Antibacterial and antifungal activities of pyroligneous acid from wood of Eucalyptus urograndis and Mimosa tenuiflora

Unraveling the organellar genomic landscape of the therapeutic and entheogenic plant Mimosa tenuiflora: insights into genetic, structural, and evolutionary dynamics

Mimosa tenuiflora, popularly known as "Jurema-Preta", is a perennial tree or shrub native to the tropical regions of the Americas, particularly among Afro-Brazilian and Indigenous Brazilian communities. Known for producing N,N-Dimethyltryptamine, a psychedelic compound with profound psychological effects, Jurema-Preta has been studied for its therapeutic potential in mental health. This study offers a comprehensive analysis of the plastid (ptDNA) and mitochondrion (mtDNA) genomes of M. tenuiflora. The 165,639 bp ptDNA sequence features the classical quadripartite structure with 130 protein-coding genes. Comparative genomics among Mimosa species shows high sequence identity in protein-coding genes, with variation in the rpoC1, clpP, ndhA, and ycf1 genes. The ptDNA junctions display distinct features, such as the deletion of the rpl22 gene, and specific simple sequence repeats highlight genetic variation and unique motifs as valuable genetic markers for population studies. Phylogenetic analysis places M. tenuiflora in the Caesalpinioideae, closely related to M. pigra and M. pudica. The 617,839 bp mtDNA sequence exhibits a complex structure with multiple genomic arrangements due to large repeats, encoding 107 protein-coding genes, including the ptDNA petG and psaA genes, and non-retroviral RNA mitoviruses sequences. Comparative analysis across Fabaceae species reveals limited conservation, emphasizing the dynamic nature of plant mitochondrial genomes. The genomic characterization of M. tenuiflora enhances understanding of its evolutionary dynamics, providing insights for population studies and potential applications in ethnopharmacology and conservation.

Extraction of wood vinegar from bagasse and its application as bio-reducer to produce stable silver nanoparticles with enhanced antibacterial activity

Global efforts have been made to address environmental and health concerns by promoting and adopting renewable natural resources. This study investigated the role of bagasse-based wood vinegar to synthesize and stabilize silver nanoparticles. We present a simple bottom-up approach to produce silver nanoparticles using the green reducing agent. Wood vinegar has been used to create and stabilize nanoparticles as well as increase the biological activity of silver nanoparticles. In the WV-AgNPs aqueous dispersion's absorption spectra, a wide surface plasmon resonance (SPR) peak with a 395 nm wavelength center was visible. Wood vinegar has been utilized not only to synthesize and stabilize nanoparticles, but it also makes silver nanoparticles biologically more active. Prepared WV-AgNPs showed remarkable antibacterial activity against three pathogenic bacteria and satisfactory antiproliferative activity against human breast (MCF-7) cell line. The stability of the prepared nanoparticles has been confirmed by zeta potential value. The surface morphology and the particle size were investigated by scanning electron microscope and transmission electron microscope. The prepared particles are spherical in shape and particle size ranges from 20 to 40 nm. WV-AgNPs are further characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Dynamic Light Scattering (DLS), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FTIR) spectroscopy. Based on the results, it can be concluded that silver nanoparticles mediated by wood vinegar showed promising properties and might find application in the biological domain.

Lignin extraction from lignocellulosic biomass and its valorization to therapeutic phenolic compounds

Lignocellulosic biomass is a sustainable alternative to finite petroleum resources, with lignin emerging as a major component of biomass for producing circular economy products. Maximizing extraction and valorization of lignin to platform chemicals, biofuels, and bioactive compounds is crucial. Unlocking lignin's full potential lies in exploring the therapeutic properties of lignin-derived phenolics, which can definitely boost the economic viability of integrated biorefineries. This review provides a broad vision of lignin valorization stages, covering various techniques of its extraction from lignocellulosic biomass with high yield and purity and its further depolymerization to phenolics. Therapeutic potential of lignin-derived phenols as antioxidants, antimicrobials, anti-inflammatory, and anticancer agents is comprehensively discussed. Lignin, with high phenolic hydroxyl content up to 97% purity, can be extracted using deep eutectic solvents (DES) and organosolv processes. Oxidative and reductive catalytic depolymerization methods efficiently break down lignin into valuable phenolic compounds like alkyl phenolics and vanillin, even at mild temperatures, making them a preferred choice for lignin valorization. Potential of lignin derived phenolics as versatile bioactive compounds with health promoting benefits is highlighted. Phenolics such as vanillin, ferulic acid, and syringic acid have demonstrated the ability to modulate cellular pathways involved in the pathogenesis of diseases like cancer and diabetes. The interplay between high purity lignin extraction and therapeutic potential of lignin-derived phenolics unveils a new frontier in sustainable healthcare solutions.

