Benzyl isothiocyanate, a major component from the roots of Salvadora persica is highly active against Gram-negative bacteria

Efficacy of outer membrane permeabilization in promoting aromatic isothiocyanates-mediated eradication of multidrug resistant Gram-negative bacteria and bacterial persisters

Multidrug resistant (MDR) bacteria are recognized to be one of the most important problems in public health. The outer membrane permeability is a critical intrinsic mechanism of bacterial resistance. In addition, bacteria produce a small number of dormant persister cells causing multidrug tolerance that reduces antimicrobial efficacy. This study aimed to evaluate the inhibitory effects of the combination of aromatic isothiocyanates (ITCs) with membrane-active agents on bacterial persisters and MDR Gram-negative bacteria. Our study demonstrated that membrane-active agents, particularly ethylenediaminetetraacetic acid (EDTA) synergistically enhanced the inhibitory activity of aromatic benzyl ITC and phenethyl ITC against most Gram-negative bacteria strains with fractional inhibitory concentration index values ranging from 0.18 to 0.5 and 0.16 to 0.5, respectively, and contributed to an 8- to 64-fold minimal inhibitory concentration reduction compared with those of aromatic ITCs alone. The EDTA-aromatic ITCs combination effectively reduced the survival rates of tested bacteria and significantly eradicated bacterial persisters (p = 0.033 and 0.037, respectively). The growth kinetics analysis also supported the enhanced inhibitory effect of EDTA-aromatic ITCs combination against tested bacteria. Our results suggested an alternate treatment strategy against Gram-negative bacteria, promoting the entry of aromatic ITCs into bacterial cytoplasm to facilitate bacterial clearance and thus preventing the development of bacterial resistance.

Plant-Derived Antimicrobials and Their Crucial Role in Combating Antimicrobial Resistance

Antibiotic resistance emerged shortly after the discovery of the first antibiotic and has remained a critical public health issue ever since. Managing antibiotic resistance in clinical settings continues to be challenging, particularly with the rise of superbugs, or bacteria resistant to multiple antibiotics, known as multidrug-resistant (MDR) bacteria. This rapid development of resistance has compelled researchers to continuously seek new antimicrobial agents to curb resistance, despite a shrinking pipeline of new drugs. Recently, the focus of antimicrobial discovery has shifted to plants, fungi, lichens, endophytes, and various marine sources, such as seaweeds, corals, and other microorganisms, due to their promising properties. For this review, an extensive search was conducted across multiple scientific databases, including PubMed, Elsevier, ResearchGate, Scopus, and Google Scholar, encompassing publications from 1929 to 2024. This review provides a concise overview of the mechanisms employed by bacteria to develop antibiotic resistance, followed by an in-depth exploration of plant secondary metabolites as a potential solution to MDR pathogens. In recent years, the interest in plant-based medicines has surged, driven by their advantageous properties. However, additional research is essential to fully understand the mechanisms of action and verify the safety of antimicrobial phytochemicals. Future prospects for enhancing the use of plant secondary metabolites in combating antibiotic-resistant pathogens will also be discussed.

Evaluation of Clinical Efficacy of Biodegradable Chip Containing Salvadora persica (miswak) Extract in Chitosan Base as an Adjunct to Scaling and Root Planing in the Management of Periodontitis

Objectives

This study attempted to develop 2 biodegradable periodontal chips containing Salvadora persica (miswak) or benzyl isothiocyanate (BITC) extracts and evaluate their clinical effectiveness in managing periodontitis.

Methods

This clinical trial was conducted at the Faculty of Dentistry, Universiti Teknologi MARA Shah Alam, Selangor, Malaysia, from September 2010 to April 2012. Periodontal chips were formulated using S. persica, benzyl isothiocyanate (BITC) and chitosan extracts. All patients were treated with full mouth scaling and root planing at baseline. Thereafter, the periodontal pockets (≥5 mm in length) were divided into 4 groups: the control group; group 2 (plain chitosan chip); group 3 (S. persica extract); and group 4 (BITC extract). Plaque index (PI), bleeding on probing (BOP), periodontal probing pocket depth and clinical attachment levels were recorded at days 0 and 60 only.

Results

A total of 12 patients participated in this study. Overall, 240 periodontal pockets were evaluated. The study revealed significant improvements in PI, BOP and reduction in periodontal pocket depth in all 4 groups (P <0.05). The improvement in clinical attachment level was significantly higher (P <0.001) among the group that received S. persica chips compared to the control and other chip-treated groups.

Conclusion

Periodontal chips containing S. persica can be used as adjuncts to treat patients with periodontitis.

Clinical Effect of Thioglycosides Extracted from White Mustard on Dental Plaque and Gingivitis: Randomized, Single-Blinded Clinical Trial

The antibacterial and anti-inflammatory effect of thioglycosides has already been established. This study investigates the effects of thioglycosides extracted from white mustard, specifically the "Bamberka" variety, in the context of oral hygiene. The aim of the study is to clarify an evidence-based link between the documented antibacterial and anti-inflammatory effects attributed to thioglycosides and their practical application in oral care. A randomized, single-blinded (patient-blinded) clinical study was performed on 66 patients using mustard-based toothpaste for oral hygiene. The patients were examined at baseline and after 6 and 12 months. The values of the Approximal Plaque Index (API), the Plaque Index (PI), and Bleeding on probing (BOP) were taken into consideration. The results show a significant reduction in plaque accumulation, especially after 6 months of using mustard-based toothpaste in all examined parameters. This suggests that thioglycosides from mustard contribute to a considerable decrease in dental plaque accumulation, confirming their potential in natural oral care solutions, which is indicated in the main conclusions or interpretations.

Cobalt complexes modulate plasmid conjugation in Escherichia coli and Klebsiella pneumoniae

Antimicrobial resistance genes (ARG), such as extended-spectrum β-lactamase (ESBL) and carbapenemase genes, are commonly carried on plasmids. Plasmids can transmit between bacteria, disseminate globally, and cause clinically important resistance. Therefore, targeting plasmids could reduce ARG prevalence, and restore the efficacy of existing antibiotics. Cobalt complexes possess diverse biological activities, including antimicrobial and anticancer properties. However, their effect on plasmid conjugation has not been explored yet. Here, we assessed the effect of four previously characterised bis(N-picolinamido)cobalt(II) complexes lacking antibacterial activity on plasmid conjugation in Escherichia coli and Klebsiella pneumoniae. Antimicrobial susceptibility testing of these cobalt complexes confirmed the lack of antibacterial activity in E. coli and K. pneumoniae. Liquid broth and solid agar conjugation assays were used to screen the activity of the complexes on four archetypical plasmids in E. coli J53. The cobalt complexes significantly reduced the conjugation of RP4, R6K, and R388 plasmids, but not pKM101, on solid agar in E. coli J53. Owing to their promising activity, the impact of cobalt complexes was tested on the conjugation of fluorescently tagged extended-spectrum β-lactamase encoding pCTgfp plasmid in E. coli and carbapenemase encoding pKpQILgfp plasmid in K. pneumoniae, using flow cytometry. The complexes significantly reduced the conjugation of pKpQILgfp in K. pneumoniae but had no impact on pCTgfp conjugation in E. coli. The cobalt complexes did not have plasmid-curing activity, suggesting that they target conjugation rather than plasmid stability. To our knowledge, this is the first study to report reduced conjugation of clinically relevant plasmids with cobalt complexes. These cobalt complexes are not cytotoxic towards mammalian cells and are not antibacterial, therefore they could be optimised and employed as inhibitors of plasmid conjugation.

