No time to waste organic waste: Nanosizing converts remains of food processing into refined materials

Nanosuspensions as carriers of active ingredients: Chemical composition, development methods, and their biological activities

Nanosuspensions (NSps) are colloidal dispersions of particles that have the potential to solve the delivery problems of active ingredients associated with their low solubility in water or instability due to environmental factors. It is essential to consider their chemical composition and preparation methods because they directly influence drug loading, size, morphology, solubility, and stability; these characteristics of nanosuspensions influence the delivery and bioavailability of active ingredients. NSps provides high loading of drugs, protection against degrading agents, rapid dissolution, high particle stability, and high bioavailability of active ingredients across biological membranes. In addition, they provide lower toxicity compared to other nanocarriers, such as liposomes or polymeric nanoparticles, and can modify the pharmacokinetic profiles, thus improving their safety and efficacy. The present review aims to address all aspects related to the composition of NSps, the different methods for their production, and the main factors affecting their stability. Moreover, recent studies are described as carriers of active ingredients and their biological activities.

Cucumber-Derived Exosome-like Vesicles and PlantCrystals for Improved Dermal Drug Delivery

(1) Background: Extracellular vesicles (EVs) are considered to be efficient nanocarriers for improved drug delivery and can be derived from mammalian or plant cells. Cucumber-derived EVs are not yet described in the literature. Therefore, the aim of this study was to produce and characterize cucumber-derived EVs and to investigate their suitability to improve the dermal penetration efficacy of a lipophilic active ingredient (AI) surrogate. (2) Methods: The EVs were obtained by classical EVs isolation methods and by high pressure homogenization (HPH). They were characterized regarding their physico-chemical and biopharmaceutical properties. (3) Results: Utilization of classical isolation and purification methods for EVs resulted in cucumber-derived EVs. Their dermal penetration efficacy for the AI surrogate was 2-fold higher when compared to a classical formulation and enabled a pronounced transdermal penetration into the viable dermis. HPH resulted in submicron sized particles composed of a mixture of disrupted plant cells. A successful isolation of pure EVs from this mixture was not possible with classical EVs isolation methods. The presence of EVs was, therefore, proven indirectly. For this, the lipophilic drug surrogate was admixed to the cucumber juice either prior to or after HPH. Admixing of the drug surrogate to the cucumber prior to the HPH resulted in a 1.5-fold increase in the dermal penetration efficacy, whereas the addition of the AI surrogate to the cucumber after HPH was not able to improve the penetration efficacy. (4) Conclusions: Results, therefore, indicate that HPH causes the formation of EVs in which AI can be incorporated. The formation of plant EVs by HPH was also indicated by zeta potential analysis.

Vegetarian “Sausages” with the Addition of Grape Flour

Vegan sausages with the addition of grape flour represent a way to reduce the intake of processed meat and at the same time to increase the intake of a healthy substance of plant origin. Grape flour obtained from grape marc as a byproduct of wine production is a source of many bioactive substances, such as antioxidants and polyphenols. The study was conducted using vegetarian sausage production: six batches of sausages with different concentrations of grape flour (0%, 1%, 3%, 7%, 10%, and 20%) were produced. The following analyses were applied for the evaluation of these vegetarian sausages: ferric reducing antioxidant power assay (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), total polyphenolic content, total protein content, and textural and sensory parameters. The results clearly indicated that the grape seed flour addition resulted in a higher antioxidant capacity of experimentally produced vegan sausages. Based on the sensory evaluation, vegan sausages with 1% (according to taste evaluation, these samples were the most acceptable by panelists) and 3% additions of grape flour were selected as the most suitable since they were statistically more acceptable than samples produced with 20% grape flour addition. The results of this study confirm that the addition of grape flour to vegan sausages is nutritionally beneficial for consumers because it increases the antioxidant capacity and polyphenol content; however, a slight decrease in protein content was recorded too. The sustainability of the product is also achieved using the grape flour since it is a waste material generated worldwide within grape processing.

Production and Characterization of Sumac PlantCrystals: Influence of High-Pressure Homogenization on Antioxidant Activity of Sumac (Rhus coriaria L.)