Mechanistic Investigation of the Pyrolysis Temperature of Reed Wood Vinegar for Maximising the Antibacterial Activity of Escherichia coli and Its Inhibitory Activity

To solve the problem of large-scale growth of wetland reeds, wood vinegar, a by-product of pyrolysed reed wood vinegar, can be used as a natural antimicrobial agent. In this study, we compare the changes in growth and bacterial morphology of Escherichia coli (E. coli) treated with reed wood vinegar at different pyrolysis temperatures (300 °C, 500 °C and 700 °C) and reveal the bacterial inhibition mechanism of reed wood vinegar by RNA-Seq. The results of bacteria inhibitory activity showed that 1/2MIC 500 °C wood vinegar had the most prominent bacteria inhibitory activity. qPCR results showed that reed wood vinegar was able to significantly inhibit the expression of E. coli biofilm and genes related to the cell membrane transporter proteins. Electron microscopy observed that the wood vinegar disrupted the cellular morphology of E. coli, resulting in the crumpling of E. coli cell membranes. RNA-Seq showed the multifaceted antimicrobial effects of wood vinegar and demonstrated that the inhibitory effect of wood vinegar on E. coli was mainly realized through the inhibition of the expression of malE, which is an ATP-binding cassette (ABC) transporter complex of E. coli. In conclusion, our study provides an effective method and a theoretical basis for the mechanism of reed wood vinegar as a natural antimicrobial agent and its pathway of bacterial inhibition.

Neem Essential Oil as an Antifungal Agent against Phyllosticta citricarpa

The fungus Phyllosticta citricarpa is a quarantine phytopathogen responsible for causing citrus black spot (CBS) disease. To export fruits to CBS-free countries, they must undergo a sanitation process to ensure disease control. In this study, neem essential oil (NEO) was tested against P. citricarpa for the first time as an alternative sanitizer. In vitro experiments were conducted to determine the inhibition concentration of NEO for P. citricarpa, and the mode of action of the essential oil was evaluated. In vivo assays were performed to simulate the sanitization process used in packinghouses. NEO was characterized by GC-MS/MS. The results revealed that NEO at 100 μL·mL-1 exhibited a similar inhibitory effect as copper oxychloride, suppressing 89.68 ± 1.14% of fungal mycelium growth. Fluorescence microscopy experiments demonstrated that NEO functions by disrupting the cytoplasmic membrane of fungal hyphae, leading to their death within 30 minutes of contact with NEO. GC-MS/MS characterization revealed a high presence of phenolic compounds, which serve as the primary antifungal agents responsible for the action against fungal hyphae. In vivo assays showed that NEO at 100 μL·mL-1 also reduced microorganisms (CFU mL-1) by 93.00 ± 3.88% compared to the negative control. Overall, the results demonstrate that NEO can effectively serve as an alternative sanitizer against P. citricarpa in citrus packinghouses. Our findings allow future studies to explore the use of NEO for sanitizing other fruits and combating different phytopathogens to broaden its potential application in fruit sanitation for export.

Slow pyrolysis of Terminalia catappa L. municipal solid waste and the use of the aqueous fraction produced for bovine mastitis control

The Terminalia catappa L. tree is an ornamental and shade tree producter of a large amount of biological waste sent to landfills. Therefore, this plant constitutes so-called municipal solid wood waste (MSWW), which causes undesirable impacts on the environment, such as the generation of methane through the action of microorganisms. Sustainable solutions for the proper use and disposal of MSWW are a topic that has assumed great relevance at present due to the high quantities of MSWW generated worldwide. Pyrolysis constitutes an attractive alternative for the sustainable use of MSWW to produce higher value-added products. This study investigated the slow pyrolysis of Terminalia catappa L. fruit and the use of the aqueous fraction produced for bovine mastitis control. We obtained four fractions from the pyrolysis process, with average yields of the aqueous phase (36.22 ± 2.0 %), bio-oil (5.52 ± 0.4 %), biochar (37.55 ± 2.8 %) and gas (20.71 ± 2.0 %). The aqueous fraction was extracted with organic solvents and analyzed by gas chromatography coupled to mass spectrometry (GC‒MS). The extracts were composed mainly of phenols (50 %), furan derivatives, cyclic ketones, and others with lower contents, such as alcohols and esters. The aqueous fraction had bactericidal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which are responsible for bovine mastitis. In addition, the fraction showed low cytotoxicity against a murine melanoma cell line from a C57BL/6J mouse, B16F10 cells and mouse peritoneal cells.

Understanding the nanoscale adhesion forces between the fungal pathogen Candida albicans and antimicrobial zinc-based layered double hydroxides using single-cell and single-particle force spectroscopy

Antifungal resistance has become a very serious concern, and Candida albicans is considered one of the most opportunistic fungal pathogens responsible for several human infections. In this context, the use of new antifungal agents such as zinc-based layered double hydroxides to fight such fungal pathogens is considered one possible means to help limit the problem of antifungal resistance. In this study, we show that ZnAl LDH nanoparticles exhibit remarkable antifungal properties against C. albicans and cause serious cell wall damage, as revealed by growth tests and atomic force microscopy (AFM) imaging. To further link the antifungal activity of ZnAl LDHs to their adhesive behaviors toward C. albicans cells, AFM-based single-cell spectroscopy and single-particle force spectroscopy were used to probe the nanoscale adhesive interactions. The force spectroscopy analysis revealed that antimicrobial ZnAl LDHs exhibit specific surface interactions with C. albicans cells, demonstrating remarkable force magnitudes and adhesion frequencies in comparison with non-antifungal negative controls, e.g., Al-coated substrates and MgAl LDHs, which showed limited interactions with C. albicans cells. Force signatures suggest that such adhesive interactions may be attributed to the presence of agglutinin-like sequence (Als) adhesive proteins at the cell wall surface of C. albicans cells. Our findings propose the presence of a strong correlation between the antifungal effect provided by ZnAl LDHs and their nanoscale adhesive interactions with C. albicans cells at both the single-cell and single-particle levels. Therefore, ZnAl LDHs could interact with C. albicans fungal pathogens by specific adhesive interactions through which they adhere to fungal cells, leading to their damage and subsequent growth inhibition.

