Antifungal activity of plant extracts with potential to control plant pathogens in pineapple

The combined effects of Aloe vera gel enriched with Adhatoda vasica Nees. Leaves extract edible coating on improving postharvest shelf-life and quality of jamun fruit (Syzygium cumini L. Skeels)

Jamun (Syzygium cumini L. Skeels), a less recognized, underutilized, and highly perishable fruit is a delicacy of tropical regions. Soft pulp and thin exocarp make these small purple berries susceptible to mechanical injury and several postharvest diseases. Therefore, this study aimed to evaluate the potential of Aloe vera gel (AG), hydroxypropyl methylcellulose (HPMC) and Adhatoda vasica Nees. leaves extract (AVLE) coatings for enhancing postharvest shelf-life and quality of jamun fruits stored at 60-65%RH and 9 ± 2 °C. Antifungal, physicochemical, biochemical and cell wall softening enzyme assays were conducted to assess the quality changes in jamun during storage. Our findings reveal that incorporating AG and AVLE in the edible coatings reduces the disease severity of the coated fruits compared to control fruits. Additionally, AG + HPMC + AVLE (2 %) and (4 %) preserved jamun for 22 and 24 days, respectively, with better nutritional quality against control (15 days). The coated fruits, especially, AG + HPMC + AVLE (4 %) showed minimal weight loss 32.92 % with no fungal incidents by the end of storage. Moreover, AG + HPMC + AVLE (4 %) maintained pH (3.68), TA (0.85 %), and TSS (9.67°Brix) than control fruits. Also, AG + HPMC + AVLE (2 %) effectively delayed fruit quality deterioration by suppressing cell wall-softening enzyme activity, and thus slowing the increase in reducing and non-reducing sugars. This study highlights a novel edible coating of Aloe vera gel and A. vasica leaves extract with excellent potential to maintain the quality and extend the shelf-life of jamun fruits after harvest.

Pharmacology, toxicology and homeopathy of Luffa operculata (L.) Cogniaux (Cucurbitaceae): Integrative review

Scientific evidence on the pharmacological and toxicological effects of Luffa operculata has been produced on a smaller scale, even though the species: (i) is edible; (ii) widely recognized in folk medicine for treating sinusitis and inducing abortion; (iii) and the basis of allopathic and homeopathic medicines. In this sense, the objective of this review is to characterize the pharmacological, toxicological and clinical profile of products based on L. operculata. After consulting 14 databases, as well as a free search on Google/Google Scholar and checking references, 85 studies were selected that met our eligibility criteria. After analysis and synthesis, we found that the products have a wide range of pharmacological activities in vitro, ex vivo and in vivo. The toxicological spectrum is also alarming in different segments such as: cytogenotoxicity, tissue toxicity, (sub-) acute, reproductive, neuro- and phytotoxicity. The intensity of the pharmacological and toxicological effects is variable, and seems to be conditioned by various factors (examples: plant organ, polarity of the extracting solvent, quantity, experimental model and route of administration). Clinical data show that the products have satisfactory efficacy, tolerability and safety in the treatment of upper airway diseases (especially rhinitis and sinusitis). Finally, we hope that the presentation of toxicological information in this review can guide the safe and rational use of L. operculata in folk medicine. It may also serve as scientific evidence for exploring the pharmacological potential of the species, avoiding its side effects.

Integration of In Vitro and In Silico Results From Chemical and Biological Assays of Rheum turkestanicum and Calendula officinalis Flower Extracts

In this study, we conducted a thorough analysis of Rheum turkestanicum (RT) and Calendula officinalis flowers (COF) extracts with varying polarities using LC-MS chemical profiling and biological tests (antioxidant, antimicrobial, enzyme inhibition, and cytotoxic effects). The highest level of total phenolic content in the ethanol extract of RT with 75.82 mg GAE/g, followed by the infusions of RT (65.00 mg GAE/g) and COF (40.99 mg GAE/g). A total of 20 bioactive compounds were identified and quantified. The ethanol extract of COF was rich in terms of 5-O-caffeoylquinic acid (2780.56 μg/g), isorhamnetin-O-rutinoside (1653.59 μg/g), and rutin (1356.97 μg/g). However, RF extracts were rich in catechin gallate (21.66-80.01 μg/g) and 5-O-caffeoylquinic acid. Except for metal chelating ability, the ethanol extract of RT exhibited the strongest ability (DPPH: 171.5 mg TE/g; ABTS: 387.35 mg TE/g; CUPRAC: 449.80 mg TE/g; FRAP: 195.60 mg TE/g; and PBD: 1.52 mmol TE/g). In the enzyme inhibition tests, the tested ethanol extracts for both species were more active than the infusion. The highest values for tyrosinase were recorded as 72.47 mg KAE/g (in RT extracts) and 71.74 mg KAE/g (in COF extracts). Furthermore, all extracts underwent assessment for their antibacterial and antifungal properties, targeting both Gram-positive and Gram-negative bacteria, as well as clinical yeast and fungal microorganisms. In silico studies yielded valuable insights into the potential therapeutic applications of the bioactive compounds identified in COF and RT extracts. Stable interactions were observed between key compounds, such as isorhamnetin 3-O-glucoside and 3-O-caffeoylquinic acid, with crucial target proteins (AChE, BChE, and MurE). These compounds formed stable hydrogen bonds with minimal root mean square deviation (RMSD) fluctuations, particularly in the isorhamnetin 3-O-glucoside-Staphylococcus aureus MurE and 3-O-caffeoylquinic acid-MurE of S. aureus complexes. These findings further underscore the potential of these compounds as promising candidates for therapeutic development.