Phytochemical Composition and Antimicrobial Efficacy of Salvadora persica Root Extracts Against Carbapenem-Resistant Acinetobacter baumannii

Background Carbapenem-resistant Acinetobacter baumannii (CRAB) are difficult to eradicate from the environment and are virtually immune to all antibiotics. Consequently, CRAB may culminate in severe outbreaks and fatal infections among people attending hospitals and nursing homes. Salvadora persica has been used as an herbal remedy and chewing sticks for dental cleansing. Evaluating S. persica's efficacy against CRAB may provide an alternative approach to treating CRAB infections in healthcare environments, considering its traditional application in dental hygiene. Employing S. persica as an herbal remedy could be a part of a more sustainable approach to control CRAB infections. Aim To investigate the phytochemical composition of S. persica and evaluate its antimicrobial properties. Materials and methods The roots were extracted by Soxhlet apparatus using n-hexane, chloroform, and methanol. Each extract was analyzed using gas chromatography-mass spectrometry (GCMS) and characterized using WN908.L and National Institute of Standards and Technology (NIST) libraries. The antimicrobial activity of each extract against CRAB was evaluated using a broth microdilution assay to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results The GCMS analysis of different solvent extracts of S. persica roots showed the presence of various phytochemical compounds such as steroids, phenolic compounds, fatty acids, alcohols, terpenoids, and vitamin E. Both chloroform and hexane extracts showed the most effective antimicrobial activity with a MIC value of 3.13 mg/mL and an MBC value of 12.50 mg/mL, respectively. Benzoic acid was the major phytochemical compound identified from S. persica extract. N-hexane, chloroform, and methanol extracts exhibited maximum antimicrobial activity due to the presence of active compounds in them. Conclusion Chloroform and hexane extracts showed the most potent antibacterial activities against CRAB.

Leverage of Salvadora persica and Pulicaria undulata extracts in Escherichia coli-challenged broiler chickens

Escherichia coli (E. coli) is a significant challenge in the poultry industry due to their related use of antimicrobial compounds and the drastic losses in production and livability. This study investigated the preventive impacts of dietary supplementation of Salvadora persica (SP) and/or Pulicaria undulata (PU) extracts on growth traits, biochemical and immune parameters, and related gene expression of E. coli-infected broilers. A total of 120 one-day-old Cobb broilers were used. The chicks were allocated into eight equal groups (3 replicates/ group; 5 chicks per each replicate) as follows: G1; control negative, G2; SP-treated, G3; PU-treated, G4; SP/PU-treated, G5; E. coli infected, G6; E. coli infected and SP-treated, G7; E. coli infected and PU-treated, G8; E. coli infected and SP/PU-treated groups. Results revealed significant improvement in average body weight (ABW), average weight gain (AWG) and feed conversion ratio (FCR) in broilers fed diets supplemented with SP and/or PU compared to control and E. coli infected groups. Moreover, significant (P < 0.05) reduction in ALT, AST, creatinine, and uric acid was reported in other treated groups compared to the single E. coli-infected broilers. On the contrary, a significant increase (P < 0.05) in serum immunoglobulin and protein concentration was also reported in treated groups when compared to E. coli-infected untreated group. In addition, feeding broilers with SP and/or PU significantly improved (P < 0.05) the relative weight of immune-related organs and gene expression of TLR-15, with subsequent down-regulation of IL-1β and TNF-α mRNA transcripts. Supplementing broilers with dietary SP and/or PU could be promising in the prevention of E. coli infection via stimulating significant improvement of immune-related gene expression, immune-related organ weight, and down-regulation of inflammatory-related genes, with subsequent enhancement of the growth performance of broiler chickens.

Antibacterial Effect of Miswak herbal toothpaste Compared to Fluoride Toothpaste in High Caries Risk Patients: Randomized Clinical Trial

Background

Modern toothbrushes origin can be traced to plant-derived chewing sticks, which were documented to be used Babylonians as early as 3500 BC. Chewing sticks are routinely used for cleaning teeth in Asia, Africa, South America, and the Middle East. The aim of the current study was to evaluate the antibacterial effect of miswak herbal toothpaste compared to fluoride toothpaste using a normal toothbrush, against Streptococcus mutans in high caries risk patients.

Material and Methods

A total of 32 participants were recruited to the current clinical trial using convenience sampling randomly either to miswak or fluoride toothpastes groups (n=16). The bacterial count represented as colony-forming units per milliliter (CFU/ml) was assessed at baseline and after 1 week, 1 month and 3 months. Moreover, the ion release for silicone, calcium, phosphorus, and fluoride from both toothpastes was analyzed in addition to the pH of both toothpastes and their supernatants. Intergroup comparison was performed using independent t test, while intragroup comparison was performed using repeated measures ANOVA followed by tukey post-hoc test and paired t test when appropriate.

Results

There was no statistically significant difference between both toothpastes for the S. mutans count within each follow up period, however the bacterial count significantly decreased over time in both groups. Signal Fluoride toothpaste exhibited statistically significant higher ion release when compared to the Dabur Miswak toothpaste. There was no statistically significant difference between either toothpastes regarding pH (P = 0.5368), while comparison between supernatants of toothpastes have shown statistically significant difference (P = 0.0194), with a higher pH in miswak toothpaste.

Conclusions

Miswak herbal toothpaste possesses a potent antibacterial effect, yet its remineralization potential is questionable due to its inferior ion release that will affect the ion substantivity in saliva, which is an important factor in remineralization. Key words:High caries risk, Miswak, Fluoride, Antibacterial, Streptococcus mutans.

Phytochemicals as Antimicrobials: Prospecting Himalayan Medicinal Plants as Source of Alternate Medicine to Combat Antimicrobial Resistance

Among all available antimicrobials, antibiotics hold a prime position in the treatment of infectious diseases. However, the emergence of antimicrobial resistance (AMR) has posed a serious threat to the effectiveness of antibiotics, resulting in increased morbidity, mortality, and escalation in healthcare costs causing a global health crisis. The overuse and misuse of antibiotics in global healthcare setups have accelerated the development and spread of AMR, leading to the emergence of multidrug-resistant (MDR) pathogens, which further limits treatment options. This creates a critical need to explore alternative approaches to combat bacterial infections. Phytochemicals have gained attention as a potential source of alternative medicine to address the challenge of AMR. Phytochemicals are structurally and functionally diverse and have multitarget antimicrobial effects, disrupting essential cellular activities. Given the promising results of plant-based antimicrobials, coupled with the slow discovery of novel antibiotics, it has become highly imperative to explore the vast repository of phytocompounds to overcome the looming catastrophe of AMR. This review summarizes the emergence of AMR towards existing antibiotics and potent phytochemicals having antimicrobial activities, along with a comprehensive overview of 123 Himalayan medicinal plants reported to possess antimicrobial phytocompounds, thus compiling the existing information that will help researchers in the exploration of phytochemicals to combat AMR.

Glucosinolates, a natural chemical arsenal: More to tell than the myrosinase story

Glucosinolates are a group of thioglucosides that belong to the class of plant nitrogen-containing natural products. So far, very little biological activity has been associated with intact glucosinolates. The hydrolysis of glucosinolates has, for long, attracted attention because of the potent biological activity of the hydrolysis products. From allelopathic to antiparasitic, antimicrobial and antineoplastic effects, the activity spectrum of the degradation products of typical glucosinolates has been the subject of much research. The present review seeks to address the various means of glucosinolate degradation (thermal, enzymatic, or chemical degradation) and the ensuing products. It also aims to draw a comparative profile of the various antimicrobial effects of these degradation products to provide a further understanding of the biological function of these important compounds.

