In vitro and in vivo antifungal efficacy of plant based lawsone against Fusarium oxysporum species complex

Lawsone Unleashed: A Comprehensive Review on Chemistry, Biosynthesis, and Therapeutic Potentials

Lawsone, a naturally occurring organic compound also called hennotannic acid, obtained mainly from Lawsonia inermis (Henna). It is a potential drug-like molecule with unique chemical and biological characteristics. Traditionally, henna is used in hair and skin coloring and is also a medicinal herb for various diseases. It is also widely used as a starting material for the synthesis of various drug molecules. In this review, we investigate on the chemistry, biosynthesis, physical and biological properties of lawsone. The results showed that lawsone has potential antioxidant, anti-inflammatory, antimicrobial and antitumor properties. It also induces cell cycle inhibition and programmed cell death in cancer, making it a potential chemotherapeutic agent. Additionally, inhibition of pro-inflammatory cytokine production makes it an essential treatment for inflammatory diseases. Exploration of its biosynthetic pathway can pave the way for its development into targets for new drug development. In future, well-thought-out clinical studies should be made to verify its safety and efficacy.

A pipeline for rapidly evaluating activity and inferring mechanisms of action of prospective antifungal compounds

BACKGROUND

Fungal phytopathogens are a significant threat to crops and food security, and there is a constant need to develop safe and effective compounds that antagonize them. In-planta assays are complex and tedious and are thus not suitable for initial high-throughput screening of new candidate antifungal compounds. We propose an in vitro screening pipeline that integrates five rapid quantitative and qualitative methods to estimate the efficacy and mode of action of prospective antifungal compounds.

RESULTS

The pipeline was evaluated using five documented antifungal compounds (benomyl, catechol, cycloheximide, 2,4-diacetylphloroglucinol, and phenylacetic acid) that have different modes of action and efficacy, against the model soilborne fungal pathogen Fusarium oxysporum f. sp. radicis cucumerinum. We initially evaluated the five compounds' ability to inhibit fungal growth and metabolic activity using green fluorescent protein (GFP)-labeled F. oxysporum and PrestoBlue staining, respectively, in multiwell plate assays. We tested the compounds' inhibition of both conidial germination and hyphal elongation. We then employed FUN-1 and SYTO9/propidium iodide staining, coupled to confocal microscopy, to differentiate between fungal growth inhibition and death at the cellular level. Finally, using a reactive oxygen species (ROS)-detection assay, we were able to quantify ROS production in response to compound application.

CONCLUSIONS

Collectively, the proposed pipeline provides a wide array of quantitative and qualitative data on the tested compounds that can help pinpoint promising novel compounds; these can then be evaluated more vigorously using in planta screening assays. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Lipopeptide C17 Fengycin B Exhibits a Novel Antifungal Mechanism by Triggering Metacaspase-Dependent Apoptosis in Fusarium oxysporum

Fusarium wilt is a worldwide soil-borne fungal disease caused by Fusarium oxysporum that causes serious damage to agricultural products. Therefore, preventing and treating fusarium wilt is of great significance. In this study, we purified ten single lipopeptide fengycin components from Bacillus subtilis FAJT-4 and found that C17 fengycin B inhibited the growth of F. oxysporum FJAT-31362. We observed early apoptosis hallmarks, including reactive oxygen species accumulation, mitochondrial dysfunction, and phosphatidylserine externalization in C17 fengycin B-treated F. oxysporum cells. Further data showed that C17 fengycin B induces cell apoptosis in a metacaspase-dependent manner. Importantly, we found that the expression of autophagy-related genes in the TOR signaling pathway was significantly upregulated; simultaneously, the accumulation of acidic autophagy vacuoles in F. oxysporum cell indicated that the autophagy pathway was activated during apoptosis induced by C17 fengycin B. Therefore, this study provides new insights into the antifungal mechanism of fengycin.