Chemical Composition, In Silico Investigations and Evaluation of Antifungal, Antibacterial, Insecticidal and Repellent Activities of Eucalyptus camaldulensis Dehn. Leaf Essential Oil from ALGERIA

This study investigated the phytochemical profile and evaluated the antimicrobial and insecticidal properties of Eucalyptus camaldulensis Dehn. essential oil (EC-EO) from Algeria, using in vitro and in silico approaches. The yield of EC-EO was 0.27%, with gas chromatography-mass spectrometry (GC-MS) revealing spathulenol (58.24%), cryptone (17.22%), and o-cymene (15.53%) as the major compounds. EC-EO exhibited notable antibacterial activity, particularly against Salmonella typhimurium (14 ± 1.00 mm) and Staphylococcus aureus (14.5 ± 0.50 mm). It also showed effective antifungal activity against Penicillium sp. (11.5 ± 0.49 mm), Candida albicans (11.2 ± 0.29 mm), and Aspergillus fumigatus (9.8 ± 0.27 mm). Insecticidal assays against Tribolium castaneum were conducted using contact toxicity, fumigation toxicity, and repellent activity methods. The median lethal concentration (LC50) for contact toxicity was 0.011 μL/insect after 72 h, while the fumigation test had an LC50 of 122.29 μL/L air. Repellent activity tests showed percentage repellency (PR) values exceeding 80% after 6 h. The molecular geometry and electronic properties of the main compounds were studied using density functional theory (DFT) calculations. In addition, the interaction mode and binding affinity of these molecules with three key enzymes involved in antimicrobial activity, DNA gyrase, dihydrofolate reductase (DHFR) and Tyrosyl-tRNA synthetase (TyrRS), were explored by molecular docking.

Cestrum tomentosum L.f. Extracts against Colletotrichum scovillei by Altering Cell Membrane Permeability and Inducing ROS Accumulation

Chili pepper anthracnose, caused by Colletotrichum spp., is a significant biotic stress affecting chili fruits globally. While fungicide application is commonly used for disease management due to its efficiency and costeffectiveness, excessive use poses risks to human health and the environment. Botanical fungicides offer advantages such as rapid degradation and low toxicity to mammals, making them increasingly popular for sustainable plant disease control. This study investigated the antifungal properties of Cestrum tomentosum L.f. crude extracts (CTCE) against Colletotrichum scovillei. The results demonstrated that CTCE effectively inhibited conidia germination and germ tube elongation at 40 µg/ml concentrations. Moreover, CTCE exhibited strong antifungal activity against C. scovillei mycelial growth, with an EC50 value of 18.81 µg/ml. In vivo experiments confirmed the protective and curative effects of CTCE on chili pepper fruits infected with C. scovillei. XTT analysis showed that the CTCE could significantly inhibit the cell viability of C. scovillei. Mechanistic studies revealed that CTCE disrupted the plasma membrane integrity of C. scovillei and induced the accumulation of reactive oxygen species in hyphal cells. These findings highlight CTCE as a promising eco-friendly botanical fungicide for managing C. scovillei infections in chili peppers.

Pyrolysed maize feedstock utilization in combination with Trichoderma viride against Macrophomina phaseolina

Maize cultivation is under the growing threat of charcoal rot (Macrophomina phaseolina). Chemical control of diseases imparts serious health hazards to humans and the ecosystem. Biochar as an alternative disease management approach has been under consideration of the researchers for some time now. The biochar utilized in this study was derived from maize stalks and cobs. Crystallographic structure, inorganic minerals content and size of maize biochar were analyzed by powder X-ray diffractometer, while scanning electron microscopy revealed rough, irregular, tubular structure of the biochar surface. EDX spectra revealed that the maize biochar composition was dominated by 'C' followed by 'O'. The current study was designed to determine the synergistic effect of maize biochar (MB), and biocontrol agent (BCA) Trichoderma viride as soil amendments on the suppression of M. phaseolina. In vitro bioassays were conducted to check the efficiency of antagonistic effect of Trichoderma spp., in combination with maize biochar. On the basis of maximum mycelial growth inhibition T. viride was selected for a glasshouse experiment. Maize plants were grown in pots containing a mixture of soil with MB at application at the rate of 3 and 6% (v/v) separately, associated with or without T. viride. Treatments amended with 3% MB inoculated with M. phaseolina significantly reduced the percentage disease severity index by 40%. While in the presence of T. viride, 3% MB showed maximum disease suppression and a minimum percentage severity index i.e. 60 and 20%, respectively. Highest nitrogen contents were 18.4 g kg-1 observed in treatment 6% MB, while highest phosphorus and potassium contents were 3.11 and 15.2 g kg-1, respectively in the treatment with 3% MB. Conclusively, the effect of variable concentrations of maize biochar and T. viride as soil amendment was evident on the development of charcoal rot, growth and physiology of maize plants. According to the available literature, our report is the first on the implementation of biochar in synergism with T. viride to suppress the charcoal rot in maize.

Pesticides vs. Biopesticides: From Pest Management to Toxicity and Impacts on the Environment and Human Health

The environmental pollution that occurs in direct response to the widespread use of man-made/conventional pesticides results from many chemicals that require a long period of time, often decades, to degrade. The synthetic nature of pesticides also harms animals, beneficial insects, microorganisms, and plants, as well as humans. Fortunately, however, there are many natural pesticides, the so-called biopesticides, that are also effective against pests and more importantly, do not interfere with the well-being of ecosystems. Consequently, most biopesticides are safer for use around people and pets than man-made pesticides because, for example, they can be easily washed away from fruits and vegetables. The natural habitat is a rich resource with a wide selection of plants, many of which are also used to treat diseases in humans, animals, and plants. Out of concern for public health, environmental safety, and the stringent regulation of pesticide residues in agricultural commodities, the use of biopesticides is becoming increasingly important, but questions regarding potential pest resistance to these products may arise, just as is the case with conventional pesticides. Therefore, the performance and potential role of biopesticides in the management of plant pests should be prioritized due to their sustainability and importance to human and environmental welfare. In this review, we propose to highlight a scenario in which we discuss in detail the main constraints posed by the use of pesticides compared to biopesticides, starting with issues regarding their definition and continuing on to issues related to their toxicity and their impact on the environment and human health.

