Structural characterization of chitosan nanoparticle loaded with Piper nigrum essential oil for biological efficacy against the stored grain pest control

Efficacy of Pogostemon cablin essential oil loaded chitosan nanoemulsion as novel coating agent for inhibition of potato sprouting and maintenance of storage quality

Application of synthetic compounds to inhibit potato sprouting is a major challenge in the storage conditions. The replacement of synthetic compounds by essential oils for inhibition of potato sprouting is of current research hotspot. This is the first time investigation on encapsulation of Pogostemon cablin essential oil into chitosan nanoemulsion (Ne-PCEO) and its application as coating agent for anti-sprouting activity of potato tubers. The Ne-PCEO was characterized through SEM, DLS, FTIR, and XRD assay along with controlled delivery of PCEO. The Ne-PCEO coating inhibited in-vivo potato sprouting and regulated gibberellins (GA3) and aminocyclopropane-1-carboxylate (ACC) content along with impediment of respiration rate over 90 days of storage at 25 ± 2 °C (RH ∼ 70 %). The Ne-PCEO coating also prevented the weight loss, starch degradation, and increased the reducing sugar content of tubers without affecting the sensory qualities (p < 0.05), which strongly recommends its potential application as novel anti-sprouting coating agent for maintenance of potato storage quality.

Chitosan-based insecticide formulations for insect pest control management: A review of current trends and challenges

Future agricultural practices necessitate green alternatives to replace hazardous insecticides while distinguishing between pests and beneficial insects. Chitosan, as a biological macromolecule derived from chitin, is biodegradable and exhibits low toxicity to non-target organisms, making it a sustainable alternative to synthetic pesticides. This review identifies chitosan-derivatives for insecticidal activity and highlights its efficacy including genotoxicity, defense mechanism, and disruption of insect's exoskeleton at different concentrations against several insect pests. Similarly, synergistic effects of chitosan in combination with natural extracts, essential oils, and plant-derived compounds, enhances insecticidal action against various pests was evaluated. The chitosan-based insecticide formulations (CHIF) in the form of emulsions, microcapsules, and nanoparticles showed efficient insecticide action on the targeted pests with less environmental impact. The current challenges associated with the field-trial application were also recognized, by optimizing potent CHIF-formulation parameters, scaling-up process, and regulatory hurdles addressed alongside potential solutions. These findings will provide insight into achieving the EU mission of reducing chemical pesticides by 50 %.

Chitosan nanoemulsion incorporated with Carum carvi essential oil as ecofriendly alternative for mitigation of aflatoxin B1 contamination in stored herbal raw materials

The present investigation entails the first report on entrapment of Carum carvi essential oil (CCEO) into chitosan polymer matrix for protection of stored herbal raw materials against fungal inhabitation and aflatoxin B1 (AFB1) production. Physico-chemical characterization of nanoencapsulated CCEO was performed through Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometry, and scanning electron microscopy. The nanoencapsulated CCEO displayed improved antifungal and AFB1 suppressing potentiality along with controlled delivery over unencapsulated CCEO. The encapsulated CCEO nanoemulsion obstructed the ergosterol production and escalated the efflux of cellular ions, thereby suggesting plasma membrane as prime target of antifungal action in Aspergillus flavus cells. The impairment in methyglyoxal production and modeling based carvone interaction with Afl-R protein validated the antiaflatoxigenic mechanism of action. In addition, CCEO displayed augmentation in antioxidant potentiality after encapsulation into chitosan nanomatrix. Moreover, the in-situ study demonstrated the effective protection of Withania somnifera root samples (model herbal raw material) against fungal infestation and AFB1 contamination along with prevention of lipid peroxidation. The acceptable organoleptic qualities of W. somnifera root samples and favorable safety profile in mice (animal model) strengthen the application of nanoencapsulated CCEO emulsion as nano-fungitoxicant for preservation of herbal raw materials against fungi and AFB1 mediated biodeterioration.

Exploring chitin: novel pathways and structures as promising targets for biopesticides

Chitin, the most prevalent polymer in nature, a significant structural polysaccharide that comes in second only to cellulose. Chitin is a crucial component of fungal cell walls and also present in many other creatures, such as viruses, plants, animals, insect exoskeletons, and crustacean shells. Chitin presents itself as a promising target for the development of biopesticides. It focuses on unraveling the unique structures and biochemical pathways associated with chitin, aiming to identify vulnerabilities that can be strategically leveraged for effective and environmentally sustainable pest control. It involves a comprehensive analysis of chitinase enzymes, chitin biosynthesis, and chitin-related processes across diverse organisms. By elucidating the molecular intricacies involved in chitin metabolism, this review seeks to unveil potential points of intervention that can disrupt essential biological processes in target pests without harming non-target species. This holistic approach to understanding chitin-related pathways aims to inform the design and optimization of biopesticides with enhanced specificity and reduced ecological impact. The outcomes of this study hold great promise for advancing innovative and eco-friendly pest management strategies. By targeting chitin structures and pathways, biopesticides developed based on these findings may offer a sustainable and selective alternative to conventional chemical pesticides, contributing to the ongoing efforts towards more environmentally conscious and effective pest control solutions.

Exploring the Biofilm Inhibition Potential of a Novel Phytic Acid-Crosslinked Chitosan Nanoparticle: In Vitro and In Vivo Investigations

The primary factor underlying the virulence of Candida albicans is its capacity to form biofilms, which in turn leads to recurrent complications. Over-the-counter antifungal treatments have proven ineffective in eliminating fungal biofilms and the inflammatory cytokines produced during fungal infections. Chitosan nanoparticles offer broad and versatile therapeutic potential as both antifungal agents and carriers for antifungal drugs to combat biofilm-associated Candida infections. In our study, we endeavoured to develop chitosan nanoparticles utilising chitosan and the antifungal crosslinker phytic acid targeting C. albicans. Phytic acid, known for its potent antifungal and anti-inflammatory properties, efficiently crosslinks with chitosan. The nanoparticles were synthesised using the ionic gelation technique and subjected to analyses including Fourier transform infrared spectroscopy, dynamic light scattering, and zeta potential analysis. The synthesised nanoparticles exhibited dimensions with a diameter (Dh) of 103 ± 3.9 nm, polydispersity index (PDI) of 0.33, and zeta potential (ZP) of 37 ± 2.5 mV. These nanoparticles demonstrated an antifungal effect with a minimum inhibitory concentration (MIC) of 140 ± 2.2 µg/mL, maintaining cell viability at approximately 90% of the MIC value and reducing cytokine levels. Additionally, the nanoparticles reduced ergosterol content and exhibited a 62% ± 1.2 reduction in biofilm susceptibility, as supported by colony-forming unit (CFU) and XTT assays-furthermore, treatment with nanoparticles reduced exopolysaccharide production and decreased secretion of aspartyl protease by C. albicans. Our findings suggest that the synthesised nanoparticles effectively combat Candida albicans infections. In vivo studies conducted on a mouse model of vaginal candidiasis confirmed the efficacy of the nanoparticles in combating fungal infections in vivo.