Oxidative stress diseases are usually treated or prevented by using antioxidants from natural or artificial sources. However, as a sustainable source of phytochemicals, plants got a renewed interest in obtaining their active agents using green extraction technologies, i.e., sustainable extraction techniques that reduce energy consumption, use renewable sources and result in less post-extraction wastes. The high-pressure homogenization (HPH) technique was introduced into the food industry since it was invented in 1900 to homogenize milk and later to produce fruit juices with a longer shelf-life without preservatives. Recently, HPH was introduced as an eco-friendly method to nanomill plants for improved extraction efficacy without using organic solvents. In this study, sumac was used as an antioxidants-rich spice model to investigate the effects of HPH on its antioxidant capacity (AOC). Sumac was rendered into PlantCrystals by using HPH. Particle size characterization proved the presence of submicron-sized particles (about 750 nm). Thus, HPH was able to produce sumac PlantCrystals and increased the AOC of bulk sumac by more than 650% according to the ORAC (oxygen radical absorbance capacity) assay. The polyphenol and flavonoid contents showed higher values after HPH. Interestingly, the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay also showed a well improved AOC (similar to ascorbic acid) after HPH. In fact, in this study, the PlantCrystal-technology was demonstrated to cause an efficient cell rupture of the sumac plant cells. This caused an efficient release of antioxidants and resulted in sumac PlantCrystals with a 6.5-fold higher antioxidant capacity when compared to non-processed sumac bulk material.

Fingerprint of Nature—Skin Penetration Analysis of a Stinging Nettle PlantCrystals Formulation

Background: PlantCrystals are a new concept to produce plant-based formulations. Their principle is based on the diminution of parts of or whole plants. In this study, the effect of a surfactant on stinging nettle leaf PlantCrystals was investigated. Secondly, the contents of bulk material and the PlantCrystals formulation were compared. In addition, for the very first time, the skin penetration of PlantCrystals was investigated. Methods: Stinging nettle leaves were milled with high-pressure homogenization. Sizes were analyzed via light microscopy and static light scattering. To investigate the effect of the milling, the flavonoid and total carotenoid content were determined, and the antioxidant capacity of the formulation was measured via total polyphenol content and DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Finally, the impact on skin penetration was investigated. Results: Size analysis showed a stabilizing effect of the surfactant, and the chemical analysis revealed higher flavonoid and polyphenol contents for PlantCrystals. The penetration of the formulation into the stratum corneum was shown to be promising; PlantCrystals possessed a visually perceived higher fluorescence and homogeneity compared to the bulk material. Conclusion: The concept of PlantCrystals improved the availability of valuable constituents and the penetration efficacy. The utilization of the natural chlorophyll fluorescence for skin penetration analysis of plant-based formulations proved itself highly effective.

Unleashing the Biological Potential of Fomes fomentarius via Dry and Wet Milling

Fomes fomentarius, usually referred to as tinder conk, is a common wood-based fungus rich in many interesting phytochemicals and with an unique porous structure. Dry or wet ball milling of this sponge on a planetary mill results in small particles with sizes in the range of 10 µm or below. Suspended in water and without preservatives or other stabilizers, the resulting micro-suspensions are sterile for around six days, probably due to the increased temperatures of around 80 °C especially during the wet milling process. The suspensions also exhibit excellent antioxidant activities as determined in the DPPH, ferric reducing antioxidant potential (FRAP) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. In the DPPH assay, IC₅₀ values of 0.02–0.04% w/v and 0.04% w/v were observed for dry and wet milled samples, respectively. In the FRAP assay, IC₅₀ values of <0.02% w/v and 0.04% w/v were observed for dry and wet milled samples, respectively. In contrast, the ABTS assay provided IC₅₀ values of 0.04% w/v and 0.005% w/v, respectively. Notably, this activity is mostly—albeit not exclusively—associated with the highly porous particles and their large surfaces, although some active ingredients also diffuse into the surrounding aqueous medium. Such suspensions of natural particles carrying otherwise insoluble antioxidants on their surfaces provide an interesting avenue to unleash the antioxidant potential of materials such as sponges and barks. As dry milling also enables longer storage and transport, applications in the fields of medicine, nutrition, agriculture, materials and cosmetics are feasible.

