined the impact of three licorice extracts (licorice acid, LA; licorice flavonoids, LF; and licorice polysaccharides, LP) on the quality of fresh-cut sweet potato slices (FCSPSs) for one week of storage. After one week of storage, the extracts showed varying effects on FCSPSs. LA and LF treatments reduced the area proportion of browning (APB), while LP treatments increased APB and decreased L* values. Antioxidant experiments revealed that LP treatments increased PPO and POD activity while reducing SOD activity. The concentrations of the three licorice extracts showed a strong negative correlation with SOD activity. In conclusion, LP harmed the appearance and antioxidant qualities of FCSPSs. LA and LF may be suitable additive components for FCSPSs, and 30 mg/mL LA and LF treatments were found to maintain the appearance and texture quality of FCSPSs during storage. Therefore, careful consideration should be given when using LP as a food additive for FCSPSs.

Effect of Some Plant-Based Substances on Microbial Content and Sperm Quality Parameters of Bull Semen

The rapid emergence of antibacterial resistance requires alternatives to antibiotics to be found, including for semen preservation. One of the possible alternatives would be to use plant-based substances with known antimicrobial effects. The objective of this study was to test the antimicrobial effect of pomegranate powder, ginger, and curcumin extract in two concentrations on bull semen microbiota after exposure for <2 h and 24 h. An additional aim was to evaluate the effect of these substances on sperm quality parameters. The bacterial count in semen was low from the beginning; however, a reduction was present for all tested substances compared with control. A reduction in bacterial count in control samples was also observed with time. Curcumin at a concentration of 5%, reduced bacterial count by 32% and was the only substance that had a slight positive effect on sperm kinematics. The other substances were associated with a decline in sperm kinematics and viability. Neither concentration of curcumin had a deleterious effect on sperm viability parameters measured by flow cytometry. The results of this study indicate that curcumin extract at a concentration of 5% can reduce the bacterial count and does not have a negative influence on bull sperm quality.

Herbal Products and Their Active Constituents Used Alone and in Combination with Antibiotics against Multidrug-Resistant Bacteria

The purpose of this review is to summarize the current knowledge acquired on herbal products and their active constituents with antimicrobial activity used alone and in combination with antibiotics against multidrug-resistant bacteria. The most promising herbal products and active constituents used alone against multidrug-resistant bacteria are Piper betle (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum beta-lactamase, Acinetobacter baumannii, Pseudomonas aeruginosa), Glycyrrhiza glabra (methicillin-resistant S. aureus, vancomycin-resistant Enterococcus, P. aeruginosa), and berberine (methicillin-resistant S. aureus, A. baumannii, P. aeruginosa), respectively. The synergistic effect of the combination of herbal products and their active constituents with antibiotics against multidrug-resistant bacteria are also described. These natural antibacterial agents can be promising sources of inhibitors, which can modulate antibiotic activity against multidrug-resistant bacteria, especially as efflux pump inhibitors. Other possible mechanisms of action of herbal therapy against multidrug-resistant bacteria including modification of the bacterial cell wall and/or membrane, inhibition of the cell division protein filamenting temperature sensitive Z-ring, and inhibition of protein synthesis and gene expression, all of which will also be discussed. Our review suggests that combination herbal therapy and antibiotics can be effectively used to expand the spectrum of their antimicrobial action. Therefore, combination therapy against multidrug-resistant bacteria may enable new choices for the treatment of infectious diseases and represents a potential area for future research.

Current Treatment Strategies Against Multidrug-Resistant Bacteria: A Review

There are several bacteria called superbugs that are resistant to multiple antibiotics which can be life threatening specially for critically ill and hospitalized patients. This article provides up-to-date treatment strategies employed against some major superbugs, like methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococcus, multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Escherichia coli. The pathogen-directed therapeutics decrease the toxicity of bacteria by altering their virulence factors by specific processes. On the other hand, the host-directed therapeutics limits these superbugs by modulating immune cells, enhancing host cell functions, and modifying disease pathology. Several new antibiotics against the global priority superbugs are coming to the market or are in the clinical development phase. Medicinal plants possessing potent secondary metabolites can play a key role in the treatment against these superbugs. Nanotechnology has also emerged as a promising option for combatting them. There is urgent need to continuously figure out the best possible treatment strategy against these superbugs as resistance can also be developed against the new and upcoming antibiotics in future. Rational use of antibiotics and maintenance of proper hygiene must be practiced among patients.

A Systematic Review of Plants With Antibacterial Activities: A Taxonomic and Phylogenetic Perspective

Background: Antimicrobial resistance represents a serious threat to human health across the globe. The cost of bringing a new antibiotic from discovery to market is high and return on investment is low. Furthermore, the development of new antibiotics has slowed dramatically since the 1950s’ golden age of discovery. Plants produce a variety of bioactive secondary metabolites that could be used to fuel the future discovery pipeline. While many studies have focused on specific aspects of plants and plant natural products with antibacterial properties, a comprehensive review of the antibacterial potential of plants has never before been attempted.

Objectives: This systematic review aims to evaluate reports on plants with significant antibacterial activities.

Methods: Following the PRISMA model, we searched three electronic databases: Web of Science, PubMed and SciFinder by using specific keywords: “plant,” “antibacterial,” “inhibitory concentration.”