Eco-friendly management strategies of insect pests: long-term performance of rosemary essential oil encapsulated into chitosan and gum Arabic

This study focused on encapsulation of Rosmarinus officinalis essential oil (EO) on chitosan and gum Arabic matrix in various ratios and with varying essential oil concentrations. Additionally, UV/VIS spectroscopy was used to determine cumulative-release profiles. The insecticidal activity was tested against Tribolium castaneum and Oryzaephilus surinamensis, both pests of stored products. In terms of encapsulation efficiency (EE%) and loading capacity (LC%), capsules had EE at 45.8% and LC at 2.31%. Furthermore, many minor compounds were lost after encapsulation, until identifying only 1,8-cineole, α-terpineol, and camphor after 60 d of storage. The fumigant tests demonstrated that encapsulated EO exhibited an effective control against insect pest during storage periods, namely, 30, 45, and 60 d with 99, 66, and 46% mortality for T. castaneum and 100, 84, 82% mortality for O. surinamensis.

A review of chitosan nanoparticles: Nature's gift for transforming agriculture through smart and effective delivery mechanisms

Chitosan nanoparticles (CNPs) have emerged as a promising tool in agricultural advancements due to their unique properties including, biocompatability, biodegradability, non-toxicity and remarkable versatility. These inherent properties along with their antimicrobial, antioxidant and eliciting activities enable CNPs to play an important role in increasing agricultural productivity, enhancing nutrient absorption and improving pest management strategies. Furthermore, the nano-formulation of chitosan have the ability to encapsulate various agricultural amendments, enabling the controlled release of pesticides, fertilizers, plant growth promoters and biocontrol agents, thus offering precise and targeted delivery mechanisms for enhanced efficiency. This review provides a comprehensive analysis of the latest research and developments in the use of CNPs for enhancing agricultural practices through smart and effective delivery mechanisms. It discusses the synthesis methods, physicochemical properties, and their role in enhancing seed germination and plant growth, crop protection against biotic and abiotic stresses, improving soil quality and reducing the environmental pollution and delivery of agricultural amendments. Furthermore, the potential environmental benefits and future directions for integrating CNPs into sustainable agricultural systems are explored. This review aims to shed light on the transformative potential of chitosan nanoparticles as nature's gift for revolutionizing agriculture and fostering eco-friendly farming practices.

Chemical Composition of Piper nigrum L. Cultivar Guajarina Essential Oils and Their Biological Activity

The essential oils and aroma derived from the leaves (L), stems (St), and spikes (s) of Piper nigrum L. cv. Guajarina were extracted; the essential oils were extracted using hydrodistillation (HD), and steam distillation (SD), and the aroma was obtained by simultaneous distillation and extraction (SDE). Chemical constituents were identified and quantified using GC/MS and GC-FID. Preliminary biological activity was assessed by determining the toxicity against Artemia salina Leach larvae, calculating mortality rates, and determining lethal concentration values (LC50). The predominant compounds in essential oil samples included α-pinene (0-5.6%), β-pinene (0-22.7%), limonene (0-19.3%), 35 linalool (0-5.3%), δ-elemene (0-10.1%), β-caryophyllene (0.5-21.9%), γ-elemene (7.5-33.9%), and curzerene (6.9-31.7%). Multivariate analysis, employing principal component analysis (PCA) and hierarchical cluster analysis (HCA), revealed three groups among the identified classes and two groups among individual compounds. The highest antioxidant activity was found for essential oils derived from the leaves (167.9 41 mg TE mL-1). Larvicidal potential against A. salina was observed in essential oils obtained from the leaves (LC50 6.40 μg mL-1) and spikes (LC50 6.44 μg mL-1). The in silico studies demonstrated that the main compounds can interact with acetylcholinesterase, thus showing the potential molecular interaction responsible for the toxicity of the essential oil in A. salina.

Chitosan nanoparticles loaded with Eucommia ulmoides seed essential oil: Preparation, characterization, antioxidant and antibacterial properties

Eucommia ulmoides seed essential oil (EUSO) is a natural plant oil rich in various nutrients, which has been widely used due to its unique medicinal effects. However, it is prone to oxidation and rancidity under many adverse environmental influences. Nanoencapsulation technology can protect and slow down the loss of its biological activity. In this study, chitosan nanoparticles (CSNPs) loaded with EUSO were prepared by emulsification and ionic gel technology. EUSO-CSNPs were characterized by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results confirmed the success of EUSO encapsulation and the encapsulation rate ranged from 36.95 % to 67.80 %. Nanoparticle size analyzer, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) showed that CSNPs were spherical particles with a range of 200.6-276.0 nm. The results of in vitro release study indicated that the release of EUSO was phased, and EUSO-CSNPS had certain sustained-release properties. Furthermore, EUSO-CSNPs had higher antioxidant and antibacterial abilities than pure EUSO and chitosan, which was verified through free radical scavenging experiments and bacteria biofilm experiments, respectively. This technology can enhance the medicinal value of EUSO in biomedical and other fields, and will provide support for in vivo research of EUSO-CSNPs in the future.

"Review of strategic methods for encapsulating essential oils into chitosan nanosystems and their applications"

Essential oils (EOs) are hydrophobic, concentrated extracts of botanical origin containing diverse bioactive molecules that have been used for their biomedical properties. On the other hand, the volatility, toxicity, and hydrophobicity limited their use in their pure form. Therefore, nano-encapsulation of EOs in a biodegradable polymeric platform showed a solution. Chitosan (CS) is a biodegradable polymer that has been intensively used for EOs encapsulation. Various approaches such as homogenization, probe sonication, electrospinning, and 3D printing have been utilized to integrate EOs in CS polymer. Different CS-based platforms were investigated for EOs encapsulation such as nanoparticles (NPs), nanofibers, films, nanoemulsions, 3D printed composites, and hydrogels. Biological applications of encapsulating EOs in CS include antioxidant, antimicrobial, and anticancer functions. This review explores the principles for nanoencapsulation strategies, and the available technologies are also reviewed, in addition to an in-depth overview of the current research and application of nano-encapsulated EOs.

Chitosan as a Control Tool for Insect Pest Management: A Review

Chitosan, a polysaccharide derived from the deacetylation of chitin, is a versatile and eco-friendly biopolymer with several applications. Chitosan is recognized for its biodegradability, biocompatibility, and non-toxicity, beyond its antimicrobial, antioxidant, and antitumoral activities. Thanks to its properties, chitosan is used in many fields including medicine, pharmacy, cosmetics, textile, nutrition, and agriculture. This review focuses on chitosan's role as a tool in insect pest control, particularly for agriculture, foodstuff, and public health pests. Different formulations, including plain chitosan, chitosan coating, chitosan with nematodes, chitosan's modifications, and chitosan nanoparticles, are explored. Biological assays using these formulations highlighted the use of chitosan-essential oil nanoparticles as an effective tool for pest control, due to their enhanced mobility and essential oils' prolonged release over time. Chitosan's derivatives with alkyl, benzyl, and acyl groups showed good activity against insect pests due to improved solubility and enhanced activity compared to plain chitosan. Thus, the purpose of this review is to provide the reader with updated information concerning the use and potential applications of chitosan formulations as pest control tools.