Improved Antioxidant Capacity of Black Tea Waste Utilizing PlantCrystals

Antioxidants are recommended to prevent and treat oxidative stress diseases. Plants are a balanced source of natural antioxidants, but the poor solubility of plant active molecules in aqueous media can be a problem for the formulation of pharmaceutical products. The potential of PlantCrystal technology is known to improve the extraction efficacy and antioxidant capacity (AOC) of different plants. However, it is not yet proved for plant waste. Black tea (BT) infusion is consumed worldwide and thus a huge amount of waste occurs as a result. Therefore, BT waste was recycled into PlantCrystals using small-scale bead milling. Their characteristics were compared with the bulk-materials and tea infusion, including particle size and antioxidant capacity (AOC) in-vitro. Waste PlantCrystals possessed a size of about 280 nm. Their AOC increased with decreasing size according to the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. The AOC of the waste increased about nine-fold upon nanonization, leading to a significantly higher AOC than the bulk-waste and showed no significant difference to the infusion and the used standard according to DPPH assay. Based on the results, it is confirmed that the PlantCrystal technology represents a natural, cost-effective plant-waste recycling method and presents an alternative source of antioxidant phenolic compounds.

Co-administration of Selenium Nanoparticles and Metformin Abrogate Testicular Oxidative Injury by Suppressing Redox Imbalance, Augmenting Sperm Quality and Nrf2 Protein Expression in Streptozotocin-Induced Diabetic Rats

Selenium nanoparticles (SeNPs) and metformin (Met) elicit individually protective effects against testicular oxidative injury in diabetic rats. However, the combined effects of both compounds have not been investigated. We investigated the effects of SeNPs and Met individual/co-treatment on testicular oxidative injury in diabetic rats. Diabetes was induced by a single intraperitoneal administration of streptozotocin (STZ-40 mg/kg bwt). The rats were equally divided into 6 groups: Group one-non-diabetic; group two-diabetic untreated; and group six-non-diabetic received citrate buffer (2 mL/kg bwt), while group three, four, and five received SeNPs (0.1 mg/kg bwt), Met (50 mg/kg bwt), and SeNPs/Met combined respectively, for 42 days. Results revealed that SeNPs, as well as Met treatment significantly (p < 0.001), lowered blood glucose levels and improved relative organ weights in treated rats than those of the untreated group. Moreover, a synergistic effect was observed in the co-administration group. Additionally, combined treatment elicited better effect, in augmenting the pituitary and testicular hormone (LH, FSH, prolactin, and testosterone) levels, marker enzymes/protein associated with steroidogenesis (3-βHSD, 17-βHSD, and StAR protein), and sperm functional parameters than those of individual treatment groups, when compared with control. Furthermore, the combinatorial effects of SeNPs and Met surpassed their influence in attenuating testicular oxidative stress/inflammation and upregulation of Nrf2 protein expression in diabetic rats when compared with control. Overall, normal rats, co-treated with SeNPs and Met, did not reveal any deleterious effect. Therefore, SeNPs and Met combined treatment may better improve testes function in diabetic conditions than an individual regimen.

PlantCrystals-Nanosized Plant Material for Improved Bioefficacy of Medical Plants

PlantCrystals are obtained by milling plant material to sizes < 10 µm. Due to the disruption of the plant cells, active compounds are easily released, rendering the PlantCrystal technology an effective and low-cost process for the production of environmentally friendly plant extracts. The extracts can be used to produce phytomedicines, nutritional supplements or cosmetic products. Previous studies could already demonstrate the use of PlantCrystals to improve the antimicrobial or antifungal activity of different plants. This study investigated whether PlantCrystal technology is suitable to produce plant derived formulations with high antioxidant capacity. The study also aimed to identify the most suitable production methods for this. Methods: Various plant materials and parts of plants, i.e., seeds, leaves and flowers, and different methods were employed for the production. PlantCrystals were characterized regarding size, physical stability and antioxidant capacity (AOC). Results: PlantCrystals with particles < 1 µm were produced from the different plant materials. Both production methods, i.e., high-pressure homogenization, bead milling or the combination of both were suitable to obtain PlantCrystals. Nano milling of the plant material greatly affected their AOC and resulted in formulations with distinctly higher AOC when compared to classical extracts. Conclusions: Rendering plant material into small sized particles is highly effective to obtain plant extracts with high biological efficacy.

