Novel Insights on Plant Extracts to Prevent and Treat Recurrent Urinary Tract Infections

In vitro-antibacterial properties of ten medicinal plants against common uropathogenic organisms and toxicity determination using brine shrimp lethality assay

BACKGROUND

In recent years, antibiotic resistance has emerged as a global health concern in bacterial infections such as urinary tract infections (UTIs). Uropathogenic Escherichia coli is the most frequent organism responsible for both simple and complex UTIs. Staphylococcus aureus and Pseudomonas aeruginosa are frequently associated with complicated UTIs. Sri Lanka has significant resources of medicinal plants used to cure UTIs in Ayurvedic and traditional medicine.

METHODS

Agar well diffusion and broth microdilution methods were used to determine the antibacterial activity of the methanolic extract of ten medicinal plants against P. aeruginosa ATCC27853, S.aureus ATCC25923, E.coli ATCC25922 and their UTI positive strains extracted from positive culture plates. As a preliminary toxicity assay, the Brine Shrimp Lethality Assay (BSLA) was used to determine its cytotoxicity.

RESULTS

The methanolic fruits extract of P. emblica demonstrated the highest antibacterial activity against both E. coli ATCC25922 and E. coli UTI-positive strains. B. diffusa roots extract exhibited the highest activity against S. aureus ATCC25923, while T. chebula fruits extract showed the highest activity against the S. aureus UTI-positive strain. T. involucrata roots extract displayed the highest activity against P. aeruginosa ATCC27853, and Z. officinale rhizomes extract showed the highest activity against the P. aeruginosa UTI-positive strain. Moreover, the plant mixture showed the most substantial antibacterial effect against P. aeruginosa ATCC27853. However, the methanolic seed extract of C. melo did not exhibit any antimicrobial effects against the selected organisms. All plant material, including the plant mixture, showed cytotoxicity according to the BSLA.

CONCLUSION

All the methanolic extracts including P. emblica fruits, O. tenuiflorum whole plant, T. chebula fruits, Z. officinale rhizome, T. terrestris roots, T. involucrata roots, A. lanata whole plant. B. diffusa roots and A. falcatus roots showed antimicrobial effects against selected strains except C. melo seed extract. The results of the present study evidently supports the traditional and ayurvedic use of these plants for the treatment of UTIs. This paves the way for another praise for new plant-based therapeutic product development for the treatment of UTIs. However, further toxicity studies are needed for medicinal dose determination.

The Antimicrobial Effect of Cornus mas L. and Sorbus aucuparia L. Fruit Extracts against Resistant Uropathogens in Correlation with the Prevalence of Urinary Tract Infections in Companion Animals

Urinary tract infections (UTIs) are a widespread condition in pets, with many antibiotics being prescribed, contributing to the rise in antimicrobial resistance, which is a worldwide threat. This study's main objective was to analyze the in vitro antimicrobial activity of Cornus mas and Sorbus aucuparia fruit hydro-ethanolic extracts towards bacteria identified in the urine of companion animals experiencing UTIs. Urine samples were collected from dogs and cats (n = 83; 47 negative, 36 positive); several bacterial strains were identified (n = 49) belonging to the Escherichia, Enterococcus, Staphylococcus, Proteus, Klebsiella, Enterobacter, Pseudomonas, Acinetobacter, Leclercia, and Kocuria genera. Bacterial susceptibility was tested using the disk diffusion method, with the majority being resistant to several beta-lactams, quinolones, trimethoprim/sulfamethoxazole, and nitrofurantoin. Subsequently, 13 resistant isolates were selected to evaluate the fruits extracts' antimicrobial potential using the agar well diffusion and broth microdilution methods. Cornus mas exhibited the greatest activity against Gram-negatives (primarily Pseudomonas luteola), while Sorbus aucuparia showed maximum effects towards Gram-positives (particularly Enterococcus faecalis). The MIC was 0.01 μg/μL for both extracts; the MBC was 0.08 μg/μL for Cornus mas and 0.05 μg/μL for Sorbus aucuparia. However, Cornus mas showed a stronger bactericidal effect. This is the first study to investigate these fruit extracts in UTI isolates of companion animals, and these extracts might be used as substitutes or adjuvants for antibiotics, thus contributing to a reduction in antimicrobial resistance.