Functionalized nanoencapsulated Curcuma longa essential oil in chitosan nanopolymer and their application for antioxidant and antimicrobial efficacy

The present study reports on the encapsulation of Curcuma longa (L.) essential oil (CLEO) in chitosan nanopolymer as a novel nanotechnology preservative for enhancing its antibacterial, antifungal, and mycotoxin inhibitory efficacy. GC-MS analysis of CLEO showed the presence of α-turmerone (42.6 %) and β- turmerone (14.0 %) as the major components. CLEO-CSNPs were prepared through the ionic-gelation technique and confirmed by TEM micrograph, DLS, XRD, and FTIR. In vitro, bactericidal activity of CLEO-CSNPs at a concentration of 100 μg/mL showed significant antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, which mostly rely on ROS production and depend on its penetration and interaction with bacterial cells. Furthermore, the CLEO-CSNPs during in vitro investigation against F. graminearum completely inhibited the growth and zearalenone and deoxynivalenol production at 0.75 μL/mL, respectively. Further, CLEO-CSNPs enhanced antioxidant activity against DPPH• and ABTS•+ with IC50 values 0.95 and 0.66 μL/mL, respectively, and without any negative impacts on germinating seeds were observed during the phytotoxicity investigation. Overall, experiments concluded that encapsulated CLEO enhances antimicrobial inhibitory efficiency against stored foodborne pathogens.

Sonication and heat-mediated synthesis, characterization and larvicidal activity of sericin-based silver nanoparticles against dengue vector (Aedes aegypti)

Fabrication, characterization and evaluation of the larvicidal potential of novel silk protein (sericin)-based silver nanoparticles (Se-AgNPs) were the prime motives of the designed study. Furthermore, investigation of the sericin as natural reducing or stabilizing agent was another objective behind this study. Se-AgNPs were synthesized using sonication and heat. Fabricated Se-AgNPs were characterized using particle size analyzer, UV spectrophotometry, FTIR and SEM which confirmed the fabrication of the Se-AgNPs. Size of sonication-mediated Se-AgNPs was smaller (7.49 nm) than heat-assisted Se-AgNPs (53.6 nm). Being smallest in size, sonication-assisted Se-AgNPs revealed the significantly highest (F4,10  = 39.20, p = .00) larvicidal activity against fourth instar lab and field larvae (F4,10  = 1864, p = .00) of dengue vector (Aedes aegypti) followed by heat-assisted Se-AgNPs and positive control (temephos). Non-significant larvicidal activity was showed by silver (without sericin) which made the temperature stability of silver, debatable. Furthermore, findings of biochemical assays (glutathione-S transferase, esterase, and acetylcholinesterase) showed the levels of resistance in field strain larvae. Aforementioned findings of the study suggests the sonication as the best method for synthesis of Se-AgNPs while the larvicidal activity is inversely proportional to the size of Se-AgNPs, i.e., smallest the size, highest the larvicidal activity. Conclusively, status of the sericin as a natural reducing/stabilizing agent has been endorsed by the findings of this study. RESEARCH HIGHLIGHTS: Incorporation of biocompatible and inexpensive sericin as a capping/reducing agent for synthesis of Se-AgNPs. A novel sonication method was used for the fabrication of Se-AgNPs which were thoroughly characterized by particle size analyzer, UV-visible spectrophotometry, SEM and FTIR. Analysis of enzymatic (GSTs, ESTs) levels in field and lab strains of Aedes aegypti larvae for evaluation of insecticides resistance.

Carvacrol-Fabricated Chitosan Nanoparticle Synergistic Potential with Topoisomerase Inhibitors on Breast and Cervical Cancer Cells

Breast and cervical cancers are the most common heterogeneous malignancies in women. Chemotherapy with conventional drug delivery systems having several limitations along with development of multidrug resistance compelled us to seek out targeted therapeutics. Nanoparticles are suitable substitutes to circumvent multidrug resistance for the targeted treatment of cancer. The current study was aimed to investigate the anticancer effect of carvacrol-loaded chitosan nanoparticles with topoisomerase inhibitors. The average size of carvacrol-loaded chitosan nanoparticles was found to be 80 nm with 24.7 mV ζ-potential, and maximum absorbance was observed at 275 nm. Among all drug combinations, the carvacrol nanoparticles with the doxorubicin combination group exerted greater dose-dependent growth inhibition of both MCF-7 and HeLa cells as compared to single carvacrol nanoparticles and doxorubicin. Combination index values of carvacrol nanoparticles and the doxorubicin combination group showed a strong synergistic effect as they were found to be between 0.2 and 0.4, 0.31 for MCF-7 and 0.34 for HeLa cells. The carvacrol nanoparticles in combination with doxorubicin on MCF-7 cells reduced the dose 16.32-fold for carvacrol nanoparticles and 4.09-fold for doxorubicin at 6.23 μg/mL IC50, while on HeLa cells, this combination reduced the dose 13.18-fold for carvacrol nanoparticles and 3.83-fold for doxorubicin at 9.33 μg/mL IC50. As the dose reduction values were greater than 1, they indicated favorable dose reduction. It was concluded that the combination of carvacrol-loaded chitosan nanoparticles with topoisomerase inhibitors may represent an innovative and promising strategy to improve the efficacy, resistance, and targeted delivery of chemotherapeutics in cancer.

Efficiency of Artemisia annua L. essential oil and its chitosan/tripolyphosphate or zeolite encapsulated form in controlling Sitophilus oryzae L

The rice weevil, Sitophilus oryzae L., is one of the most widespread and destructive stored-product pests and resistant to a wide range of chemical insecticides. In this research, Artemisia annua L. essential oil (EO) and its encapsulated form by chitosan/TPP (tripolyphosphate) and zeolite were tested against S. oryzae adults. The order of toxicity was chitosan/TPP (LC30: 30.83, LC50: 39.52, and LC90: 72.50 μL/L air) > pure EO (LC30: 35.75, LC50: 46.25, and LC90: 86.76 μL/L air) > EO loaded in the zeolite (LC30: 43.35, LC50: 55.07, and LC90: 98.80 μL/L air). These encapsulated samples were characterized by dynamic light scattering (DLS) and field emission scanning electron microscope (FE-SEM) which revealed the size and morphology of the droplets measuring 255.2 to 272 nm and 245 to 271.8 nm for EO loaded in chitosan and zeolite respectively. The encapsulation efficiency and loading percentages of A. annua EO in chitosan/TPP and zeolite were 40.16% and 6.01%, and 88% and 85%, respectively. Fumigant persistence was increased from 6 days for pure EO then, 20 and 22 days for encapsulated oil in zeolite and chitosan/TPP, respectively. Our results showed that A. annua EO contains (±)-camphor (29.29%), 1,8-cineole (12.56%), β-caryophyllene (10.29%), α-pinene (8.68%), and artemisia ketone (8.48%) as its major composition. The activity level of glutathione S-transferase increased while general esterase and acetylcholinesterase activity were significantly inhibited in the treated group compared with the control. Antioxidant enzymes, including catalase, peroxidase, and superoxide dismutase were activated in treated adults compared to controls. The current results suggest that encapsulation of A. annua EO by chitosan/TPP and zeolite in addition to safety and environmentally friendly approach could increase its sustainability and therefore enhancing the efficiency in controlling S. oryzae in storage.