In Vitro Antiviral Effect and Potential Neuroprotection of Salvadora persica L. Stem Bark Extract against Lipopolysaccharides-Induced Neuroinflammation in Mice: LC-ESI-MS/MS Analysis of the Methanol Extract

Neuroinflammation is a serious immunomodulatory complex disorder that causes neurological and somatic ailments. The treatment of brain inflammation with new drugs derived from natural sources is a significant therapeutic goal. Utilizing LC-ESI-MS/MS analysis, the active constituents of Salvadora persica extract (SPE) were identified tentatively as exerting antioxidant and anti-inflammatory effects in natural medicine. Herein, we determined the antiviral potential of SPE against herpes simplex virus type 2 (HSV-2) using the plaque assay. HSV-2 is a neurotropic virus that can cause neurological diseases. SPE exhibited promising antiviral potential with a half-maximal cytotoxic concentration (CC50) of 185.960 ± 0.1 µg/mL and a half-maximal inhibitory concentration (IC50) of 8.946 ± 0.02 µg/mL. The in vivo study of the SPE impact against lipopolysaccharide (LPS)-induced neuroinflammation was performed using 42 mice divided into seven groups. All groups were administered LPS (0.25 mg/kg) intraperitoneally, except for the normal and SPE groups 1 and 2. Groups 5, 6, and 7 received 100, 200, and 300 mg/kg SPE. It was revealed that SPE inhibited acetylcholinesterase in the brain. It increased superoxide dismutase and catalase while decreasing malondialdehyde, which explains its antioxidative stress activity. SPE downregulated the gene expression of the inducible nitric oxide synthase, as well as the apoptotic markers (caspase-3 and c-Jun). In addition, it decreased the expression of the proinflammatory cytokines (interleukin-6 and tumor necrosis factor-alpha). Mice administered SPE (300 mg/kg) with LPS exhibited normal neurons in the cerebral cortices, hippocampus pyramidal layer, and cerebellum, as determined by the histopathological analysis. Therefore, using S. persica to prevent and treat neurodegeneration could be a promising new therapeutic strategy to be explored.

Phytochemical and functional analysis of horseradish (Armoracia rusticana) fermented and non-fermented root extracts

BACKGROUND

The roots of horseradish (Armoracia rusticana) are used for infections of respiratory airway and for urinary tract infections due to isothiocyanates (ITC), enzymatically formed during fermentation of glucosinolates by myrosinase.

HYPOTHESIS/PURPOSE

The present study aims to present a comprehensive overview on the phytochemical composition of A. rusticana roots, especially concerning isothiocyanates and respective glucosinolates. The complex flavonoid spectrum of the herbal material is reviewed. Published data on in vitro activity of horseradish extracts and isolated compounds are summarized. These data indicate well-established use of horseradish as an antibacterial remedy against bacterial infections of the airway and urinary tract.

STUDY DESIGN

To answer the question if other compounds from A. rusticana beside ITC contribute to the antibacterial activity, non-targeted LC-MS studies were performed with fermented and non-fermented horseradish extracts, and detailed phytochemical profiles were established.

RESULTS

Comparative investigations on the antibacterial activity indicated that only ITC-containing extracts and fractions exert antibacterial activity. The huge variety of non-ITC compounds do not significantly contribute to the antibacterial activity, but can be used for analytical characterisation and quality control of the herbal material. Detailed phytochemical analysis additionally revealed a variety of compounds, not described until now for horseradish roots: the flavonol glycosides kaempferol-3-O-β-d-xylopyranosyl-(1''' → 2'')-β-d-galactopyranoside, kaempferol-3-O-α-l-rhamnopyranosyl-(1''' → 6'')-β-d-glucopyranoside, kaempferol-3-O-β-d-glucopyranoside, Kaempferol-3-O-β-d-xylopyranosyl-7-O-β-d-glucopyranoside, Kaempferol-3-O-β-d-xylopyranosyl-(1'''' → 2''')-β-d-galactopyranoside-7-O-β-d-glucopyranoside, the oxo-indole derivative spirobrassinin, the phenylthiazole 2-methylsulfanyl-4-phenyl-4,5-dihydro-1,3-thiazole, a series of lysophophatidylethanolamine and 13 different N-phenylpropenoyl-L-amino acids.

CONCLUSION

The antibacterial effects of horseradish are only due to the presence of glucosinolates resp. the corresponding ITC, and the detailed overall composition of horseradish extracts has been reported.

Plant pathogenic bacterium can rapidly evolve tolerance to an antimicrobial plant allelochemical

Crop losses to plant pathogens are a growing threat to global food security and more effective control strategies are urgently required. Biofumigation, an agricultural technique where Brassica plant tissues are mulched into soils to release antimicrobial plant allelochemicals called isothiocyanates (ITCs), has been proposed as an environmentally friendly alternative to agrochemicals. Whilst biofumigation has been shown to suppress a range of plant pathogens, its effects on plant pathogenic bacteria remain largely unexplored. Here, we used a laboratory model system to compare the efficacy of different types of ITCs against Ralstonia solanacearum plant bacterial pathogen. Additionally, we evaluated the potential for ITC-tolerance evolution under high, intermediate, and low transfer frequency ITC exposure treatments. We found that allyl-ITC was the most efficient compound at suppressing R. solanacearum growth, and its efficacy was not improved when combined with other types of ITCs. Despite consistent pathogen growth suppression, ITC tolerance evolution was observed in the low transfer frequency exposure treatment, leading to cross-tolerance to ampicillin beta-lactam antibiotic. Mechanistically, tolerance was linked to insertion sequence movement at four positions in genes that were potentially associated with stress responses (H-NS histone like protein), cell growth and competitiveness (acyltransferase), iron storage ([2-Fe-2S]-binding protein) and calcium ion sequestration (calcium-binding protein). Interestingly, pathogen adaptation to the growth media also indirectly selected for increased ITC tolerance through potential adaptations linked with metabolism and antibiotic resistance (dehydrogenase-like protein) and transmembrane protein movement (Tat pathway signal protein). Together, our results suggest that R. solanacearum can rapidly evolve tolerance to allyl-ITC plant allelochemical which could constrain the long-term efficiency of biofumigation biocontrol and potentially shape pathogen evolution with plants.

Combining in vitro and in vivo screening to identify efficient Pseudomonas biocontrol strains against the phytopathogenic bacterium Ralstonia solanacearum

Although plant pathogens are traditionally controlled using synthetic agrochemicals, the availability of commercial bactericides is still limited. One potential control strategy could be the use of plant growth‐promoting bacteria (PGPB) to suppress pathogens via resource competition or the production of antimicrobial compounds. This study aimed to conduct in vitro and in vivo screening of eight Pseudomonas strains against Ralstonia solanacearum (the causative agent of bacterial wilt) and to investigate underlying mechanisms of potential pathogen suppression. We found that inhibitory effects were Pseudomonas strain‐specific, with strain CHA0 showing the highest pathogen suppression. Genomic screening identified 2,4‐diacetylphloroglucinol, pyoluteorin, and orfamides A and B secondary metabolite clusters in the genomes of the most inhibitory strains, which were investigated further. Although all these compounds suppressed R. solanacearum growth, only orfamide A was produced in the growth media based on mass spectrometry. Moreover, orfamide variants extracted from Pseudomonas cultures showed high pathogen suppression. Using the “Micro‐Tom” tomato cultivar, it was found that CHA0 could reduce bacterial wilt disease incidence with one of the two tested pathogen strains. Together, these findings suggest that a better understanding of Pseudomonas–Ralstonia interactions in the rhizosphere is required to successfully translate in vitro findings into agricultural applications.

The Effect of Benzyl Isothiocyanate on the Expression of Genes Encoding NADH Oxidase and Fibronectin-Binding Protein in Oral Streptococcal Biofilms

Recent studies have shown that antimicrobial treatment results in up- or down regulation of several virulence-associated genes in bacterial biofilms. The genes encoding NADH oxidase (nox) and fibronectin-binding protein (fbp) are known to play important roles in biofilm growth of some oral bacterial species. The objective was to study the effect of benzyl isothiocyanate (BITC), an antimicrobial agent from Miswak plant, on the expression of nox and fbp genes in some oral streptococci. The biofilms were treated with BITC and mRNA expression of nox and fbp genes was measured by comparative ΔΔCt method. The highest amount of biofilm mass was produced by A. defectiva, followed by S. gordonii, S. mutans, G. elegans and G. adiacens. Upon treatment with BITC, S. gordonii biofilms showed highest folds change in mRNA expression for both fbp and nox genes followed by S. mutans, A. defectiva, and G. adiacens. G. elegans mRNA levels for nox were extremely low. In conclusion, BITC treatment of the biofilms caused an upregulation of biofilm-associated genes fbp and nox genes in most of the tested species suggesting the significance of these genes in biofilm lifestyle of these oral bacteria and needs further investigation to understand if it contributes to antimicrobial resistance.

