Antibacterial activity of naringin derivatives against pathogenic strains

Antimicrobial efficiency and cytocompatibility of resveratrol and naringin as chemical decontaminants on SLA surface

Bacterial biofilms are the major etiology agent of peri-implant disease. Chemical decontamination is a promising treatment strategy against bacterial biofilms; however, its applications are limited by its low efficiency and poor biocompatibility. In contrast to three conventional cleaners (sterile saline, hydrogen peroxide, and chlorhexidine), this study used resveratrol and naringin solutions to remove mature Staphylococcus aureus and Porphyromonas gingivalis biofilm on sandblasted (with large grit and acid-etched (SLA) titanium surface. To determine changes in surface characteristics, the surface wettability and roughness were measured, and micromorphology was observed by scanning electron microscopy. With crystal violet (CV) and live/dead bacterial staining, residual plaque quantity and composition were measured. The biocompatibility was tested using pH and cytotoxicity, as well as by osteoblasts (MC3T3-E1) adhesion, proliferation, and differentiation, and fibroblasts (L-929) proliferation were also analyzed. It was found that resveratrol and naringin solutions were more effective in restoring surface characteristics and also showed that less plaque and viable bacteria were left. Naringin removed S. aureus biofilms better than chlorhexidine. Alkaline resveratrol and naringin solutions increased cell adhesion, proliferation, and osteogenic differentiation without any cytotoxicity. Resveratrol increased the expression of mRNA and protein associated with osteogenesis. In conclusion, resveratrol and naringin effectively restored SLA titanium surface characteristics and decontaminated the biofilm with good biocompatibility, suggesting their therapeutic potential as chemical decontaminants.

IMPORTANCE

Bacterial biofilms are considered the primary etiology of peri-implant disease. Physical cleaning is the most common way to remove bacterial biofilm, but it can cause grooving, melting, and deposition of chemicals that alter the surface of implants, which may hamper biocompatibility and re-osseointegration. Chemical decontamination is one of the most promising treatments but is limited by low efficiency and poor biocompatibility. Our study aims to develop safer, more effective chemical decontaminants for peri-implant disease prevention and treatment. We focus on resveratrol and naringin, two natural compounds, which have shown to be more effective in decontaminating biofilms on dental implant surfaces and exerting better biocompatibility. This research is groundbreaking as it is the first exploration of natural plant extracts' impact on mature bacterial biofilms on rough titanium surfaces. By advancing this knowledge, we seek to contribute to more effective and biocompatible strategies for combating peri-implant diseases, enhancing oral health, and prolonging implant lifespan.

Fabrication of ibuprofen/naringenin-coloaded into zein/sodium caseinate nanoparticles: evaluation of antiproliferative activity and apoptosis induction in liver cancer cells

Nowadays, liver cancer is one of the most disturbing types of cancer that can affect either sex. Nanoparticles (NPs) of zein/sodium caseinate incorporating ibuprofen (IBU) and naringenin (NAR) have improved bioavailability and a high encapsulation efficiency (EE%). These nanoparticles are uniformly spherical. In vitro, cytotoxicity analysis on HepG2 cell lines, which are used to study human liver cancer, shows that encapsulated drugs (86.49% ± 1.90, and 78.52% ± 1.98 for NAR and IBU, respectively) have significantly lower IC50 values than individual drugs or their combined free form. In addition, the combination indices of 0.623 and 0.155 for IBU and NAR, respectively, show that the two have joint beneficial effects. The scratch wound healing assay results also show that the free drugs and the engineered NPs have a more significant anti-migratory effect than the untreated cells. The designed nanoparticles also reduce angiogenesis and proliferation while inducing apoptosis, according to in vitro results. In conclusion, a new approach to treating liver cancer may lie in the nanoencapsulation of numerous drugs within nanoparticles.

Naringin exerts antibacterial and anti-inflammatory effects on mice with Staphylococcus aureus-induced osteomyelitis

Osteomyelitis is an invasive bone infection that can lead to severe pain and even disability, posing a challenge for orthopedic surgery. Naringin can reduce bone-related inflammatory conditions. This study aimed to elucidate the function and mechanism of naringin in a Staphylococcus aureus-induced mouse model of osteomyelitis. Femurs of S. aureus-infected mice were collected after naringin administration and subjected to microcomputed tomography to analyze cortical bone destruction and bone loss. Bacterial growth in femurs was also assessed. Proinflammatory cytokine levels in mouse femurs were measured using enzyme-linked immunosorbent assays. Pathological changes and bone resorption were analyzed using hematoxylin and eosin staining and tartrate-resistant acid phosphatase staining, respectively. Quantitative reverse transcription polymerase chain reaction and western blot analysis were used to quantify the messenger RNA and protein expression of osteogenic differentiation-associated genes in the femurs. The viability of human bone marrow-derived stem cells (hBMSCs) was determined using cell counting kit-8. Alizarin Red S staining and alkaline phosphatase staining were performed to assess the formation of mineralization nodules and bone formation in vitro. Notch signaling-related protein levels in femur tissues and hBMSCs were assessed using western blot analysis. Experimental results revealed that naringin alleviated S. aureus-induced cortical bone destruction and bone loss in mice by increasing the bone volume/total volume ratio. Naringin suppressed S. aureus-induced bacterial growth and inflammation in femurs. Moreover, it alleviated histopathological changes, inhibited bone resorption, and increased the expression of osteogenic markers in osteomyelitic mice. It increased the viability of hBMSCs and promoted their differentiation and bone mineralization in vitro. Furthermore, naringin activated Notch signaling by upregulating the protein levels of Notch1, Jagged1, and Hes1 in the femurs of model mice and S. aureus-stimulated hBMSCs. In conclusion, naringin reduces bacterial growth, inflammation, and bone resorption while upregulating the expression of osteogenic markers in S. aureus-infected mice and hBMSCs by activating Notch signaling.

Prunin Laurate Derived from Natural Substances Shows Antibacterial Activity against the Periodontal Pathogen Porphyromonas gingivalis

Periodontal disease is an inflammatory disease caused by infection with periodontopathogenic bacteria. Oral care is essential to prevent and control periodontal disease, which affects oral and systemic health. However, many oral hygiene products currently on the market were developed as disinfectants, and their intense irritation makes their use difficult for young children and older people. This study investigated the antibacterial effects of prunin laurate (Pru-C12) and its analogs on periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis). Pru-C12 and its analogs inhibited in vitro bacterial growth at more than 10 μM and biofilm formation at 50 µM. Among its analogs, only Pru-C12 showed no cytotoxicity at 100 µM. Three of the most potent inhibitors also inhibited the formation of biofilms. Furthermore, Pru-C12 inhibited alveolar bone resorption in a mouse experimental periodontitis model by P. gingivalis infection. These findings may be helpful in the development of oral hygiene products for the prevention and control of periodontal disease and related disorders.

Neurospora sp. Mediated Synthesis of Naringenin for the Production of Bioactive Nanomaterials

The application of Neurospora sp., a fungus that commonly thrives on complex agricultural and plant wastes, has proven successful in utilizing citrus peel waste as a source of naringin. A UV-Vis spectrophotometric method proved the biotransformation of naringin, with an absorption maximum (λmax) observed at 310 nm for the biotransformed product, naringenin (NAR). Further verification of the conversion of naringin was provided through thin layer chromatography (TLC). The Neurospora crassa mediated biotransformation of naringin to NAR was utilized for the rapid (within 5 min) synthesis of silver (Ag) and gold (Au) nanoconjugates using sunlight to accelerate the reaction. The synthesized NAR-nano Ag and NAR-nano Au conjugates exhibited monodispersed spherical and spherical as well as polygonal shaped particles, respectively. Both of the nanoconjugates showed average particle sizes of less than 90 nm from TEM analysis. The NAR-Ag and NAR-Au nanoconjugates displayed potential enhancement of the antimicrobial activities, including antibacterial and nematicidal properties over either standalone NAR or Ag or Au NPs. This study reveals the potential of naringinase-producing Neurospora sp. for transforming naringin into NAR. Additionally, the resulting NAR-Ag and NAR-Au nanoconjugates showed promise as sustainable antibiotics and biochemical nematicides.