Potentials of Aloe barbadensis inclusion in fish feeds on resilience to Aeromonas hydrophila infection in freshwater fish Labeo rohita

Aquatic bacterial pathogens can cause severe economic loss in aquaculture industry. An opportunistic pathogen, Aeromonas hydrophila is responsible for Motile Aeromonas Septicemia, leading to high mortality rates in fish. The present study was focused on the efficacy of Aloe barbadensis replacing fishmeal diets on hematological, serum biochemical, antioxidant, histopathological parameters, and disease resistance against A. hydrophila infection in Labeo rohita. Isonitrogenous fishmeal replaced diets (FMR) were prepared with varying levels of A. barbadensis at D1 (0%) (control), D2 (25%), D3 (50%), D4 (75%) and D5 (100%) then fed to L. rohita. After 60 days of post-feeding, the experimental fish were challenged with A. hydrophila. Blood and organs were collected and examined at 1- and 15-days post infection (dpi). The results demonstrated that on 1 dpi, white blood cells (WBC), total protein, cholesterol and low-density lipoprotein (LDL) levels were significantly increased in D3 diet fed groups. The D2 and D3 diet fed group showed decreasing trends of serum glutamic pyruvic transaminase (SGPT) and antioxidant enzymes activity on 15 dpi. The histopathological architecture results clearly illustrated that the D3 diet fed group had given a higher protective effect by reducing the pathological changes associated with A. hydrophila infection in liver, intestine and muscle. Higher percentage of survival rate was also observed in D3 diet fed group. Therefore, the present study suggested that the dietary administration of A. barbadensis up to 50% fishmeal replacement (D3 diet) can elicit earlier antioxidant activity, innate immune response and improve survival rate in L. rohita against A. hydrophila infection.

Natural product osthole can significantly disrupt cell wall integrity and dynamic balance of Fusarium oxysporum

Dendrobium officinale Kimura et Migo is a traditional Chinese herbal medicinal plant. However, the frequent occurrence of soft rot disease (SRD) is one of the most harmful diseases in D. officinale production in recent years, which can seriously affect its yield and quality. In this study, the major pathogenic fungus (SR-1) was isolated from D. officinale with typical symptoms of SRD, and was identified as Fusarium oxysporum through morphological and molecular identification. The biological activities of five natural products were determined against F. oxysporum using a mycelial growth inhibition assay. The results showed that osthole had the highest antifungal activity against F. oxysporum, with an EC50 value of 6.40 mg/L. Scanning electron microscopy (SEM) showed that osthole caused F. oxysporum mycelia to shrink and deform. Transmission electron microscopy (TEM) showed that the organelles were blurred and the cell wall was thickened in the presence of osthole. The sensitivity of F. oxysporum to calcofluor white (CFW) staining was significantly enhanced by osthole. Relative conductivity measurements and propidium iodide (PI) observation revealed that osthole had no significant effect on the cell membrane. Further experiments showed that the activity of chitinase and β-1,3-glucanase were decreased, and expression levels of chitinase and β-1,3-glucanase related genes were significantly down-regulated after treatment with osthole. In conclusion, osthole disrupted the cell wall integrity and dynamic balance of F. oxysporum, thereby inhibiting normal mycelial growth.

Inhibitory effect of O-propargyllawsone in A549 lung adenocarcinoma cells

BACKGROUND

Lung cancer is the deadliest type of cancer in the world and the search for compounds that can treat this disease is highly important. Lawsone (2-hydroxy-1,4-naphtoquinone) is a naphthoquinone found in plants from the Lawsone genus that show a high cytotoxic effect in cancer cell lines and its derivatives show an even higher cytotoxic effect.

METHODS

Sulforhodamine B was used to evaluate the cytotoxic activity of compounds on tumor cells. Clonogenic assay was used to analyze the reduction of colonies and wound healing assay to the migratory capacity of A549 cells. Apoptosis and necrosis were analyzed by flow cytometer and Giemsa staining. Hemolysis assay to determine toxicity in human erythrocytes.

RESULTS

Lawsone derivatives were evaluated and compound 1 (O-propargyllawsone) was the one with the highest cytotoxic effect, with IC50 below 2.5 µM in A549 cells. The compound was able to reduce colony formation and inhibit cell migration. Morphological changes and cytometry analysis show that the compound induces apoptosis and necrosis in A549 cells.

CONCLUSIONS

These results show that O-propargyllawsone show a cytotoxic effect and may induce apoptosis in A549 cells.

Hypothetical protein FoDbp40 influences the growth and virulence of Fusarium oxysporum by regulating the expression of isocitrate lyase