High Homogenization Pressures to Improve Food Quality, Functionality and Sustainability

Interest in high homogenization pressure technology has grown over the years. It is a green technology with low energy consumption that does not generate high CO2 emissions or polluting effluents. Its main food applications derive from its effect on particle size, causing a more homogeneous distribution of fluid elements (particles, globules, droplets, aggregates, etc.) and favoring the release of intracellular components, and from its effect on the structure and configuration of chemical components such as polyphenols and macromolecules such as carbohydrates (fibers) and proteins (also microorganisms and enzymes). The challenges of the 21st century are leading the processed food industry towards the creation of food of high nutritional quality and the use of waste to obtain ingredients with specific properties. For this purpose, soft and nonthermal technologies such as high pressure homogenization have huge potential. The objective of this work is to review how the need to combine safety, functionality and sustainability in the food industry has conditioned the application of high-pressure homogenization technology in the last decade.

Loranthus micranthus nanoparticles abates streptozotocin-instigated testicular dysfunction in Wistar rats: Involvement of glucose metabolism enzymes, oxido-inflammatory stress, steroidogenic enzymes/protein and Nrf2 pathway

Loranthus micranthus (African mistletoe)-Loranthaceae family, is used in Nigerian traditional medicine for treating male infertility and lowering diabetic blood sugar levels. We investigated possible mechanism(s) involved in mitigation of L. micranthus leaves nanoparticles (LMLNPs) on streptozotocin (STZ)-induced testicular alterations. Type two diabetes mellitus (T2DM) was induced in male rats following 2 weeks feeding with fructose and single intraperitoneal injection of STZ. Control (nondiabetic) and (diabetic) rats received buffer only. Diabetic rats were treated with metformin or LMLNPs (two different doses) for 28 days. Hormonal profile, oxido-inflammatory stress parameters, glucose metabolism and steroidogenic enzymes/regulatory protein (StAR) and Nuclear factor erythroid 2-related factor 2 (Nrf2) protein in testes and sperm parameters were evaluated. Metformin and LMLNPs treatment significantly reduced blood glucose level in diabetic rats. Furthermore, LMLNPs enhanced glucose metabolism and testicular steroidogenic enzymes/protein, increased reproductive hormone levels and sperm functional parameters in diabetic rats. Additionally, LMLNPs suppressed testicular oxido-inflammatory stress biomarkers and inhibited lipid peroxidation in diabetic rats while augmenting Nrf2 pathway. Conclusively, LMLNPs potently reversed adverse effects of T2DM testicular dysfunction of rats. Use of LMLNPs in abating diabetic consequences proves an acceptable alternative to traditional crude extract preparations, as a result of better packaging and preservation.

Silver nanoparticles: Toxicity in model organisms as an overview of its hazard for human health and the environment

Silver nanoparticles (AgNPs) have attracted remarkable attention due to their powerful antimicrobial action as well as their particular physicochemical properties. This has led to their application in a wide variety of products with promising results. However, their interaction with the environment and toxicity in live terrestrial or aquatic organisms is still a matter of intense debate. More detailed knowledge is still required about the toxicity of AgNPs, their possible uptake mechanisms and their adverse effects in live organisms. Several studies have reported the interactions and potential negative effects of AgNPs in different organisms. In this review, we report and discuss the current state of the art and perspectives for the impact of AgNPs on different organisms present in the environment. Recent progress in interpreting uptake, translocation and accumulation mechanisms in different organisms and/or living animals are discussed, as well as the toxicity of AgNPs and possible tolerance mechanisms in live organisms to cope with their deleterious effects. Finally, we discuss the challenges of accurate physicochemical characterization of AgNPs and their ecotoxicity in environmentally realistic conditions such as soil and water media.