Assessment of Methodological Pipelines for the Determination of Isothiocyanates Derived from Natural Sources

Isothiocyanates are biologically active secondary metabolites liberated via enzymatic hydrolysis of their sulfur enriched precursors, glucosinolates, upon tissue plant disruption. The importance of this class of compounds lies in their capacity to induce anti-cancer, anti-microbial, anti-inflammatory, neuroprotective, and other bioactive properties. As such, their isolation from natural sources is of utmost importance. In this review article, an extensive examination of the various parameters (hydrolysis, extraction, and quantification) affecting the isolation of isothiocyanates from naturally-derived sources is presented. Overall, the effective isolation/extraction and quantification of isothiocyanate is strongly associated with their chemical and physicochemical properties, such as polarity-solubility as well as thermal and acidic stability. Furthermore, the successful activation of myrosinase appears to be a major factor affecting the conversion of glucosinolates into active isothiocyanates.

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.

Biocompatibility and Antibacterial Action of Salvadora persica Extract as Intracanal Medication (In Vitro and Ex Vivo Experiment)

This study aimed to test the biocompatibility and antibacterial properties of Salvadora persica (S. persica) extract, a natural product, as an intracanal medication in comparison with calcium hydroxide (Metapaste, META BIOMED, Cheongju, Korea). The pH values of both materials were tested. The biocompatibility of S. persica extract and Metapaste was determined using light microscopy and MTT assays. The antibacterial action was tested using the zone of bacterial inhibition on four common bacterial species. In addition, intracanal medication was administered using 68 extracted single-rooted teeth contaminated with Enterococcus faecalis (E. faecalis), and the percentage reduction in colony count (% RCC) at 1, 3, and 7 days was measured. The extension of activity for both materials was assessed using histological sections and scanning electron microscopy. S. persica was found to be acidic in nature. Both materials showed significantly lower cell viability than the positive control cells on days 1 and 3 but not on day 7. S. persica showed better antibacterial effects against E. faecalis and S. mutans. S. persica extract showed 97.6%, 98.9%, and 99.3% RCC values at 1, 3, and 7 days, respectively, which are comparable to those of Metapaste. S. persica herbal extract is a promising material that can be utilized as an intracanal medication, but its use requires further research.

GC/MS Profiling and Ex Vivo Antibacterial Activity of Salvadora persica (Siwak) against Enterococcus faecalis as Intracanal Medicament

INTRODUCTION

Salvadora persica L. (S. persica, Siwak) has been used for many centuries as oral hygiene tools, particularly in Saudi Arabia. This study aimed to assess the effectiveness of S. persica petroleum ether extract (SPE) as an intracanal bactericidal for endodontic treatment against Enterococcus faecalis. Calcium hydroxide Ca(OH)₂ gold standard intracanal medicament was used for comparison.

METHODS

The gas chromatography mass spectrometry (GC/MS) analysis was carried out to identify the components of SPE. First, the consistency of SPE was accomplished according to ANSI/ADA specification no 57. Forty-five single-rooted mandibular premolars were infected with that of E. faecalis suspension. Colony-forming units (CFU) were counted before the medicaments' application (CFU-1) and after seven days of their applications (CFU-2). Group I: SPE, Group II: positive control Ca(OH)₂, and Group III: saline solution negative control. The microdilution method was applied to determine minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of SPE.

RESULTS

Thirty-two compounds were identified (89.09%), with main components of benzyl isothiocyanate (BITC) (33.32%) and steroids (34%). CFU before and after using SPE and Ca(OH)₂ recorded a statistically significant reduction in bacterial count (P=0.006) and (P=0.01), respectively. There was an insignificant difference between CFU after using SPE and Ca(OH)₂ (P=0.210). On the contrary, comparing both medicaments with the negative control saline group resulted in significant differences, (P=0.001) and (P=0.007), respectively. Moreover, the equality of minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of SPE is recorded.

CONCLUSION

This finding could be referred to the high content of bactericidal BITC in synergism with other antimicrobial components, representing 70.71% of SPE. Thus, SPE is a good candidate as an intracanal medicament, which warrants further investigation.

HPLC/MSn Profiling and Healing Activity of a Muco-Adhesive Formula of Salvadora persica against Acetic Acid-Induced Oral Ulcer in Rats

Salvadora persica L. (S. persica, Siwak) is an ethnic plant that is widely used for improving oral hygiene. This study aimed to provide a phytochemical profiling of S. persica ethyl acetate fraction (SPEAF) and to evaluate the healing activity of a muco-adhesive formula of the fraction against acetic acid-induced oral ulcers in rats. HPLC-ESI-QTOF-MS-MS analysis of SPEAF resulted in the tentative identification of 56 metabolites containing fatty acids (23%), urea derivatives (10.5%) and sulphur compounds (10%), in addition to several amides, polyphenols and organic acids (6.5%, 5% and 2%, respectively). For the first time, 19 compounds were identified from S. persica. In vitro and in vivo experiments indicated that the extract is non-toxic. SPEAF exhibited superior healing activities compared to both the negative and positive control groups on days 7 and 14 of tongue ulcer induction. This was confirmed by histopathological examinations of haematoxylin and eosin-stained (H&E) and Masson's trichrome-stained tongue sections. Moreover, SPEAF showed potent anti-inflammatory activities, as evidenced by the inhibited expression of interleukin-6 (IL-6) and tumour necrosis alpha (TNF-α). Moreover, SPEAF exhibited potent antioxidant activity, as it prevented malondialdehyde (MDA) accumulation, reduced glutathione (GSH) depletion and superoxide dismutase (SOD) exhaustion. SPEAF significantly enhanced hydroxyproline tongue content and upregulated collagen type I alpha 1 (Col1A1) mRNA expression. SPEAF also improved angiogenesis, as shown by the increased mRNA expression of the angiopoietin-1 (Ang-1). In conclusion, S. persica has a wide range of secondary metabolites and ameliorates acetic acid-induced tongue ulcers in rats. This can be attributed, at least partly, to its anti-inflammatory, antioxidant, procollagen and angiogenic activities. These findings provide support and validity for the use of S. persica as a traditional and conventional treatment for oral disorders.

Efficacy of herbal versus chlorhexidine-based mouthwashes towards oral hygiene maintenance in patients undergoing fixed orthodontic therapy: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The review aims to fill the gap in literature by comparing the efficacy of herbal and chlorhexidine-based mouthwashes towards oral hygiene maintenance (OHM) in patients undergoing fixed orthodontic treatment (OT).

METHODS

Indexed databases were searched electronically to include randomized controlled trials (RCTs) for data gathering. The protocol was registered in PROSPERO (CRD42020182497). Risk of bias assessment, quality of evidence investigation, and meta-analysis were performed to evaluate reported OHM related parameters at time points before and after the use of chlorhexidine (control group) and herbal mouthwashes (intervention group). With 95% confidence intervals, mean difference (MD) or standardized mean difference (SMD) were used to estimate effect size.