Fungal growth is closely related to virulence. Finding the key genes and pathways that regulate growth can help elucidate the regulatory mechanisms of fungal growth and virulence in efforts to locate new drug targets. Fusarium oxysporum is an important plant pathogen and human opportunistic pathogen that has research value in agricultural and medicinal fields. A mutant of F. oxysporum with reduced growth was obtained by Agrobacterium tumefaciens-mediated transformation, the transferred DNA (T-DNA) interrupted gene in this mutant coded a hypothetical protein that we named FoDbp40. FoDbp40 has an unknown function, but we chose to explore its possible functions as it may play a role in fungal growth regulatory mechanisms. Results showed that F. oxysporum growth and virulence decreased after FoDbp40 deletion. FOXG_05529 (NCBI Gene ID, isocitrate lyase, ICL) was identified as a key gene that involved in the reduced growth of this mutant. Deletion of FoDbp40 results in a decrease of more than 80% in ICL expression and activity, succinate level, and energy level, plus a decrease in phosphorylated mammalian target of rapamycin level and an increase in phosphorylated 5′-adenosine monophosphate activated protein kinase level. In summary, our study found that the FoDbp40 regulates the expression of ICL at a transcriptional level and affects energy levels and downstream related pathways, thereby regulating the growth and virulence of F. oxysporum.

Exploration of novel TOSMIC tethered imidazo[1,2-a]pyridine compounds for the development of potential antifungal drug candidate

New candidates of imidazo[1,2-a]pyridine were designed by combining 2-amino pyridine, TOSMIC and various assorted aldehydes to explore their antioxidant and antifungal potential. The design of these derivatives was based on utilizing the antifungal potential of azoles and TOSMIC moiety. These derivatives were synthesized by adopting multi-component reaction methodology, as it serves as a rapid and efficient tool to target structurally diverse heterocyclic compounds in quantitative yield. The resulting imidazo[1,2-a]pyridine derivatives were structurally verified by ¹ HNMR, ¹³ CNMR, HRMS, and HPLC. The compounds were analyzed for their antioxidant and fluorescent properties and it was observed that compound 15 depicted highest potential. The compounds were evaluated for their antifungal potential to highlight their medical application in the area of Invasive Fungal Infections (IFI). Compound 12 gave the highest antifungal inhibition against Aspergillus fumigatus 3007 and Candida albicans 3018. To elucidate the antifungal mechanism, confocal images of treated fungi were analyzed, which depicted porous nature of fungal membrane. Estimation of fungal membrane sterols by UPLC indicated decrease in ergosterol component of fungal membrane. In silico studies further corroborated with the in vitro results as docking studies depicted interaction of synthesized heterocyclic compounds with amino acids present in the active site of target enzyme (lanosterol 14 alpha demethylase). Absorption, distribution, metabolism, and excretion (ADME) analysis was indicative of drug-likeliness of the synthesized compounds.

Antifungal Activity In Vitro and In Vivo of Mesquite Extract (Prosopis glandulosa) Against Phytopathogenic Fungi

Fungi are the primary infectious agents in plant crops and many post-harvest fungal diseases of fruit and vegetables causing significant economic losses worldwide. Here, the antifungal effect of Prosopis glandulosa extract (PgE) against phytopathogenic fungi was evaluated. The effect with PgE (5, 4, 2, 1, 0%) as AI (%) and radial growth rate reduction (K_r %) were determined in vitro in Colletotrichum gloeosporoides, Fusarium oxysporum, Rhizopus oryzae and R. stolonifer (1 × 10⁵ spores/mL). The phytopathogenicity of fungal strains was performed under in vivo conditions (room temperature, 25-30 °C and refrigeration, ~ 4 °C) by fruit surface inoculation method on strawberries, tomatoes and carrots by recording the development of mycelial growth, necrosis, soft rot and dehydration symptoms showed on each fruit at 14 days. The extract (5%) showed the highest AI against C. gloesporioides (~ 96%), and F. oxysporum (~ 79%) and growth rate reduction of 74.92% and 64.82% respectively. Likewise, the extract controls the development of phytopathogenicity symptoms against C. gloesporioides and F. oxysporum in vivo conditions, nevertheless, was less efficiency against both Rhizopus species. The P. glandulosa extract represents an efficient, economical, and eco-friendly alternative to preserve the quality of the agricultural products and to increase their shelf life.

Microwave-Assisted Green Synthesis and Characterization of Silver Nanoparticles Using Melia azedarach for the Management of Fusarium Wilt in Tomato