The management of recurrent urinary tract infections within a nurse-led urology team

The aim of this article is to share experience and learning of managing recurrent urinary tract infections (UTIs) within a specialist urology nurse-led team based at a district general hospital. It looks at current practice and supporting evidence for how to manage and treat recurrent UTIs in both male and female patients. Two case studies are presented to illustrate the management strategies and outcomes, demonstrating a planned approach that informs the design of a local management guideline to organise patients' care.

Health Benefits of Antioxidant Bioactive Compounds in the Fruits and Leaves of Lonicera caerulea L. and Aronia melanocarpa (Michx.) Elliot

Lonicera caerulaea L. and Aronia melanocarpa (Michx.) Elliot fruits are frequently used for their health benefits as they are rich in bioactive compounds. They are recognized as a source of natural and valuable phytonutrients, which makes them a superfood. L. caerulea presents antioxidant activity three to five times higher than other berries which are more commonly consumed, such as blackberries or strawberries. In addition, their ascorbic acid level is the highest among fruits. The species A. melanocarpa is considered one of the richest known sources of antioxidants, surpassing currants, cranberries, blueberries, elderberries, and gooseberries, and contains one of the highest amounts of sorbitol. The non-edible leaves of genus Aronia became more extensively analyzed as a byproduct or waste material due to their high polyphenol, flavonoid, and phenolic acid content, along with a small amount of anthocyanins, which are used as ingredients in nutraceuticals, herbal teas, bio-cosmetics, cosmeceuticals, food and by the pharmaceutical industry. These plants are a rich source of vitamins, tocopherols, folic acid, and carotenoids. However, they remain outside of mainstream fruit consumption, being well known only to a small audience. This review aims to shed light on L. caerulaea and A. melanocarpa and their bioactive compounds as healthy superfoods with antioxidant, anti-inflammatory, antitumor, antimicrobial, and anti-diabetic effects, and hepato-, cardio-, and neuro-protective potential. In this view, we hope to promote their cultivation and processing, increase their commercial availability, and also highlight the ability of these species to be used as potential nutraceutical sources, helpful for human health.

Phytochemical Screening, Toxic Effects, and Antimicrobial Activity Studies of Digitaria abyssinica (Hochst. ex A.Rich.) Stapf (Poaceae) Rhizome Extracts against Selected Uropathogenic Microorganisms

In Kenya, the D. abyssinica rhizome's decoction is traditionally used to treat urinary tract infections (UTIs), mainly gonorrhea and candidiasis. UTIs are the most severe public health problems that affect over one hundred and fifty million people worldwide annually. They are caused by a wide range of microorganisms where Escherichia coli is known to be the main causative pathogen. Medicinal plants are used in traditional Kenya set up for treatment and most recently as an alternative source of treatment for UTIs due to the increased cost of treatment and many challenges experienced with antibiotic therapy. The current study is designed to investigate the phytochemical composition, acute oral toxicity, and antimicrobial activity of Digitaria abyssinica rhizome extracts against Staphylococcus aureus, Escherichia coli, Neisseria gonorrhea, and Candida albicans. The rhizomes of D. abyssinica were obtained, dried, ground, and extracted using water and organic solvents. The phytochemical assay was carried out using standard phytochemical screening methods. Single-dose toxicity studies were done to determine LD₅₀ while disk diffusion and microbroth dilution techniques were used to determine antimicrobial activity. Results revealed that saponins, phenolics, alkaloids, cardiac glycosides, tannins, flavonoids, steroids, and terpenes were present in the powder, aqueous, methanol, and dichloromethane : methanol extracts. All the extracts had an LD₅₀ of above 2,000 mg/kg of body weight and there was no observation of behavioral changes. Also, the aqueous and methanol extracts revealed antifungal activity against Candida albicans with the lowest average minimum zone of inhibition at MIC of 31.25 mg/ml. The study did not reveal antibacterial activity for any extract against the studied uropathogenic bacteria, Staphylococcus aureus, Escherichia coli, and Neisseria gonorrhoeae. The results from the current study suggested that D. abyssinica rhizome aqueous and methanol extracts have potential antifungal activity against C. albicans, thus validating the folklore of its use to treat candidiasis.