Wood fiber biomass pyrolysis solution as a potential tool for plant disease management: A review

Wood vinegar is a high-value acidic byproduct of biomass pyrolysis used for charcoal production. It is widely used in agriculture and forestry. The adverse effects of synthetic fungicides on the environment and human health have prompted the increasing use of biofungicides as alternatives to traditional products in integrated plant disease management programs. In recent years, there has been an increasing interest in the potential of wood vinegar as a disease management tool in agriculture and forestry. In this paper, the composition and preparation process of wood vinegar and its application in agriculture and forestry were introduced, and the effect and mechanism of wood vinegar against fungi, viruses and bacteria were summarized. The potential of wood vinegar as a sustainable and eco-friendly alternative to conventional chemical fungicides is also discussed. Finally, some suggestions on the application and development of wood vinegar were put forward.

Physiological and Biochemical Mechanisms of Wood Vinegar-Induced Stress Response against Tomato Fusarium Wilt Disease

Wood vinegar, a by-product of charcoal biomass pyrolysis, has been used as a biofungicide in plant disease management because of its antimicrobial properties. However, the physiological and biochemical mechanisms through which wood vinegar alleviates biotic stress are poorly understood. In this study, pot experiments were conducted to investigate the resistance and regulation mechanism of wood vinegar prepared from different raw materials (ZM) and from a single raw material (SM) in controlling tomato (Solanum lycopersicum "Bonny Best") Fusarium wilt at different concentrations (0.3%, 0.6%, 0.9%, 1.2%, and 1.5%). The results showed that ZM and SM had significant control effects on tomato fusarium wilt under different concentrations in the same growth cycle. Under biotic stress, the two kinds of wood vinegar significantly increased the plant height, stem diameter, leaf area and yield of tomato under the concentration of 0.3%, 0.6%, 0.9% and 1.2%, and significantly reduced the content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in tomato leaves. The effect of 0.9% treatment was the most significant, ZM and SM significantly increased tomato yield by 122% and 74%, respectively, compared with CK under 0.9% treatment. However, the plant height, stem diameter and leaf area of tomato were significantly reduced under 1.5% treatment, but the content of soluble sugar, soluble protein and vitamin C in tomato fruit was the best. Compared with CK, ZM significantly increased by 14%, 193% and 67%, respectively, and SM significantly increased by 28%, 300% and 159%, respectively. Except for 0.3% treatment, both significantly increased the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in tomato leaves. The response intensity of two kinds of wood vinegar-physiological and biochemical-to tomato disease resistance, growth and development, showed ZM > SM. The disease index of tomato showed highly significant negative correlation with plant height, stem thickness, leaf area and antioxidant physiology CAT, and highly significant positive correlation with MDA and H2O2 content. In conclusion, ZM was more effective than SM in enhancing tomato disease resistance by promoting tomato growth and development, decreasing leaf MDA and H2O2 content, and inducing antioxidant enzyme activity in leaves at moderate concentrations.

Reducing nitrogen leaching using wood vinegar treated in urea-fertilized soil

Wood vinegar (WV) is known to retard the release of ammonium (NH4+) from urea by inhibiting urea hydrolysis. However, the effect of WV on nitrogen leaching in soil is not known, and there are few studies on the effect of WV on microbial activity although WV exhibits antibacterial properties against pathogens in agriculture. Therefore, the purpose of this study was to investigate the effect of WV on controlling nitrogen leaching and soil microbial activity. Soils were treated with urea and WV, and the available inorganic nitrogen concentrations in the soil were compared with those from soils treated with N-(n-butyl)thiophosphoric triamide (NBPT), a commonly used urease inhibitor. The nitrate concentration in the soil was significantly decreased in the WV treatment, although the ammonium concentration was not affected by the WV treatment. Basal soil respiration was significantly increased in the WV and NBPT treatments although the microbial biomass was increased in the urea only treatment. The ammonium nitrogen concentration in the leachate was not significantly different in the WV and urea-treated soil compared to the urea-only treatment. However, the nitrate leaching increased in the soil treated only with urea at 16 days after the treatment although there was no statistically significant difference in the total leached nitrate. Therefore, WV can be used to reduce nitrogen leaching and enhance soil microbial activity.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptus grandis - clone I144) and bamboo (Bambusa vulgaris)

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Use of a product based on wood vinegar of Eucalyptus clone I144 used in the control of bovine mastitis

Bovine mastitis is one of the most frequent diseases in dairy cattle worldwide. The use of antiseptics in milking, if properly used, can lead to a reduction in potentially pathogenic microorganisms and their transmission between herds. Several medicinal plants have antiseptic potential, including eucalyptus (Eucalyptus spp.). Therefore, the objective of this study was to evaluate the effectiveness of wood vinegar from Eucalyptus urograndis clone GG I144 (EU) as an antiseptic in vitro and in vivo; in addition, to its cytotoxicity and antimicrobial resistance. Fifteen bovines were used, lactating females 3-6 years of age and divided into three groups of five animals each. The wood vinegar was placed in the teats of the animal for 28 days and collections of cellular debris were performed every 7 days. At the Veterinary Microbiology Laboratory (LAMIV) of UFERSA, the samples were processed and serial dilution was performed in Petri plates with plate count agar (PCA) at 37 °C. Cytotoxicity was verified based on morphological alterations and metabolic activity. Morphological changes were not observed in all cells incubated with 1 % pyroligneous extract. The in vitro data demonstrated antimicrobial activity against S. aureus, S. agalactiae, Salmonella, E. coli and P. aeruginosa. The bacteria of the genus Staphylococcus and Corynebacterium were resistant to penicillin (PEN), rifampicin (RIF), nitrofurantoin (NIT), erythromycin (ERI), and ciprofloxacin (CIP). The extract was used in vivo in the post-dipping of dairy cows, which reduced the microbiological load present in the mammary glands from 4.74 to 2.54 CFU, indicating its future use as an antiseptic.