RESULTS

Out of eight RCTs, results from one RCT favored chlorhexidine and the results from a second RCT favored herbal mouthwashes. Results from three RCTs showed comparable effects for the respective investigated OHM related parameters. Chlorhexidine demonstrated higher antimicrobial efficacy against Streptococcus mutans (S.mutans) in two studies, and one RCT found comparable antimicrobial efficacies. Risk of bias was low in 4 studies, and moderate and high in two studies each. Quality of evidence was very low to moderate for the respective investigated parameters. Sub-group analysis for parameters colony forming units (CFU) {SMD (0.40) [95% CI (-0.22, 1.03)], gingival index (GI) {MD (0.06) [95% CI (-0.08, 0.20)]}, plaque index (PI) {SMD 0.22 [95% CI (-0.23, 0.67)]} before the use of chlorhexidine and herbal mouthwashes remained inconclusive.

CONCLUSION

The comparison between efficacy of herbal and chlorhexidine towards OHM in patients undergoing fixed OT remains debatable.

Antibacterial Activities of Methanol and Aqueous Extracts of Salvadora persica against Streptococcus mutans Biofilms: An In Vitro Study

The use of herbal products in oral hygiene care has a long history, and their use is popular today. A tree stick, named Salvadora persica (S. persica), is commonly used to remove dental plaque and clean teeth in many countries. In addition, extracts of S. persica can be used as a mouthwash, as they demonstrate antimicrobial properties. This study aimed to investigate the antibacterial effect of S. persica methanol and aqueous extracts against Streptococcus mutans (S. mutans) biofilm. A S. mutans biofilm formation assay was conducted using different concentrations of S. persica methanol or water extracts in tryptic soy broth (TSB) supplemented with 1% sucrose. The biofilm was stained with crystal violet dye, and the absorbance was assessed to examine biofilm formation. One-way analysis of variance (ANOVA) and Tukey tests were used to analyze the results. The S. persica methanol extract displayed a significant inhibition (p ≤ 0.001) against the S. mutans biofilm. The 10 mg/mL concentration of the S. persica methanol extract was determined as the minimum biofilm inhibitory concentration (MBIC). The used methanol concentration, mixed with TSB supplemented with 1% sucrose and without the S. persica extract, did not inhibit the S. mutans biofilm. The S. persica aqueous extract did not demonstrate any biofilm inhibition at any concentration (p ≥ 0.05). The findings of this study suggest the potential of using S. persica methanol extract as a mouthwash or adjunctive to oral hygiene tools.

Effect of bioactive compounds released from Brassicaceae defatted seed meals on bacterial load in pig manure

Animal manure application to soils is considered to be one of the main cause of antibiotic and bacterial pathogen spread in the environment. Pig livestock, which is the source of one of the most used fertilizer for cultivated land, is also a hotspot for antibiotics and antibiotic-resistant bacteria. Besides harsh chemical and physical sanitization treatments for the abatement of antibiotics and bacterial load in livestock waste, more sustainable and environmentally friendly strategies need to be considered. In this context, the use of natural substances which are proved useful for pest and disease control is currently under exploration for their role in the reduction of bacterial pathogen population. Among these, plants and derived products from the Brassicaceae family, characterized by the presence of a defensive glucosinolate-myrosinase enzymatic system, have been successfully exploited for years in agriculture using the so-called biofumigation technique against crop diseases. Although the application of biofumigation to suppress a range of soil borne pests has been well documented, no studies have been examined to reduce bacterial population in animal waste. In the present study, the release and the antibacterial activity of bioactive compounds deriving from different Brassicaceae defatted seed meals against pathogens and bacterial population in pig manure is addressed. Rapistrum rugosum and Brassica nigra defatted seed meals were found to be the most active products against tested pathogens and able to significantly reduce the bacterial load in the manure.

The Essential Oil-Bearing Plants in the United Arab Emirates (UAE): An Overview

Essential Oils (EOs) are expensive hydrocarbons produced exclusively by specific species in the plant kingdom. Their applications have deep roots in traditional herbal medicine, which lacks scientific evidence. Nowadays, more than ever, there is a growing global interest in research-based discoveries that maintain and promote health conditions. Consequently, EOs became a much attractive topic for both research and industry, with revenues reaching billions of dollars annually. In this work, we provide key guidance to all essential oil-bearing plants growing in the United Arab Emirates (UAE). The comprehensive data were collected following an extensive, up-to-date literature review. The results identified 137 plant species, including indigenous and naturalized ones, in the UAE, citing over 180 published research articles. The general overview included plant botanical names, synonyms, common names (Arabic and English), families and taxonomic authority. The study acts as a baseline and accelerator for research, industry and discoveries in multiple disciplines relying on essential oil-bearing plants.

Characterization of Conjugates between α-Lactalbumin and Benzyl Isothiocyanate-Effects on Molecular Structure and Proteolytic Stability

In complex foods, bioactive secondary plant metabolites (SPM) can bind to food proteins. Especially when being covalently bound, such modifications can alter the structure and, thus, the functional and biological properties of the proteins. Additionally, the bioactivity of the SPM can be affected as well. Consequently, knowledge of the influence of chemical modifications on these properties is particularly important for food processing, food safety, and nutritional physiology. As a model, the molecular structure of conjugates between the bioactive metabolite benzyl isothiocyanate (BITC, a hydrolysis product of the glucosinolate glucotropaeolin) and the whey protein α-lactalbumin (α-LA) was investigated using circular dichroism spectroscopy, anilino-1-naphthalenesulfonic acid fluorescence, and dynamic light scattering. Free amino groups were determined before and after the BITC conjugation. Finally, mass spectrometric analysis of the BITC-α-LA protein hydrolysates was performed. As a result of the chemical modifications, a change in the secondary structure of α-LA and an increase in surface hydrophobicity and hydrodynamic radii were documented. BITC modification at the ε-amino group of certain lysine side chains inhibited tryptic hydrolysis. Furthermore, two BITC-modified amino acids were identified, located at two lysine side chains (K32 and K113) in the amino acid sequence of α-LA.

Effect of Salvadora persica Extract (Miswak) on the Dentinal Tubules of Sound Root Dentin: Scanning Electron Microscope Study

BACKGROUND/PURPOSE

Root dentin is vulnerable to a higher risk of demineralization than coronal enamel. This study aimed to evaluate the effect of miswak extract on the dentinal tubules of sound root dentin.

MATERIALS AND METHODS

Twenty bovine root dentin blocks, approximately 2 mm × 3 mm × 3 mm (width × length × depth) in dimensions, were prepared from freshly extracted sound bovine incisors. The sample was divided into two groups: control and miswak group. The control group had sound root dentin block and the miswak test group was treated with miswak extract 20% for 24 h. The two groups of all specimens were subjected to ultrasonication for 10 min. Scanning electron microscope images were analyzed for surface typography.

RESULTS

Fifty percent of the control group had surface particles (SPs), while the other 50% had no SPs. For the dentinal tubules, all (100%) the control group had a mixture of opened and partially opened dentinal tubules. On the other hand, for the miswak group, all (100%) the sample had SPs and blocked dentinal tubules.

CONCLUSION

Miswak showed total blocking of the dentinal tubules compared to the control group. This might indicate that miswak has a role in reducing dentinal hypersensitivity of exposed root dentin.

Towards Advances in Medicinal Plant Antimicrobial Activity: A Review Study on Challenges and Future Perspectives

The increasing incidence of drug- resistant pathogens raises an urgent need to identify and isolate new bioactive compounds from medicinal plants using standardized modern analytical procedures. Medicinal plant-derived compounds could provide novel straightforward approaches against pathogenic bacteria. This review explores the antimicrobial activity of plant-derived components, their possible mechanisms of action, as well as their chemical potential. The focus is put on the current challenges and future perspectives surrounding medicinal plants antimicrobial activity. There are some inherent challenges regarding medicinal plant extracts and their antimicrobial efficacy. Appropriate and optimized extraction methodology plant species dependent leads to upgraded and selective extracted compounds. Antimicrobial susceptibility tests for the determination of the antimicrobial activity of plant extracts may show variations in obtained results. Moreover, there are several difficulties and problems that need to be overcome for the development of new antimicrobials from plant extracts, while efforts have been made to enhance the antimicrobial activity of chemical compounds. Research on the mechanisms of action, interplay with other substances, and the pharmacokinetic and/or pharmacodynamic profile of the medicinal plant extracts should be given high priority to characterize them as potential antimicrobial agents.