Antimicrobial Activity of Grapefruit Seed Extract on Edible Mushrooms Contaminations: Efficacy in Preventing Pseudomonas spp. in Pleurotus eryngii

Pleurotus eryngii is an edible mushroom that suffers significant losses due to fungal contamination and bacteriosis. The Pseudomonadaceae family represents one of the most frequent etiologic agents. Grapefruit seed extract (GSE) is a plant extract that contains different bioactive components, such as naringin, and exhibits a strong antibacterial and antioxidant activity. Over the last decade, GSE use as an alternative to chemical treatments in the food sector has been tested. However, to our knowledge, its application on mushroom crops has never been investigated. This study focuses on evaluating GSE efficacy in preventing P. eryngii yellowing. GSE antibiotic activity, inhibitory and bactericidal concentrations, and antibiofilm activity against several microorganisms were tested with the Kirby-Bauer disk diffusion assay, the broth microdilution susceptibility test, and the Crystal violet assay, respectively. In vitro, the extract exhibited antimicrobial and antibiofilm activity against Staphylococcus aureus 6538 and MRSA (wild type), Escherichia coli ATCC 8739, and Pseudomonas spp. (Pseudomonas aeruginosa 9027, P. fluorescens (wild type)). GSE application in vivo, in pre- and post-sprouting stages, effectively prevented bacterial infections and subsequent degradation in the mushroom crops: none of the P. eryngii treated manifested bacteriosis. Our findings support the use of GSE as an eco-friendly and sustainable alternative to chemical treatments for protecting P. eryngii crops from bacterial contamination, consequently ensuring food safety and preventing financial losses due to spoilage. Furthermore, GSE's potential health benefits due to its content in naringin and other bioactive components present new possibilities for its use as a nutraceutical in food fortification and supplementation.

Co-Delivery of Naringin and Ciprofloxacin by Oleic Acid Lipid Core Encapsulated in Carboxymethyl Chitosan/Alginate Nanoparticle Composite for Enhanced Antimicrobial Activity

A novel combination of antibiotic, ciprofloxacin (CIP) with herbal counterpart naringin (NAR) was encapsulated by an oleic acid lipid core and carboxymethyl chitosan (CM-CS)/Alginate (AG) nanoparticle composite (CIP + NAR-CM-CS/AG-NPs) for improved antimicrobial efficacy of antibiotic. Herein, this study explored the design and preparation of a composite system that enables to deliver both CIP and NAR from the oleic acid lipid core of CM-CS/AG nanoparticles using a nonsolvent ionic gelation technique. The nanoparticles (NPs) were fabricated with improved long-acting antimicrobial activity against E. coli and S. aureus. The optimized composition was investigated for physicochemical properties particle size, particle distribution, and ζ-potential. A diverse array of analytical tools was employed to characterize the optimized formulation including DSC, XRD, Malvern Zetasizer for particle size, ζ-potential, TEM, and SEM. Further, the preparation was investigated for % drug release, flux determination, antioxidant, and antimicrobial activity. The formulation stability was tested for 90 days and also evaluated formulation stability in fetal bovine serum to inspect the modification in physicochemical characteristics. NPs size was determined at 85 nm, PDI, and ζ-potential was recorded at 0.318, and 0.7 ± 0.4 mV. The % CIP and NAR entrapment efficiency and % loading were incurred as 91 ± 1.9, and 89.5 ± 1.2; 11.5 ± 0.6, and 10.8 ± 0.5%, respectively. The drug release erupted in the beginning phase followed by sustained and prolonged release for 48 h. The analytical experiments by DSC ensured the noninteracting and safe use of excipients in combination. X-ray studies demonstrated the amorphous state of the drug in the formulation. The insignificant alteration of formulation characteristics in FBS suggested stable and robust preparation. Storage stability of the developed formulation ensured consistent and uniform stability for three months. The DPPH assays demonstrated that NAR had good antioxidant capacity and supported improving antimicrobial activity of CIP. The hemolytic test suggested the developed formulation was compatible and caused insignificant RBC destruction. The in-house built formulation CIP + NAR-CM-CS/AG-NPs significantly improved the antimicrobial activity compared to CIP alone, offering a novel choice in antimicrobial application.

Naringin and graphene oxide incorporated Moringa oleifera gum/poly(vinyl) alcohol patch for enhanced wound healing

Patients and healthcare systems stand to gain much from the use of substances that can accelerate wound healing. In this research work, a polymeric patch was fabricated using polymers like poly (vinyl alcohol) (PVA) and Moringa oleifera gum (MO) incorporated with graphene oxide (GO) and naringin (Nar) (drug). This study determined the impact of using PVA/MO/GO/Nar polymeric patch on wound healing via in vitro and in vivo investigations. Graphene oxide was synthesized by modified Hummer's method. The synthesized sample was characterized using XRD, FT-IR, RAMAN Spectroscopy, FESEM and HRTEM. Antibacterial analysis of the GO on four different bacteria was studied through well diffusion, colony count, growth curve and biofilm assay. Biocompatibility was analysed by haemolysis assay. The morphology, antibacterial activity, haemolysis assay, swelling, degradation, porosity, water vapour transmission rate, drug release, blood pump model, in-vitro scratch assay and MTT assay were analysed for the fabricated polymeric patches under in-vitro condition. The PVA/MO/GO/Nar patch has shown enhanced wound healing in in-vivo wound healing experiments on albino Wistar rats.

Fluorinated 2-arylchroman-4-ones and their derivatives: synthesis, structure and antiviral activity

A number of new biologically interesting fluorinated 2-arylchroman-4-ones and their 3-arylidene derivatives were synthesized based on the p-toluenesulfonic acid-catalyzed one-pot reaction of 2-hydroxyacetophenones with benzaldehydes. It was found that obtained (E)-3-arylidene-2-aryl-chroman-4-ones reacted with malononitrile under base conditions to form 4,5-diaryl-4H,5H-pyrano[3,2-c]chromenes. The structures of the synthesized fluorinated compounds were confirmed by 1H, 19F, and 13C NMR spectral data, and for some representatives of heterocycles also using NOESY spectra and X-ray diffraction analysis. A large series of obtained flavanone derivatives as well as products of their modification (35 examples) containing from 1 to 12 fluorine atoms in the structure was tested in vitro for cytotoxicity in MDCK cell line and for antiviral activity against influenza A virus. Among the studied heterocycles 6,8-difluoro-2-(4-(trifluoromethyl)phenyl)chroman-4-one (IC50 = 6 μM, SI = 150) exhibited the greatest activity against influenza A/Puerto Rico/8/34 (H1N1) virus. Moreover, this compound appeared active against phylogenetically distinct influenza viruses, A(H5N2) and influenza B (SI's of 53 and 42, correspondingly). The data obtained suggest that the fluorinated derivatives of 2-arylchroman-4-ones are prospective scaffolds for further development of potent anti-influenza antivirals.

Naringenin biosynthesis and fabrication of naringenin mediated nano silver conjugate for antimicrobial potential

The development of resistance, instability and high doses are some drawbacks of biologically active natural products. Modification of natural compounds to make it broad spectrum is the standard approach in drug design. This paper sets to modify the naringenin by silver nanoparticle conjugation to enhance its already reported pharmacological activities. The naringenin-nano silver conjugate was synthesized by one-step green synthesis, that is, sunlight exposure confirmed by UV spectroscopy. The biosynthesized naringenin-nanosilver conjugate was tested for antiacanthamoebal and antimicrobial potential. The antibacterial potential was increased by 5.8-6.14 fold against Gram positive bacteria, that is, S. aureus and Bacillus subtilis and 4.5-13.6 fold against Gram negative bacteria, that is, Escherichia coli and Pseudomonas aeruginosa. The standard naringenin-nanosilver conjugate significantly reduced the LC50 values against the Acanthamoeba cells, by, 66% and 36%, as compared to substrate naringin and standard naringenin respectively while biotransformed naringinin-nanosilver conjugate reduced LC50 by 50.56%, compared with biotransformed naringenin. Hence modification of natural product as nanoconjugate is the best practice for improvement as an effective drug.

