Horsetail (Equisetum Arvense) as a Functional Filler for Natural Rubber Biocomposites

Equisetum arvense standardized dried extract hinders age-related osteosarcopenia

Age-associated osteosarcopenia is an unresolved syndrome characterized by the concomitant loss of bone (osteopenia) and skeletal muscle (sarcopenia) tissues increasing falls, immobility, morbidity, and mortality. Unbalanced resorption of bone in the remodeling process and excessive protein breakdown, especially fast type II myosin heavy chain (MyHC-II) isoform and myofiber metabolic shift, are the leading causes of bone and muscle deterioration in the elderly, respectively. Equisetum arvense (EQ) is a plant traditionally recommended for many pathological conditions due to its anti-inflammatory properties. Thus, considering that a chronic low-grade inflammatory state predisposes to both osteoporosis and sarcopenia, we tested a standardized hydroalcoholic extract of EQ in in vitro models of muscle atrophy [C2C12 myotubes treated with proinflammatory cytokines (TNFα/IFNγ), excess glucocorticoids (dexamethasone), or the osteokine, receptor activator of nuclear factor kappa-B ligand (RANKL)] and osteoclastogenesis (RAW 264.7 cells treated with RANKL). We found that EQ counteracted myotube atrophy, blunting the activity of several pathways depending on the applied stimulus, and reduced osteoclast formation and activity. By in silico target fishing, IKKB-dependent nuclear factor kappa-B (NF-κB) inhibition emerges as a potential common mechanism underlying EQ's anti-atrophic effects. Consumption of EQ (500 mg/kg/day) by pre-geriatric C57BL/6 mice for 3 months translated into: i) maintenance of muscle mass and performance; ii) restrained myofiber oxidative shift; iii) slowed down age-related modifications in osteoporotic bone, significantly preserving trabecular connectivity density; iv) reduced muscle- and spleen-related inflammation. EQ can preserve muscle functionality and bone remodeling during aging, potentially valuable as a natural treatment for osteosarcopenia.

Bioactive and biodegradable cotton fabrics produced via synergic effect of plant extracts and essential oils in chitosan coating system

Functional antibacterial textile materials are in great demand in the medical sector. In this paper, we propose a facile, eco-friendly approach to the design of antibacterial biodegradable cotton fabrics. Cotton fiber fabrics were enhanced with a chitosan coating loaded with plant extracts and essential oils. We employed Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometry, optical microscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to characterize the color, structure, and thermal properties of the modified fabrics. The fabrics were found to effectively induce growth inhibition of Gram-positive and Gram-negative bacteria, especially when a synergic system of aloe vera extract and cinnamon essential oil was applied in the coating formulation. Additionally, we observed significant color and weight changes after 5, 10, and 20 days in soil biodegradability tests. Given the straightforward modification process and the use of non-toxic natural materials, these innovative bio-based and biodegradable cotton fabrics show great promise as protective antimicrobial textiles for healthcare applications.

Potential Utilization of Ground Eggshells as a Biofiller for Natural Rubber Biocomposites

The aim of this work was application of ground eggshells in various amounts by weight as a biofiller for natural rubber (NR) biocomposites. Cetyltrimethylammonium bromide (CTAB), ionic liquids (ILs), i.e., 1-butyl-3-methylimidazolium chloride (BmiCl) and 1-decyl-3-methylimidazolium bromide (DmiBr), and silanes, i.e., (3-aminopropyl)-triethoxysilane (APTES) and bis [3-(triethoxysilyl)propyl] tetrasulfide (TESPTS), were used to increase the activity of ground eggshells in the elastomer matrix and to ameliorate the cure characteristics and properties of NR biocomposites. The influence of ground eggshells, CTAB, ILs, and silanes on the crosslink density, mechanical properties, and thermal stability of NR vulcanizates and their resistance to prolonged thermo-oxidation were explored. The amount of eggshells affected the curing characteristics and crosslink density of the rubber composites and therefore their tensile properties. Vulcanizates filled with eggshells demonstrated higher crosslink density than the unfilled sample by approximately 30%, whereas CTAB and ILs increased the crosslink density by 40-60% compared to the benchmark. Owing to the enhanced crosslink density and uniform dispersion of ground eggshells, vulcanizates containing CTAB and ILs exhibited tensile strength improved by approximately 20% compared to those without these additives. Moreover, the hardness of these vulcanizates was increased by 35-42%. Application of both the biofiller and the tested additives did not significantly affect the thermal stability of cured NR compared to the unfilled benchmark. Most importantly, the eggshell-filled vulcanizates showed improved resistance to thermo-oxidative aging compared to the unfilled NR.