Engineered Metal Oxide Nanoparticles as Fungicides for Plant Disease Control

Metal oxide nanoparticles are considered to be good alternatives as fungicides for plant disease control. To date, numerous metal oxide nanoparticles have been produced and evaluated as promising antifungal agents. Consequently, a detailed and critical review on the use of mono-, bi-, and tri-metal oxide nanoparticles for controlling phytopathogenic fungi is presented. Among the studied metal oxide nanoparticles, mono-metal oxide nanoparticles-particularly ZnO nanoparticles, followed by CuO nanoparticles -are the most investigated for controlling phytopathogenic fungi. Limited studies have investigated the use of bi- and tri-metal oxide nanoparticles for controlling phytopathogenic fungi. Therefore, more studies on these nanoparticles are required. Most of the evaluations have been carried out under in vitro conditions. Thus, it is necessary to develop more detailed studies under in vivo conditions. Interestingly, biological synthesis of nanoparticles has been established as a good alternative to produce metal oxide nanoparticles for controlling phytopathogenic fungi. Although there have been great advances in the use of metal oxide nanoparticles as novel antifungal agents for sustainable agriculture, there are still areas that require further improvement.

Insect repellent pellets - an application of botanicals against red flour beetle - their antifungal activity during storage and use as potential fumigants

BACKGROUND

The protection of grains from insect infestation is critical during storage. Insect repellent pellets (IRPs) are a potential technique to repel insects by hindering insect movement toward the grains. The basic principle of IRPs is the use of active components found in the oils of lemongrass, eucalyptus, and neem leaves for the controlled release of fumes, thereby avoiding the need for reapplication after a few days. Here, we examined the antifungal activity, the lethal dose, and the repelling effect of IRPs against red flour beetle, Tribolium castaneum, over a 30 day period.

RESULTS

We observed that IRPs possessed antifungal properties and were able to repel the adults of T. castaneum. These insects ultimately died from the fumes if they manage to stay near the IRPs (LD₅₀  = 2 and LD₉₉  = 7 days). The active components (phenol, 2,4-di-tert-butyl-, citral, neral, geraniol, n-hexadecanoic acid) present in IRP during the initial stage were also found after a storage period of 35 days.

CONCLUSION

The active components present in IRPs have antifungal, repellent, and fumigant properties. The IRPs can thus be termed potent botanical insecticides and are an alternative to synthetic insecticides. © 2022 Society of Chemical Industry.

Phytochemical Screening, Antioxidant and Antifungal Activities of Aconitum chasmanthum Stapf ex Holmes Wild Rhizome Extracts

Aconitum chasmanthum Stapf ex Holmes, an essential and critically endangered medicinal plant from Kashmir Himalayas, was studied for its antioxidant and antifungal properties. The shade-dried powdered rhizome was extracted sequentially with hexane, ethyl acetate, and methanol. These subsequent fractions were evaluated for total phenolic content (TPC); total flavonoid content (TFC); antioxidant assays, such as 1,1-diphenyl 1-2-picryl-hydrazyl (DPPH); ferric-reducing antioxidant power (FRAP); superoxide radical scavenging (SOR); hydroxyl radical scavenging (OH) and antifungal activity using the poisoned food technique. Highest TPC (5.26 ± 0.01 mg/g) and TFC (2.92 ± 0.04 mg/g) were reported from methanolic extracts. The highest values of radical scavenging activities were also observed in methanolic extracts with IC₅₀ values of 163.71 ± 2.69 μg/mL in DPPH, 173.69 ± 4.91 μg/mL in SOR and 159.64 ± 2.43 μg/mL in OH. The chemical profile of ethyl acetate extract was tested using HR-LCMS. Methanolic extracts also showed a promising inhibition against Aspergillus niger (66.18 ± 1.03), Aspergillus flavus (78.91 ± 1.19) and Penicillium notatum (83.14 ± 0.97) at a 15% culture filtrate concentration with minimum inhibitory concentration (MIC) values of 230 μg/mL, 200 μg/mL and 190 μg/mL, respectively. Overall, the methanolic fractions showed significant biological potential, and its pure isolates might be used to construct a potential new medicinal source.

Toxicology of diatomaceous earth, phyto oils and their admixed emulsions against adults of Tribolium castaneum (Herbst)

Tribolium castaneum (Herbst), one of the invasive stored pest, is resistant to the most of synthetic insecticides used against this it. Moreover, synthetic insecticides are a major threat to human health, the environment, and the ecosystem. The development of some smart tools is needed to minimize the use of hazardous chemicals. As an alternative, nano-insecticides are on the horizon. Emulsions are expressed as sustain release of insecticidal components to achieve maximum efficacy and low residual toxicity. In this study, some essential oils (Cymbopogon citratus (DC.) Stapf, Ocimum basilicum L., Curcuma longa L., and Trachyspermum ammi L.), diatomaceous earth (DE), and their nano-emulsions are evaluated against T. castaneum. Essential oils and DE were tested at four (60 ppm, 30 ppm, 15 ppm, 7.5 ppm) different concentrations with and without emulsions, and data was recorded after 6, 12, 24, 48, and 72 h of exposure respectively. The mortality observed in essential oils of C. citratus, O. basilicum, and C. longa without emulsion after 72 h of treatment at the highest concentration was 98%, 95%, and 85%, respectively. While, at the highest concentration the lowest mortalities were observed with DE and T. ammi i.e. 65%. Insecticidal activity of emulsion essential oils increased to 100%, 98%, 90%, and 68.3% for C. longa, C. citratus, O. basilicum, and T. ammi, respectively. The results support that these admixed emulsions could be used as an alternative to synthetic insecticides in conventional formulations.