Nanoencapsulation of garlic essential oil using chitosan nanopolymer and its antifungal and anti-aflatoxin B1 efficacy in vitro and in situ

The present study investigated the comparative efficacy of garlic essential oil (GEO) and its nanoencapsulated within chitosan nanomatrix (GEO-CSNPs) as a novel preservative for the protection of stored food commodities from fungal infestations, aflatoxin B1 (AFB1) contamination and lipid peroxidation against a toxigenic strain of Aspergillus flavus. GC-MS examination of GEO showed the presence of allyl methyl tri-sulfide (23.10 %) and diallyl sulfide (19.47 %) as the major components. GEO-CSNPs were characterized through TEM micrograph, DLS, XRD, and FTIR instrumentation. During the in-vitro investigation, GEO-CSNPs at 1.0 μL/mL dose completely inhibited the growth of A. flavus while preventing the synthesis of AFB₁ at 0.75 μL/mL compared to the pure GEO. The biochemical analysis reveals that A. flavus exposed to GEO-CSNPs significantly changed its ergosterol level, ions leakage, mitochondrial membrane potential (MMP), and antioxidant system. Additionally, GEO-CSNPs exhibited enhanced antioxidant activity against DPPH compared with GEO. Likewise, during in-situ experiments on A. hypogea GEO-CSNPs MIC and 2 MIC concentration prohibited fungal development, AFB₁ synthesis, and lipid peroxidation or inflicting any negative impacts on germinating seeds. Overall, investigations concluded that GEO-CSNPs could be used as a novel preservative agent to improve the shelf life of stored food commodities.

Chitosan based encapsulation of Valeriana officinalis essential oil as edible coating for inhibition of fungi and aflatoxin B1 contamination, nutritional quality improvement, and shelf life extension of Citrus sinensis fruits

In this study, a novel chitosan nanoemulsion coating embedded with Valeriana officinalis essential oil (Ne-VOEO) was synthesized in order to improve the postharvest quality of Citrus sinensis fruits against infesting fungi, and aflatoxin B₁ (AFB₁) mediated nutritional deterioration. The developed nanoemulsion was characterized through SEM, FTIR, XRD, and DLS analyses. The nanoemulsion showed controlled delivery of VOEO responsible for effective inhibition of Aspergillus flavus, A. niger, A. versicolor, Penicillium italicum, and Fusarium oxysporum growth at 6.5, 5.0, 4.0, 5.5, and 3.5 μL/mL, respectively and AFB₁ production at 5.0 μL/mL. The biochemical and molecular mechanism of aflatoxigenic A. flavus inhibition, and AFB₁ diminution was associated with impairment in ergosterol biosynthesis, methylglyoxal production, and stereo-spatial binding of valerianol in the cavity of Ver-1 protein. During in vivo investigation, Ne-VOEO coating potentially restrained the weight loss, and respiratory rate of C. sinensis fruits with delayed degradation of soluble solids, titrable acidity, pH, and phenolic contents along with maintenance of SOD, CAT, APX activities (p < 0.05) and sensory attributes under specific storage conditions. Based on overall findings, Ne-VOEO nanoemulsion could be recommended as green, and smart antifungal coating agent in prolonging the shelf-life of stored fruits with enhanced AFB₁ mitigation.

Effects of Piper nigrum L. Fruit Essential Oil Toxicity against Stable Fly (Diptera: Muscidae)

The efficacy of Piper nigrum L. fruit essential oil (EO) against Stomoxys calcitrans (stable fly), a blood-feeding fly distributed worldwide, was investigated. This study aimed to evaluate the insecticidal activity of EO based on contact and fumigant toxicity tests. Chemical analysis of the EO using gas chromatography-mass spectrometry revealed that sabinene (24.41%), limonene (23.80%), β-caryophyllene (18.52%), and α-pinene (10.59%) were the major components. The results demonstrated that fly mortality increased with increasing EO concentration and time during the first 24 h of exposure. The median lethal dose was 78.37 µg/fly for contact toxicity, while the 90% lethal dose was 556.28 µg/fly. The median lethal concentration during fumigant toxicity testing was 13.72 mg/L air, and the 90% lethal concentration was 45.63 mg/L air. Our findings suggested that essential oil extracted from P. nigrum fruit could be a potential natural insecticidal agent for control of stable fly. To examine the insecticidal properties of P. nigrum fruit EO, further field trials and investigation into the efficacy of nano-formulations are required.

Critical Review on Nutritional, Bioactive, and Medicinal Potential of Spices and Herbs and Their Application in Food Fortification and Nanotechnology

Medicinal or herbal spices are grown in tropical moist evergreen forestland, surrounding most of the tropical and subtropical regions of Eastern Himalayas in India (Sikkim, Darjeeling regions), Bhutan, Nepal, Pakistan, Iran, Afghanistan, a few Central Asian countries, Middle East, USA, Europe, South East Asia, Japan, Malaysia, and Indonesia. According to the cultivation region surrounded, economic value, and vogue, these spices can be classified into major, minor, and colored tropical spices. In total, 24 tropical spices and herbs (cardamom, black jeera, fennel, poppy, coriander, fenugreek, bay leaves, clove, chili, cassia bark, black pepper, nutmeg, black mustard, turmeric, saffron, star anise, onion, dill, asafoetida, celery, allspice, kokum, greater galangal, and sweet flag) are described in this review. These spices show many pharmacological activities like anti-inflammatory, antimicrobial, anti-diabetic, anti-obesity, cardiovascular, gastrointestinal, central nervous system, and antioxidant activities. Numerous bioactive compounds are present in these selected spices, such as 1,8-cineole, monoterpene hydrocarbons, γ-terpinene, cuminaldehyde, trans-anethole, fenchone, estragole, benzylisoquinoline alkaloids, eugenol, cinnamaldehyde, piperine, linalool, malabaricone C, safrole, myristicin, elemicin, sinigrin, curcumin, bidemethoxycurcumin, dimethoxycurcumin, crocin, picrocrocin, quercetin, quercetin 4'-O-β-glucoside, apiol, carvone, limonene, α-phellandrene, galactomannan, rosmarinic acid, limonene, capsaicinoids, eugenol, garcinol, and α-asarone. Other than that, various spices are used to synthesize different types of metal-based and polymer-based nanoparticles like zinc oxide, gold, silver, selenium, silica, and chitosan nanoparticles which provide beneficial health effects such as antioxidant, anti-carcinogenic, anti-diabetic, enzyme retardation effect, and antimicrobial activity. The nanoparticles can also be used in environmental pollution management like dye decolorization and in chemical industries to enhance the rate of reaction by the use of catalytic activity of the nanoparticles. The nutritional value, phytochemical properties, health advantages, and both traditional and modern applications of these spices, along with their functions in food fortification, have been thoroughly discussed in this review.