Semi-VOCs of Wood Vinegar Display Strong Antifungal Activities against Oomycete Species Globisporangium ultimum and Pythium aphanidermatum

Plant disease outbreaks are increasingly exacerbated by climate change and the conditions of stress combinations. They are negatively affecting crop yield and driving threats to food security in many areas of the world. Although synthetic pesticides offer relative success in the control of pests and plant diseases, they are often overused, and this method faces numerous drawbacks, including environmental toxicity, soil degradation, and adverse effects on human health. Therefore, alternatives are being developed and examined, including the biocontrol of pests and pathogens and biomass pyrolysis leading to wood vinegar that has shown great promise in agriculture and organic farming. However, while wood vinegar use is expanding and allows the control of numerous pests and bacterial and fungal diseases, its application to control oomycete diseases is limited. This study aimed to test wood vinegar for the control of oomycete plant pathogens from which six wood vinegars of pistachio, pomegranate, almond, pine, cypress, and walnut were produced. The inhibitory effects of volatile metabolites (semi-VOCs) of different wood vinegars concentrations (100%, 50%, 25%, 12.5%, and 6.25%) were examined against the hyphal growth of Globisporangium ultimum and Pythium aphanidermatum isolates. An in vitro analysis unambiguously demonstrated that for Globisporangium ultimum, the wood vinegar semi-VOCs of almond, pistachio (C 100% and 50%), and walnut (C 100%) totally inhibited mycelial growth. On the other hand, Pythium aphanidermatum, pistachio (C 100%, 50%, and 25%), and cypress (C 100%) expressed their abilities to completely inhibit the mycelial growth. Other treatments, including relevant concentrations of pine and pomegranate significantly inhibited the growth of mycelia of both species compared to the control (p ≤ 0.05). Therefore, wood vinegar could be considered a natural and organic product to use in agriculture to cope not only against pests, bacterial and fungal pests but also against emerging oomycete plant diseases.

2-Octylcyclopentanone Inhibits Beta Lactam Resistant Diabetic Wound Pathogens

Microbial infection is a frequent complication of diabetic foot ulcers, with up to 82% of ulcers being infected at the initial stage of diabetes. Furthermore, the emergence of beta lactam resistant pathogens managed to eliminate the use of beta lactam antibiotics as a chemotherapeutic alternative. This further increases the amputation and mortality rate. Hence, the aim of this study is to evaluate antimicrobial efficacy of a ketone derivative 2-octylcyclopentanone against diabetic wound pathogens. The inhibitory activity of the compound was determined using disc diffusion and broth microdilution assay. Generally, 2-octylcyclopentanone showed broad-spectrum antimicrobial activity, particularly against beta lactam resistant pathogens. The compound showed comparably better antimicrobial activity than all reference antibiotics, including chloramphenicol, streptomycin, ampicillin and penicillin. In addition, the same compound also inhibits a clinically isolated Pseudonomas aeruginosa that was resistant to all reference antibiotics. The activity was microbicidal based on the low minimal lethality concentration recorded, particularly on MRSA, P. aeruginosa and Candida utilis. The killing efficiency of the compound was concentration dependent. During kill curve analysis, the inhibitory activity of 2-octylcyclopentanone was concentration and time-dependent. 99.9% of reduction of bacterial growth was observed. MRSA and P. aeruginosa, two significant diabetic wound infections, are totally inhibited by the molecule at a concentration of minimum lethality concentration. In short, 2-octylcyclopentanone exhibited significant inhibitory towards wide range of diabetic wound pathogens. Which is considered crucial since it will provide a safe and effective alternative treatment for diabetic ulcer infection.

Dual action of pyroligneous acid in the eco-friendly synthesis of bactericidal silver nanoparticles

In the present study, we demonstrate that pyroligneous acid (PA), also known as wood vinegar, functions efficiently as both reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs). The synthesis and stabilization of AgNPs take place in the following fashion: 1) in alkaline environment, oxygenated species (phenols in the present case) contained in PA reduce silver ions to metallic silver; 2) acetic acid, abundantly present in PA, adsorb onto the AgNPs conferring electrostatic stabilization. This mechanism is supported by GC-MS and RAMAN analysis, with the former revealing the compounds lacking in PA after nanoparticle synthesis and the latter demonstrating acetic acid adsorbed on the nanoparticles. The AgNPs produced via this method were quite stable up to 150 days (zeta potential = -56 mV). The AgNPs were then found to inhibit the growth of Escherichia coli and Staphylococcus aureus. Concerning PA, we showed that it displays bactericidal properties only under acidic conditions. This study contributes to the development of more environmentally benign routes to produce nanomaterials.

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Pyroligneous acid as reducing and stabilizing agent to produce silver nanoparticles.