Benzyl isothiocyanate-modified α-lactalbumin - Two-dimensional high-performance thin-layer chromatography for analyzing modified peptides

In complex food matrices, non-directed reactions between food proteins and secondary plant metabolites (SPM) are conceivable. In this study, the interaction between the bioactive metabolite from garden cress (Lepidium sativum) and selected Brassicaceae - benzyl isothiocyanate (BITC) - and the dairy protein α-lactalbumin (α-LA) was investigated. It was focused on monitoring the proteolytic degradation behaviour of unmodified and BITC-modified α-LA with two-dimensional high-performance thin-layer chromatography (2D-HPTLC). The two-dimensional approach of HPTLC offers high resolution in the separation of complex peptide mixtures and might enable differentiation of protein modifications. Based on the specific peptide patterns of native and modified peptides, conclusions can be drawn about differences in protein/peptide polarity, location of a modification, and digestibility. The aim was to characterize tryptically hydrolyzed unmodified and BITC-modified peptides using the 2D method and to investigate the influence of BITC modification of α-LA on polarity and digestibility. To determine the repeatability of peptide separation by 2D-HPTLC, the unmodified and BITC-modified protein hydrolyzates were separated six times. The absolute standard deviations between the retardation factors of the individual peptide spots varied between 0.52 and 4.79 mm for the x-coordinates and between 0.41 and 6.47 mm for the y-coordinates for all three samples. Here, the mean relative standard deviations ranged from 5.80 to 10.4% for the x-coordinates and from 5.91 to 18.3% for the y-coordinates. The results of the tryptic hydrolysis indicated that, depending on the concentration of BITC used, the modification sterically hinders the cleavage sites for the enzyme, resulting in a reduced digestibility. Covalent binding of the hydrophobic BITC altered the digestibility and polarity of the protein, leading to a difference in peptide patterns between the unmodified and modified α-LA. It was concluded that the reaction was undirected, resulting in a mixture of unmodified and modified peptides, and that elongated modified peptides were formed by BITC blocking of trypsin cleavage sites.

Review on the Antibacterial Mechanism of Plant-Derived Compounds against Multidrug-Resistant Bacteria (MDR)

Microbial resistance has progressed rapidly and is becoming the leading cause of death globally. The spread of antibiotic-resistant microorganisms has been a significant threat to the successful therapy against microbial infections. Scientists have become more concerned about the possibility of a return to the pre-antibiotic era. Thus, searching for alternatives to fight microorganisms has become a necessity. Some bacteria are naturally resistant to antibiotics, while others acquire resistance mainly by the misuse of antibiotics and the emergence of new resistant variants through mutation. Since ancient times, plants represent the leading source of drugs and alternative medicine for fighting against diseases. Plants are rich sources of valuable secondary metabolites, such as alkaloids, quinones, tannins, terpenoids, flavonoids, and polyphenols. Many studies focus on plant secondary metabolites as a potential source for antibiotic discovery. They have the required structural properties and can act by different mechanisms. This review analyses the antibiotic resistance strategies produced by multidrug-resistant bacteria and explores the phytochemicals from different classes with documented antimicrobial action against resistant bacteria, either alone or in combination with traditional antibiotics.

Salvadora persica L.: Toothbrush tree with health benefits and industrial applications - An updated evidence-based review

Salvadora persica L. is also known as Arak (in Arabic) and Peelu (in Urdu). Its frequent use as a toothbrush (miswak) is highly recommended by Prophet Muhammad. With a long history in folk medicine for centuries, S. persica was used in oral hygiene, food, cosmetics, fuel, and even as a medicine. Previous phytochemical investigation of its different parts afforded different classes of secondary metabolites such as flavonoids, glycosides, sterols, terpenes, carbohydrates and alkaloids. Organic sulfur-containing compounds and elemental sulfur are also present. In addition, there is a huge research on its biological potentials and industrial applications. Many pharmacological activities were reported experimentally, including antimicrobial, antioxidant, analgesic, anthelmintic, anti-inflammatory, antiulcer, sedative, anticonvulsant, anti-osteoporosis, antidiabetic, hypo-lipidemic, in addition to wound-healing, antidepressant and antitumor activities. Recently, a possible activity against COVID-19 protease was documented by molecular docking. This review tries to provide a recent detailed documentation of folk and modern uses of S. persica, focusing on the possible relations between its chemical constituents, pharmacological properties, and industrial applications. Moreover, a brief about recent analytical and validation methods for the major antimicrobial component is reported.

Benzyl isothiocyanates modulate inflammation, oxidative stress, and apoptosis via Nrf2/HO-1 and NF-κB signaling pathways on indomethacin-induced gastric injury in rats

The present study investigated the gastroprotective activity of benzyl isothiocyanates (BITC) on indomethacin (IND)-induced gastric injury in a rat model and explicated the possible involved biochemical, cellular, and molecular mechanisms. The rat model with gastric ulcers was established by a single oral dose of IND (30 mg per kg b.wt). BITC (0.75 and 1.5 mg kg^-1) and esomeprazole (20 mg per kg b.wt) were orally administered for 3 weeks to rats before the induction of gastric injury. Compared with the IND group, BITC could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. BITC significantly preserved the antioxidants (glutathione GSH, superoxide dismutase SOD), nitric oxide (NO), and prostaglandin E2 (PGE2) contents, while decreasing the gastric mucosal malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), and myeloperoxidase (MPO) contents. Moreover, BITC remarkably upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemoxygenase-1 (HO-1), and NAD(P)H : quinone oxidoreductase (NQO1). In addition, BITC activates the expression of heat shock protein 70 (HSP-70) and downregulated the expression of nuclear factor-κB (NF-κB) and caspase-3 to promote gastric mucosal cell survival. To the best of our knowledge, this study is the first published report to implicate the suppression of inflammation, oxidative stress, and Nrf2 signaling pathway as a potential mechanism for the gastroprotective activity of BITC.

Salvadora persica: Nature's Gift for Periodontal Health

Salvadora persica (SP) extract, displays very valuable biotherapeutic capacities such as antimicrobial, antioxidant, antiparasitic and anti-inflammatory effects. Numerous investigations have studied the pharmacologic actions of SP in oral disease therapies but its promising outcomes in periodontal health and treatment are not yet entirely described. The current study has been planned to analyze the reported effects of SP as a support to periodontal therapy to indorse regeneration and healing. In consort with clinical trials, in vitro investigations show the advantageous outcomes of SP adjunctive to periodontal treatment. Yet, comprehensive supplementary preclinical and clinical investigations at molecular and cellular levels are indispensable to reveal the exact therapeutic mechanisms of SP and its elements for periodontal health and therapy.

Phytochemical Analysis, Antioxidant and Antimicrobial Screening of Seriphidium Oliverianum Plant Extracts

The aim of this study was to investigate the phytochemicals using reverse-phase high pressure liquid chromatography (RP-HPLC), antioxidant, antifungal and antibacterial activities of Seriphidium oliverianum stem extracts. The extraction was carried out by conventional shaking process (CSP) and ultrasonic assisted process (UAP). The highest total phenolic contents (97.85 ± 0.735 mg gallic acid equivalent (GAE)/g sample) and flavonoid contents (188.15 ± 0.53 mg catechin equivalent (CE)/g sample) were found in methanol extract obtained by CSP. Antioxidant activity was investigated using DPPH° scavenging assay and reducing power assay. Methanol extract using UAP showed the highest DPPH° scavenging activity (79.95% ± 1.80%) followed by methanol and butanol extracts obtained through CSP. Moreover, methanol extracts using CSP showed highest reducing activity (1.032 ± 0.0205 absorbance). In-vitro antimicrobial activity was studied using most common infection causing fungal and bacterial strains. Anti-fungal activity of methanol extract using CSP showed the highest zone of inhibition (10.5 mm) against F. avenaceum fungal strain, while aqueous extracts obtained through showed the highest antibacterial activity (22 ± 1.32 mm zone of inhibition) against S. aureus. The results showed that the methanol stem extract of S. oliverianum is a valued candidate for further screening and could be processed for in-vivo infection induced animal trials.

