Search Results (37)

Biochar has been used to improve soils and promote sustainable agricultural development. The effects of applying different doses of biochar on soil aggregate structure and stability, aggregate-associated microbial communities, aggregate carbon fractions, and underlying mechanisms in planted forest soil ecosystems remain unclear. This study aimed to explore the effects of biochar amendment (7 years) on carbon stabilization in plantation soils. The effects of biochar application (0%, 0.5%, 1.0%, 2%, 4%, and 6%) on water-stable aggregate distribution, stability indices such as mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimension (D), aggregate-associated microbial communities (fungal and bacterial phospholipid fatty acids (PLFAs)), and carbon fractions such as soil organic carbon (SOC), easily oxidized organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC), microbial biomass carbon (MBC), recalcitrant organic carbon (ROC) and black carbon (BC) were investigated based on a seven-year in situ field experiment in a Eucalyptus plantation in northern Guangxi. The results showed that after 7 years, biochar application significantly increased the proportion of macroaggregates (≥0.25 mm). The MWD and GMD increased significantly with increasing biochar application rates, whereas D decreased significantly, indicating enhanced soil structural stability. Biochar significantly increased the abundance of fungi and bacteria across all aggregate size classes and changed the microbial community structure towards conditions that promoted increased carbon stabilization. Additionally, biochar application significantly increased both recalcitrant (ROC and BC) and labile carbon (EOC, POC, DOC, and MBC) in all aggregate fractions, with the largest increments in macroaggregates. Based on correlation analysis and structural equation modeling (SEM), we speculated that biochar might enhance the physical protection and chemical sequestration of organic carbon by optimizing the physical structure of the aggregates and synergizing with the microbial carbon pump. The 7-year application of biochar significantly enhanced the SOC content in plantation soils, primarily by increasing recalcitrant organic carbon, demonstrating that biochar application constitutes a viable approach to augmenting persistent soil carbon stabilization in plantation ecosystems. The 4% and 6% treatments produced the largest responses for most of the measured indicators, underscoring the importance of biochar application. Full article

This study aimed to reveal the rhizosphere microbial community structure, carbon–nitrogen–phosphorus (C-N-P) nutrient cycling processes, and functional gene characteristics of Pinus massoniana and Schima superba in mixed forests. Furthermore, we sought to elucidate the microbial mechanisms by which mixed-species afforestation enhances soil quality improvement, providing a theoretical basis in soil microbiology for the cultivation of these mixed forests. The research subjects included pure P. massoniana plantations (CLPs), pure S. superba plantations (CLSs), and individual P. massoniana (HJP) and S. superba (HJS) trees within mixed plantations (HJLs). We collected rhizosphere and bulk soil samples to analyze their physicochemical properties and enzyme activities. Metagenomic sequencing was employed to profile the rhizosphere microbial communities and functional genes involved in C-N-P cycling. Furthermore, by integrating a functional gene co-occurrence network analysis with structural equation modeling (SEM), we systematically elucidated the coupling relationships among the stand types, soil properties, microbial communities, and nutrient cycling. Mixed planting significantly improved soil quality; compared to the CLP and CLS forests, the nitrate nitrogen (NO₃⁻-N) content in the mixed forest soils increased by 121.01% and 120.10% (p < 0.05), and the activity of urease (URE) also significantly increased by 123.99% and 49.56%, respectively. Mixing significantly altered the microbial community structure. In the bacterial community of the mixed forests, the abundance of nitrogen-fixing and potentially phosphorus-solubilizing bacteria from the genera Paraburkholderia and Burkholderia increased. In the fungal community, the arbuscular mycorrhizal fungus Rhizophagus, which possesses a nutrient absorption advantage, exhibited absolute dominance, with its relative abundance ranging from 14.84% to 88.81%. The abundances of genes associated with denitrification and phosphorus starvation regulation were significantly upregulated in the mixed forests; notably, the abundance of phosphorus starvation regulation genes in the HJSs was 18.84% higher than that in the CLSs. A co-occurrence network analysis demonstrated that the proportion of positive correlation edges in the HJP nitrogen cycling network reached as high as 75.0%, and the average degree of the HJS phosphorus cycling network (2.691) surpassed that of the CLSs. The structural equation modeling further revealed that the association strength between the fungi and phosphorus cycling genes in the mixed forests increased to R² = 0.915 (p < 0.01) from R² = 0.213 in the pure forests. This mixed planting practice transforms nutrient cycling from a resource-competitive mode to a microbially synergized mode, thereby forming an efficient endogenous nutrient cycling system. This synergistic rhizosphere microbial effect is a key internal mechanism for overcoming nutrient bottlenecks and should serve as a diagnostic indicator of soil recovery in the ecological restoration of degraded pine forests. Full article