Horsetail (Equisetum hyemale) Extract Accelerates Wound Healing in Diabetic Rats by Modulating IL-10 and MCP-1 Release and Collagen Synthesis

Traditionally, Equisetum hyemale has been used for wound healing. However, its mechanism of action remains to be elucidated. For this purpose, a 40% ethanolic extract of E. hyemale was prepared. Phytochemical screening revealed the presence of minerals, sterols, phenolic acids, flavonols, a lignan, and a phenylpropenoid. The extract reduced the viability of RAW 264.7 cells and skin fibroblasts at all times evaluated. On the third day of treatment, this reduction was 30–40% and 15–40%, respectively. In contrast, the extract increased the proliferation of skin fibroblasts only after 48 h. In addition, the extract increased IL-10 release and inhibited MCP-1 release. However, the extract did not affect both TGF-β1 and TNF-α released by RAW 264.7 cells. The higher release of IL-10 could be related to the up-/downregulation of inflammatory pathways mediated by the extract components associated with their bioactivity. The extract inhibited the growth of Staphylococcus aureus and Escherichia coli. Topical application of the extract accelerated wound healing in diabetic rats by increasing fibroblast collagen synthesis. These results suggest that E. hyemale extract has great potential for use in the treatment of wounds thanks to its phytochemical composition that modulates cytokine secretion, collagen synthesis, and bacterial growth.

Equisetum hyemale-derived unprecedented bioactive composite for hard and soft tissues engineering

Although Bioactive Glasses (BGs) have been progressively optimized, their preparation often still involves the use of toxic reagents and high calcination temperatures to remove organic solvents. In the present work, these synthesis related drawbacks were overcome by treating the ashes from the Equisetum hyemale plant in an ethanol/water solution to develop a bioactive composite [glass/carbon (BG-Carb)]. The BG-Carb was characterized by scanning electron microscopy, and transmission electron microscopy; and its chemical composition was assessed by inductively coupled plasma-optical emission spectroscopy. Brunauer-Emmett-Teller gas adsorption analysis showed a specific surface area of 121 m² g^-1. The formation of hydroxyapatite (HA) surface layer in vitro was confirmed by Fourier-transform infrared spectroscopy analysis before and after immersion in simulated body fluid (SBF) solution. The Rietveld refinement of the XRD patterns and selected area electron diffraction analyses confirmed HA in the sample even before immersing it in SBF solution. However, stronger evidences of the presence of HA were observed after immersion in SBF solution due to the surface mineralization. The BG-Carb samples showed no cytotoxicity on MC3T3-E1 cells and osteo-differentiation capacity similar to the positive control. Altogether, the BG-Carb material data reveals a promising plant waste-based candidate for hard and soft tissue engineering.

Dose-Dependent Variation in Anticancer Activity of Hexane and Chloroform Extracts of Field Horsetail Plant on Human Hepatocarcinoma Cells