Evaluation of Bacterial Perpetuation Assays and Plant Biomolecules Antimicrobial Activity against Cotton Blight Bacterium Xanthomonas citri subsp. malvacearum; An Alternative Source for Food Production and Protection

Cotton (Gossypium hirsutum) is a global cash crop which has gained importance in earning foreign exchange for each country. Bacterial blight caused by Xanthomonascitri subsp. malvacearum (Xcm) has been a seriousdisease in Pakistan’s cotton belt on multiple occasions. Bacterium was isolated and identified through various biochemical and diagnostic tests wherehypersensitivity reaction, Gram staining, KOH (potassium hydroxide), catalase, starch hydrolysis, lecithinase and Tween 80 hydrolysis tests confirmed bacterium as Gram-negative and plant pathogenic. Xcm perpetuation assays wereevaluated on various cotton varieties under glasshouse conditions in completely randomized design by three different methods, wherein the scratch method proved to be the best upon CIM-496 and showed 83.33% disease incidence as compared with the other two methods, where Bt-3701 responded with 53.33% incidence via the spray gun method, and 50% with the water splash method on CIM-616, as compared with the control. Similarly, for disease severity percentage, Bt-3701 was pragmatic with 47.21% through scratch method, whereas, in the spray gun method, 45.51% disease severity was noted upon Bt-802, and 31.27% was calculated on Cyto-179 through the water splash method. Owing to the unique antibacterial properties of aqueous plant extracts, the poison food technique showed Aloe vera, Mentha piperita, Syzygiumcumini and Azadirachta indica with 17.77, 29.33, 18.33 and 20.22 bacterial colonies counted on nutrient agarmedium petri plate, respectively, as compared with the control. Measurement of the inhibition zone by disk diffusion technique showed Mentha piperita, Syzygiumcumini, Citrus limon, Moringa oleifera and Syzygium aromaticum to present the most promising results by calculating the maximum diameter of the inhibition zone, viz., 8.58, 8.55, 8.52, 8.49 and 8.41 (mm), respectively, at the highest tested concentration (75 ppm, parts per million) compared with the control. It is probable that the decoction’s interaction with the pathogen population on the host plant will need to be considered in future experiments. However, at this moment, more research into the effective management of cotton bacterial blight by plant extracts in terms of concentration determination and development of biopesticides will provide future avenues to avoid environmental pollution.

Antioxidant, Antimicrobial and Antibiofilm Properties of Glechoma hederacea Extracts Obtained by Supercritical Fluid Extraction, Using Different Extraction Conditions

Glechoma hederacea var. longituba is a herbaceous plant from the Lamiaceae family, used in herbal medicine. In this work, we aimed to assess the total phenolic content, antioxidant, antimicrobial and antibiofilm activity of extracts obtained from G. hederacea via supercritical dioxide extraction with methanol as a co-solvent under different extraction conditions. The results showed that the activity of the obtained SC-CO2 extracts is strongly dependent on the extraction temperature. Significantly higher total polyphenol content, as well as antioxidant and antimicrobial activity towards bacteria and yeasts, was observed in the extract obtained at 40 °C, compared to extracts obtained at 50 °C and 60 °C; however, antifungal activity against filamentous fungi was not dependent on the extraction conditions. Antimicrobial activity also depended on the microorganism type. Higher sensitivity was exhibited by Gram-positive bacteria than by Gram-negative bacteria, with S. aureus and P. aeruginosa being the most sensitive species among each group. The most susceptible fungi were Candida albicans and Sclerotinia sclerotiorum. The antibiofilm activity was differentiated and depended on the extraction conditions, the microorganism and the method of biofilm treatment. All tested extracts inhibited biofilm formation, with the extract obtained at 40 °C showing the highest value, whereas only extract obtained at 60 °C efficiently removed mature biofilm.

Antioxidant, antifungal, and aphicidal activity of the triterpenoids spinasterol and 22,23-dihydrospinasterol from leaves of Citrullus colocynthis L

Terpenoids from natural plant sources are valuable for their diverse biological activities that have important roles in the medical and agrochemical industries. In this study, we assessed the antioxidant, antifungal, and aphicidal activities of a mixture of spinasterol and 22,23-dihydrospinasterol from the leaves of Citrullus colocynthis. We used 1,1-diphenyl-2-picrylhydrazyl (DPPH) to assess antioxidant activity, and we measured antifungal activity using mycelium growth inhibition assays with three pathogenic fungi, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora infestans. Aphicidal activity against adults of Myzus persicae was determined using in vitro and in vivo assays. Spinasterol and 22,23-dihydrospinasterol exhibited moderate antioxidant activity, even at lower concentrations: 19.98% at 0.78 µg mL⁻¹, 31.52% at 3.0 µg mL⁻¹, 36.61% at 12.5 µg mL⁻¹, and 49.76% at 50 µg mL⁻¹. Spinasterol and 22,23-dihydrospinasterol showed reasonable levels of fungicidal activity toward R. solani and M. grisea, with EC₅₀ values of 129.5 and 206.1 µg mL⁻¹, respectively. The positive controls boscalid and carbendazim were highly effective against all fungi except boscalid for M. grisea (EC₅₀ = 868 µg mL⁻¹) and carbendazim for P. infestans (EC₅₀ = 8721 µg mL⁻¹). Significant insecticidal activity was observed in both residual and greenhouse assays, with LC₅₀ values of 42.46, 54.86, and 180.9 µg mL⁻¹ and 32.71, 42.46, and 173.8 µg mL⁻¹ at 72, 48, and 24 h, respectively. The antioxidant activity of spinasterol and 22,23-dihydrospinasterol was strongly positively correlated with their antifungal and insecticidal activity. Spinasterol and 22,23-dihydrospinasterol therefore show good antioxidant and aphicidal activity with moderate fungicidal activity, making them suitable candidates for an alternative to synthetic agents.