Vegetatively propagated crops, including cassava, sweet potato, banana, and potato, are susceptible to mixed-pathogen infections resulting from the continuous use of clonal planting material and infrequent seed replacement. A diverse array of viruses, bacteria, and fungi can accumulate within these materials over successive cultivation cycles, precipitating seed degeneration and complex disease syndromes that complicate diagnosis and management. Mixed infections frequently trigger synergistic interactions that exacerbate disease severity and yield losses. This review synthesizes data on mixed-pathogen complexes in vegetatively propagated crops, with particular focus on vascular and systemically colonizing pathogens and analyzing starch crops to highlight the epidemiological, biological, and ecological drivers of synergism and antagonism. Furthermore, the review examines host defense responses during coinfection, including the modulation of plant immune pathways, and evaluates how interpathogen dynamics influence pathological outcomes. Although advancements in molecular diagnostics—notably next-generation sequencing and metagenomics—have revolutionized the detection of mixed infections, they have also introduced challenges in differentiating causal agents from commensal microorganisms. Finally, we discuss the implications for integrated disease management, emphasizing clean seed systems, resistance breeding, and phenotyping strategies tailored to multipathogen environments. The dynamics of mixed infections is critical for resilient and sustainable management strategies amidst increasingly complex agricultural and climatic shifts. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with a rising global incidence in recent years. Dengzhan shengmai (DZSM), a plant-based formulation clinically used in the management of cerebrovascular diseases, possesses documented anti-inflammatory and antioxidant properties; however, its effects on UC are unclear. In this study, we investigated the therapeutic potential and underlying mechanism of DZSM in a dextran sulfate sodium (DSS)-induced murine colitis model. Our results showed that DZSM significantly alleviated UC-related parameters. Mechanistically, DZSM remodeled gut microbiota dysbiosis, specifically enriching the abundance of short-chain fatty acid (SCFA)-producing bacteria and elevating colonic levels of SCFAs. Notably, butyrate upregulated the expression of the sodium-dependent vitamin C transporter 1 (SVCT1) in colonic epithelial cells, thereby enhancing cellular vitamin C (VitC) uptake. The accumulated VitC synergized with butyrate to exert potent antioxidant and anti-inflammatory effects, further reinforcing epithelial barrier function. Importantly, fecal microbiota transplantation (FMT) confirmed that the protective effects of DZSM on UC were achieved by modulating gut microbiota, at least partially. Collectively, our findings demonstrate for the first time that DZSM alleviates DSS-induced colitis in mice through a novel butyrate-SVCT1-VitC axis driven by gut microbiota remodeling, providing new mechanistic insights into the microbiota-dependent efficacy of plant-based medicine. Full article