Aqueous core epigallocatechin gallate PLGA nanocapsules: characterization, antibacterial activity against uropathogens, and in vivo reno-protective effect in cisplatin induced nephrotoxicity

Epigallocatechin-3-gallate (EGCG) was isolated from Cycas thouarsii leaves for the first time and encapsulated in aqueous core poly(lactide-co-glycolide) (PLGA) nanocapsules (NCs). This work investigates antimicrobial activity and in vivo reno-protective effects of EGCG-PLGA NCs in cisplatin-induced nephrotoxicity. A double emulsion solvent evaporation process was adopted to prepare PLGA NCs loaded with EGCG. Particle size, polydispersity index (PDI), zeta potential, percent entrapment efficiency (%EE), structural morphology, and in vitro release platform were all studied in vitro. The optimum formula (F2) with particle size (61.37 ± 5.90 nm), PDI (0.125 ± 0.027), zeta potential (-11.83 ± 3.22 mV), %EE (85.79 ± 5.89%w/w), initial burst (36.85 ± 4.79), and percent cumulative release (87.79 ± 9.84) was selected for further in vitro/in vivo studies. F2 exhibited an enhanced antimicrobial activity against uropathogens as it had lower minimum inhibitory concentration (MIC) values and a more significant impact on bacterial growth than free EGCG. Forty male adult mice were randomly allocated into five groups: control vehicle, untreated methotrexate, MTX groups treated with a daily oral dose of free EGCG, placebo PLGA NCs, and EGCG PLGA NCs (F2) for 10 days. Results showed that EGCG PLGA NCs (F2) exerted promising renoprotective effects compared to free EGCG. EGCG PLGA NCs group induced a significant decrease in kidney index, serum creatinine, kidney injury molecule-1 (KIM-1), NGAL serum levels, and pronounced inhibition of NLPR-3/caspase-1/IL/1β inflammasome pathway. It also significantly ameliorated oxidative stress and decreased NFκB, Bax expression levels. Aqueous core PLGA NCs are a promising formulation strategy that provides high polymeric protection and sustained release pattern for hydrophilic therapeutic agents.

Urinary Tract Infections Caused by Uropathogenic Escherichia coli Strains—New Strategies for an Old Pathogen

Urinary tract infections (UTIs) are among the most common infections worldwide. Uropathogenic Escherichia coli (UPECs) are the main causative agent of UTIs. UPECs initially colonize the human host adhering to the bladder epithelium. Adhesion is followed by the bacterial invasion of urothelial epithelial cells where they can replicate to form compact aggregates of intracellular bacteria with biofilm-like properties. UPEC strains may persist within epithelial urothelial cells, thus acting as quiescent intracellular bacterial reservoirs (QIRs). It has been proposed that host cell invasion may facilitate both the establishment and persistence of UPECs within the human urinary tract. UPEC strains express a variety of virulence factors including fimbrial and afimbrial adhesins, invasins, iron-acquisition systems, and toxins, which cooperate to the establishment of long lasting infections. An increasing resistance rate relative to the antibiotics recommended by current guidelines for the treatment of UTIs and an increasing number of multidrug resistant UPEC isolates were observed. In order to ameliorate the cure rate and improve the outcomes of patients, appropriate therapy founded on new strategies, as alternative to antibiotics, needs to be explored. Here, we take a snapshot of the current knowledge of coordinated efforts to develop innovative anti-infective strategies to control the diffusion of UPECs.

Bioactive Compounds from Natural Products: Separation, Characterization, and Applications

The study of bioactive compounds represents a new and innovative section of biotechnology, with applications to the well-being of humans [...]