Edible Plant Extracts against Aedes aegypti and Validation of a Piper nigrum L. Ethanolic Extract as a Natural Insecticide

The Aedes aegypti mosquito significantly impacts public health, with vector control remaining the most efficient means of reducing the number of arboviral disease cases. This study screened the larvicidal and pupicidal activity of common edible plant extracts. Piper nigrum L. (black pepper) extract production was optimized using accelerated solvent extraction (ASE) and validated following regulatory requirements using HPLC-PDA analytical methodology to quantify its major component-piperine. Larvicidal activity was determined for the standardized P. nigrum fruit ethanol extract (LC₅₀ 1.1 µg/mL) and piperine standard (LC₅₀ 19.0 µg/mL). Furthermore, 9-day residual activity was determined for the extract (4 µg/mL) and piperine (60 µg/mL), with daily piperine quantification. Semi-field trials of solid extract formulations demonstrated 24-day activity against Ae. aegypti larvae. Thus, the standardized P. nigrum extract emerges as a potential candidate for insecticide development to control the arboviral vector.

A Scientometric Review of Grain Storage Technology in the Past 15 Years (2007-2022) Based on Knowledge Graph and Visualization

Food storage helps to ensure the food consumption needs of non-agricultural populations and to respond to major natural disasters or other emergencies, and the application of food storage technology can reduce post-harvest food losses. However, there are still obvious shortcomings in coping with large grain losses. Therefore, quantitative analysis of the research hotspots and evolutionary trends of grain storage technology is important to help the development of grain storage technology. This article uses the Web of Science database from 2007 to 2022 as a data sample with the help of CiteSpace software to analyze the basic situation, research hotspots, and evolutionary trends to draw a series of relevant knowledge maps. Visual analysis revealed that the number of publications had grown rapidly since 2015. First, the Journal of Stored Products Research, Journal of Economic Entomology, and Journal of Agricultural and Food Chemistry, with citation frequencies of 929, 536, and 453, should be focused on in order to keep up with the latest research developments in this field. The United States, China, and Brazil occupy dominant positions in relation to grain storage technology studies in general. Purdue University, Kansas State University, and Agricultural Research Institute ranked the top three in terms of the number and centrality of publications. In terms of research hotspots, the centrality of temperature, insects, carbon dioxide, and quality were 0.16, 0.09, 0.08, and 0.08. It shows that the field of grain storage technology in recent years has focused on grain storage temperature, pest control, and grain storage quality research. From the perspective of the evolution trend, the life cycle of emergent words lasts for several years, after which the strength of emergent words slowly decreases and is replaced by new emergent words. Mortality was the first keyword to appear and remained from 2007 to 2011, indicating that research on fumigants and their toxicity, as well as pest mortality under air fumigation and chemical fumigation conditions, became more popular during this period. In recent years, new terms have emerged that had never been used before, such as "grain quality" (2019-2022) and "stability" (2020-2022). We can find that people pursue food quality more with the improvement of people's living standards. In this context, future research should seek more efficient, safe, economical, and environmentally friendly methods of grain storage and continuously improve the level of scientific grain storage.

Nano-Encapsulation of Citrus Essential Oils: Methods and Applications of Interest for the Food Sector

Citrus essential oils possess many health-promoting benefits and properties of high interest in the food and agri-food sector. However, their large-scale application is limited by their sensitivity to environmental factors. Nanostructures containing citrus essential oils have been developed to overcome the high volatility and instability of essential oils with respect to temperature, pH, UV light, etc. Nanostructures could provide protection for essential oils and enhancement of their bioavailability and biocompatibility, as well as their biological properties. Nano-encapsulation is a promising method. The present review is mainly focused on methods developed so far for the nano-encapsulation of citrus essential oils, with emphasis on lipid-based (including liposomes, solid lipid nanoparticles, nanostructured lipid particles, and nano- and micro-emulsions) and polymer-based nanostructures. The physico-chemical characteristics of the obtained structures, as well as promising properties reported, with relevance for the food sector are also discussed.

Zingiber officinale essential oil-loaded chitosan-tripolyphosphate nanoparticles: Fabrication, characterization and in-vitro antioxidant and antibacterial activities

Zingiber officinale essential oil (ZEO) was encapsulated in chitosan nanoparticles at different concentrations using the emulsion-ionic gelation technique and its antioxidant and antibacterial effects were investigated. The results indicated that ZEO level had a significant effect on encapsulation efficiency (EE), loading capacity (LC), particle size and zeta potential. The value obtained for EE, LC, mean particle size and zeta potential were 49.11%-68.32%, 21.16%-27.54%, 198.13-318.26 nm and +21.31-43.57 mV, respectively. According to scanning electron micrographs, the nanoparticles had a spherical shape with some invaginations due to the drying process. The presence of essential oil within the chitosan nanoparticles was confirmed by Fourier transform infrared (FTIR) spectroscopy. In vitro release studies in simulated gastrointestinal fluid (SGF) and simulated intestinal fluid (SIF) indicated an initial burst effect followed by slow release with higher release rate in acidic medium of SGF. ZEO-loaded nanoparticles showed DPPH radical scavenging activity of 20%-61% which increased by raising the ZEO level. Moreover, results of antibacterial activity revealed that Staphylococcus aureus (with inhibition zones of 19-35.19 mm2) and Salmonella typhimurium (with inhibition zones of 9.78-17.48 mm2) were the most sensitive and resistant bacteria to ZEO, respectively. Overall, chitosan nanoparticles can be considered as suitable vehicles for ZEO and improve its stability and solubility.

Chemical Profiling, Formulation Development, In Vitro Evaluation and Molecular Docking of Piper nigrum Seeds Extract Loaded Emulgel for Anti-Aging

Emulgel is a new innovatory technique for drug development permitting controlled release of active ingredients for topical administration. We report a stable emulgel of 4% Piper nigrum extract (PNE) prepared using 80% ethanol. The PNE-loaded formulation had an antioxidant activity of 84% and tyrosinase inhibition was 82%. Prepared formulation rendered spherical-shaped globules with high zeta potential (−45.5 mV) indicative of a stable system. Total phenolic contents were 58.01 mg GAE/g of dry extract whereas total flavonoid content was 52.63 mg QE/g of dry extract. Sun protection factor for PNE-loaded emulgel was 7.512 and formulation was stable without any evidence of physical and chemical changes following 90 days of storage. Gas chromatography-mass spectroscopy (GC-MS) revealed seventeen bioactive compounds in the PNE including monoterpenoids, triterpenoids, a tertiary alcohol, fatty acid esters, and phytosterols. In silico studies of GC-MS identified compounds show higher binding affinity in comparison to standard kojic acid indicating tyrosinase inhibition. It can be concluded that PNE-loaded emulgel had prominent antioxidant and tyrosinase inhibition and can be utilized as a promising topical system for anti-aging skin formulation.