Potentialities and Limits of Some Non-thermal Technologies to Improve Sustainability of Food Processing

In the whole food production chain, from the farm to the fork, food manufacturing steps have a large environmental impact. Despite significant efforts made to optimize heat recovery or water consumption, conventional food processing remains poorly efficient in terms of energy requirements and waste management. Therefore, in the few last decades, much research has focused on the development of alternative non-thermal technologies. Some of them, such as membrane separation processes, hydrostatic or dynamic high pressure, dense phase or high-pressure carbon dioxide, and pulsed electric fields (PEFs) have been extensively studied for cold pasteurization, concentration, extraction, or food functionalization. However, it is still difficult to evaluate the actual advantages or limits of these innovative processing technologies to replace conventional processes. Thus, the overall aim of this paper is to present an overview of the most relevant studies dealing with the potentialities and limits of these non-thermal technologies to improve sustainability of food processing. After a brief presentation of the physical principles of these technologies, the paper illustrates how these technologies could play a decisive role for sustainable food preservation or valorization of raw materials and by-products.

Flush with a flash: natural three-component antimicrobial combinations based on S-nitrosothiols, controlled superoxide formation and "domino" reactions leading to peroxynitrite

S-Nitrosothiols are ˙NO releasing agents renowned for vasodilatory and antioxidant properties. O2˙- promotes their decomposition, forming highly aggressive peroxynitrite ions (ONOO-). Since the production of O2˙- can be controlled by enzymes or by visible light, such otherwise harmless components can be turned into effective antimicrobial and nematicidal combinations with numerous potential applications in medicine.

Milling the Mistletoe: Nanotechnological Conversion of African Mistletoe (Loranthus micranthus) Intoantimicrobial Materials

Nanosizing represents a straight forward technique to unlock the biological activity of complex plant materials. The aim of this study was to develop herbal nanoparticles with medicinal value from dried leaves and stems of Loranthus micranthus with the aid of ball-milling, high speed stirring, and high-pressure homogenization techniques. The milled nanoparticles were characterized using laser diffraction analysis, photon correlation spectroscopy analysis, and light microscopy. The average size of leaf nanoparticles was around 245 nm and that of stem nanoparticles was around 180 nm. The nanoparticles were tested for their antimicrobial and nematicidal properties against a Gram-negative bacterium Escherichia coli, a Gram-positive bacterium Staphylococcus carnosus, fungi Candida albicans and Saccharomyces cerevisiae, and a nematode Steinernemafeltiae. The results show significant activities for both leaf and (particularly) stem nanoparticles of Loranthus micranthus on all organisms tested, even at a particle concentration as low as 0.01% (w/w). The results observed indicate that nanoparticles (especially of the stem) of Loranthus micranthus could serve as novel antimicrobial agents with wide-ranging biomedical applications.

Resuspendable Powders of Lyophilized Chalcogen Particles with Activity against Microorganisms

Many organic sulfur, selenium and tellurium compounds show considerable activity against microorganisms, including bacteria and fungi. This pronounced activity is often due to the specific, oxidizing redox behavior of the chalcogen-chalcogen bond present in such molecules. Interestingly, similar chalcogen-chalcogen motifs are also found in the elemental forms of these elements, and while those materials are insoluble in aqueous media, it has recently been possible to unlock their biological activities using naturally produced or homogenized suspensions of respective chalcogen nanoparticles. Those suspensions can be employed readily and often effectively against common pathogenic microorganisms, still their practical uses are limited as such suspensions are difficult to transport, store and apply. Using mannitol as stabilizer, it is now possible to lyophilize such suspensions to produce solid forms of the nanoparticles, which upon resuspension in water essentially retain their initial size and exhibit considerable biological activity. The sequence of Nanosizing, Lyophilization and Resuspension (NaLyRe) eventually provides access to a range of lyophilized materials which may be considered as easy-to-handle, ready-to-use and at the same time as bioavailable, active forms of otherwise insoluble or sparingly substances. In the case of elemental sulfur, selenium and tellurium, this approach promises wider practical applications, for instance in the medical or agricultural arena.