Horsetail fern plant is botanically known as Equisetum arvense L., and it is a good source of phenolic flavonoids, phenolic acids, and compounds. Anticancer properties of hexane and chloroform extracts of the horsetail fern plant and their mechanisms involved in the anticancer activity on human hepatocarcinoma (HuH-7) cells were examined. Cytotoxicity was evaluated by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and NRU (neutral red uptake) assays. Other parameters such as oxidative stress and apoptosis in pretreated hexane and chloroform extracts of the horsetail fern plant were examined in HuH-7 cells. The observation showed that hexane and chloroform extract of the horsetail fern plant exhibited cytotoxicity against HuH-7 cells. The value of IC₅₀-24 h of hexane and chloroform extract of the horsetail fern plant was determined as 199.0 μg/ml and 161.90 0 μg/ml for HuH-7 cells, respectively, and on the basis of IC₅₀ value, three acute concentrations, viz., 75% of IC₅₀, 50% of IC₅₀, and 25% of IC₅₀, were determined for further study. The lower dose of extracts hexane and chloroform extract of the horsetail fern plant did not show significant toxicity. Higher concentrations of extract induced significant antioxidant effects as well as apoptosis effects. However, exposure to hexane and chloroform extract of the horsetail fern plant upregulated the expression of Bax and p53 in HuH-7 cells. These data suggest that hexane and chloroform extract of the horsetail fern plant plays a significant role in the induction of toxicity via the regulation of oxidative stress in HuH-7 cells. This work may be useful for cancer chemotherapy.

Antioxidant and Anti–Aging Activity of Freeze–Dried Alcohol–Water Extracts from Common Nettle (Urtica dioica L.) and Peppermint (Mentha piperita L.) in Elastomer Vulcanizates

The research article aimed to examine the antioxidant nature of freeze–dried extracts from Urtica dioica L. and Mentha piperita L. and to present a deep characterization of their influence on the properties of natural rubber–based vulcanizates before and after simulated aging processes. Natural extracts were prepared in three solvent systems at selected volume ratios: water (100), methanol–water (50/50), ethanol–water (50/50), which were further lyophilized and used as additive to natural rubber mixtures. Freeze–dried materials were investigated by UV–VIS diffuse reflectance spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), thermal stability by thermogravimetric analysis (TGA). Antioxidant activity and total phenolic content (TPC) were also examined. Prepared samples were subjected to accelerated simulated degradation processes by using ultraviolet and thermo-oxidative aging. Vulcanizates resistance to degradation effects was determined by the study of cross-linking density (equilibrium swelling method), mechanical properties (tensile strength, elongation at break) and color change in comparison with the results of the reference samples. The research showed that analyzed extracts are characterized by a high content of polyphenols and antioxidant activity, thus have a protective influence on elastomer vulcanizates against damaging effects of aging processes, which consequently extends the lifetime of materials.

Surface Modified Nanocellulose and Its Reinforcement in Natural Rubber Matrix Nanocomposites: A Review

Natural rubber is of significant economic importance owing to its excellent resilience, elasticity, abrasion and impact resistance. Despite that, natural rubber has been identified with some drawbacks such as low modulus and strength and therefore opens up the opportunity for adding a reinforcing agent. Apart from the conventional fillers such as silica, carbon black and lignocellulosic fibers, nanocellulose is also one of the ideal candidates. Nanocellulose is a promising filler with many excellent properties such as renewability, biocompatibility, non-toxicity, reactive surface, low density, high specific surface area, high tensile and elastic modulus. However, it has some limitations in hydrophobicity, solubility and compatibility and therefore it is very difficult to achieve good dispersion and interfacial properties with the natural rubber matrix. Surface modification is often carried out to enhance the interfacial compatibilities between nanocellulose and natural rubber and to alleviate difficulties in dispersing them in polar solvents or polymers. This paper aims to highlight the different surface modification methods employed by several researchers in modifying nanocellulose and its reinforcement effects in the natural rubber matrix. The mechanism of the different surface medication methods has been discussed. The review also lists out the conventional filler that had been used as reinforcing agent for natural rubber. The challenges and future prospective has also been concluded in the last part of this review.

Potential Application of Peppermint (Mentha piperita L.), German Chamomile (Matricaria chamomilla L.) and Yarrow (Achillea millefolium L.) as Active Fillers in Natural Rubber Biocomposites

In this study, peppermint (Mentha piperita L.), German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) were applied as natural fibrous fillers to create biocomposites containing substances of plant origin. The purpose of the work was to investigate the activity and effectiveness of selected plants as a material for the modification of natural rubber composites. This research was the first approach to examine the usefulness of peppermint, German chamomile and yarrow in the field of polymer technology. Dried and ground plant particles were subjected to Fourier transmission infrared spectroscopy (FTIR) and UV–Vis spectroscopy, thermogravimetric analysis (TGA), goniometric measurements (contact angle) and scanning electron microscopy (SEM). The characterization of natural rubber composites filled with bio-additives was performed including rheometric measurements, FTIR, TGA, cross-linking density, mechanical properties and colour change after simulated aging processes. Composites filled with natural fillers showed improved barrier properties and mechanical strength. Moreover, an increase in the cross-linking density of the materials before and after the simulated aging processes, compared to the reference sample, was observed.