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No hazardous chemicals employed in the synthesis of the nanoparticles.

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Pyroligneous acid displays bactericidal activity only under acidic conditions.

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Mitigation of the environmental impact of pyrolysis gasses.

Efficiency of Pyroligneous Extract from Jurema Preta (Mimosa tenuiflora [Willd.] Poiret) as an Antiseptic in Cats (Felis catus) Subjected to Ovariosalpingohysterectomy

Simple Summary

The pyroligneous extract from Mimosa tenuiflora was used as an antiseptic in cats. The objective of this study was to analyze the action of 20% pyroligneous extract from M. tenuiflora as an antiseptic for surgical wounds of cats subjected to ovariohysterectomy. In addition to the absence of cytotoxicity, the number of bacteria was reduced after treatment. Tissue dehiscence, hyperemia, edema, crust, and secretions were not observed. Thus, the pyroligneous extract of M. tenuiflora has potential as a natural antiseptic alternative.

Abstract

Pyroligneous extract of Jurema preta (Mimosa tenuiflora [Willd.] Poiret) was evaluated for its efficacy as a cutaneous antiseptic in cats (Felis catus) that were subjected to ovariosalpingohysterectomy. For this purpose, 30 cats without a defined breed were sterilized and divided into two groups. The first group was the positive control, treated with 0.5% chlorhexidine-alcohol solution, and the second group was treated with 20% pyroligneous extract of M. tenuiflora. Regardless of age and sex, all animals had visible healing at similar times. A significant reduction in bacterial growth was observed in animals treated with the extract, and no cytotoxicity was observed in the feline epithelial cells. In addition, surgical wounds of cats treated with M. tenuiflora extract exhibited improved healing. On agar plates, treatment with both chlorhexidine and M. tenuiflora extract resulted in the inhibition zones for all bacterial strains isolated from surgical wounds. Therefore, M. tenuiflora extract is demonstrated to have antiseptic effects on the surgical wounds of cats undergoing ovariosalpingohysterectomy.

Present scenarios and future prospects of herbal nanomedicine for antifungal therapy

The current COVID-19 epidemic is a sobering reminder that human susceptibility to infectious diseases remains even in our modern civilization. After all, infectious diseases are still the major reason of death globally. Healthcare authorities have often underestimated and ignored the threat posed by "microbial dangers," although they put millions of lives at risk every year. Overlooked developing diseases including fungal infections (FIs) contribute to roughly 1.7 million fatalities per year. As many as 150 million cases of severe and potentially life-threatening FIs are reported each year. In the last few years, the number of instances has steadily increased. Most of them are invasive fungal infections that require specialized treatment and hospital care. In recent years herbal antifungal compounds have been explored to acquire effective and safe therapy against fungal infections. However, potential therapeutic effects are hampered by the poor solubility, stability, and bioavailability of these important chemicals as well as the gastric degradation that occurs in the gastrointestinal tract. To get around this issue, researchers have turned to novel drug delivery systems such as nanoemulsions, ethosomes, metallic nanoparticles, liposomes, lipid nanoparticles, transferosomes, etc by improving their limits, nanocarriers can enhance the medicinal effects of herbal oils and extracts. The present review article focuses on the available antifungal agents and their characteristics, mechanism of antifungal drugs resistance, herbal oils and extract as antifungal agents, challenges in the delivery of herbal drugs, and application of nano-drug delivery systems for effective delivery of antifungal herbal compounds.

Sustainable Plant Growth Promotion and Chemical Composition of Pyroligneous Acid When Applied with Biochar as a Soil Amendment

The pyrolysis of biomass material results in pyroligneous acid (PA) and biochar, among other by-products. In agriculture, PA is recognized as an antimicrobial agent, bio-insecticide, and bio-herbicide due to antioxidant activity provided by a variety of constituent materials. Application of PA to crop plants and soil can result in growth promotion, improved soil health, and reduced reliance on polluting chemical crop inputs. More detailed information regarding chemical compound content within PA and identification of optimal chemical profiles for growth promotion in different crop species is essential for application to yield effective results. Additionally, biochar and PA are often applied in tandem for increased agricultural benefits, but little is known regarding the optimal proportion of each crop input. This work reports on the effect of combined applications of different proportions of PA (200- and 800-fold dilutions) and chemical fertilizer rates (100%, 75%, 50%, and 0%) in the presence or absence of biochar on Komatsuna (Brassica rapa var. perviridis, Japanese mustard spinach) plant growth. To elucidate the chemical composition of the applied PA, four different spectroscopic measurements of fluorescence excitation were utilized for analysis—excitation-emission matrix, ion chromatography, high-performance liquid chromatography, and gas chromatography-mass spectrometry. It was determined that PA originating from pyrolysis of Japanese pine wood contained different classes of biostimulants (e.g., tryptophan, humic acid, and fulvic acid), and application to Komatsuna plants resulted in increased growth when applied alone, and in different combinations with the other two inputs. Additionally, application of biochar and PA at the higher dilution rate increased leaf accumulation of nutrients, calcium, and phosphorus. These effects reveal that PA and biochar are promising materials for sustainable crop production.