Development and Evaluation of Clove and Cinnamon Supercritical Fluid Extracts-Loaded Emulgel for Antifungal Activity in Denture Stomatitis

Denture stomatitis (DS), usually caused by Candida infection, is one of the common denture-related complications in patients wearing dentures. Clove and cinnamon oils have been acknowledged for their anti-inflammatory, antimicrobial activity, and antifungal effects in the oral cavity. The aim of this study, therefore, was to prepare clove/cinnamon oils-loaded emulgel and to assess its efficacy in treating Candida albicans-associated denture stomatitis. Central composite design was adopted to formulate and optimize clove/cinnamon extracts-loaded emulgel. The formulated preparations were assessed for their physical appearance, particle size, viscosity, spreadability, and in-vitro drug release. In addition, in-vivo therapeutic experiments were conducted on 42 patients with denture stomatitis. The prepared emulgel formulations showed good physical characteristics with efficient drug release within 3 h. In addition, in-vivo antifungal studies revealed that the optimized formula significantly (p < 0.001) reduced Candida colony counts from the denture surface, compared to commercially available gel (240.38 ± 27.20 vs. 398.19 ± 66.73 CFU/mL, respectively). Furthermore, the optimized formula and succeeded in alleviating denture stomatitis-related inflammation with a better clinical cure rate compared to commercially available gel Collectively, herbal extracts-loaded emulgel might be considered an evolution of polyherbal formulations and might represent a promising alternative to the existing allopathic drugs for the treatment of denture stomatitis, with better taste acceptability and no side effects.

GC-MS screening and antiparasitic action of Putranjiva roxburghii leaves against sensitive and resistant strains of Leishmania donovani

Looming drug resistance cases of leishmaniasis infection are an undeniably serious danger to worldwide public health, also jeopardize the efficacy of available drugs. Besides this, no successful vaccine is available till date. Since the ancient era, many plants and their parts have been used as medicines against various ailments. Hence, the importance of drug development for new molecules against Leishmania infection is significant that is a cost-effective and safer drug preferably from the natural herbal resources. We evaluated the GC-MS screening and efficacy of Putranjiva roxburghii (PR) against the sensitive and resistant promastigotes of L. donovani. GC-MS profiling revealed that the extract was rich in myo-inositol-4-C-methyl, azulene and desulphosinigrin. Quantitative investigation of phytoconstituents confirmed that PR was rich in phenols, flavonoids and terpenoids. We found an IC50 25.61 ± 0.57 µg/mL and 29.02 ± 1.21 µg/mL of PR against sodium stibogluconate sensitive and resistant strain respectively. It was found to be safer in cytotoxicity assay and generated ROS mediated oxidative stress in the parasitic cells which was evidenced by the increased and decreased levels of superoxide radicals, lipid peroxidation products, lipid bodies and levels of thiol, plasma membrane integrity respectively. Therefore, our results support the importance of P. roxburghii as a medicinal plant against L. donovani and showed potential for exploration as an antileishmanial agent.

Metal Nanoparticles as Novel Antifungal Agents for Sustainable Agriculture: Current Advances and Future Directions

The use of metal nanoparticles is considered a good alternative to control phytopathogenic fungi in agriculture. To date, numerous metal nanoparticles (e.g., Ag, Cu, Se, Ni, Mg, and Fe) have been synthesized and used as potential antifungal agents. Therefore, this proposal presents a critical and detailed review of the use of these nanoparticles to control phytopathogenic fungi. Ag nanoparticles have been the most investigated nanoparticles due to their good antifungal activities, followed by Cu nanoparticles. It was also found that other metal nanoparticles have been investigated as antifungal agents, such as Se, Ni, Mg, Pd, and Fe, showing prominent results. Different synthesis methods have been used to produce these nanoparticles with different shapes and sizes, which have shown outstanding antifungal activities. This review shows the success of the use of metal nanoparticles to control phytopathogenic fungi in agriculture.

Transcriptomic changes in green bean pods against grey mould and white rot diseases via field application of chemical elicitor nanoparticles

The authors tested the efficacy of two salt nanoparticles (NPs), namely, copper dioxide (CuO) and tri-calcium phosphate [Ca₃(PO₄)₂] to induce resistance in green bean pods against grey mould and white rot diseases caused by Botrytis cinerea and Sclerotinia sclerotiorum, respectively. High amounts of phytoalexins, kievitone, coumestrol, phaseollidin, 6-ά-hydroxyphaseollin, and phaseollin, were detected in naturally infected and artificially inoculated green bean pods in response to the tested NPs. Green bean plants treated in the field with CuO and Ca₃(PO₄)₂ NPs had the highest mRNA quantity of all the studied defence genes, receptor-like kinase (PvRK20), pathogenesis-related protein (PR1), 1,3-β-D-glucanase (pvgluc), polygalacturonase inhibitor protein (PvGIP), and alpha-dioxygenase (a-DOX) than that of the control group. CuO NPs followed by Ca₃(PO₄)₂ NPs at 0.15 mg ml^-1 were the most potent in increasing the transcriptomic levels of pk20, DOX, PR1, PvGIP, and pvgluc. Field applications of both chemical elicitor NPs exhibited a non-genotoxic effect on the Paulista green bean DNA using eight ISSR primers. The field application of the studied NPs could effectively extend the shelf life of green bean pods by up to 21 days at 7 ± 1°C during marketing and export due to its potent effect against grey mould and white rot diseases.

