Antifungal Activity Of Extracts Research Articles

Antagonistic Interactions in Onychomycosis: Antifungal Activity of Extracts from Pure and Mixed Cultures of Candida parapsilosis and Trichophyton spp.

Antagonistic Interactions in Onychomycosis: Antifungal Activity of Extracts from Pure and Mixed Cultures of Candida parapsilosis and Trichophyton spp.

Phytochemical analysis, in vitro antioxidant and antifungal activities of extracts and essential oil derived from Artemisia herba-alba Asso

Abstract Artemisia herba-alba Asso is an endemic plant from North-East Morocco offering a diverse range of pharmacological, cosmetic, and agro-ecological uses. However, Artemisia herba-alba has not been well exploited in the field of plant protection (post-harvest diseases). This is why the main objective of the present study is to evaluate the antifungal and antioxidant activities of extracts or the essential oil of this plant. Antifungal activity was assessed against Botrytis cinerea, Penicillium expansum, and Penicillium digitatum using the agar dilution method for the aqueous extracts and fumigation for the essential oil. Antioxidant activity was assessed using the DPPH scavenging test and the FRAP ferric ion reduction capacity. The chemical composition of the extracts was determined by HPLC and that of the essential oil by GC-MS/MS. In addition, the polyphenol, flavonoid, and tannin content was determined using colorimetric methods. The results of this study showed that the total content of polyphenols (217.60 mg GAE/g E), flavonoids (43.59 mg QE/g E), and tannins (32.58 mg GAE/g E) was significantly higher (p ≤ 0.05) in the ethanolic extract than in the aqueous and hexanoic extracts. Moreover, the HPLC analysis of the aqueous extract revealed the presence of six compounds, namely, catechin, gallic acid, hydroxybenzoic acid, syringic acid, caffeic acid, and rutin. In addition, the ethanolic extract was found to contain seven phenolic compounds. On the one hand, 35 compounds were identified in the essential oil of Artemisia herba-alba, representing 99.7% of the total. According to this study, the dominant compounds in the essential oil of Artemisia herba-alba Asso are camphor (46.57%), endo-borneol (5.65%), eucalyptol (5.64%), and thymol (3.85%). Furthermore, the biological evaluation showed that the extracts and essential oil of Artemisia herba-alba have significant antioxidant and antibacterial activities. The findings show that Artemisia herba-alba is a plant that can be used as a source of antifungal chemicals to prevent putrefaction of foodstuffs and, more specifically, postharvest diseases.

Comparison of Phytochemical Composition, Antibacterial, and Antifungal Activities of Extracts from Three Organs of Pistacia lentiscus from Saudi Arabia.

This in vitro study focused on the antimicrobial activity of methanolic and aqueous extracts of three organs (stems, roots, and leaves) of Pistacia lentiscus against nine bacterial species, two fungal, and one yeast strain. A comparative study of the yield, high-performance liquid chromatography (HPLC) composition, and polyphenol content of the different extracts was conducted. The obtained data showed that the yield of the methanolic extracts (between 13% and 33.3%) was greater than that of the aqueous extracts (between 10% and 18%). The highest yield recorded was in the presence of the methanolic leaf extract, followed by the stem and root extracts. Methanolic extracts are richer in polyphenols than aqueous extracts. Indeed, the highest content was observed in the leaf methanolic extract (28.4 mg GAE/g), followed by the stem (2.96 mg GAE/g), and then the root (2.62 mg GAE/g). HPLC revealed variability in the chemical compositions of the different methanolic extracts. The leaf extract was richer in phenolic acids and flavonoids than the stem and root extracts. Regarding antimicrobial activity, it was concluded that the different methanolic extracts of lentisk were more active than the aqueous extracts. In addition, the different methanolic extracts exhibited antimicrobial activity against all tested strains, despite their morphology and Gram-staining. Indeed, the maximum inhibition zones and the minimum inhibitory concentrations for the bacterial strains sensitive to the different methanolic extracts of the mastic tree were in the range of 7 to 11 mm and 12.5 to 25 µg/mL, respectively. In addition, these extracts showed greater inhibitory activity against the tested fungal strains (A. niger and A. flavus) and yeast (C. albicans) than against the bacterial strains. These extracts can be used to treat antimicrobial infections and as food preservatives.