Antimicrobial Activity of Slow Pyrolysis Distillates from Pine Wood Biomass against Three Pathogens

The aim of this study was to evaluate the antimicrobial activity of wood distillates obtained from Scots pine (Pinus sylvestris) sawdust in order to explore new alternatives for the utilization of wood industry by-products. The distillates were produced by slow pyrolysis thermal conversion in three process phases with increasing temperatures, namely drying, torrefaction and pyrolysis, and three cooling units with different temperatures to condensate the distillates. This yielded nine different liquid fractions. The food-related pathogens, Salmonella, Listeria monocytogenes and Candida albicans, were evaluated for their susceptibility to the distillate fractions using an agar diffusion test. The antimicrobial activity was estimated by measuring the formed inhibition zones after the incubation period. In addition, the minimum inhibitory concentration (MIC) and microbicidic concentration were assayed for a selected fraction (T2) from the torrefaction phase with Bio-screen C. The results indicated that the distillates from the torrefaction and pyrolysis phases had antimicrobial activity against the tested microbes. The MIC value of the T2 fraction for all tested microbes was 0.83% (v/v). Furthermore, the T2 fraction was microbicidic for Salmonella and Listeria strains in 0.83% (v/v) solution and Candida strain in 1.67% (v/v) solution. In conclusion, Scots pine wood distillates obtained from slow pyrolysis have the potential to be developed as antimicrobial agents against pathogenic microbes. Next, research is needed to investigate the chemical composition of the distillates and to assess their safe use.

Effect of Pyroligneous Acid on the Microbial Community Composition and Plant Growth-Promoting Bacteria (PGPB) in Soils

Pyroligneous acid (PA) is often used in agriculture as a plant growth and yield enhancer. However, the influence of PA application on soil microorganisms is not often studied. Therefore, in this study, we investigated the effect of PA (0.01–5% w/w in soil) on the microbial diversity in two different soils. At the end of eight weeks of incubation, soil microbial community dynamics were determined by Illumina-MiSeq sequencing of 16S rRNA gene amplicons. The microbial composition differed between the lower (0.01% and 0.1%) and the higher (1% and 5%) concentration in both PA spiked soils. The lower concentration of PA resulted in higher microbial diversity and dehydrogenase activity (DHA) compared to the un-spiked control and the soil spiked with high PA concentrations. Interestingly, PA-induced plant growth-promoting bacterial (PGPB) genera include Bradyrhizobium, Azospirillum, Pseudomonas, Mesorhizobium, Rhizobium, Herbaspiriluum, Acetobacter, Beijerinckia, and Nitrosomonas at lower concentrations. Additionally, the PICRUSt functional analysis revealed the predominance of metabolism as the functional module’s primary component in both soils spiked with 0.01% and 0.1% PA. Overall, the results elucidated that PA application in soil at lower concentrations promoted soil DHA and microbial enrichment, particularly the PGPB genera, and thus have great implications for improving soil health.

The Antioxidant Guaiacol Exerts Fungicidal Activity Against Fungal Growth and Deoxynivalenol Production in Fusarium graminearum

The main component of creosote obtained from dry wood distillation—guaiacol—is a natural antioxidant that has been widely used in pharmaceutical and food preservation applications. However, the antifungal mechanism of guaiacol against phytopathogens remains unclear. In this study, we found that guaiacol exerts inhibitory effects against mycelial growth, conidial formation and germination, and deoxynivalenol (DON) biosynthesis in Fusarium graminearum in a dose-dependent manner. The median effective concentration (EC₅₀) value of guaiacol for the standard F. graminearum strain PH-1 was 1.838 mM. Guaiacol strongly inhibited conidial production and germination. The antifungal effects of guaiacol may be attributed to its capability to cause damage to the cell membrane by disrupting Ca²⁺ transport channels. In addition, the decreased malondialdehyde (MDA) levels and catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activity by guaiacol treatment indicate that guaiacol displays activity against DON production by modulating the oxidative response in F. graminearum. Taken together, this study revealed the potentials of antioxidant in inhibiting mycotoxins in F. graminearum.

Antimicrobial and cytotoxic capacity of pyroligneous extracts films of Eucalyptus grandis and chitosan for oral applications

Chitosan films containing distilled pyroligneous extracts of Eucalyptus grandis (DPEC), characterized and developed by Brazilian Agricultural Research Corporation-Embrapa Temperate Agriculture (EMBRAPA-CPACT), were evaluated for antimicrobial activity against Candida albicans, Streptococcus mutans, and Lactobacillus acidophilus by direct contact test. Further, their capacity for the prevention of teeth enamel demineralization and cytotoxicity in vitro were also determined. The natural polymers were tested at different concentrations (1500-7500 µg mL-1) and the formulation of an experimental fluoride varnish with antimicrobial activity was evaluated by direct contact test, whereas cytotoxicity was analyzed through the colorimetric MTT assay. Preliminary data showed no statistically significant differences in cytotoxicity to NIH/3T3 cell line when DPEC is compared to the control group. On the other hand, the antimicrobial capacity and demineralization effects were found between the test groups at the different concentrations tested. Chitosan films containing distilled pyroligneous extracts of E. grandis may be an effective control strategy to prevent biofilm formation related to dental caries when applied as a protective varnish. They may inhibit the colonization of oral microorganisms and possibly control dental caries through a decrease in pH and impairment of enamel demineralization.

Pyroligneous acid and antibacterial activity: criticism of a paper by Araújo et al. (2018)

AIMS

A paper by Araújo et al. (2018) claims that a variety of compounds present in pyroligneous acid (guaiacol, phenols and furfural) are responsible for the observed antimicrobial activity. We show, on the other hand, that the low pH due to acetic acid present in pyroligneous acid is the real cause of the activity.