Pharmacological Properties of Chemically Characterized Extracts from Mastic Tree: In Vitro and In Silico Assays

The mastic tree, scientifically known as Pistacia lentiscus, which belongs to the Anacardiaceae family, was used in this study. The aim of this research was to analyze the chemical composition of this plant and assess its antioxidant and antibacterial properties using both laboratory experiments and computer simulations through molecular docking, a method that predicts the binding strength of a small molecule to a protein. The soxhlet method (SE) was employed to extract substances from the leaves of P. lentiscus found in the eastern region of Morocco. Hexane and methanol were the solvents used for the extraction process. The n-hexane extract was subjected to gas chromatography-mass spectrometry (GC/MS) to identify its fatty acid content. The methanolic extract underwent high-performance liquid chromatography with a diode-array detector (HPLC-DAD) to determine the presence of phenolic compounds. Antioxidant activity was assessed using the DPPH spectrophotometric test. The findings revealed that the main components in the n-hexane extract were linoleic acid (40.97 ± 0.33%), oleic acid (23.69 ± 0.12%), and palmitic acid (22.83 ± 0.10%). Catechin (37.05 ± 0.15%) was identified as the predominant compound in the methanolic extract through HPLC analysis. The methanolic extract exhibited significant DPPH radical scavenging, with an IC50 value of 0.26 ± 0.14 mg/mL. The antibacterial activity was tested against Staphylococcus aureus, Listeria innocua, and Escherichia coli, while the antifungal activity was evaluated against Geotrichum candidum and Rhodotorula glutinis. The P. lentiscus extract demonstrated notable antimicrobial effects. Additionally, apart from molecular docking, other important factors, such as drug similarity, drug metabolism and distribution within the body, potential adverse effects, and impact on bodily systems, were considered for the substances derived from P. lentiscus. Scientific algorithms, such as Prediction of Activity Spectra for Substances (PASS), Absorption, Distribution, Metabolism, Excretion (ADME), and Pro-Tox II, were utilized for this assessment. The results obtained from this research support the traditional medicinal usage of P. lentiscus and suggest its potential for drug development.

Analysis of bioactive compounds using LC-ESI-MS/MS, cytotoxic, antimicrobial effects, and enzyme activities from Cyclotrichium origanifolium

Cyclotrichium origanifolium is a medicinal plant belonging to the Lamiaceae family. In this study, phenolic content analysis, antimicrobial effects, and cytotoxic effects of extracts of C. origanifolium were investigated. In the extracts, phenolic compound analysis by the liquid chromatography-electrospray ionization-tandem mass spectrometry method, antimicrobial effect by the minimum inhibition concentration method, and cytotoxic effect on human dermal fibroblasts (HDF), glioblastoma cell (U87), ovarian adenocarcinoma cell (Skov-3), and human colorectal adenocarcinoma cell (CaCo-2) cancer cell lines were investigated. Cytotoxicity analyses were performed by the MTT method. In addition, the GST and AChE enzyme activities of the extracts were also measured. Around 18 compounds were detected in both the methanol and ethanol extract. It was found that the best antimicrobial effect on Gram-negative Pseudomonas aeruginosa was on methanol extract, while the ethanol extract was on Candida albicans fungus (respectively, 2.50 mg/ml, 5.0 μg/ml). A 500 μg/ml of methanol extract has been shown to have cytotoxic activity high effect on HDF cells. GST and AChE activity were found to decrease in a concentration-dependent manner.

Naringenin and Its Derivatives-Health-Promoting Phytobiotic against Resistant Bacteria and Fungi in Humans

Naringenin is a trihydroxyflavanone present in large amount in different citrus fruits, e.g., oranges, pomelos, grapefruits, but also in tomatoes, fenugreek and coffee. It has a wide range of pharmacological and biological effects beneficial to human health. Its antioxidant, anti-cancer, anti-inflammatory, antifungal and antimicrobial activity is frequently reported in scientific literature. In this review we presented the current state of knowledge on the antimicrobial activity of naringenin and its natural and synthetic derivatives as a phytobiotic against resistant Gram-positive and Gram-negative bacteria as well as fungi in humans. Most of the data reported here have been obtained from in vitro or in vivo studies. Over the past few years, due to the overuse of antibiotics, the occurrence of bacteria resistant to all available antibiotics has been growing. Therefore, the main focus here is on antibiotic resistant strains, which are a significant, worldwide problem in the treatment of infectious diseases. The situation is so alarming that the WHO has listed microbial resistance to drugs on the list of the 10 most important health problems facing humanity. In addition, based on scientific reports from recent years, we described the potential molecular mechanism of action of these bioflavonoids against pathogenic strains of microorganisms. As plant-derived substances have been pushed out of use with the beginning of the antibiotic era, we hope that this review will contribute to their return as alternative methods of preventing and treating infections in the epoch of drug resistance.

Flavonoids-Rich Plant Extracts Against Helicobacter pylori Infection as Prevention to Gastric Cancer

Gastric cancer is the fifth most common and fourth type to cause the highest mortality rates worldwide. The leading cause is related to Helicobacter pylori (H. pylori) infection. Unfortunately, current treatments have low success rates, highlighting the need for alternative treatments against carcinogenic agents, specifically H. pylori. Noteworthy, natural origin products contain pharmacologically active metabolites such as flavonoids, with potential antimicrobial applications.

Objective: This article overviews flavonoid-rich extracts’ biological and pharmacological activities. It focuses on using these substances against Helicobacter pylori infection to prevent gastric cancer. For this, PubMed and Science Direct databases were searched for studies that reported the activity of flavonoids against H. pylori, published within a 10-year time frame (2010 to August 2020). It resulted in 1,773 publications, of which 44 were selected according to the search criteria. The plant family primarily found in publications was Fabaceae (9.61%). Among the flavonoids identified after extraction, the most prevalent were quercetin (19.61%), catechin (13.72), epicatechin (11.76), and rutin (11.76). The potential mechanisms associated with anti-H. pylori activity to the extracts were: inhibition of urease, damage to genetic material, inhibition of protein synthesis, and adhesion of the microorganism to host cells.

Conclusion: Plant extracts rich in flavonoids with anti-H. pylori potential proved to be a promising alternative therapy source, reinforcing the relevance of studies with natural products.

Naringin generates three types of reactive oxygen species contributing differently to apoptosis-like death in Escherichia coli

AIMS

Naringin is a flavonoid with a polyphenolic structure which induces formation of reactive oxygen species (ROS). Although the antibacterial effect of naringin has been demonstrated, the mechanism underlying this effect has not yet been elucidated. We focused on investigating the antibacterial mode of action of naringin in Escherichia coli following ROS generation. The contributions of ROS, hydroxy radicals (OH^-), super oxide (O₂^-), and hydrogen peroxide (H₂O₂) were investigated.

MAIN METHODS

ROS accumulation was detected using fluorescence dyes, and all experiments were conducted using the scavenger including tiron, sodium pyruvate, and thiourea to assess the contribution of each ROS. Western blotting assays were used to observe the activation of the SOS response for DNA repair. DNA fragmentation, membrane depolarization, and phosphatidylserine exposure were estimated using TUNEL, DiBAC₄(3), and Annexin V/PI.

KEY FINDINGS

Accumulation of ROS was observed in Escherichia coli after treatment with naringin. Oxidative stress induced cellular dysfunction including DNA damage, which results in SOS response activation. Eventually, apoptosis-like death occurred in cells treated with naringin. The cells had different contributions of each ROS and accompanying apoptotic factors. The ROS most destructive to E. coli was OH^-, followed by H₂O₂ and O₂^-.