Psidium cattleyanum Sabine (strawberry guava, araçá) is an ethnomedicinal plant with reputed health benefits; however, its potential for treating skin disorders remains underexplored. This study aimed to characterize the phytochemical profile of P. cattleyanum leaves from Cabo Verde and evaluate their bioactivity relevant to skin health. Phytochemical analysis was performed using high-performance liquid chromatography-mass spectrometry (LC-MS) and spectrophotometric assays. Key biological activities were assessed in vitro, including antioxidant capacity (free radical scavenging assays), anti-aging enzyme inhibition (collagenase, elastase, and tyrosinase), and antibacterial activity against skin pathogens (agar diffusion, minimum inhibitory concentration, and combination studies with standard antibiotics). Cytotoxicity was evaluated using Vero cells (MTT assay). Additionally, a topical cream containing the leaf extract was formulated and subjected to physicochemical stability and sensory testing. LC-MS revealed a rich polyphenolic composition in the leaf extract, including abundant phenolic acids (gallic and ellagic acid derivatives) and flavonoid glycosides. The extract exhibited a high total phenolic content and strong antioxidant activity in DPPH/ABTS assays. It showed potent inhibition of collagenase, elastase, and tyrosinase, indicating an anti-aging effect against wrinkle formation and hyperpigmentation. The extract also demonstrated broad antimicrobial efficacy against skin-associated bacteria, such as Staphylococcus aureus and Cutibacterium acnes, with no antagonism and partial synergism observed when combined with certain antibiotics. The P. cattleyanum extract was successfully incorporated into a cream formulation that remained physically and chemically stable (no phase separation, consistent droplet size, and pH) over 90 days, with good homogeneity and acceptable sensory characteristics (neutral odor, smooth texture, and good spreadability). P. cattleyanum leaves from Cabo Verde are a rich source of bioactive compounds with multifunctional dermatological benefits. This study demonstrates that the P. cattleyanum leaf extract exhibits significant antioxidant, antimicrobial, and anti-aging activities in vitro, supporting its potential use as a natural ingredient for skin care. Full article

The rapid rise of antimicrobial resistance (AMR) has emerged as a critical global health crisis, driven by the widespread emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) pathogens. This growing threat, coupled with the stagnation in the development of novel antibiotics, necessitates the investigation of alternative antimicrobial strategies. Plant-derived essential oils (EOs) have emerged as promising candidates due to their broad-spectrum antibacterial activity, multi-targeted mechanisms, and capacity to enhance the efficacy of existing antibiotics. Recent studies have underscored the potential of EOs in disrupting biofilms, inhibiting quorum sensing, modulating efflux pumps, and reversing resistance in a variety of bacterial pathogens, including those listed as priorities by the World Health Organization. Notably, many of these effects have been demonstrated against resistant strains isolated directly from clinical samples, thereby enhancing the translational significance of EOs. In addition to their antimicrobial properties, advances in analytical, omics-based, and microfluidic technologies have further elucidated the mechanisms of EOs and may accelerate their therapeutic development. Nevertheless, challenges such as variability in composition, lack of standardized testing protocols, and limited in vivo data continue to impede clinical application. Therefore, the aim of this scoping review is to critically examine the advances over the past decade in the antibacterial activity of plant EOs against clinical isolates, with a particular focus on their efficacy against resistant bacterial pathogens and their potential role in combating AMR. Full article

Background/Objectives: For many years, herbs and spices have been used, due to their aroma and flavor, in the food industry and cuisine. It is also well known that phytochemicals from these plant parts have many health benefits and are used for the prevention and treatment of many human diseases. Basil (with the most representative species Ocimum basilicum) is a perennial herb with a characteristic aroma, containing many bioactive components such as phenolic acids, flavonoids, tannins, saponins, alkaloids, polysaccharides, vitamins, proteins, amino acids, and essential oils, with beneficial effects on human health. The aim of this study is to review the antioxidant, antimicrobial, and anticancer activity of basil, according to recent literature. Methods: A thorough search in the international databases (Scopus, PubMed, Google Scholar, and Web of Sciences) was conducted from January 2015 to October 2025, using characteristic keywords in combinations. Results: Bioactive components of basil show a significant antioxidant activity, as detected by radical scavenging activity (measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays), activation of antioxidant enzymes (glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT)), enhancement of reduced glutathione (GSH) and reduction in malondialdehyde (MDA) and thiobarbituric acid-reactive substance (TBARS) levels, and protection of cells from hydrogen peroxide (H₂O₂)-toxicity. Additionally, inhibition of growth and cell death of many Gram-positive and Gram-negative bacteria strains, maintained by cell membrane damage, inhibition of efflux pumps, as well as inhibition of biofilm formation, anti-protozoan, antifungal, and antiviral activities, have been noticed for basil bioactive components. A synergism with antibiotics has also been reported. Finally, anticancer activity has been reported, according to apoptosis induction, cell cycle arrest, anxiety reduction, and health improvement of cancer patients. Conclusions: Basil bioactive components have been reported for their high antioxidant, antimicrobial, and anticancer properties. However, future studies, especially at the clinical level, are strongly proposed in order to unravel the significant role of basil in human health and the safety of its bioactive components in healthcare usage. Full article