Results: We identified a total of 6,083 articles published between 1946 and 2019 and then reviewed 66% of these (4,024) focusing on articles published between 2012 and 2019. A rigorous selection process was implemented using clear inclusion and exclusion criteria, yielding data on 958 plant species derived from 483 scientific articles. Antibacterial activity is found in 51 of 79 vascular plant orders throughout the phylogenetic tree. Most are reported within eudicots, with the bulk of species being asterids. Antibacterial activity is not prominent in monocotyledons. Phylogenetic distribution strongly supports the concept of chemical evolution across plant clades, especially in more derived eudicot families. The Lamiaceae, Fabaceae and Asteraceae were the most represented plant families, while Cinnamomum verum, Rosmarinus vulgaris and Thymus vulgaris were the most studied species. South Africa was the most represented site of plant collection. Crude extraction in methanol was the most represented type of extraction and leaves were the main plant tissue investigated. Finally, Staphylococcus aureus was the most targeted pathogenic bacteria in these studies. We closely examine 70 prominent medicinal plant species from the 15 families most studied in the literature.

Conclusion: This review depicts the current state of knowledge regarding antibacterials from plants and provides powerful recommendations for future research directions.

Considerations and Caveats in Combating ESKAPE Pathogens against Nosocomial Infections

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are among the most common opportunistic pathogens in nosocomial infections. ESKAPE pathogens distinguish themselves from normal ones by developing a high level of antibiotic resistance that involves multiple mechanisms. Contemporary therapeutic strategies which are potential options in combating ESKAPE bacteria need further investigation. Herein, a broad overview of the antimicrobial research on ESKAPE pathogens over the past five years is provided with prospective clinical applications.

DRDO Herbal Technologies: Military and Civil Applications

The novel herbal technologies developed by India’s Defence Research and Development Organization are discussed with a view to improving the lives of soldiers and civilians. The life sciences laboratories of DRDO are engaged in R&D with the aim to develop processes, products and technologies and effective strategies to protect and enhance the operational efficiency of the Indian Armed Forces. Over the last five decades, the endeavours have resulted in creating specialized human capital through selection and training; enhancing efficiency through customized nutrition; optimizing human efficiency through traditional systems; optimizing performance through human engineering approach; protecting against health hazards like CBRN and vectors; reducing combat stress by counselling, training and resilience building; reinforcing adaptation through acclimatization processes and saving lives through life support systems. Several technologies with holistic and pragmatic applications for defence and civil sector from a herbal perspective are presented.

Zingiber officinale: Its antibacterial activity on Pseudomonas aeruginosa and mode of action evaluated by flow cytometry

Biofilm formation, low membrane permeability and efflux activity developed by Pseudomonas aeruginosa, play an important role in the mechanism of infection and antimicrobial resistance. In the present study we evaluate the antibacterial effect of Zingiber officinale against multi-drug resistant strain of P. aeruginosa. The study explores antibacterial efficacy and time-kill study concomitantly the effect of herbal extract on bacterial cell physiology with the use of flow cytometry and inhibition of biofilm formation. Z. officinale was found to inhibit the growth of P. aeruginosa, significantly. A major decline in the Colony Forming Units was observed with 3 log10 at 12 h of treatment. Also it is found to affect the membrane integrity of the pathogen, as 70.06 ± 2.009% cells were found to stain with Propidium iodide. In case of efflux activity 86.9 ± 2.08% cells were found in Ethidium bromide positive region. Biofilm formation inhibition ability was found in the range of 68.13 ± 4.11% to 84.86 ± 2.02%. Z.officinale is effective for killing Multi-Drug Resistant P. aeruginosa clinical isolate by affecting the cellular physiology and inhibiting the biofilm formation.

Effect of aquo-alchoholic extract of Glycyrrhiza glabra against Pseudomonas aeruginosa in Mice Lung Infection Model

The prevalence of lung infection caused by Pseudomonas aeruginosa strains that are classified as multi-drug resistant has increased considerably and is mainly attributed to relative insufficiency of potent chemotherapeutic modalities. The present study was conducted to evaluate the antimicrobial activity of aquo-alcoholic extract of Glycyrrhiza glabra against the P. aeruginosa causing lung infection in Swiss albino mice. The study involves evaluation of lethal dose of P. aeruginosa in Swiss albino mice and analysis of disease manifestation that includes bacteremia, hypothermia, reduction in body weight and other parameters for 48h of infection. Physical manifestations of infected mice showed a significant decline in body temperature that is 29±0.57°C (at 48th h) from 38.81±0.33°C (0h) and 30% weight loss was observed at the end of the study. Further the efficacy of G. glabra extract against lung infection induced with the calculated lethal dose was evaluated by employing bacteremia, histopathology and radiological analysis. Bacterial burden showed that 2.30±0.02 Log10CFU/mL at day 7, a significant decline in the bacterial load as compared to day 1 when the bacterial burden was found to be 3.32±0.1 Log10CFU/mL. Histopathological results showed more diffuse and patchy accumulation of inflammatory cells within the alveolar space also the infiltrates were noted in all the lung section of infected mice. In treated animal group improved lung histology was seen with the exudates were less seen in D1 dose (20mg/kg) and disappeared in D2 dose (80mg/kg). The study clearly declares that the G. glabra extract is effective against lung infection caused by P. aeruginosa at dose of 80mg/kg. The LCMS results revealed that the extract contains Glycyrrhizin, Stigmasterol and Ergosterol, Licochalcone and Glabridin. The current study expected to further exploit the biomedical properties of this extract in the preparation of a potent regimen against such threatening pathogen.