SIGNIFICANCE

Due to its efficacy, naringin is a useful antimicrobial agent. An initial investigation into the antibacterial mode of action of naringin is presented in this paper. The contribution of each ROS to apoptosis-like cell death (ALD) was investigated, and the results enhanced our understanding of the correlation between the SOS response and oxidative stress in bacteria.

Transparent, UV-blocking, and high barrier cellulose-based bioplastics with naringin as active food packaging materials

Free-standing, robust, and transparent bioplastics were obtained by blending cellulose and naringin at different proportions. Optical, thermal, mechanical, antioxidant, and antimicrobial properties were systematically investigated. In general, the incorporation of naringin produced important UV blocking and plasticizer effects and good antioxidant and antibacterial properties. Moreover, the barrier properties were characterized by determination of their water and oxygen transmission rates, finding that both parameters decreased by increasing the naringin content and reaching values similar to other petroleum-based plastics and cellulose derivatives used for food packaging applications. Finally, the biodegradability of these films was determined by measurement of the biological oxygen demand (BOD) in seawater, demonstrating an excellent decomposition in such conditions.

Major Biological Control Strategies for Plant Pathogens

Food security has become a major concern worldwide in recent years due to ever increasing population. Providing food for the growing billions without disturbing environmental balance is incessantly required in the current scenario. In view of this, sustainable modes of agricultural practices offer better promise and hence are gaining prominence recently. Moreover, these methods have taken precedence currently over chemical-based methods of pest restriction and pathogen control. Adoption of Biological Control is one such crucial technique that is currently in the forefront. Over a period of time, various biocontrol strategies have been experimented with and some have exhibited great success and promise. This review highlights the different methods of plant-pathogen control, types of plant pathogens, their modus operandi and various biocontrol approaches employing a range of microorganisms and their byproducts. The study lays emphasis on the use of upcoming methodologies like microbiome management and engineering, phage cocktails, genetically modified biocontrol agents and microbial volatilome as available strategies to sustainable agricultural practices. More importantly, a critical analysis of the various methods enumerated in the paper indicates the need to amalgamate these techniques in order to improve the degree of biocontrol offered by them.

Potential effects of Saudi Shaoka (Fagonia bruguieri) honey against multi-drug-resistant bacteria and cancer cells in comparison to Manuka honey

The global spread of antimicrobial-resistant infectious diseases and cancer are the most widespread public health issue and has led to high mortality rates. This study aims to evaluate and verify the antibacterial and antitumor activities of Shaoka and Manuka honey against pathogenic bacteria, human hepatocarcinoma (HepG2) and breast cancer (MCF-7) cell lines. Shaoka hone was analyzed using HPLC, UV–vis, and GC/MC, while antibacterial activity was measured by agar diffusion, broth microdilution methods, and Transmission Electron Microscopy (TEM). Antitumor activity was investigated morphologically and by MTT assay. According to the presented data of HPLC analysis, Shaoka honey was generally richer in polyphenolic components, the antibacterial activity showed that Shaoka honey is equivalent or relatively more active than Manuka honey against a broad spectrum of multi-drug-resistant bacteria. It inhibited the growth of ESBL Escherichia coli in the absence or presence of catalase enzyme with a concentration approximately 8.5%–7.3% equivalent to phenol, which supported the highest level of non-peroxide-dependent activity. The minimum bactericidal concentrations (MBCs) ranged between 5.0% and 15.0% honey (w/v). TEM observation revealed distorted cell morphology, cytoplasmic shrinkage, and cell wall destruction of treated bacteria. The selected honey exerted cytotoxicity on both cancer cell lines, inhibiting cell proliferation rate and viability percent in HepG2 and MCF-7 cancer cells, by different degrees depending on the honey quality, Shaoka honey competed Manuka inhibitory effects against both cancer cells. The obtained data confirmed the potential for use of Saudi Shaoka honey as a remedy, this well introduces a new honey template as medical-grade honey for treating infectious disease and cancer.

Antioxidant and Antimicrobial Activity of Cleome droserifolia (Forssk.) Del. and Its Biological Effects on Redox Status, Immunity, and Gut Microflora

Simple Summary

The antioxidant, antimicrobial, and immunomodulatory activities of the Cleome droserifolia (Forssk.) Del. (Cd) shrub were investigated considering the biological activity of its phytogenic compounds. Cd shrub encompasses several phenolic compounds, mainly phenolic acids, such as benzoic acid. The methanolic extract of Cd exhibited strong in vitro antioxidant and antimicrobial activities. Anin vivo study using rabbits as an animal model confirmed the ability of a powder of Cd aerial parts to improve humoral and innate immunity, as well as gastrointestinal microbiota homeostasis. In conclusion, Cd shrub represents a novel source of secondary active metabolites that can be employed as antibiotic alternative in the livestock production field and/or in human pharmaceutical applications.

Abstract

This study aimed to investigate the antioxidant, antimicrobial, and immunomodulatory activities of a Cleome droserifolia (Forssk.) Del. (Cd) shoot methanolic extracts considering the biological activity of its phytogenic compounds. For this purpose, the Cd phenolic compounds were detected, and an in vitro evaluation of the antioxidant and antimicrobial activities of the Cd extract was performed. For a biological evaluation, 30 v-line rabbits were randomly distributed into three groups with treatments including: a basal diet without Cd shoots powder supplement (C group) or supplemented with 1.25- (Cdl group) or 2.5 (Cdh group)-mg Cd/kg dry matter (DM). The Cd extract showed a linear scavenging activity for 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), with the maximal activity observed at a concentration of 1 mg/mL. A total of 16 phenolic compounds were identified by reverse-phase high-performance liquid chromatography (RP-HPLC) in the Cd methanolic extract, among which benzoic acid, rutin, ellagic acid, naringenin, and o-coumaric acid were the major compounds. The methanolic extract of Cd showed inhibitory actions against microbial pathogen species. The in vivo study showed that the two concentrations of Cd significantly improved the redox status of the blood plasma and lysozyme activity. Treatment with Cdh significantly decreased the levels of interleukin-β1 in the blood plasma compared with the control. Moreover, the two concentrations of Cd significantly increased the counts of intestinal and cecal yeast and Lactobacillus species and decreased the Salmonella and Coliform species compared with the control. The aerial parts of the Cd shrub had strong antioxidant, antimicrobial, and immunomodulatory activities, which can improve the overall health status and seem to be related to its impressive range of biologically active phenolic compounds.

Naringin-generated ROS promotes mitochondria-mediated apoptosis in Candida albicans

Naringin is a flavonoid which has a therapeutic effect. However, the details of its antifungal mechanism have not yet been fully elucidated. This study focused on clarifying the relationship between naringin and Candida albicans, to understand its mode of antifungal action. In general, naringin is an antioxidant, but our results indicated that 1 mM naringin generates intracellular superoxide (O₂ ^- ) and hydroxyl radicals (OH^- ). Reactive oxygen species (ROS) have a serious impact on Ca²⁺ signaling and the production of mitochondrial ROS. After exposure to enhanced O₂ ^- and OH^- , mitochondrial Ca²⁺ overload and mitochondrial O₂ ^- generation were confirmed in C. albicans. It was verified that mitochondrial O₂ ^- transforms mitochondrial glutathione (GSH) to oxidized GSH (GSSG), leading to extreme oxidative stress in mitochondria. The previously observed Ca²⁺ accumulation and oxidative stress resulted in mitochondrial membrane potential (MMP) alteration and increased mitochondrial mass. In succession, cytochrome c release from the mitochondria to the cytosol was detected due to MMP loss. Cytochrome c promotes the initiation of apoptosis, and further experiments were performed to assess the apoptotic hallmarks. Metacaspases activation, chromosomal condensation, DNA fragmentation, and phosphatidylserine exposure were observed, indicating that naringin induces apoptosis in C. albicans. In conclusion, our findings manifested that naringin-generated O₂ ^- and OH^- damage the mitochondria and that mitochondrial dysfunction-mediated apoptosis is novel antifungal mechanism of naringin.