Biomaterials for the Prevention of Oral Candidiasis Development

Thousands of microorganisms coexist within the human microbiota. However, certain conditions can predispose the organism to the overgrowth of specific pathogens that further lead to opportunistic infections. One of the most common such imbalances in the normal oral flora is the excessive growth of Candida spp., which produces oral candidiasis. In immunocompromised individuals, this fungal infection can reach the systemic level and become life-threatening. Hence, prompt and efficient treatment must be administered. Traditional antifungal agents, such as polyenes, azoles, and echinocandins, may often result in severe adverse effects, regardless of the administration form. Therefore, novel treatments have to be developed and implemented in clinical practice. In this regard, the present paper focuses on the newest therapeutic options against oral Candida infections, reviewing compounds and biomaterials with inherent antifungal properties, improved materials for dental prostheses and denture adhesives, drug delivery systems, and combined approaches towards developing the optimum treatment.

Natural Rubber Biocomposites Filled with Phyto-Ashes Rich in Biogenic Silica Obtained from Wheat Straw and Field Horsetail

The rich structural hierarchy of plants permits the obtainment of porous structures which can be expected to show improved performances in fields such as pharmaceuticals and cosmetics, catalysis, drug delivery, adsorption, separation or sensors in various chemical reactions. On the other hand, porous materials can be an active additive to polymer composites. The aim of the study was to obtain natural rubber (NR) biocomposites with the addition of phyto-ashes reach in biogenic silica from plant biomass. For the production of bioadditives, a two-stage method of high-temperature heat treatment was used, preceded by acid hydrolysis of plant tissues in the form of horsetail and wheat straw. Hydrolysis was performed with hydrochloric and citric acid. The efficiency of the processes and their influence on the elemental composition, surface morphology, thermal stability and particle size of the fillers were determined. Modified bioadditives were introduced into the elastomer matrix and their processing properties, as well as the vulcanization characteristics, were examined. Static mechanical properties (tensile strength, elongation at break, stress at 100%, 200% and 300% elongation), dynamic-mechanical analysis and the influence of additives on the cross-link density of the composites were determined. Structural analysis was performed using scanning electron microscopy. It was found that the field horsetail and cereal straw are plants rich in many valuable chemical compounds, especially silica. The specific and appropriate treatment of these plants can lead to bioadditives that significantly affect the properties of rubber materials.

Anti-Oxidative Activity of Alcohol-Water Extracts from Field Horsetail (Equisteum arvense) in Elastomer Vulcanizates Subjected to Accelerated Aging Processes

The article aimed to highlight the antioxidant potential of natural extracts obtained from Equisteum arvense in elastomer vulcanizatec made of natural rubber. Horsetail extracts were prepared using four solvent systems at different volume ratios: methanol–water (50/50 and 70/30) and ethanol–water (50/50 and 70/30), which were then lyophilized and added to the polymer matrix. A deep characterization of the obtained bio-additives was performed. The obtained vulcanizates were subjected to various aging processes: thermo-oxidative, ultraviolet and solar. Then, the resistance and susceptibility of vulcanizates to selected processes of accelerated, simulated degradation were determined based on the changes in the spatial structure (network nodes), material strength and physical properties (color). The research showed the presence of polyphenols in the extracts of horsetail, which resulted in their high anti-oxidative activity. Moreover, the extracts were able to absorb UV radiation. As a consequence, they were active additives that protected rubber vulcanizates against the damaging effects of the aging processes, securing their functional properties. Samples containing natural extracts were characterized by better stability of: mechanical strength parameters, the increase in cross-linking density and color changes after simulating aging processes in comparison with the control sample.