These days, research in agriculture is focusing on the theme of sustainability along with protection of agriculture produce. Nanotechnology in the agriculture sector aims for the enhancement of agricultural produce and the reduction of pesticides through providing innovative agrochemical agents and their novel delivery mechanisms. The current investigation involved the green synthesis of silver nanoparticles (AgNPs) from the aqueous leaf extract of Melia azedarach by following a microwave-assisted method to control Fusarium oxysporum, the causal agent of tomato wilt. Biosynthesized Melia leaf extract (MLE)-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectrometry, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential analysis. The intensity of the peak at 434 nm in UV-vis spectra, attributed to the surface plasmon resonance of MLE-AgNPs, changes with reaction parameters. TEM exhibits spherical shaped nanoparticles with an average particle size range from 12 to 46 nm. Efficient inhibition of F. oxysporum, the causal agent of tomato wilt, was achieved after exposure to MLE-AgNPs both in vivo and in vitro. In vitro studies exhibited repressed fungal mycelial growth with 79-98% inhibition as compared to the control. Significant increases in growth parameters of tomato seedlings were observed after treatment with biosynthesized nanoparticles as compared to F. oxysporum-infected plants grown without them under greenhouse conditions. Furthermore, SEM imaging was done to reveal the prominent damage on the cell wall of hyphae and spores after MLE-AgNP treatment. Propidium iodide (PI) staining of mycelium indicated the extent of cell death, causing irretrievable damage and disintegration of cellular membranes by altering the membrane permeability. Also, 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence specifies intracellular reactive oxygen species (ROS) production in F. oxysporum after treatment with MLE-AgNPs. The current investigation suggested that biosynthesized nanoparticles can revolutionize the field of plant pathology by introducing an environment-friendly approach for disease management and playing a potential part in agriculture industry. However, to date, little work has been done to integrate nanotechnology into phytopathology so, this area of research is in need of adoption and exploration for the management of plant diseases.

Fermentation optimization and disease suppression ability of a Streptomyces ma. FS-4 from banana rhizosphere soil

Background

Fusarium wilt of banana is one of the most destructive diseases in banana-growing regions worldwide. Soil-borne diseases and soil microbial communities are closely related. The screening of antagonistic bacteria from soil microorganisms in areas with Fusarium wilt of banana is of great practical significance for controlling this disease.

Results

A strain designated FS-4 was isolated from healthy banana rhizosphere soil in an area affected by Fusarium wilt. This strain exhibited a significant antagonistic effect on the pathogen. Pot experiments revealed that the fermentation broth of strain FS-4 not only decreased the incidence of banana Fusarium wilt, but also promoted the growth of banana seedlings. The strain was identified as Streptomyces ma. by its morphological, physiological, and biochemical characteristics and 16S rRNA gene sequence analysis. The culture and fermentation conditions for this strain were optimized by single-factor and response surface experiments. The optimum culture conditions for Streptomyces ma. FS-4 were as follows: peptone 0.5%, saccharose 2.4, 0.05% K₂HPO₄, 0.05% MgCl₂, and 0.05% NaCl at an initial pH of 7.0; 180 g at 28 °C; and inoculation size of 6% for 62 h. The diameter of bacteriostasis circle for Bacillus subtilis reached 26.7 mm.

Conclusion

Streptomyces ma. FS-4 is an important microbial resource as a biological agent for the control of plant pathogenic fungi and can be used to promote banana growth.

Aqueous-phase synthesis of nanoparticles of copper/copper oxides and their antifungal effect against Fusarium oxysporum

Different copper based-materials have been used for controlling some fungal and bacterial pathogens. However, the antifungal activity of the copper-based materials depends on different parameters, such as the crystal phase, synthesis route, and size of the particles. Herein a facile route synthesis method of Cu/Cu_xO-NPs was achieved through the aqueous phase. The influence of NaBH₄ concentration on the phase composition was studied. The synthesized Cu/Cu_xO-NPs were characterized by X-Ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering. Five Cu/Cu_xO-NPs with different phase composition and nanoparticle size were obtained. The antifungal activity of the synthesized Cu/Cu_xO-NPs was studied in vitro against Fusarium oxysporum. The results indicate that a high percent of inhibition of radial growth (IGR) was obtained with NPs, which have a higher proportion of Cu₂O phase and relatively smaller size particles. Furthermore, hypha morphology, membrane damage and production of reactive oxygen species (ROS) was evaluated with SEM and confocal microscopy.

Novel nucleosides as potential inhibitors of fungal lanosterol 14α-demethylase: an in vitro and in silico study

Aim: The global burden of fungal infections has transitioned from a case-specific observation to a major cause of high human mortality. Therefore, novel compounds with innovative methodologies need to be synthesized and evaluated for their antifungal potential to keep pace with the current clinical demands. Results: An efficient synthetic pathway was developed for the synthesis of 21 synthetic novel nucleosides. Two compounds had significant antifungal effect on Aspergillus fumigatus 3007, which was comparable to fluconazole. The experimental data (confocal microscopy, ultrahigh-performance liquid chromatography and flow cytometry) demonstrated the inhibition of fungal lanosterol 14α-demethylase. Conclusion: Owing to the therapeutic relevance of the synthesized nucleosides and simplicity of the procedure, the method may find its potential application for synthesis of antifungal agents.