Antibiotic resistance is a major health priority, with the concern over antibiotic resistance growing. The rise in antibiotic-resistant bacteria coupled with the limited new therapeutics puts pressure on community and hospital healthcare systems and leads to excessive morbidity and mortality. Given this, there has been significant interest into potential new and/or combination antibacterial treatments including certain plant extracts. When combined with resistance medicines, these extracts can re-sensitize their potency. One such plant is Cirsium arvense which has been traditionally used for its anti-inflammatory and antimicrobial properties. Preliminary findings suggest that its extracts may enhance the activity of conventional antibiotics against resistant strains like MRSA. The current study assessed cefixime’s and Cirsium arvense extracts’ synergistic antibacterial efficacy against Escherichia coli, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus (MRSA). The antibacterial activity of extracts and the susceptibility profile of antibiotics were assessed using the disc diffusion and microbroth dilution assays. Chequerboard, time-kill kinetics, and protein content tests were performed to verify synergistic antibacterial effect. Our results demonstrated that when these extracts were applied to clinical strains of bacteria along with the cefixime, there was complete or partial synergy was displayed. Time-kill kinetics demonstrated that synergism was dependent on both concentration and time, and bacterial isolates treated with these exhibited significantly reduced bacterial growth and protein content. Taken together, these results show that Cirsium arvense extracts enhance the efficacy of conventional antibiotics against antibiotic-resistant strains of Escherichia coli, Acinetobacter baumannii, and MRSA and clearly suggest that these plant extracts could be used as additives to current resistant antibiotics for the future management or treatment of resistant bacterial infections. Full article

The synergism between plant growth-promoting bacteria species (PGPB) was evaluated regarding the effect of inoculation on productivity and the physiological aspects of Urochloa brizantha. The study included seven experimental groups arranged in a 3 × 2 + 1 factorial design consisting of three inoculants (Azospirillum brasilense, Bacillus sp. isolate EB-40, and Bacillus sp. isolate EB-40 + A. brasilense mixture), two application methods (seed and foliar spray), and controls. The MIX conjugate inoculation significantly increased plant height in all three harvests, with gains of 57%. At 60 and 90 days, MIX increased the number of tillers by 47% and the number of leaves by 61% compared to other treatments in all harvests. MIX also increased shoot dry mass in the second and third harvests, with improvements of 57–60% compared to the control. MIX improved the quantum efficiency of photosystem II and the ratio between variable and maximum chlorophyll fluorescence. Maximum fluorescence (Fm) was 11% higher in MIX-treated plants compared to the control, indicating increased potential photosynthesis. Variable fluorescence (Fv) efficiency improved by 22% for inoculation with A. brasilense and Bacillus sp. Our study reveals that A. brasilense plus the Bacillus sp. isolate EB-40 (MIX) has the potential to improve the resilience and productivity of U. brizantha. Full article