Chitosan encompassed Aniba rosaeodora essential oil as innovative green candidate for antifungal and antiaflatoxigenic activity in millets with emphasis on cellular and its mode of action

The present study demonstrates first time investigation on encapsulation of Aniba rosaeodora essential oil into chitosan nanoemulsion (AREO-CsNe) with the aim of improvement of its antifungal, and aflatoxin B₁ (AFB₁) inhibitory performance in real food system. The GC–MS analysis of AREO revealed the presence of linalool (81.46%) as a major component. The successful encapsulation of EO into CsNe was confirmed through SEM, FTIR, and XRD analysis. The in-vitro release study showed the controlled release of AREO. AREO-CsNe caused complete inhibition of Aspergillus flavus (AFLHPSi-1) growth and AFB₁ production at 0.8 and 0.6 μl/ml, respectively, which was far better than AREO (1.4 and 1.2 μl/ml, respectively). Impairment of ergosterol biosynthesis coupled with enhancement of cellular materials leakage confirmed plasma membrane as the possible antifungal target of both AREO and AREO-CsNe. Significant inhibition of methylglyoxal (AFB₁ inducer) synthesis in AFLHPSi-1 cells by AREO and AREO-CsNe confirmed their novel antiaflatoxigenic mode of action. In-silico molecular docking studies revealed effective interaction of linalool with Ver-1 and Omt-A proteins, leading to inhibition of AFB₁ biosynthesis. Further, AREO-CsNe showed enhanced antioxidant activity with IC₅₀ values 3.792 and 1.706 μl/ml against DPPH^• and ABTS^•+ radicals, respectively. In addition, AREO-CsNe caused 100% protection of stored millets (Setaria italica seeds) from AFB₁ contamination and lipid peroxidation over a period of 1 year without compromising its sensory properties and exhibited high safety profile with LD₅₀ value 9538.742 μl/kg body weight. Based on enhanced performance of AREO-CsNe over AREO, it can be recommended as a novel substitute of synthetic preservative for preservation of stored millets.

When Scent Becomes a Weapon—Plant Essential Oils as Potent Bioinsecticides

Crop protection still mostly relies on synthetic pesticides for crop pest control. However, the rationale for their continued use is shaded by the revealed adverse effects, such as relatively long environmental persistence that leads to water and soil contamination and retention of residues in food that brings high risks to human and animal health. As part of integrated pest management, biopesticides may provide crop protection, being eco-friendly and safe for humans and non-target organisms. Essential oils, complex mixtures of low-molecular-weight, highly volatile compounds, have been highlighted as major candidates for plant-derived bioinsecticides that are up to the sustainable biological standard. In this review, we screened the insecticidal activity of essential oils or their purified compounds, with focus given to their modes of action, along with the analyzed advantages and problems associated with their wider usage as plant-derived insecticides in agriculture.

Antibacterial and antibiofilm activities of chitosan nanoparticles loaded with Ocimum basilicum L. essential oil

Nanoencapsulation has been verified to be an effective technique to improve the physical stability of essential oils. In this study, Ocimum basilicum L. essential oil (BEO) was encapsulated into chitosan nanoparticles by emulsion and ionic gelation. The success of BEO loading was revealed by Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectrophotometry and X-ray diffraction (XRD) analyses. Scanning electron microscopy (SEM) images and dynamic light scattering (DLS) illustrated regular distribution and spherical morphology with a particle size range of 198.7 - 373.4 nm. The prepared samples had an encapsulation efficiency (EE) range of 50.39 - 5.13% and a loading capacity (LC) range of 7.22-19.78%. Encapsulation of BEO into chitosan nanocarriers demonstrated strong antibacterial and antibiofilm capacity against E. coli and S. aureus with inhibition diameter of 15.3 mm and 21.0 mm, respectively, and the obtained nanoparticles were found to damage cell membranes and cause the leakage of biological macromolecules.

Multifunctional Role of Silica in Pharmaceutical Formulations

Due to the high surface area, adjustable surface and pore structures, and excellent biocompatibility, nano- and micro-sized silica have certainly attracted the attention of many researchers in the medical fields. This review focuses on the multifunctional roles of silica in different pharmaceutical formulations including solid preparations, liquid drugs, and advanced drug delivery systems. For traditional solid preparations, it can improve compactibility and flowability, promote disintegration, adjust hygroscopicity, and prevent excessive adhesion. As for liquid drugs and preparations, like volatile oil, ethers, vitamins, and self-emulsifying drug delivery systems, silica with adjustable pore structures is a good adsorbent for solidification. Also, silica with various particle sizes, surface characteristics, pore structure, and surface modification controlled by different synthesis methods has gained wide attention owing to its unparalleled advantages for drug delivery and disease diagnosis. We also collate the latest pharmaceutical applications of silica sorted out by formulations. Finally, we point out the thorny issues for application and survey future trends pertaining to silica in an effort to provide a comprehensive overview of its future development in the medical fields. Graphical Abstract.

Nanotechnology-Based Bioactive Antifeedant for Plant Protection

The productivity of vegetable crops is constrained by insect pests. The search for alternative insect pest control is becoming increasingly important and is including the use of plant-derived pesticides. Plant-derived pesticides are reported as effective in controlling various insect pests through natural mechanisms, with biodegradable organic materials, diverse bioactivity, and low toxicity to non-target organisms. An antifeedant approach for insect control in crop management has been comprehensively studied by many researchers, though it has only been restricted to plant-based compounds and to the laboratory level at least. Nano-delivery formulations of biopesticides offer a wide variety of benefits, including increased effectiveness and efficiency (well-dispersion, wettability, and target delivery) with the improved properties of the antifeedant. This review paper evaluates the role of the nano-delivery system in antifeedant obtained from various plant extracts. The evaluation includes the research progress of antifeedant-based nano-delivery systems and the bioactivity performances of different types of nano-carrier formulations against various insect pests. An antifeedant nano-delivery system can increase their bioactivities, such as increasing sublethal bioactivity or reducing toxicity levels in both crude extracts/essential oils (EOs) and pure compounds. However, the plant-based antifeedant requires nanotechnological development to improve the nano-delivery systems regarding properties related to the bioactive functionality and the target site of insect pests. It is highlighted that the formulation of plant extracts creates a forthcoming insight for a field-scale application of this nano-delivery antifeedant due to the possible economic production process.