The efficacy of Virkon-S for the control of saprolegniasis in common carp, Cyprinus carpio L

Background

Saprolegnia parasitica is a fish pathogen that causes severe economic losses worldwide. Virkon-S is a well-known disinfectant known to exhibit antimicrobial activities against bacteria, viruses, and fungi. In this study, we tested the anti-fungal activity of Virkon-S against S. parasitica, the major causal agent of saprolegniasis.

Methods

The lowest concentration of Virkon-S that prevented germination or the visible growth of spores and the percent spore germination were determined using potato dextrose agar plates containing different concentrations of Virkon-S. The cytotoxic effect was evaluated using the Ez-Cytox Cell Viability Assay with epithelioma papulosum cyprini (EPC) cells grown in L-15 medium and acute toxicity tests were carried out with cultured fingerlings of common carp for 96 h. Artificial infection with S. parasitica was performed by placing the fish in tanks containing zoospores of S. parasitica after descaling and wounding at three positions. The diseased fish were kept in tanks containing 2, 4, and 10 ppm of Virkon-S for 10 days to observe the treatment effect.

Results

The in vitro assay results showed that Virkon-S could inhibit spore germination and the resulting mycelial growth at a concentration as low as 4 ppm. No cytotoxic effect on EPC cells was observed even at a concentration as high as 100 ppm. Additionally, no acute toxicity in the common carp was observed at 10 ppm following 96 h exposure. Ten days of treatment with 4 and 10 ppm Virkon-S resulted in complete reversal of artificially-induced saprolegniasis in the common carp.

Discussion

This data indicates that Virkon-S can be used for the control of saprolegniasis without harmful effects in fish. However, further research on the effect in humans and food supplies is necessary.

Methodologies for in vitro and in vivo evaluation of efficacy of antifungal and antibiofilm agents and surface coatings against fungal biofilms

Unlike superficial fungal infections of the skin and nails, which are the most common fungal diseases in humans, invasive fungal infections carry high morbidity and mortality, particularly those associated with biofilm formation on indwelling medical devices. Therapeutic management of these complex diseases is often complicated by the rise in resistance to the commonly used antifungal agents. Therefore, the availability of accurate susceptibility testing methods for determining antifungal resistance, as well as discovery of novel antifungal and antibiofilm agents, are key priorities in medical mycology research. To direct advancements in this field, here we present an overview of the methods currently available for determining (i) the susceptibility or resistance of fungal isolates or biofilms to antifungal or antibiofilm compounds and compound combinations; (ii) the in vivo efficacy of antifungal and antibiofilm compounds and compound combinations; and (iii) the in vitro and in vivo performance of anti-infective coatings and materials to prevent fungal biofilm-based infections.

Gene Cloning, Expression, and Antifungal Activities of Permatin from Naked Oat (Avena nuda)

Thaumatin-like proteins (TLPs) are the products of a large, highly complex gene family involved in host defense. TLPs also belong to the pathogenesis-related family 5 (PR-5) of plant defense proteins. Most TLPs exhibit potential antifungal activities, and their accumulation in the plant is related to many physiological processes. In this study, a gene encoding TLP named permatin with an open reading frame of 678 bp encoding a protein of 225 amino acids with a calculated molecular mass of 23.5 kDa was cloned from naked oat leaves. Phylogenetic analysis revealed that permatin shares high homology with a number of other TLPs among diverse taxa. Model of structure by homology modeling showed that permatin consists of an acidic cleft region consistent with most TLPs. Recombinant NusA-permatin was overexpressed in Escherichia coli strain BL21 and purified by Heparin column combined with Sephacryl S-200 column. The protein exhibited antifungal activity to Fusarium oxysporum (half maximal inhibitory concentration, IC₅₀ = 21.42 μM). Morphological observation showed that NusA-permatin can induce mycelium deformation of F. oxysporum, the cell membrane is blurred, and the diaphragm is not obvious. NusA-permatin also causes membrane permeabilization and reactive oxygen species accumulation in the mycelium of F. oxysporum. Permatin may play an important role in the disease resistance responses of plants against pathogen attacks through its antifungal activity.

Fluorescent microspheres for one-photon and two-photon imaging of mesenchymal stem cells

Preparation of fluorescent beads to quantitatively evaluate the one-photon and two-photon imaging of hMSCs that have endocytosed AO-PLGA nanospheres.