Bamboo shoot processing wastewater (BBPW) is rich in organic matter and organic acids and can be used as a nutrient source for microbial growth and biofertilization. In this study, Pseudomonas K22-D and Terribacillus goriness CS3 were isolated from bamboo forest soil with plant growth-promoting properties. Biofertilizers were prepared by inoculating bacteria into BBPW, and the effects of their application in a bamboo forest were evaluated. The chemical oxygen demand, TOC, TN, and NH₄-N contents decreased after inoculation, indicating that the bacteria were able to degrade macromolecules in BBPW. The BBPW biofertilizer produced by mixed bacteria (CS3 + K22-D) significantly improved the soil organic carbon and mineral-associated organic carbon content and reduced the pH, alkali-hydrolysable nitrogen, available phosphorus, and available potassium content of the soils in the bamboo forest, which might be attributed to the high C:N ratio and microbial synergism in the biofertilizer and the fast growth period of bamboo shoots. Notably, the CS3 biofertilizer significantly increased soil-available phosphorus (90.25%), and the K22-D biofertilizer significantly decreased soil-available phosphorus (70.33%) compared with CK, suggesting that the presence of inorganic phosphorus-solubilizing bacteria can promote soil P. We believe that the return of inoculated bamboo shoot processing wastewater to bamboo plantations can be an eco-friendly, sustainable practice for bamboo forest management. Full article

Biofilm formation is considered one of the primary virulence mechanisms in Gram-positive and Gram-negative pathogenic species, particularly those responsible for chronic infections and promoting bacterial survival within the host. In recent years, there has been a growing interest in discovering new compounds capable of inhibiting biofilm formation. This is considered a promising antivirulence strategy that could potentially overcome antibiotic resistance issues. Effective antibiofilm agents should possess distinctive properties. They should be structurally unique, enable easy entry into cells, influence quorum sensing signaling, and synergize with other antibacterial agents. Many of these properties are found in both natural systems that are isolated from plants and in synthetic systems like nanoparticles and nanocomposites. In this review, we discuss the clinical nature of biofilm-associated infections and some of the mechanisms associated with their antibiotic tolerance. We focus on the advantages and efficacy of various natural and synthetic compounds as a new therapeutic approach to control bacterial biofilms and address multidrug resistance in bacteria. Full article

The rapid increase in strains that are resistant to antibiotics requires new active compounds to be found whose mechanism of action on bacteria is different to those that are currently known. Of particular interest are compounds that occur in plants as secondary metabolites. The focus of this study concerns the examination of the effects of synthetic cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety on Enterococcus spp. with HLAR (high-level aminoglycoside resistance) and VRE (vancomycin-resistant Enterococcus) mechanisms. The minimum inhibitory concentration (MIC) values of the tested compounds were determined using the serial dilution method for Enterococcus spp. groups, and the most active compounds were as follows: 16d, 17c, 16a, 16c and 16f (2–4 µg/mL). These compounds, at a concentration of 4 × MIC, inhibited the biofilm formation of HLAR strains (70 to 94%). At concentrations of 2 × MIC and 4 × MIC, they also inhibited the growth of VRE strains (42 to 96%). The best effect produced on the formed biofilm was demonstrated by compound 16f (from 62% MIC concentration to 89% 4 × MIC concentration) on the tested HLAR strains. In vitro studies, using the peripheral blood of domestic sheep, demonstrated the stable bacteriostatic activity of the tested compounds against Enterococcus spp. The compounds 16a, 16c, 16d, 16f and 17c showed synergism and additivity with ampicillin, streptomycin, gentamicin and vancomycin against resistant strains of Enterococcus spp. The tested compounds, when combined, reduce the MIC for antibiotics by 800 to 10,000 times for HLAR strains and by 8 to 10,000 times for VRE strains. The MIC of the tested compounds, in combination with antibiotics, is reduced 2–16-fold for HLAR strains and 2–32-fold for VRE strains. These studies demonstrate the potential for the therapeutic use of synthetic, cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety, to work against clinical strains of Enterococcus spp. Full article