Ag@MOF-loaded p-coumaric acid modified chitosan/chitosan nanoparticle and polyvinyl alcohol/starch bilayer films for food packing applications

Developing novel bilayer food packing film having the ability to prevent bacterial infections and capable of inhibiting oxidation is utmost important, since bacterial infections and oxidation can cause food spoilage. Ag-Metal-organic framework loaded p-coumaric acid modified chitosan (P-CS/Ag@MOF) or chitosan nanoparticles (P-CSNPs/Ag@MOF) and polyvinyl alcohol/starch (PVA/ST) were used as the upper film and lower layer film to successfully prepare a bilayer composite film. The microscopic morphology, water resistance, oil resistance, oxidation resistance, optical properties, cytotoxicity and antibacterial properties of the composite films were compared. The results showed that the surface of P-CS/Ag@MOF bilayer was relatively smooth and its tensile strength (TS) was higher (27.67 MPa). Among them, P-CS/Ag@MOF bilayer films had better oil resistance and oxidation resistance activity. In addition, the P-CS/Ag@MOF bilayer film had good UV-blocking properties and transparency. P-CSNPs/Ag@MOF bilayer film had higher antibacterial activity and cytotoxicity.

Chemically characterized nanoencapsulated Homalomena aromatica Schott. essential oil as green preservative against fungal and aflatoxin B1 contamination of stored spices based on in vitro and in situ efficacy and favorable safety profile on mice

Present study deals with the efficacy of nanoencapsulated Homalomena aromatica essential oil (HAEO) as a potent green preservative against toxigenic Aspergillus flavus strain (AF-LHP-NS 7), storage fungi, AFB1, and free radical-mediated deterioration of stored spices. GC-MS analysis revealed linalool (68.51%) as the major component of HAEO. HAEO was encapsulated into chitosan nanomatrix (CS-HAEO-Ne) and characterized through SEM, FTIR, and XRD. CS-HAEO-Ne completely inhibited A. flavus growth and AFB1 biosynthesis at 1.25 μL/mL and 1.0 μL/mL, respectively in comparison to unencapsulated HAEO (1.75 μL/mL and 1.25 μL/mL, respectively). CS-HAEO-Ne caused significant reduction in ergosterol content in treated A. flavus and provoked leakage of cellular ions (Ca+2, Mg+2, and K+) as well as 260 nm and 280 nm absorbing materials. Depletion of methylglyoxal level in treated A. flavus cells illustrated the novel antiaflatoxigenic efficacy of CS-HAEO-Ne. CS-HAEO-Ne exhibited superior antioxidant efficacy (IC50 (DPPH) = 4.5 μL/mL) over unencapsulated HAEO (IC50 (DPPH) = 15.9 μL/mL) and phenolic content. CS-HAEO-Ne depicted excellent in situ efficacy by inhibiting fungal infestation, AFB1 contamination, lipid peroxidation, and mineral loss with acceptable sensorial profile. Moreover, broad safety paradigm (LD50 value = 7150.11 mg/kg) of CS-HAEO-Ne also suggests its application as novel green preservative to enhance shelf life of stored spices.

Assessing the efficacy of chitosan nanomatrix incorporated with Cymbopogon citratus (DC.) Stapf essential oil against the food-borne molds and aflatoxin B1 production in food system

The chitosan nanomatrix incorporated with Cymbopogon citratus essential oil (Ne-CcEO) possess enhanced efficacy against the food-borne molds and aflatoxin B₁ production compared to free essential oil. The CcEO was encapsulated inside the chitosan nanomatrix with an average size 147.41 ± 16.18 nm and characterized by Scanning electron microscopy, Fourier transforms infrared spectroscopy, and X-ray diffraction assay. The encapsulation efficiency and loading capacity were ranged between (41.68-76.78%) and (5.3-8.80%). The biochemical and in-silico analysis results revealed the interference in functioning of membrane integrity, mitochondrial membrane potential, antioxidant defense, carbon source metabolism, methylglyoxal, and laeA gene in response to treatment of Ne-CcEO (0.5 μl/ml). In addition, Ne-CcEO significantly protects the deterioration of Pennisetum glaucum (L.) R. Br. seed samples by A. flavus, aflatoxin B₁ contamination, and lipid peroxidation. The Ne-CcEO could be considered as promising antifungal additives for the control of food-borne molds and aflatoxin B₁ contamination in the food system.

Preparation and applications of chitosan and cellulose composite materials

Chitosan is a natural fiber, chemically cellulose-like biopolymer, which is processed from chitin. Its use as a natural polymer is getting more attention because it is non-toxic, renewable, and biocompatible. However, its poor mechanical and thermal strength, particle size, and surface area restrict its industrial use. Consequently, to improve these properties, cellulose and/or inorganic nanoparticles have been used. This review discusses the recent progress of chitosan and cellulose composite materials, their preparation, and their applications in different industrial sectors. It also discusses the modification of chitosan and cellulose composite materials to allow their use on a large scale. Finally, the recent development of chitosan composite materials for drug delivery, food packaging, protective coatings, and wastewater treatment are discussed. The challenges and perspectives for future research are also considered. This review suggests that chitosan and cellulose nano-composite are promising, low-cost products for environmental remediation involving a simple production process.

Development of chitosan-coated nanoemulsions of two sulfides present in onion (Allium cepa) essential oil and their nematicidal activities against the pine wood nematode, Bursaphelenchus xylophilus

Pine wood nematode, Bursaphelenchus xylophilus, is a plant parasitic nematode which causes severe damage to several Pinus species. Two natural compounds, dipropyl trisulfide (DPTS) and methyl propyl trisulfide (MPTS), showed strong nematicidal activity against the pine wood nematode, presenting 4.24 and 17.81 μg/mL LC₅₀ values, respectively. However, hydrophobicity and low stability have limited their practical use in the field as nematicides. To overcome these problems, chitosan-coated nanoemulsions of DPTS and MPTS were developed. The optimum chitosan concentration for the delivery system of the two sulfides was 0.5%. Optimized chitosan-coated nanoemulsions of sulfides have a uniform size distribution (mean diameter = 203.7 and 207.7 nm, mean polydispersity index = 0.176 and 0.178) with sufficient colloidal stability (mean zeta potential = +40 and +45 mV). The LC₅₀ values of DPTS and MPTS nanoemulsions coated with 0.5% chitosan against the pine wood nematode were 5.01 and 16.60 μg/mL, respectively. In addition, chitosan coating improved the long-term storage stability and persistence of nematicidal activity of the nanoemulsions. This study indicates that the chitosan-coated nanoemulsion is a suitable formulation for sulfides as novel nematicides against the pine wood nematode for field application.

The use of chemometric modelling to determine chemical composition-antimicrobial activity relationships of essential oils used in respiratory tract infections

The antimicrobial effects of essential oils are commonly cited within aromatherapeutic texts for use in respiratory tract infections. These essential oils are inhaled or applied to the skin to treat infections and manage symptoms associated with these conditions. A limited number of these essential oils have been scientifically studied to support these claims, specifically, against respiratory pathogens. This study reports on the minimum inhibitory concentration (MIC) of 49 commercial essential oils recommended for respiratory tract infections, and identifies putative biomarkers responsible for the determined antimicrobial effect following a biochemometric workflow. Essential oils were investigated against nine pathogens. Three essential oils, Amyris balsamifera (amyris), Coriandrum sativum (coriander) and Santalum austrocaledonicum (sandalwood) were identified as having greater activity (MIC value = 0.03-0.13 mg/ml) compared to the other essential oils investigated. The essential oil composition of all 49 oils were determined using Gas Chromatography coupled to Mass Spectroscopy (GC-MS) analysis and the GC-MS data analysed together with the antimicrobial data using chemometric tools. Eugenol was identified as the main biomarker responsible for antimicrobial activity in the majority of the essential oils. The ability of a chemometric model to accurately predict the active and inactive biomarkers of the investigated essential oils against pathogens of the respiratory tract was 80.33%.