Antibacterial and Antifungal Activities of Extracts from Some Woody Trees on Some Plant Pathogenic Agents

Antibacterial and Antifungal Activities of Extracts from Some Woody Trees on Some Plant Pathogenic Agents

Uji aktivitas antimikroba ekstrak etanol buah renggak (Amomum dealbatum Roxb.) terhadap Staphylococcus aureus dan Candida albicans

Staphylococcus aureus and Candida albicans are microorganisms that cause infection in humans and have developed resistance to several classes of antibiotics and antifungals. Plants in the genus Amomum have been used in traditional medicine and have scientific potential as alternatives to natural antibacterial and antifungal agents. Renggak (Amomum dealbatum Roxb.) is a species of the genus Amomum that is commonly found in Lombok. Scientific research related to the antibacterial and antifungal activity of the fruit is still limited. The aim of this study was to determine the antibacterial and antifungal activity of ethanol extract of renggak fruit against Staphylococcus aureus and Candida albicans. The extraction method used sonication with 96% ethanol. Testing of antibacterial and antifungal activity by disc diffusion method. The positive control used chloramphenicol for antibacterial testing and ketoconazole for antifungal testing, while the negative control used 10% DMSO solution. The antibacterial and antifungal activity of the extract was measured based on the diameter of the inhibition zone formed around the disc. Data analysis used the Kruskall-Wallis statistical test with a 95% confidence level. The results showed that the ethanol extract had moderate activity against S. aureus at concentrations of 20% w/v & 30%w/v with inhibitory diameters ranging from 5-7 mm, while at concentrations of 40% w/v & 50% w/v. has strong activity with inhibitory diameters ranging from 10-15 mm. The ethanol extract showed no activity at concentrations of 50%, 75%, and 100% in inhibiting the growth of the fungus C. albicans. Statistical test of each extract concentration had a significant effect on the inhibition of growth of S. aureus compared to the negative control. Based on the description above, it can be concluded that the extract of renggak fruit has the potential to inhibit the growth of S. aureus.

In vitro antibacterial and antifungal activities of extracts and fractions of leaves of Ricinus communis Linn against selected pathogens

In vitro antibacterial and antifungal activities of extracts and fractions of leaves of Ricinus communis Linn against selected pathogens

Triterpene and Steroids from Ludwigia abyssinica A. Rich (Onagraceae) Displayed Antimicrobial Activities and Synergistic Effects with Conventional Antibiotics.

Difficulties encountered in treating drug-resistant pathogens have created a need for new therapies. Synergistic combinations of antibiotics are considered as ideal strategies in combating clinical and multidrug-resistant (MDR) infections. In this study, the antimicrobial activities of triterpenes and steroids from Ludwigia abyssinica A. Rich (Onagraceae) and their combined effects with antibiotics were assessed. The associations between plant constituents and antibiotics were evaluated by determining their fractional inhibitory concentrations (FICs). Sitost-5-en-3β-ol formiate (1), 5α,6β-dihydroxysitosterol (2), and maslinic acid (3) were isolated from the L. abyssinica ethyl acetate (EtOAc) extract. The EtOAc extract, compounds 1, 2, and 3 (MIC = 16-128 µg/mL) would be the best antibacterial and antifungal agents. The antimicrobial activities of amoxicillin were relatively weak against MDR Escherichia coli and Shigella flexneri and significant against Staphylococcus aureus ATCC 25923. However, when used in association with plant constituents, it displayed an interesting synergistic effect. Among plant components-antibiotic combinations, the EtOAc extract and compound 1 (steroid) showed a synergistic effect with amoxicillin/fluconazole against all the tested microorganisms whereas the association of compound 3 (triterpenoid) and amoxicillin/fluconazole displayed an additive effect against Shigella flexneri and Escherichia coli and a synergistic effect on Staphylococcus aureus, Cryptococcus neoformans, Candida tropicalis, and Candida albicans ATCC 10231. Overall, the results of the present study demonstrated antibacterial and antifungal activities of extracts and compounds isolated from L. abyssinica. The findings of the current study also showed that the potency of antibiotics was improved when screened in combination with L. abyssinica components, supporting the drug combination strategy to combat antimicrobial resistance.