Potential development of non-synthetic food additives from orange processing by-products—a review

Citrus is the largest fruit crop worldwide. Meanwhile, oranges account for 60 per cent of the total, with their main application in juice production. During orange juice production, only about 50 per cent of the fresh orange weight is transformed into juice, with the remaining 50 per cent comprised of residue (peel, pulp, seeds, orange leaves and whole orange fruits that do not reach the quality requirements). With the resulting tons of orange by-products, there has been an initiative to research possible ways to reutilize and revalorize citrus waste. Orange pomace, the by-product from juicing process, is currently used to extract the essential oils for fragrance and flavor, and a majority of the waste is used as cattle feed; however, these applications do not account for all of the waste or capture all of its potential value. Meanwhile, these by-products are put into landfills at the owner’s expense, and contribute to global warming through carbon emissions. On the other hand, orange by-products still contain many useful nutraceutical components, such as dietary fiber and phytochemicals, which could be utilized for value-added ingredients and new product development. Some research approaches in this area include the production of organic fertilizers and biofuels, or the extraction of essential oils, pectins, and antioxidant compounds. There is little information in the literature and in the food industry in terms of utilizing the orange pomace directly or with some simple treatments. Orange pomace may be used for food product development as a ‘clean-label’, non-synthetic preservative, which rationalizes this review.

Naringin inhibits the biofilms of metallo-β-lactamases (MβLs) producing Pseudomonas species isolated from camel meat

Food producing animals harbouring bacteria carrying drug resistance genes especially the metallo-beta-lactamase (MBL) pose high risk for the human population. In addition, formation of biofilm by these drug resistant pathogens represents major threat to food safety and public health. In this study, metallo-β-lactamases (MβLs) producing Pseudomonas spp. from camel meat were isolated and assessed for their biofilm formation. Further, in vitro and in silico studies were performed to study the effect of flavone naringin on biofilm formation against isolated Pseudomonas spp. A total of 55% isolates were found to produce metallo-β-lactamase enzyme. Naringin mitigated biofilm formation of Pseudomonas isolates up to 57%. Disturbed biofilm architecture and reduced the colonization of bacteria on glass was observed under scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). The biofilm related traits such as exopolysaccharides (EPS) and alginate production was also reduced remarkably in the presence of naringin. Eradication of preformed biofilms (32–60%) was also observed at the respective 0.50 × MICs. Molecular docking revealed that naringin showed strong affinity towards docked proteins with binding energy ranging from −8.6 to −8.8 kcal mol⁻¹. Presence of metallo-β-lactamase producers indicates that camel meat could be possible reservoir of drug-resistant Pseudomonas species of clinical importance. Naringin was successful in inhibiting biofilm formation as well as eradicating the preformed biofilms and demonstrated strong binding affinity towards biofilm associated protein. Thus, it is envisaged that naringin could be exploited as food preservative especially against the biofilm forming food-borne Pseudomonas species and is a promising prospect for the treatment of biofilm based infections.

Metabolomics by UHPLC-HRMS reveals the impact of heat stress on pathogen-elicited immunity in maize

INTRODUCTION

Studies investigating crop resistance to abiotic and biotic stress have largely focused on plant responses to singular forms of stress and individual biochemical pathways that only partially represent stress responses. Thus, combined abiotic and biotic stress treatments and the global assessment of their elicited metabolic expression remains largely unexplored. In this study, we employed targeted and untargeted metabolomics to investigate the molecular responses of maize (Zea mays) to abiotic, biotic, and combinatorial stress.

OBJECTIVE

We compared the inducible metabolomes of heat-stressed (abiotic) and C. heterostrophus-infected (biotic) maize and examined the effects of heat stress on the ability of maize to defend itself against C. heterostrophus.

METHODS

Ultra-high-performance liquid chromatography-high-resolution mass spectrometry was performed on plants grown under control conditions (28 °C), heat stress (38 °C), Cochliobolus heterostrophus infection, or combinatorial stress [heat (38 °C) + C. heterostrophus infection].

RESULTS

Multivariate analyses revealed differential metabolite expression between heat stress, C. heterostrophus infection, and their respective controls. In combinatorial experiments, treatment with heat stress prior to fungal inoculation negatively impacted maize disease resistance against C. heterostrophus, and distinct metabolome separation between combinatorial stressed plants and the non-heat-stressed infected controls was observed. Targeted analysis revealed inducible primary and secondary metabolite responses to abiotic/biotic stress, and combinatorial experiments indicated that deficiency in the hydroxycinnamic acid, p-coumaric acid, may contribute to the heat-induced susceptibility of maize to C. heterostrophus.

CONCLUSION

These findings demonstrate that abiotic stress can predispose crops to more severe disease symptoms, underlining the increasing need to investigate defense chemistry in plants under combinatorial stress.

Antibacterial Effect of Aluminum Surfaces Untreated and Treated with a Special Anodizing Based on Titanium Oxide Approved for Food Contact

One of the main concerns of the food industry is microbial adhesion to food contact surfaces and consequent contamination. We evaluated the potential bacteriostatic/bactericidal efficacy of aluminum surfaces with different large-scale roughness (0.25, 0.5 and 1 μm) before and after the surface treatment with a special anodizing based on titanium oxide nanotechnology (DURALTI®) and after 3 different sanitizing treatments, e.g., UV, alcohol and a natural product named Gold lotion. Four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) bacteria were screened. As far as concerns aluminum surfaces without nanotechnology surface treatment, an overall bacteriostatic effect was observed for all strains with respect to the initial inoculum that was 106 CFU/mL. Conversely, an overall bactericidal effect was observed both for Gram-negative and -positive bacteria on DURALTI®-treated aluminum disks, regardless of roughness and sanitizing treatment. These results are innovative in terms of the great potential of the antibacterial activity of nanotechnologically treated food contact surfaces and their combination with some sanitizing agents that might be exploited in the food industry.

Re-appraising the potential of naringin for natural, novel orthopedic biotherapies

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin’s osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.

Anti-quorum Sensing and Protective Efficacies of Naringin Against Aeromonas hydrophila Infection in Danio rerio

It is now well known that the quorum sensing (QS) mechanism coordinates the production of several virulence factors and biofilm formation in most pathogenic microorganisms. Aeromonas hydrophila is a prime pathogen responsible for frequent outbreaks in aquaculture settings. Recent studies have also continuously reported that A. hydrophila regulates virulence factor production and biofilm formation through the QS system. In addition to the presence of antibiotic resistance genes, biofilm-mediated antibiotic resistance increases the severity of A. hydrophila infections. To control the bacterial pathogenesis and subsequent infections, targeting the QS mechanism has become one of the best alternative methods. Though very few compounds were identified as QS inhibitors against A. hydrophila, to date, the screening and identification of new and effective natural QS inhibitors is a dire necessity to control the infectious A. hydrophila. The present study endorses naringin (NA) as an anti-QS and anti-infective agent against A. hydrophila. Initially, the NA showed a concentration-dependent biofilm reduction against A. hydrophila. Furthermore, the results of microscopic analyses and quantitative virulence assays displayed the promise of NA as a potential anti-QS agent. Subsequently, the downregulation of ahh1, aerA, lip and ahyB validate the interference of NA in virulence gene expression. Furthermore, the in vivo assays were carried out in zebrafish model system to evaluate the anti-infective potential of NA. The outcome of the immersion challenge assay showed that the recovery rate of the zebrafish has substantially increased upon treatment with NA. Furthermore, the quantification of the bacterial load upon NA treatment showed a decreased level of bacterial counts in zebrafish when compared to the untreated control. Moreover, the NA treatment averts the pathogen-induced histoarchitecture damages in vital organs of zebrafish, compared to their respective controls. The current study has thus analyzed the anti-QS and anti-infective capabilities of NA and could be employed to formulate effective treatment measures against A. hydrophila infections.