Phytochemical Investigation, Antimicrobial, Antioxidant and Anticancer Activities of Acer cappadocicum Gled

The appearance of novel microbial resistance, diverse cancer ailment and several other morbidities such as appetite loss, hair loss, anemia, cell damage, etc., are among most critical situation that keeps the phytochemical quest on. Thus, this study characterized the antimicrobial, antioxidant, and anticancer potentials of a rarely accessed Acer cappadocicum gled (AC) population thriving in a remote Palas Valley in northern Pakistan. Leaf extracts of the plant were prepared in organic solvents with different polarities through maceration. Extracts were subjected to antimicrobial, antioxidant, and anticancer activities using agar well, DPPH and cell viability assays. A. cappadocicum methanolic extract (ACM) significantly inhibited bacterial growth, followed by n-butanolic extract (ACB) with the second-highest bacterial inhibition. Similar activity was observed against mycelial growth inhibition in plant-fungal pathogen by ACM and ACB. However, human pathogenic fungi did not affect much by extracts. In antioxidant assessment, the chloroform extract (ACC) showed strong scavenging activity and in cytotoxic evaluation, extracts restricted growth proliferation in cancer cells. The inhibitory evidence of extracts, potent scavenging ability, and low cell viability of human-derived cell lines supports the antimicrobial, antioxidant and anticancerous potential of A. cappadocicum. It advances our quest for natural product research.

African Herbal Medicines: Adverse Effects and Cytotoxic Potentials with Different Therapeutic Applications

The African continent is naturally endowed with various plant species with nutritional and medicinal benefits. About 80% of the people in developing countries rely on folk medicines to treat different diseases because of indigenous knowledge, availability, and cost-effectiveness. Extensive research studies have been conducted on the medicinal uses of African plants, however, the therapeutic potentials of some of these plants has remained unexploited. Over the years, several studies have revealed that some of these African floras are promising candidates for the development of novel drugs. Despite the plethora of studies on medicinal plant research in Africa, there is still little scientific data supporting the folkloric claims of these plants. Besides, safety in the use of folk medicines has been a major public health concern over the year. Therefore, it has become mandatory that relevant authority should take measures in safeguarding the populace on the use of herbal mixtures. Thus, the present review extracted relevant information from different scientific databases and highlighted some problems associated with folk medicines, adverse effects on reproductive systems, issue about safety due to the toxicity of some plants and their toxicity effects with potential therapeutic benefits are discussed.

Analysis of Chemical Composition and In Vitro and In Vivo Antifungal Activity of Raphanus raphanistrum Extracts against Fusarium and Pythiaceae, Affecting Apple and Peach Seedlings

The goal of this investigation was to evaluate the in vitro and in vivo efficiency of Raphanus raphanistrum extracts against Fusarium and Pythiaceae species associated with apple and peach seedling decline in Tunisian nurseries. A chemical composition of organic extracts was accomplished using liquid chromatography, thin layer chromatography, and gas chromatography analysis. The in vitro test of three aqueous extract doses of R. raphanistrum against some apple and peach decline agents showed its efficacy in reducing mycelia growth. The in vivo assay of fine powder of this plant on peach seedlings revealed that treatment 8-weeks before the inoculation and planting was more efficient than the treatment before one week. This experiment revealed that the root weight of peach seedlings inoculated by F. oxysporum was improved to 207.29%. For apple seedlings, the treatment 8 weeks before the inoculation and plantation was more efficient than the treatment one week before; it reduced the root browning index. The study of R. raphanistrum chemical composition and its efficiency showed that the glucosinolates products: nitrile (4-Hydroxy-3-(4-methylphenylthio) butane nitrile, benzene acetonitrile, 4-fluoro,butane nitrile, 4-hydroxy-3-[(4-methylphenyl) thio] nitrile), and thiocyanate molecules (thiocyanic acid, ethyle) are responsible for the anti-fungal activities.

Synthesis of Eugenol Derivatives and Evaluation of their Antifungal Activity Against Fusarium solani f. sp. piperis

BACKGROUND

Fusarium solani f. sp. piperis is a phytopathogen that causes one of the most destructive diseases in black pepper crops, resulting in significant economic and crop production losses. Consequently, the control of this fungal disease is a matter of current and relevant interest in agriculture.

OBJECTIVE

The objective was to synthesize eugenol derivatives with antifungal activity.

METHODS

In this study, using bimolecular nucleophilic substitution and click chemistry approaches, four new and three known eugenol derivatives were obtained. The eugenol derivatives were characterized and their antifungal and cytotoxic effects were evaluated.

RESULTS

Eugenol derivative 4 (2-(4-allyl-2-methoxyphenoxy)-3-chloronaphthalene-1,4-dione) was the most active against F. solani f. sp. piperis and showed acceptable cytotoxicity. Compound 4 was two-fold more effective than tebuconazole in an antifungal assay and presented similar cytotoxicity in macrophages. The in silico study of β-glucosidase suggests a potential interaction of 4 with amino acid residues by a cation-π interaction with residue Arg177 followed by a hydrogen bond with Glu596, indicating an important role in the interactions with 4, justifying the antifungal action of this compound. In addition, the cytotoxicity after metabolism was evaluated as a mimic assay with the S9 fraction in HepG2 cells. Compound 4 demonstrated maintenance of cytotoxicity, showing IC50 values of 11.18 ± 0.5 and 9.04 ± 0.2 μg mL-1 without and with the S9 fraction, respectively. In contrast, eugenol (257.9 ± 0.4 and 133.5 ± 0.8 μg mL-1), tebuconazole (34.94 ± 0.2 and 26.76 ± 0.17 μg mL-1) and especially carbendazim (251.0 ± 0.30 and 34.7 ± 0.10 μg mL-1) showed greater cytotoxicity after hepatic biotransformation.