Plant oils: From chemical composition to encapsulated form use

The last decade has witnessed a burgeoning global movement towards essential and vegetable oils in the food, agriculture, pharmaceutical, cosmetic, and textile industries thanks to their natural and safe status, broad acceptance by consumers, and versatile functional properties. However, efforts to develop new therapy or functional agents based on plant oils have met with challenges of limited stability and/or reduced efficacy. As a result, there has been increased research interest in the encapsulation of plant oils, whereby the nanocarriers serve as barrier between plant oils and the environment and control oil release leading to improved efficacy, reduced toxicity and enhanced patient compliance and convenience. In this review, special concern has been addressed to the encapsulation of essential and vegetable oils in three types of nanocarriers: polymeric nanoparticles, liposomes and solid lipid nanoparticles. First, the chemical composition of essential and vegetable oils was handled. Moreover, we gather together the research findings reported by the literature regarding the different techniques used to generate these nanocarriers with their significant findings. Finally, differences and similarities between these nanocarriers are discussed, along with current and future applications that are warranted by their structures and properties.

Advanced Material Against Human (Including Covid-19) and Plant Viruses: Nanoparticles As a Feasible Strategy

The SARS-CoV-2 virus outbreak revealed that these nano-pathogens have the ability to rapidly change lives. Undoubtedly, SARS-CoV-2 as well as other viruses can cause important global impacts, affecting public health, as well as, socioeconomic development. But viruses are not only a public health concern, they are also a problem in agriculture. The current treatments are often ineffective, are prone to develop resistance, or cause considerable adverse side effects. The use of nanotechnology has played an important role to combat viral diseases. In this review three main aspects are in focus: first, the potential use of nanoparticles as carriers for drug delivery. Second, its use for treatments of some human viral diseases, and third, its application as antivirals in plants. With these three themes, the aim is to give to readers an overview of the progress in this promising area of biotechnology during the 2017-2020 period, and to provide a glance at how tangible is the effectiveness of nanotechnology against viruses. Future prospects are also discussed. It is hoped that this review can be a contribution to general knowledge for both specialized and non-specialized readers, allowing a better knowledge of this interesting topic.

Development of encapsulated peppermint essential oil in chitosan nanoparticles: characterization and biological efficacy against stored-grain pest control

Peppermint oil (PO) has widely been reported for their nutritional and biomedical properties. Essential oil (EO) has several properties, usage restricted due to environmental condition, polymer based nanoencapsulation of EOs is developed as one of the promising technique to address this limitation. In this current study emphasizes on developing Peppermint oil (PO) encapsulated chitosan nanoparticles (CS NPs) by ionic gelation method in order to improving its insecticidal potential effective management of two stored grain pest. The nano-encapsulated PO (CS/PO NPs) was confirmed by UV-Vis spectrophotometry and X-ray diffraction (XRD) techniques. The physicochemical characterization of CS/PO NPs revealed <563.3 nm size, Zeta potential of -12.12 mV, encapsulation efficiency >64% and loading capacity >12.31% respectively. Developed CS/PO NPs demonstrated the toxicity studies have significantly efficacy against both stored product pest compared to control. In-vivo percent inhibition of AChE activity ranged between S. oryzae (52.43% and 37.71% and and T. castaneum (37.80% and 31.29). Overall, these results highlighted that polymer chitosan nanoparticle encapsulated with essential oil is a promising novel design that could be promoted in stored food pest management schedule for T. castaneum and S. oryzae.

Antibacterial, Antifungal, Antimycotoxigenic, and Antioxidant Activities of Essential Oils: An Updated Review

The interest in using natural antimicrobials instead of chemical preservatives in food products has been increasing in recent years. In regard to this, essential oils-natural and liquid secondary plant metabolites-are gaining importance for their use in the protection of foods, since they are accepted as safe and healthy. Although research studies indicate that the antibacterial and antioxidant activities of essential oils (EOs) are more common compared to other biological activities, specific concerns have led scientists to investigate the areas that are still in need of research. To the best of our knowledge, there is no review paper in which antifungal and especially antimycotoxigenic effects are compiled. Further, the low stability of essential oils under environmental conditions such as temperature and light has forced scientists to develop and use recent approaches such as encapsulation, coating, use in edible films, etc. This review provides an overview of the current literature on essential oils mainly on antifungal and antimycotoxigenic but also their antibacterial and antioxidant activities. Additionally, the recent applications of EOs including encapsulation, edible coatings, and active packaging are outlined.

Anti-bacterial activity of chitosan loaded plant essential oil against multi drug resistant K. pneumoniae

The development of antibiotic resistant in K. pneumoniae is an emerging thread worldwide due to the poor antimicrobial drugs. To overcome this issue, researchers are focused on plant material and their essential oils to fight against multi drug resistant bacteria. In this context, the current study was concentrated in medicinal plant of guva leaves and their essential oils to combat multi drug resistant bacterial infections. The essential oils were successfully screened and confirmed by HRLC-MS analysis. The anti-bacterial ability of the compounds were loaded into the chitosan nanoparticles and proved by FT-IR analysis. In addition, the chitosan loaded essential oils morphology was compared with chitosan alone in SEM analysis and suggested that the material was loaded successfully. Further, the anti-bacterial ability of the chitosan loaded essential oils were primarily confirmed by agar well diffusion method. At the 100 µg/mL of lowest concentration of chitosan loaded essential oils, the multi-drug resistant K. pneumoniae was inhibited with 96% and confirmed by minimum inhibition concentration experiment. Hence, all the experiments were proved that the essential oils were successfully loaded into the chitosan nanoparticles, and it has more anti-bacterial activity against multi-drug resistant K. pneumoniae.

Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

Chitosan is a cationic natural polysaccharide, which has emerged as an increasingly interesting biomaterialover the past few years. It constitutes a novel perspective in drug delivery systems and nanocarriers' formulations due to its beneficial properties, including biocompatibility, biodegradability and low toxicity. The potentiality of chemical or enzymatic modifications of the biopolymer, as well as its complementary use with other polymers, further attract the scientific community, offering improved and combined properties in the final materials. As a result, chitosan has been extensively used as a matrix for the encapsulation of several valuable compounds. In this review article, the advantageous character of chitosan as a matrix for nanosystemsis presented, focusing on the encapsulation of natural products. A five-year literature review is attempted covering the use of chitosan and modified chitosan as matrices and coatings for the encapsulation of natural extracts, essential oils or pure naturally occurring bioactive compounds are discussed.