Naringenin derivatives as glucosamine-6-phosphate synthase inhibitors: synthesis, antioxidants, antimicrobial, preservative efficacy, molecular docking and in silico ADMET analysis

BACKGROUND

Preservatives have to be added in food, pharmaceuticals and cosmetics products to maintain their shelf life. However, the existing chemical based preservatives have been associated with severe side effects that compel the researchers to find better safe preservatives based on natural products. G-6-P synthase is an important enzyme for bacterial and fungal cell wall synthesis and offers as a potential target to find better G-6-P synthase inhibitors based antimicrobial compounds. Naringenin, a flavanone, has been reported for a wide range of pharmacological activities including antimicrobial activity, which makes it a potential candidate to be explored as novel G-6-P synthase inhibitor.

RESULTS

The synthesis of naringenin derivatives with potent G-6-P synthase inhibitor having remarkable antioxidant, antimicrobial and preservative efficacy was performed. Among the synthesized compounds, the compound 1 possessed good antioxidant activity (IC50 value, 6.864 ± 0.020 µM) as compared to standard ascorbic acid (IC50 value, 8.110 ± 0.069 µM). The antimicrobial activity of synthesized compounds revealed compound 1 as the most potent compound (pMIC 1.79, 1.79, 1.49, 1.49, 1.49 and 1.49 μM/mL for P. mirabilis, P. aeruginosa, S. aureus, E. coli, C. albicans and A. niger respectively) as compared to standard drugs taken. The compound 2 showed comparable activity against P. mirabilis (pMIC 1.14 μM/mL), C. albicans (pMIC 1.14 μM/mL) while the compound 3 also showed comparable activity against C. albicans (pMIC 1.16 μM/mL) as well A. niger (pMIC 1.46 μM/mL), likewise the compound 4 showed comparable activity against P. mirabilis (pMIC 1.18 μM/mL) as compared to the standard drugs streptomycin (pMIC 1.06, 1.36, 1.06 and 1.96 μM/mL for P. mirabilis, P. aeruginosa, S. aureus and E. coli respectively), ciprofloxacin (pMIC 1.12, 1.42, 1.12 and 1.42 μM/mL for P. mirabilis, P. aeruginosa, S. aureus and E. coli respectively), ampicillin (pMIC 1.14, 0.84, 0.84 and 1.74 μM/mL for P. mirabilis, P. aeruginosa, S. aureus and E. coli respectively) and fluconazole (pMIC 1.08 and 1.38 μM/mL for C. albicans and A. niger respectively). The molecular docking with the target G-6-P synthase pdb id 1moq resulted with an better dock score for compound 1 (- 7.42) as compared to standard antimicrobial drugs, ciprofloxacin (- 5.185), ampicillin (- 5.065) and fluconazole (- 5.129) that supported the wet lab results. The preservative efficacy test for compound 1 in White Lotion USP showed the log CFU/mL value within the prescribed limit and results were comparable to standard sodium benzoate, ethyl paraben and propyl paraben as per USP standard protocol.

CONCLUSIONS

The synthesized naringenin derivatives exhibited significant G-6-P synthase inhibitory potential with good selectivity towards the selected target G-6-P synthase. Compound 1, bearing nitro group showed good antioxidant, antimicrobial and preservative efficacy compared with the standard drugs taken. The mechanistic insight about the compounds within the active site was completed by molecular docking that supported the results for novel synthesized G-6-P synthase inhibitors.

Naringin derivatives as glucosamine-6-phosphate synthase inhibitors based preservatives and their biological evaluation

Glucosamine-6-Phosphate synthase enzyme has been targeted for development of better and safe preservative due to its role in microbial cell wall synthesis. In recent year's demand of preservatives for the food, cosmetics and pharmaceuticals have increased. Although, the available synthetic preservatives have associated unwanted adverse effects, soa chain of naringin derivatives were schemed synthesized and judged for antioxidant, antimicrobial, preservative efficacy, stability study and topical evaluation. Molecular docking resulted with excellent dock score and binding energy for compound 7, compound 6 and compound 1 as compared to standard drugs. Resultant data of antimicrobial activity revealed compound 7as most potent antimicrobial compound for P. mirabilis, P. aeruginosa, S. aureus, E. coli, C. albicans, and A. niger, respectively, as compared to the standard drugs. The preservative efficacy test of compound 7 in White Lotion USP showed the log cfu/mL value within prescribed limit of USP standard. Compound 7 stabilize the White lotion USP from microbial growth for a period of six months under accelerated storage condition. Compound 7 was further evaluated for toxicity by using the Draize test in rabbits and showed no sign of eye and skin irritation. The outcome demonstrated that synthesized naringin compounds showed glorious antioxidant, antimicrobial, preservative efficacy, stable and safe as compared to standards.

Outgoing and potential trends of composition, health benefits, juice production and waste management of the multi-faceted Grapefruit Citrus Χ paradisi: A comprehensive review for maximizing its value

Grapefruit (GF) Citrus Χ paradisi Macfad (F. Rutaceae) is one of the major citrus fruits that encompass a myriad of bioactive chemicals and most unique among citrus fruits. Nevertheless, no study has yet to assess comprehensively its multitudinous constituents, health benefits, and valuable waste products. Hereto, the present review provides an updated comprehensive review on the different aspects of GF, its juice production, waste valorization, enhancement of its byproducts quality, and compared to other citrus fruits. Grapefruit uniqueness among other citrus fruits stands from its unique taste, flavor, and underlying complex chemical composition. Despite limonene abundance in peel oil and grapefruit juice (GFJ) aroma, nootkatone and sulfur compounds are the key determinants of its flavor, whereas flavanones contribute to its bitter taste and in conjunction with limonoids. Different postharvest treatments and juice processing are reviewed and in context to its influence on final product quality and or biological effects. Flavanones, furanocoumarins, and limonoids appear as the most prominent in GF drug interactions affecting its metabolism and or excretion. Valorization of GF peel is overviewed for its utilization as biosrobent, its oil in aromatherapy, limonene as antimicrobial or in cosmetics, fruit pectin for bioethanol production, or as biosorbent, and peel phenolics biotransformation. The present review capitalizes on all of the aforementioned aspects in GF and further explore novel aspects of its juice quality presenting the full potential of this valued multi-faceted citrus fruit.

Antimicrobial O-Alkyl Derivatives of Naringenin and Their Oximes Against Multidrug-Resistant Bacteria

New antimicrobial agents are needed to address infections caused by multidrug-resistant bacteria. Here, we are reporting novel O-alkyl derivatives of naringenin and their oximes, including novel compounds with a naringenin core and O-hexyl chains, showing activity against clinical strains of clarithromycin-resistant Helicobacter pylori, vancomycin-resistant Enterococcus faecalis, methicillin-resistant Staphylococcus aureus, and beta-lactam-resistant Acinetobacter baumannii and Klebsiella pneumoniae. The minimum inhibitory concentrations (MICs), which provide a quantitative measure of antimicrobial activity, were in the low microgram range for the selected compounds. Checkerboard assays for the most active compounds in combination with antibiotics revealed interactions that varied from synergistic to neutral.

Antimicrobial Capacity of Plant Polyphenols against Gram-positive Bacteria: A Comprehensive Review

BACKGROUND

Multi-drug-resistant bacteria such as Methicillin-Resistant Staphylococcus aureus (MRSA) disseminate rapidly amongst patients in healthcare facilities and suppose an increasingly important cause of community-associated infections and associated mortality. The development of effective therapeutic options against resistant bacteria is a public health priority. Plant polyphenols are structurally diverse compounds that have been used for centuries for medicinal purposes, including infections treatment and possess, not only antimicrobial activity, but also antioxidant, anti-inflammatory and anticancer activities among others. Based on the existing evidence on the polyphenols' antibacterial capacity, polyphenols may be postulated as an alternative or complementary therapy for infectious diseases.