METHODS AND RESULTS

Pyroligneous acid (PA) was synthesized according to a previous method (Medeiros et al. 2019) with its inhibition activity tested on Escherichia coli and Staphylococcus aureus via the agar diffusion method. The activity of acetic acid at different concentrations was also evaluated for comparison. As expected, crude PA (pH 3.0) and acetic acid produced inhibition halos whose diameters varied according to their employed concentration. However, any PA inhibitory activity completely vanished upon neutralization (pH 7.0), a behaviour also observed for neutralized acetic acid.

CONCLUSIONS

The claim that guaiacol, phenols and furfural are responsible for any inhibitory activity is unsubstantiated. The authors should have neutralized the pyroligneous acid if any activity was to be discovered.

SIGNIFICANCE AND IMPACT OF STUDY

To increase awareness that interfering species may play a detrimental role on the interpretation of results. In this case, the action of acetic acid is vastly more important for the inhibitory activity than any other compound present in PA.

Alternative Control of Phragmidium rubi-idaei Infecting Two Rubus Species

Organic berry plantations have been gaining popularity among farmers during recent years. Even so, farmers experience serious challenges in disease control management, which is a concern in organic farming. Phragmidium rubi-idaei (DC) P. Karst is the pathogen responsible for blackberry and raspberry rust disease, one of the most present and active diseases in plantations. The antifungal certified products found on the organic farming market offer the opportunity for an efficient control strategy over plant pathogens in fruit shrub plantations. In this study, 5 natural based products—namely Altosan, Mimox, Canelys, Zitron, and Zeolite—were tested for their fungistatic effect over P. rubi-idaei. The experiments were carried out under laboratory conditions, performing observations over the impact of organic products, used at different concentration levels, on rust conidia germination. Moreover, field experiments were conducted in order to evaluate the efficiency of different treatments for rust control on raspberry (‘Polka’, ‘Veten’ and ‘Heritage’) and blackberry (‘Thorn Free’, ‘Chester’ and ‘Loch Ness’) varieties. Data analysis based on ANOVA tests showed significant differences between the tested variants and the control sample at p < 0.001. Furthermore, LSD test confirmed differences between all substances tested (p < 0.005). The natural products Canelys (formulated with cinnamon) and Zytron (based on citrus extract) have proven the highest inhibitory capacity for conidia germination during in vitro tests registering values of 80.42% and 78.34%, respectively. The same high inhibitory rates against rust pathogen were kept also in the field tests using the same two natural-based products mentioned earlier. In addition, outcomes from this study demonstrated that Zeolite is not recommended for raspberry or blackberry rust control.

A Comprehensive Review of the Ethnotraditional Uses and Biological and Pharmacological Potential of the Genus Mimosa

The Mimosa genus belongs to the Fabaceae family of legumes and consists of about 400 species distributed all over the world. The growth forms of plants belonging to the Mimosa genus range from herbs to trees. Several species of this genus play important roles in folk medicine. In this review, we aimed to present the current knowledge of the ethnogeographical distribution, ethnotraditional uses, nutritional values, pharmaceutical potential, and toxicity of the genus Mimosa to facilitate the exploitation of its therapeutic potential for the treatment of human ailments. The present paper consists of a systematic overview of the scientific literature relating to the genus Mimosa published between 1931 and 2020, which was achieved by consulting various databases (Science Direct, Francis and Taylor, Scopus, Google Scholar, PubMed, SciELO, Web of Science, SciFinder, Wiley, Springer, Google, The Plant Database). More than 160 research articles were included in this review regarding the Mimosa genus. Mimosa species are nutritionally very important and several species are used as feed for different varieties of chickens. Studies regarding their biological potential have shown that species of the Mimosa genus have promising pharmacological properties, including antimicrobial, antioxidant, anticancer, antidiabetic, wound-healing, hypolipidemic, anti-inflammatory, hepatoprotective, antinociceptive, antiepileptic, neuropharmacological, toxicological, antiallergic, antihyperurisemic, larvicidal, antiparasitic, molluscicidal, antimutagenic, genotoxic, teratogenic, antispasmolytic, antiviral, and antivenom activities. The findings regarding the genus Mimosa suggest that this genus could be the future of the medicinal industry for the treatment of various diseases, although in the future more research should be carried out to explore its ethnopharmacological, toxicological, and nutritional attributes.

Influence of Pyroligneous Acid on Fermentation Parameters, CO2 Production and Bacterial Communities of Rice Straw and Stylo Silage

Carbon dioxide (CO₂) is a primary greenhouse gas and the main cause of global warming. Respiration from plant cells and microorganisms enables CO₂ to be produced during ensiling, a method of moist forage preservation applied worldwide. However, limited information is available regarding CO₂ emissions and mitigation during ensiling. Pyroligneous acid, a by-product of plant biomass pyrolysis, has a strong antibacterial capacity. To investigate CO₂ production and the influence of pyroligneous acid, fresh stylo, and rice straw were ensiled with or without 1% or 2% pyroligneous acid. Dynamics of the fermentation characteristics, CO₂ production, and bacterial communities during ensiling were analyzed. Pyroligneous acid increased the lactic acid content and decreased the weight losses, pH, ammonia-N content, butyric acid content, and coliform bacterial numbers (all P < 0.05). It also increased the relative abundance of Lactobacillus and decreased the relative abundances of harmful bacteria such as Enterobacter and Lachnoclostridium. Adding pyrolytic acids reduced the gas production, especially of CO₂. It also increased the relative abundances of CO₂-producing bacterial genera and of genera with the potential for CO₂ fixation. In conclusion, adding pyroligneous acid improved the fermentation quality of the two silages. During ensiling, CO₂ production was correlated with bacterial community alterations. Using pyroligneous acid altered the bacterial community to reduce CO₂ production during ensiling. Given the large production and demand for silage worldwide, application of pyroligneous acid may be an effective method of mitigating global warming via CO₂ emissions.