CONCLUSION

The results suggest that 4 is a potential candidate for use in the design of new and effective compounds that could control this pathogen.

Evaluation of the antifungal activity of Rumex vesicarius L. and Ziziphus spina-christi (L) Desf. Aqueous extracts and assessment of the morphological changes induced to certain myco-phytopathogens

Many Plant extracts had proved a potential antifungal activity against a wide range of phytopathogenic fungi. The aim of this study was to evaluate the antifungal activity of the aqueous extracts of Rumex vesicarius L. and Ziziphus spina-christi (L) Desf. against some fungal species. The effect on growth inhibition, conidia germination, sporogenesis, morphological, and ultrastructural characterizations of fungal growth by scanning and transmission electron microscopes, have been investigated. Both plant extracts exhibited an antifungal activity against Fusarium, Helminthosporium, Alternaria, and Rhizoctonia species, besides, the sporogenesis of Alternaria and Fusarium species was suppressed. Both plants induced severe morphological changes in the hyphal shape and surface. We concluded that the aqueous extracts of these plants had strong antifungal activities. More investigations should be performed to evaluate the possible applications in agriculture and in vivo.

In-vitro Bactericidal Activity of a Novel Plant Source Plumeria pudica against Some Human and Fish Pathogenic Bacteria

BACKGROUND

The only remedy for up surging problem of antibiotic resistance is the discovery of antibacterial agents of natural origin.

OBJECTIVE

The present study was aimed at finding antibacterial potential of crude and solvent extracts of mature leaves of Plumeria pudica.

METHODS

Antibacterial activity of three different solvent extracts were evaluated in four human and four fish pathogenic bacteria by measuring the zone of inhibition and determining Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values. Standard antibiotics were used as positive control. Preliminary phytochemical screening of most effective extract i.e., ethyl acetate extract, Fourier Transform Infra Red analysis and GC-MS analysis of the Thin Layer Chromatographic (TLC) fraction of ethyl acetate extract were done meticulously. All experiments were done thrice and analyzed statistically.

RESULTS

Crude leaf extracts and solvent extracts caused good inhibition of bacterial growth in all selected bacteria. Ethyl acetate extract showed highest inhibition zones in all tested strains with maximum inhibition (19.50±0.29 mm) in Escherichia coli (MTCC 739). MBC/MIC of the extracts indicated that all three solvent extracts were bactericidal. Preliminary phytochemical tests revealed the presence of tannins, steroids and alkaloids and FT-IR analysis revealed presence of many functional groups namely alcoholic, amide, amine salt and aldehyde groups. From the GC-MS analysis of TLC fraction of ethyl acetate extract, five different bioactive compounds e.g., 2,4-ditert -butylphenyl 5-hydroxypentanoate, Oxalic acid; allyl nonyl ester, 7,9-Ditert-butyl-1-oxaspiro(4,5)deca-6,9-diene- 2,8-dione, Dibutyl phthalate and 2,3,5,8-tetramethyl-decane were identified.

CONCLUSION

Leaf extracts of P. pudica contain bioactive compounds that can be used as broad spectrum bactericidal agent.

Antibacterial and Antifungal Activity of Novel Freshwater Bacterium Tabrizicola aquatica as a Prominent Natural Antibiotic Available in Qurugol Lake

Background : Recently, resistant pathogenic microorganisms have become increasingly wide spread. The search for new natural antibiotics is a viable solution to this problem. For this aim we investigated the antimicrobial ability of Tabrizicola aquatica, the novel bacterium isolated from Qurugol Lake located nearby Tabriz city, Iran. Methods: The antimicrobial properties of Tabrizacola aquatica was investigated using well diffusion test. Tabtizicola aquatica was incubated at 40℃ in shaking incubator at 150 rpm for 14 days. The culture was centrifuged to obtain cell free supernatant, which was sterilized using 0.2 μm filter paper and lyophilized. Microorganisms were lawn and then wells were prepared over the agar plates. About 100 ml of the diluted lyophilized supernatant was added to the wells. The plates then were incubated at 37℃. After 48 hours, antimicrobial activity was defined by measuring the inhibition zone diameter. Results: The bacterial filtrates had considerable antagonistic effect against Escherichia coli, Rhizobium radiobacter, Pseudomonas syringae, Erwinia amylovora, Botrytis cinerea, Neurospora crassa and Fusarium oxysporum. However, the filtrates did not show any inhibitory action on the Aspergillus flavus and Klebsiella pneumonia. The supernatant decreased the growth zone on Streptococcus aureus, Pseudomonas aeruginosa, Shigella flexneri, Xanthomonas camoestris and Bassilus cereos. The result of MIC against pathogens was found for Neurospora crassa in the 50 µg/mL. Conclusion: The results, suggested that Tabrizicola aquatica and similar bacteria can be helpful to control freshwater natural water sources from pathogenic microorganism. Moreover, microbial natural products are still the most promising source of new antibiotics. Our results point out a scope for characterization of the metabolites and could be a candidate in the identification of novel antibiotics.