OBJECTIVE

To review the antimicrobial activity of plant polyphenols against Gram-positive bacteria, especially against S. aureus and its resistant strains. Determine the main bacterial molecular targets of polyphenols and their potential mechanism of action.

METHODOLOGY

The most relevant reports on plant polyphenols' antibacterial activity and their putative molecular targets were studied. We also performed virtual screening of thousand different polyphenols against proteins involved in the peptidoglycan biosynthesis to find potential valuable bioactive compounds. The bibliographic information used in this review was obtained from MEDLINE via PubMed.

RESULTS

Several polyphenols: phenolic acids, flavonoids (especially flavonols), tannins, lignans, stilbenes and combinations of these in botanical mixtures, have exhibited significant antibacterial activity against resistant and non-resistant Gram-positive bacteria at low μg/mL range MIC values. Their mechanism of action is quite diverse, targeting cell wall, lipid membrane, membrane receptors and ion channels, bacteria metabolites and biofilm formation. Synergic effects were also demonstrated for some combinations of polyphenols and antibiotics.

CONCLUSION

Plant polyphenols mean a promising source of antibacterial agents, either alone or in combination with existing antibiotics, for the development of new antibiotic therapies.

Functionalization of Ti substrate with pH-responsive naringin-ZnO nanoparticles for the reconstruction of large bony after osteosarcoma resection

After bone tumor resection, the large bony deficits are commonly reconstructed with Ti-based metallic endoprosthesis, which provide immediate stable fixation and allow early ambulation and weight bearing. However, when used in osteosarcoma resection, Ti implant-relative infection and tumor recurrence were recognized as the two critical factors for implantation failure. Hence, in this work, a novel zinc oxide nanoparticle decorating with naringin was prepared and immobilized onto Ti substrate. The drugs delivery profiles proved that in the bacterial infection and Warburg effect of osteosarcoma-induced acidic condition, naringin and Zn²⁺ can be released easily from the functional Ti substrate. The anti-osteosarcoma and antibacterial assay showed the delivered naringin and Zn²⁺ can induce a remarkable increase of oxidative stress in bacteria (Escherichia coli and Staphylococcus aureus) and osteosarcoma (Saos-2 cells) by producing reactive oxygen species (ROS). Accumulation of ROS results in damage of bacterial biofilm and bacterial membrane, leading to the leakage of bacterial RNA and DNA. Meanwhile, the increase of ROS induces osteosarcoma cell apoptosis by activating ROS/extracellular signal-regulated kinase signaling pathway. Furthermore, in vitro cellular experiments, including cell viability, alkaline phosphatase activity, collagen secretion, extracellular matrix mineralization level, indicated that the functional Ti substrate exhibited great potential for osteoblasts proliferation and differentiation. Hence, this study provides a simple and promising strategy of developing multifunctional Ti-based implants for the reconstruction of large bony after osteosarcoma resection.

Polyphenol Profile and Antimicrobial and Cytotoxic Activities of Natural Mentha × piperita and Mentha longifolia Populations in Northern Saudi Arabia

New sources of polyphenols with anticancer, antioxidant, and antimicrobial properties in arid environments are critical for the development of alternative medicines and natural remedies. This study explored the polyphenol profiles and biological activities of methanolic leaf extracts from natural Mentha × piperita and Mentha longifolia populations in northern Saudi Arabia. Chromatographic analyses identified several polyphenols in M. × piperita including phenolic acids: rosmarinic acid (1547.6 mg/100 g DW (dry weight)), cryptochlorogenic acid (91.7 mg/100 g DW), and chlorogenic acid (69.4 mg/100 g DW), as well as flavonoids: naringin (328.8 mg/100 g DW) and cynaroside (162.8 mg/100 g DW). The major polyphenols in M. longifolia were: rosmarinic acid (781.6 mg/100 g DW), cryptochlorogenic acid (191.1 mg/100 g DW), p-coumaric acid (113.0 mg/100 g DW), m-coumaric acid (112.2 mg/100 g DW), and chlorogenic acid (63.8 mg/100 g DW). M. × piperita and M. longifolia leaf extracts had high antioxidant activities due to the major polyphenols (cynaroside, rosmarinic and cryptochlorogenic acids). M. × piperita had higher activities against different cancer cells than M. longifolia. Naringin, cryptochlorogenic acid, and rosmarinic acid had the highest activities against cancer cells. The leaf extracts had antibacterial effects against most bacteria species (Pseudomonas aeruginosa was most sensitive), which was attributed to the polyphenols. Antifungal activities were similarly broad (Aspergillus flavus was most sensitive) and attributed to naringin, cryptochlorogenic acid, and caffeic acid. Populations of M. × piperita and M. longifolia in Northern Riyadh may be a valuable source of natural biologically active compounds.

Unsubstituted Oximes as Potential Therapeutic Agents

Oximes, which are highly bioactive molecules, have versatile uses in the medical sector and have been indicated to possess biological activity. Certain oximes exist in nature in plants and animals, but they are also obtained by chemical synthesis. Oximes are known for their anti-inflammatory, antimicrobial, antioxidant and anticancer activities. Moreover, they are therapeutic agents against organophosphate (OP) poisoning. Two oximes are already commonly used in therapy. Due to these abilities, new oxime compounds have been synthesized, and their biological activity has been verified. Often, modification of carbonyl compounds into oximes leads to increased activity. Nevertheless, in some cases, oxime activity is connected to the activity of the substrate. Recent works have revealed that new oxime compounds can demonstrate such functions and thus are considered to be potential drugs for pathogenic diseases, as adjuvant therapy in various types of cancer and inflammation and as potential next-generation drugs against OP poisoning.

Accelerating healing of excisional wound with alginate hydrogel containing naringenin in rat model

Wounds have always been considered as one of the most common physical damages. Therefore, various researches have been conducted to find an appropriate method to improve wound healing process. Among various materials, since hydrogels have appropriate properties for wound healing, they are widely used for this purpose. In this study, to develop a potential wound dressing, different concentrations of naringenin (0%, 1%, 10% and 20%) were incorporated in alginate hydrogel followed by evaluating its characters such as morphology, swelling properties, weight loss, antibacterial activity, releasing profile of the naringenin, hemo-, and cytocompatibility. Finally, to evaluate the effect of developed hydrogels on wound healing, the full-thickness dermal wound model in rat was used. Our results provided that the prepared hydrogels have appropriate porosity (86.7 ± 5.3%) with the interconnected pores. Moreover, weight loss assessment confirmed that fabricated hydrogels have suitable biodegradability (about 89% after 14 days). MTT assay also revealed the positive effect of hydrogels on cell viabilities, and they have no toxicity effect on cells. In vivo study indicated that the prepared hydrogels had better wound closure than the gauze-treated wound (the control), and alginate/20% naringenin group had the best wound closure among other groups. All in all, this study concluded that alginate/naringenin hydrogel has positive effect on wound healing process, and it can be used to treat skin injuries in the clinic. Graphical abstract.

Naringin sensitizes the antibiofilm effect of ciprofloxacin and tetracycline against Pseudomonas aeruginosa biofilm

The study aims to explore the combinatorial effect of naringin with antibiotics, ciprofloxacin and tetracycline on Pseudomonas aeruginosa biofilms. The antibiofilm efficacy of selected treatment regimes against P. aeruginosa biofilm were quantified by crystal violet assay, MTT assay, Congo red binding assay, and were visualized by confocal laser scanning microscopy and scanning electron microscopy. All the assays reflected antibiofilm activities, however, combinatorial performances of naringin with antibiotics were found to be more significant. A significant reduction in swimming and swarming motilities along with pellicle formation and altered colony morphology were observed as a result of combinatorial effect. The cytotoxicity of naringin and its antibiotic combinations was assayed on murine macrophage cell line. The applicability of such combinations was tested for their relative eradication against pre-formed biofilm on urinary catheter surface. This finding indicated that naringin potentiates the efficacy of both ciprofloxacin and tetracycline on P. aeruginosa biofilm in comparison to their solo treatment. The finding would help to open hitherto unexplored possibilities of establishing naringin as a potential antibiofilm agent and suggest on the possibility of its use in drug-herb combinations for managing biofilm-associated bacterial infections.