Hydrogel with silver nanoparticles synthesized by Mimosa tenuiflora for second-degree burns treatment

In this work we use Mimosa tenuiflora (MtE) extracts as reducing agents to synthesize silver nanoparticles (AgMt NPs) which were characterized by DPPH and Total Polyphenols Assays, UV-visible, X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). AgMt NPs possess average sizes of 21 nm and fcc crystalline structure, it was also confirmed that the MtE is present in the AgMt NPs even after the cleaning protocol applied. Subsequently, carbopol hydrogels were made and the MtE and the synthesized AgMt NPs were dispersed in different gels (MtE-G and AgMt NPs-G, respectively) at 100 µg/g concentration. The gels were characterized by UV-Vis, IR, and rheology. Antimicrobial tests were performed using Staphylococcus aureus and Escherichia coli. Burn wound healing was evaluated in a second-degree burn injury on a Wistar rats model for 14 days and additional skin biopsies were examined with histopathological analysis. Gel with commercial silver nanoparticles (Ag NPs) was prepared and employed as a control on the biological assays. Hydrogel system containing silver nanoparticles synthesized with Mimosa tenuiflora (AgMt NPs-G) is a promising therapeutic strategy for burn wound healing, this due to bactericidal and anti-inflammatory effects, which promotes a more effective recovery (in percentage terms) by damaged area.

Mimosa tenuiflora's antimicrobial activity on bacteria and fungi from medical importance: an integrative review

The misuse of antimicrobials has led to the appearance of several multi-resistant pathogens and, as a result, it has been necessary to search for new compounds that are effective against these microorganisms. Faced with this scenario, one of the forms that has been arousing the interest of scholars is the obtaining of antimicrobial compounds from medicinal plants, since, through them, effective compounds are usually obtained against pathogens and with low toxicity to humans and animals. In Brazilian Caatinga, there are several medicinal plants with antimicrobial properties, and one of them is Mimosa tenuiflora (Willd.) Poir., also known as Jurema Preta, popularly used to treat comorbidities that affect mainly the skin. In view of this, to investigate its antimicrobial potential, a bibliographical survey of experimental articles, published in the last 10 years, which analyzed the antimicrobial activity of M. tenuiflora in bacteria and fungi of importance, was made. Thus, it was possible to observe that the extracts obtained from M. tenuiflora showed in vitro antimicrobial activity. In addition, the compounds flavonoids and tannins are likely to be the main responsible for Mimosa tenuiflora's antimicrobial activity. Thus, M. tenuiflora presents a high study potential in microbial growth control.

Pyroligneous acid from Mimosa tenuiflora and Eucalyptus urograndis as an antimicrobial in dairy goats

AIMS

To evaluate the applicability of the Mimosa tenuiflora and Eucalyptus urograndis pyroligneous acids (PAs) as alternative antiseptics in dairy goats.

METHODS AND RESULTS

Cytotoxicity was evaluated in vitro using bacteria, as well as in vivo using goats, and the influence of PAs on the physicochemical parameters of fresh milk were examined. The cytotoxicity of PAs was evaluated in terms of morphology, cell viability and metabolic activity of goat tegumentary cells. The PA of M. tenuiflora had results similar to those of 2% iodine. For the in vitro tests, strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used with the well technique, demonstrating inhibition halos greater than 9 mm. In the in vivo test, 15 animals were used per phase of the experiment, and the plate counting technique showed that there was antiseptic action of both extracts, with emphasis on the M. tenuiflora PA. Physicochemical analysis of the milk showed that neither PAs interfered with its physical-chemical parameters.

CONCLUSIONS

The PA of M. tenuiflora presented potential as an alternative antiseptic in dairy goats.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the use of PA as an antimicrobial agent in animals.

Bioassay-Guided Isolation of Fungistatic Compounds from Mimosa caesalpiniifolia Leaves

A bioassay-guided phytochemical study of a Mimosa caesalpiniifolia leaf extract with antifungal activity permitted the identification of 28 compounds, including the new 6-(β-boivinopyranosyl)apigenin (1), 8-(β-oliopyranosyl)apigenin (2), (E)-6-(2-carboxyethenyl)apigenin (3), (E)-8-(2-carboxyethenyl)apigenin (4), and 7,5″-anhydro-6-(α-2,6-dideoxy-5-hydroxyarabinohexopyranosyl)apigenin (5). The structures of the new compounds were determined by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, and by mass spectrometry. Compound 3 showed promising activity and selectivity against Candida krusei (IC₅₀ 44 nM), which exhibits resistance to azoles. The association of the major components 3-β-d-glucopyranosyloxysitosterol (8) and ethyl gallate (10) was synergistic against C. krusei, especially the IC values of compound 10, which were reduced by more than 100-fold.