The Impacts of Asparagus Extract Fractions on Growth and Fumonisins Biosynthesis in Fusarium Proliferatum

Asparagus is a genus consisting of over two hundred species of perennial plants. Fusarium proliferatum is a major asparagus pathogen and it biosynthesizes a variety of mycotoxins, of which fumonisins B are prevalent. Our previous studies on F. proliferatum strains indicated that asparagus extract affects the expression of FUM1 gene, encoding polyketide synthase, a key enzyme of the FUM gene cluster governing the biosynthesis of fumonisins. An asparagus-derived F. proliferatum strain increased fumonisin B₁ production after extract fractions’ addition, reaching the maximum 2 or 24 h after treatment. The cultures yielded between 40 and 520 mg of dry weight of mycelia after 14 days of cultivation. The differences in fungal biomass amounts between the whole extract and its fractions may result from synergistic effect of all bioactive compounds present in asparagus extract. Among extract fractions, the methanolic fraction had the highest effect on the dry weight of the mycelium reaching about a 13-fold increase compared to the control. Furthermore, we measured the relative expression of the FUM1 gene. Due to the possible antifungal activity of tested extract fractions, future research will be focused on the identification of the Asparagus officinalis L. compounds responsible for this activity.

Purification and characterization of two grandiuvarones from Desmos chinensis leaves and their antimicrobial activities

A novel aromatic compound, grandiuvarone B (5-acetoxy-3-benzoyloxymethyl-5H-oxepin-4-one), along with a known compound grandiuvarone A (5-acetoxy-6-benzoyloxymethyl-5H-oxepin-4-one) were isolated from methanol extracts of Desmos chinensis leaves. Their structures were determined by various spectroscopic techniques including nuclear magnetic resonance (NMR), high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) and circular dichroism (CD). Grandiuvarone A and grandiuvarone B are isomers and the S configuration of grandiuvarone B was reported for the first time. We then determined their antifungal activity against Aspergillus flavus. Results revealed that grandiuvarone B exhibited better antifungal activity against A. flavus, with MIC values of 0.01 mg/mL compared to grandiuvarone A (MIC values of 0.02 mg/mL). In the presence of each active compound at 160 μg/g of aquafeed, A. flavus growth was completely inhibited. Grandiuvarone B also showed antibacterial activity against the plant pathogen Ralstonia solanacearum.

Antifungal activity of recombinant thanatin in comparison with two plant extracts and a chemical mixture to control fungal plant pathogens

The most common method for controlling plant diseases is the application of chemical pesticides and sometimes use of resistant cultivars. Due to the effects of chemical pesticides on human and environmental health, mutation in pathogens and resistance to various toxins besides the challenges with resistant cultivar production, the constant use of these methods are not recommended any longer. Thus, use of biological control agents along with the natural ingredient extracted from plants and application of peptide with antimicrobial activity, have been the focus of many researchers. In the present study, the antifungal activity of two plant extracts named Turmeric and Persian lilac in comparison with a chemical mixture and recombinant thanatin were evaluated against five following fungal plant pathogens; Geotrichum candidum, Botrytis cinerea, Rhizoctonia solani, Alternaria tenuissima and Gibberella fujikuroi. The results showed that, all treatments have antifungal activity against tested fungi. Both plant extracts were shown an acceptable antifungal activity against tested fungi but their inhibition effects was not comparable with chemical mixture. Turmeric showed a higher rate of mycelial inhibition than Persian lilac. Amongst all treatment, thanatin showed a great antifungal activity by its application at µg level under both in vitro and in vivo condition. Considering to the compatibility of thanatin with human health and environmental safety we could imagine a clear perspective for the application of this recombinant peptide in sustainable agriculture.

Baccharis reticularia DC. and Limonene Nanoemulsions: Promising Larvicidal Agents for Aedes aegypti (Diptera: Culicidae) Control

Baccharis reticularia DC. is a plant species from the Asteraceae family that is endemic to Brazil. Despite the great importance of Baccharis genus, no study has been carried out regarding either the phytochemical composition of B. reticularia or the evaluation of its larvicidal potential. Considering the intrinsic immiscibility of essential oils, this study shows larvicidal nanoemulsions containing the B. reticularia phytochemically characterized essential oil and its main constituent against Aedes aegypti. The major compound found was d-limonene (25.7%). The essential oil inhibited the acetylcholinesterase, one of the main targets of insecticides. The required hydrophile-lipophile balance of both nanoemulsions was 15.0. The mean droplet sizes were around 90.0 nm, and no major alterations were observed after 24 h of preparation for both formulations. After 48 h of treatment, the estimated LC₅₀ values were 118.94 μg mL^-1 and 81.19 μg mL^-1 for B. reticularia essential oil and d-limonene nanoemulsions, respectively. Morphological alterations evidenced by scanning electron micrography were observed on the larvae treated with the d-limonene nanoemulsion. This paper demonstrated a simple and ecofriendly method for obtaining B. reticularia essential oil and d-limonene aqueous nanoemulsions by a non-heating and solvent-free method, as promising alternatives for Aedes aegypti control.

Host extracts induce changes in the proteome of plant pathogen Fusarium proliferatum

Fusarium proliferatum is a polyphagous pathogenic fungus able to infect many crop plants worldwide. Differences in proteins accumulated were observed when maize- and asparagus-derived F. proliferatum strains were exposed to host extracts prepared from asparagus, maize, garlic, and pineapple tissues. Seventy-three unique proteins were up-regulated in extract-supplemented cultures compared to the controls. They were all identified using mass spectrometry and their putative functions were assigned. A major part of identified proteins was involved in sugar metabolism and basic metabolic processes. Increased accumulation of proteins typically associated with stress response (heat shock proteins, superoxide dismutases, and glutaredoxins) as well as others, putatively involved in signal transduction, suggests that some metabolites present in plant extracts may act as elicitors inducing similar reaction as the abiotic stress factors. As a case study, thirteen genes encoding the proteins induced by the extracts were identified in the genomes of diverse F. proliferatum strains using gene-specific DNA markers. Extract-induced changes in the pathogen's metabolism are putatively a result of differential gene expression regulation. Our findings suggest that host plant metabolites present in the extracts can cause biotic stress resulting in elevated accumulation of diverse set of proteins, including those associated with pathogen's stress response.