Natural Products-Derived Chemicals: Breaking Barriers to Novel Anti-HSV Drug Development

Recently, the problem of viral infection, particularly the infection with herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), has dramatically increased and caused a significant challenge to public health due to the rising problem of drug resistance. The antiherpetic drug resistance crisis has been attributed to the overuse of these medications, as well as the lack of new drug development by the pharmaceutical industry due to reduced economic inducements and challenging regulatory requirements. Therefore, the development of novel antiviral drugs against HSV infections would be a step forward in improving global combat against these infections. The incorporation of biologically active natural products into anti-HSV drug development at the clinical level has gained limited attention to date. Thus, the search for new drugs from natural products that could enter clinical practice with lessened resistance, less undesirable effects, and various mechanisms of action is greatly needed to break the barriers to novel antiherpetic drug development, which, in turn, will pave the road towards the efficient and safe treatment of HSV infections. In this review, we aim to provide an up-to-date overview of the recent advances in natural antiherpetic agents. Additionally, this paper covers a large scale of phenolic compounds, alkaloids, terpenoids, polysaccharides, peptides, and other miscellaneous compounds derived from various sources of natural origin (plants, marine organisms, microbial sources, lichen species, insects, and mushrooms) with promising activities against HSV infections; these are in vitro and in vivo studies. This work also highlights bioactive natural products that could be used as templates for the further development of anti-HSV drugs at both animal and clinical levels, along with the potential mechanisms by which these compounds induce anti-HSV properties. Future insights into the development of these molecules as safe and effective natural anti-HSV drugs are also debated.

Natural Compounds as Elicitors of Plant Resistance Against Diseases and New Biocontrol Strategies

The goal of sustainable and organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals, and people. Organic plant production uses natural products and natural self-regulation processes occurring in the ecosystem. The availability of innovative applications and molecular techniques opens up new possibilities in the approach to plant protection for sustainable and organic agriculture. New strategies not only directly protect plants against pathogens but can also induce enhanced immunity that permanently protects against pathogenic strains. This review focuses on the bioactive properties of selected natural compounds (of plant and animal origin), their action on pathogens, and their roles in the mechanism of inducing plant resistance. The author presents selected activities of organic bioactive compounds, such as allicin, naringin, terpenes, laminarin, carrageenans, chitin and chitosan, and outlines the possibilities for their application in protecting crop plants against diseases. In addition, this mini review describes the mechanism of action of the above compounds as elicitors of defense reactions in the plant and the possibility of their utilization in the production of biological preparations as elements of a new plant protection strategy.

Herbal Dentifrices: Emerging Trends and Patterns

Background:

Herbal extracts have been employed since ages in dentistry as tooth cleansing and antimicrobial agents. The use of herbal medicines continues to expand and trend rapidly across the world. Herbal extracts have been used in dentistry for multiple uses as reducing inflammation, as antimicrobial plaque agents, for preventing release of histamine and as antiseptics, antioxidants, antimicrobials and analgesics. They also aid in healing process and are very effective in controlling microbial plaque and other disorders related to gums.

Objective:

The present review aims towards the combined review as well as compilation of available herbs under the category of various dental associated problems.

Materials and Methods:

The herbs were studied by sectioning them as for looking after different works or findings done against dental caries, tooth ache, scouring teeth, gum troubles and herbs as mouth fresheners.

Results:

Herbal extracts have been used on a large scale in dentistry as tooth cleansing and antimicrobial plaque agents. Many people take herbal derived medicines or herbal based products for the purpose of reducing inflammation, as antimicrobial agents, for preventing release of histamine and as antiseptics, antioxidants, antifungals, antibacterials, antivirals and analgesics. Herbal extracts are used in dentistry for treatment of various dental disorders.

Conclusion:

The use of herbal medicines are blooming rapidly across the world. Herbal extracts and the various herbs on the whole or their specific parts have been used in dentistry. They relieve the problems of gums and act as excellent mouth fresheners. The natural herbal remedies act as an effective substitute to antibiotics and represent a promising approach for prevention and as therapeutic strategies for various oral infections as they are natural, eradicate the problem from its root and provide long lasting relief. The herbal remedies are advantageous over conventional treatment.

Antibacterial Activity of Some Flavonoids and Organic Acids Widely Distributed in Plants

Among natural substances widespread in fruits, vegetables, spices, and medicinal plants, flavonoids and organic acids belong to the promising groups of bioactive compounds with strong antioxidant and anti-inflammatory properties. The aim of the present work was to evaluate the antibacterial activity of 13 common flavonoids (flavones, flavonols, flavanones) and 6 organic acids (aliphatic and aromatic acids). The minimal inhibitory concentrations (MICs) of selected plant substances were determined by the micro-dilution method using clinical strains of four species of pathogenic bacteria. All tested compounds showed antimicrobial properties, but their biological activity was moderate or relatively low. Bacterial growth was most strongly inhibited by salicylic acid (MIC = 250-500 μg/mL). These compounds were generally more active against Gram-negative bacteria: Escherichia coli and Pseudomonas aeruginosa than Gram-positive ones: Enterococcus faecalis and Staphylococcus aureus. An analysis of the antibacterial effect of flavone, chrysin, apigenin, and luteolin showed that the presence of hydroxyl groups in the phenyl rings A and B usually did not influence on the level of their activity. A significant increase in the activity of the hydroxy derivatives of flavone was observed only for S. aureus. Similarly, the presence and position of the sugar group in the flavone glycosides generally had no effect on the MIC values.

Pharmacokinetic parameters of ifosfamide in mouse pre-administered with grapefruit juice or naringin

Grapefruit juice (GFJ) and naringin when consumed previously or together with medications may alter their bioavailavility and consequently the clinical effect. Ifosfamide (IF) is an antitumoral agent prescribed against various types of cancer. Nevertheless, there is no information regarding its interaction with the ingestion of GFJ or naringin. The aims of the present report were validating a method for the quantitation of IF in the plasma of mouse, and determine if mice pretreated with GFJ or naringin may modify the IF pharmacokinetics. Our HPLC results to quantify IF showed adequate intra and inter-day precision (RSD < 15%) and accuracy (RE < 15%) indicating reliability. Also, the administration of GFJ or naringin increased C_max of IF 22.9% and 17.8%, respectively, and decreased T_max of IF 19.2 and 53.8%, respectively. The concentration of IF was higher when GFJ (71.35 ± 3.5 µg/mL) was administered with respect to that obtained in the combination naringin with IF (64.12 ± µg/mL); however, the time required to reach such concentration was significantly lower when naringin was administered (p < 0.5). We concluded that pre-administering GFJ and naringin to mice increased the T_max and decreased the C_max of IF.

Site-selective acylation of natural products with BINOL-derived phosphoric acids

The site-selective acylation of a steroidal natural product 19-hydroxydehydroepiandrosterone catalyzed by 1,1'-Bi(2-napthol)-derived (BINOL) chiral phosphoric acids (CPA's) is described. Systematic variation and multivariate linear regression analysis reveal that the same steric parameters typically needed for high enantioselectivity with this class of CPAs are also required for site-selectivity in this case. Density functional theory calculations identify additional weak CH-π interactions as contributors to site discrimination. We further report a rare example of site-selective acylation of phenols through the evaluation of naringenin, a flavonoid natural product, using CPA catalysis. These results suggest that BINOL-derived CPA's may have broader applications in site-selective catalysis.