(1) Background: A possible solution to antimicrobial resistance (AMR) is synergism with plants like Artemisia brevifolia Wall. ex DC. (2) Methods: Phytochemical quantification of extracts (n-hexane (NH), ethyl acetate (EA), methanol (M), and aqueous (Aq)) was performed using RP-HPLC and chromogenic assays. Extracts were screened against resistant clinical isolates via disc diffusion, broth dilution, the checkerboard method, time–kill, and protein quantification assays. (3) Results: M extract had the maximum phenolic (15.98 ± 0.1 μg GAE/mgE) and flavonoid contents (9.93 ± 0.5 μg QE/mgE). RP-HPLC displayed the maximum polyphenols in the M extract. Secondary metabolite determination showed M extract to have the highest glycosides, alkaloids, and tannins. Preliminary resistance profiling indicated that selected isolates were resistant to cefixime (MIC 20–40 µg/mL). Extracts showed moderate antibacterial activity (MIC 60–100 µg/mL). The checkerboard method revealed a total synergy between EA extract and cefixime with 10-fold reductions in cefixime dose against resistant P. aeruginosa and MRSA. Moreover, A. brevifolia extracts potentiated the antibacterial effect of cefixime after 6 and 9 h. The synergistic combination was non- to slightly hemolytic and could inhibit bacterial protein in addition to cefixime disrupting the cell wall, thus making it difficult for bacteria to survive. (4) Conclusion: A. brevifolia in combination with cefixime has the potential to inhibit AMR. Full article

Antimicrobial resistance is considered a “One-Health” problem, impacting humans, animals, and the environment. The problem of the rapid development and spread of bacteria resistant to multiple antibiotics is a rising global health threat affecting both rich and poor nations. Low- and middle-income countries are at highest risk, in part due to the lack of innovative research on the surveillance and discovery of novel therapeutic options. Fast and effective drug discovery is crucial towards combatting antimicrobial resistance and reducing the burden of infectious diseases. African medicinal plants have been used for millennia in folk medicine to cure many diseases and ailments. Over 10% of the Southern African vegetation is applied in traditional medicine, with over 15 species being partially or fully commercialized. These include the genera Euclea, Ficus, Aloe, Lippia. And Artemisia, amongst many others. Bioactive compounds from indigenous medicinal plants, alone or in combination with existing antimicrobials, offer promising solutions towards overcoming multi-drug resistance. Secondary metabolites have different mechanisms and modes of action against bacteria, such as the inhibition and disruption of cell wall synthesis; inhibition of DNA replication and ATP synthesis; inhibition of quorum sensing; inhibition of AHL or oligopeptide signal generation, broadcasting, and reception; inhibition of the formation of biofilm; disruption of pathogenicity activities; and generation of reactive oxygen species. The aim of this review is to highlight some promising traditional medicinal plants found in Africa and provide insights into their secondary metabolites as alternative options in antibiotic therapy against multi-drug-resistant bacteria. Additionally, synergism between plant secondary metabolites and antibiotics has been discussed. Full article

The essential oil of Pelargonium graveolens L. is valuable for its therapeutic benefits, so this study aimed to determine the synergistic effect of the combination of the essential oil of this plant with antibiotics instead of the extracts prepared with various solvents. In addition, the second goal of this study was to determine whether the essential oil combined with various antibiotics increased the overall killing activity in mouse macrophage cells with the aim of introducing an immunotherapeutic approach to the infection treatments used today. Herein, the volatile profile of Geranium oil (G.O) was analyzed using GC/MS. The current study sought to assess the synergistic characteristics of several antibiotic combinations using G.O against pneumococci, as well as the oil’s antioxidant and antimicrobial activities. The major components of the oil were citronellol, geraniol, and isomenthone. In the combinations of G.O and antibiotics, the synergism of the Streptococcus pneumoniae to antibiotics advanced. When the time-kill data were evaluated, G.O + antibiotic combinations quickly diminished the viable cell count of S. pneumoniae from the 6th h. In this study, the combined use of existing antibiotics used in infection treatments with G.O could improve antibiotic effectiveness and thus prevent bacteria from developing antibiotic resistance. Full article