Immunological Analysis of Isothiocyanate-Modified α-Lactalbumin Using High-Performance Thin Layer Chromatography

Undirected modifications between food proteins and secondary plant metabolites can occur during food processing. The results of covalent interactions can alter the functional and biological properties of the proteins. The present work studied the extent of which covalent conjugation of the bioactive metabolite benzyl isothiocyanate (BITC; a glucosinolate breakdown product) to the whey protein α-lactalbumin affects the protein’s allergenicity. Additional to the immunological analysis of native untreated and BITC-modified α-lactalbumin, the analysis of antigenic properties of proteolytically digested protein derivatives was also performed by high performance thin layer chromatography and immunostaining. As a result of the chemical modifications, structural changes in the protein molecule affected the allergenic properties. In this process, epitopes are destroyed or inactivated, but at the same time, buried epitopes can be exposed or newly formed, so that the net effect was an increase in allergenicity, in this case. Results from the tryptic hydrolysis suggest that BITC conjugation sterically hindered the cleavage sites for the enzyme, resulting in reduced digestibility and allergenicity. Residual antigenicity can be still present as short peptide fragments that provide epitopes. The desire to make food safer for allergy sufferers and to protect sensitized individuals from an allergenic reaction makes it clear that the detection of food antigens is mandatory; especially by considering protein interactions.

Assessment of benzyl isothiocyanate as an adjunct to conventional periodontal therapy

Background:

Conventional nonsurgical periodontal therapy eliminates the pathogenic microbes, yet residual deposits promote the recurrence of the disease. As antimicrobials may pose undesirable effects, alternate therapies are probed.

Aim:

The aim of the study is to evaluate the efficacy of locally delivered benzyl isothiocyanate (BITC) as an adjunct to scaling and root planing to treat patients with chronic periodontitis.

Materials and Methods:

The study included 30 patients diagnosed with chronic periodontitis. Test (scaling and root planing along with BITC intervention) and control (scaling and root planing) sites were randomly assigned to each patient. These sites were in the contralateral quadrants, having a probing depth of 4–6 mm. The plaque index (PI), gingival index (GI), pocket probing depth (PPD), clinical attachment level (CAL), and microbial load (colony forming unit [CFU]) were assessed at baseline, 1-week, and 6-week time interval. Data were analyzed by ANOVA/Friedman test, Mann–Whitney U-test, pairwise paired t-test, and Wilcoxon test, with P ≤ 0.05 set as statistically significant.

Results:

The scores of PI, GI, PPD, and CAL from baseline to 6-week follow-up within both the test and control sites were noted to be statistically significant (P < 0.0001). The CFU showed a significant reduction (P = 0.0229) within the test site at varying time intervals. The change in the mean PI score from baseline to 6-week time interval between the test and control site was noted to be statistically significant (P = 0.0039).

Conclusion:

The local application of BITC chips effectively reduced the PI, GI, PPD, and CFU, subsequently with the gain in CAL, and improved the tissue integrity and thereby oral hygiene.

Effects of virgin olive oil and grape seed oil on physicochemical and antimicrobial properties of pectin-gelatin blend emulsified films

The active emulsified blend films based on gelatin-pectin (5% w/w) containing virgin olive oil (VOO) (0.1-0.3 g/g biopolymer) and grape seed oil (GSO) (0.1-0.3 g/g biopolymer) were prepared by casting method. GSO showed slightly more decreasing effect than VOO on ultimate tensile strength (UTS) and strain at break (SAB) of blend films however; VOO had more reducing effect than GSO on the water vapor permeability (WVP). The scanning electron microscopy (SEM) images showed that incorporating 0.3 g GSO and VOO oils had not considerable effect on the morphology of the emulsified films. Atomic force microscopy (AFM) topography images indicated that adding of oils considerably could increase roughness of emulsified film. Fourier transforms infrared (FTIR) revealed that no new chemical bond formed by adding oils into biopolymer matrix. The minimum inhibitory concentration (MIC) of VOO, GSO and Savory essential oil (SEO) against four important spoilage bacteria showed that GSO had higher antibacterial effect than VOO however; both showed very lower antimicrobial effect than SEO. All active films showed lower inhibitory zone for S. aureus than S. typhimurium and P. fluorescence. The chicken breast fillets wrapped in the films containing VOO-GSO-SEO (0.15-0.15-0.02 g/g polymer) showed considerably lower total viable count (TVC), Pseudomonas spp., Enterobacteriaceae, E. coli 157:H7 and S. typhimurium count than the control one during 12 days storage. Also, it caused significant decrease in peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N) of fillet samples.

A clinical investigation into the efficacy of miswak chewing sticks as an oral hygiene aid: A crossover randomized trial

OBJECTIVES

This study evaluates the effect of using miswak chewing sticks on dental plaque, selected oral microbiota and gingival inflammation among patients with gingivitis.

METHODS

The study was a single-centre, single-examiner blind, randomized, crossover study. Twenty healthy participants were randomly assigned into two equal groups (n = 10). Group 1 were instructed to use both toothbrush and miswak (TB+M) for the first 2 weeks from baseline (T1) and only toothbrush for the next 2 weeks (T2); and Group 2, only TB during T1 and TB+M during T2. Gingival index (GI), plaque index (PI) and bleeding on probing (BOP) were evaluated at baseline (T0), T1 and T2 visits. Supra-gingival plaque samples were taken at T0, T1 and T2. Quantification of Streptococcus mutans and Aggregatibacter actinomycetemcomitans from the supra-gingival plaque samples were performed by real-time polymerase chain reaction (qPCR).

RESULTS

The scores of GI, PI and BOP had significantly improved for both groups between T0 and T1. A significantly greater reduction in the percentage of sites with BOP was observed for TB+M group compared with TB group (TB+M group: from 32.2 to 14.93; TB group: from 34.00 to 26.0; p = .014). At T2, TB+M group had significant improvements (p < .05) in the PI, GI and BOP scores compared with TB group. There was no significant difference in the microbial counts of S. mutans and A. actinomycetemcomitans between the two groups at the end of the study period.

CONCLUSIONS

Oral hygiene and gingival health may be improved by complementing miswak chewing sticks with toothbrushing.

Enhancing the fungicidal activity of amphotericin B via vacuole disruption by benzyl isothiocyanate, a cruciferous plant constituent

Amphotericin B (AmB), a typical polyene macrolide antifungal agent, is widely used to treat systemic mycoses. In the present study, we show that the fungicidal activity of AmB was enhanced by benzyl isothiocyanate (BITC), a cruciferous plant-derived compound, in the budding yeast, Saccharomyces cerevisiae. In addition to forming a molecular complex with ergosterol present in fungal cell membranes to form K⁺ -permeable ion channels, AmB has been recognized to mediate vacuolar membrane disruption resulting in lethal effects. BITC showed no effect on AmB-induced plasma membrane permeability; however, it amplified AmB-induced vacuolar membrane disruption in S. cerevisiae. Furthermore, the BITC-enhanced fungicidal effects of AmB significantly decreased cell viability due to the disruption of vacuoles in the pathogenic fungus Candida albicans. The application of the combinatorial antifungal effect of AmB and BITC may aid in dose reduction of AmB in clinical antifungal therapy and consequently decrease side effects in patients. These results also have significant implications for the development of vacuole-targeting chemotherapy against fungal infections.

Unraveling the metabolome composition and its implication for Salvadora persica L. use as dental brush via a multiplex approach of NMR and LC-MS metabolomics

Salvadora persica L. (toothbrush tree, Miswak) is well recognized in most Middle Eastern and African countries for its potential role in dental care, albeit the underlying mechanism for its effectiveness is still not fully understood. A comparative MS and NMR metabolomics approach was employed to investigate the major primary and secondary metabolites composition of S. persica in context of its organ type viz., root or stem to rationalize for its use as a tooth brush. NMR metabolomics revealed its enrichment in nitrogenous compounds including proline-betaines i.e., 4-hydroxy-stachydrine and stachydrine reported for the first time in S. persica. LC/MS metabolomics identified flavonoids (8), benzylurea derivatives (5), butanediamides (3), phenolic acids (8) and 5 sulfur compounds, with 21 constituents reported for the first time in S. persica. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) of either NMR or LC/MS dataset clearly separated stem from root specimens based on nitrogenous compounds abundance in roots and is justifying for its preference as toothbrush versus stems. The presence of betaines at high levels in S. persica (9-12 μg/mg dry weight) offers novel insights into its functioning as an osmoprotectant that maintains the hydration of oral mucosa. Additionally, the previously described anti-inflammatory activity of stachydrine along with the antimicrobial effects of sulfonated flavonoids, benzylisothiocynate and ellagic acid derivatives are likely contributors to S. persica oral hygiene health benefits. Among root samples, variation in sugars and organic acids levels were the main discriminatory criterion. This study provides the first standardization of S. persica extract using qNMR for further inclusion in nutraceuticals.

Inhibitory effect of Salvadora persica extract (Miswak) on collagen degradation in demineralized dentin: In vitro study

Background/purpose

Root dentin is vulnerable to acid attack, suggesting a higher risk of demineralization than coronal enamel. This study aimed to evaluate the inhibitory effect of Miswak extract on collagen degradation of demineralized dentin lesion.

Materials and methods

Demineralized bovine root dentin specimens were treated for 1 h by 20% Miswak extract and 0.12% Chlorehexidine (CHX) as a positive control group, and then subjected to collagenolytic attack (clostridium histolyticum 0.5 CDU/mL, 16 h). These cyclic treatments were repeated for 3 days. After the cyclic treatment, the images of the specimens were captured with a light microscope and the lesion depth of degraded collagen layer of all specimens was measured. The mean lesion depth was calculated and compared between the groups using descriptive and One-way ANOVA followed by Post hoc Tukey's tests. Significant level was set at p < 0.05.

Results

The mean lesion depth of CHX (28.6 ± 3.37 μm) had the least value, followed by Miswak (37.5 ± 4.01 μm) then the control (78.4 ± 18.43 μm) group. There was a significant difference in the mean lesion depth among the three groups (p = 0.000).

Conclusion

Miswak aqueous extract from S. persica was found to preserve the dentin collagen matrix from collagenase enzyme. This could be due to the organic compounds like flavonoids, saponins, alkaloids, tannins, and others which have been reported in literature. Present finding suggests that Miswak might play a positive effect in dentin caries prevention.

Antimicrobial effects of mustard oil-containing plants against oral pathogens: an in vitro study

Background

The present study examines the antimicrobial activity of nasturtium herb (Tropaeoli maji herba) and horseradish root (Armoraciae rusticanae radix) against clinically important oral bacterial pathogens involved in periodontitis, gingivitis, pulpitis, implantitis and other infectious diseases.

Methods

A total of 15 oral pathogens, including members of the genera Campylobacter, Fusobacterium, Prevotella, Parvimonas, Porphyromonas, Tanerella, Veillonella, and HACEK organisms, were exposed to [1] a combination of herbal nasturtium and horseradish using a standardized gas test and [2] a mixture of synthetic Isothiocyantes (ITCs) using an agardilution test. Headspace gas chromatography mass spectrometry was employed to quantify the amount of allyl-, benzyl-, and 2- phenyl- ethyl-ITC.

Results

With exception of Veillonella parvula, all tested species were highly susceptible to herbal nasturtium and horseradish in the gas test with minimal inhibitory concentrations (MICs) between 50/20 mg and 200/80 mg and to synthetic ITCs in the agardilution with MICs between 0.0025 and 0.08 mg ITC/mL, respectively. Minimal bactericidal concentrations extended from 0.005 mg ITC/mL to 0.34 mg ITC/mL.

Conclusions

ITCs may be considered an interesting alternative to antibiotics for prevention and treatment of oropharyngeal infections, periodontitis and related diseases. Furthermore, the suitability of ITCs for endocarditis prophylaxis in dental procedures might be worth further investigation.

Evaluation of the Antimicrobial Efficacy of Herbal Extracts Added to Root Canal Sealers of Different Bases: An In Vitro Study

Aim

This study aimed to evaluate and compare the antimicrobial efficacy of root canal sealers of different bases when mixed with herbal extracts.

Materials and methods

An evaluation of three sealers (Endomethasone, AH plus, Apexit plus) mixed with three herbal extracts [Emblica officinalis (Amla), Myristica fragrans (Nutmeg) and Salvadora persica (Miswak)] was done against nine strains of bacteria at various time intervals using the agar diffusion test. Moreover, measurement of the mean zones of inhibition was done.

Results

The largest zones of bacterial growth inhibition were observed with Endomethasone mixed with Myristica fragrans (Nutmeg) followed in the descending order by AH plus mixed with Salvadora persica (Miswak) and Apexit plus mixed with Salvadora persica (Miswak) respectively. The differences between zones of inhibition among different groups were found to be statistically significant.

Conclusion

Zinc-oxide-eugenol-based sealer (Endomethasone) mixed with herbal extracts produced the largest inhibitory zones followed in the descending order by resin-based sealer (AH plus) and calcium-hydroxide-based sealer (Apexit plus), respectively.

Clinical significance

Herbal plants such as [Emblica officinalis (Amla), Myristica fragrans (Nutmeg) and Salvadora persica (Miswak)] are rich sources of bioactive compounds that possess antimicrobial properties. Mixing their extracts with endodontic sealers can produce additive antimicrobial effect against microbes found in inflamed pulp.

How to cite this article

Devi MT, Saha S, Tripathi AM, et al. Evaluation of the Antimicrobial Efficacy of Herbal Extracts Added to Root Canal Sealers of Different Bases: An In Vitro Study. Int J Clin Pediatr Dent 2019;12(5):398–404.

Modelling the combined effect of chlorine, benzyl isothiocyanate, exposure time and cut size on the reduction of Salmonella in fresh-cut lettuce during washing process

This work aimed to study the effect of the combination of Sodium hypochlorite, the most used disinfectant by the vegetable industry, with a natural antimicrobial, benzyl-isothiocyanate (BITC), considering cutting surface and contact time, on the reduction of Salmonella in fresh-cut produce in washing operations under typical industrial conditions. Overall, the combinations of disinfectant and process parameters resulted in a mean reduction of Salmonella of 2.5 log CFU/g. According to statistical analysis, free chlorine and BITC concentrations, contact time and cut size exerted a significant effect on the Salmonella reduction (p ≤ 0.05). The optimum combination of process parameter values yielding the highest Salmonella reduction was a lettuce cut size of 15 cm2 washed for 110 s in industrial water containing 160 mg/L free chlorine and 40 mg/L BITC. A predictive model was also derived, which, as illustrated, could be applied to optimize industrial disinfection and develop probabilistic Exposure Assessments considering the effect of washing process parameters on the levels of Salmonella contamination in leafy green products. The present study demonstrated the efficacy of chlorine to reduce Salmonella populations in fresh-cut lettuce while highlighting the importance of controlling the washing process parameters, such as, contact time, cut size and concentration of the disinfectant to increase disinfectant efficacy and improve food safety.