In Vitro Anti-Bacterial and Anti-Fungal Activities of Extracts from Different Parts of 7 Zingiberaceae Plants

This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family. The inhibitory rate, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of leaf and stem, and root and rhizome extracts from Alpinia katsumadai Hayata, Alpinia oxyphylla Miq × Alpinia henryi K. Schumann, Alpinia oblongifolia Hayata, Alpinia nigra (Gaertn.) Burtt, Amomum villosum Lour, Alpinia zerumbet (Pers.) Burtt. et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method. The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi. At a 1.5 mg mL−1, A. zerumbet root and rhizome extracts exhibited strong inhibitory activity against S. aureus and E. coli, with 83.23% and 79.62%, respectively. In addition, A. zerumbet leaf and stem extracts had an inhibitory rate of 90.85% against P. aeruginosa. At the same concentration, the leaf and stem, root and rhizome extracts of A. katsumadai had the best antibacterial effect against F. oxysporum, with inhibition rates of 84.46% and 84.73%, respectively. Moreover, A. katsumadai and A. zerumbet leaf and stem extracts had the most significant antibacterial effect against S. aureus, with a MIC of 0.063 mg mL−1 . Thus, both A. katsumadai and A. zerumbet extracts had significant antibacterial activity. In addition, by comparing the inhibitory effect of extracts from different parts, it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome. The chemical constituents of A. katsumadai and A. zerumbet, determined by the high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), revealed that citric acid (CA), alpinetin, and pinocembrin (PNCB) were the functional constituents yielding the antibacterial activity. Overall, A. katsumadai and A. zerumbet have the potential to be developed as new plant fungicides and bactericides.

GC-MS Analysis, Antioxidant and Antifungal Studies of Different Extracts of Chaetomium globosum Isolated from Urginea indica.

To discover new natural resources with biological effects, the chemical investigation of antioxidant and antimicrobial activities of extract's Chaetomium globosum isolated from roots of Urginea indica. Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated the presence of the major chemical constituents present in the methanol extract (1,3-oxathiolane, 1,3-cyclopentadiene, 5-(1-methylethylidene), 5,9-hexadecadienoic acid, methyl ester, decane), chloroform extract (acetic acid, diethoxy-, ethyl ester, 2,2-bis(ethylsulfonyl)propane, 3-methyl-2-(2-oxopropyl) furan), and hexane extract (3-hexanone, 4,4-dimethyl, decane,2,6-dimethyldecane, decane, 2,4,6-trimethyl, decane, 2,4,6-trimethyl, 1-butanesulfinamide, 1,1,2,2,3,3,4,4,4-nonafluoro-N-methyl, decane). The total compound identified (56.2%) in chloroform extract, (54.72%) in hexane extract, and (65%) in methanol extract. The antioxidant effects were performed using diphenylpicrylhydrazyl radical (DPPH). The results showed that the methanol extract showed significantly the highest anti-DPPH with an IC50 value of 37.61 ± 1.37 μg/mL, followed by chloroform and hexane extracts with IC50 values of 40.82 ± 3.60 and 45.20 ± 2.54 μg/mL, respectively. The antifungal activity of extracts was evaluated against pathogens fungi including Fusarium oxysporum, Rosellinia necatrix, Cladosporium xanthochromaticum, and Sclerotinia sclerotiorum. Methanolic and chloroform extracts showed maximum inhibition against all test pathogens, while hexane extract showed minimum inhibition.

Determination of Allelopathic and Antimicrobial Effects of Four Different Plant Species

The investigation of allelopathic and antimicrobial effects of four different plant extracts is the aim of this study. The aqueous extract of plants (Lepidium draba L., Acroptilon repens (L.) DC., Thymus kotchyanus Boiss&Hohen. var. kotchyanus, Inula peacockiana (Aitch.&Hemsl.) Koravin,) were applied to seedlings of cultivated (Pisum sativum L. and Hordeum vulgare L.) and weed (Amaranthus retroflexus L. and Portulaca oleraceae L.). Seedlings were irrigated with aqueous extract (1 %) for 15 days to observe the physiological responses. The morphological changes, chlorophyll levels and phytohormone concentrations were determined. The Lepidium draba and Inula peacockiana extracts affected development of all of the target seedlings and caused lesion on the leaves. Acroptilon repens and Thymus kotschyanus extracts caused a decrease in gibberellic acid (GA) whereas increase in absisic acid (ABA) levels. For investigation of antimicrobial activities, hexane, methanol and water extracts were prepared. Extracts were applied on Bacillus cereus, Staphylococ aureus, Pseudomonas syringae and Escherichia coli for antibacterial and Rhizoctonia solani, Fusarium oxysporum and Aspergillus niger for antifungal effects. Inula peacockiana and Acroptilon repens extracts had a great antimicrobial activity. While all plant extracts inhibited Rhizoctonia solani, Fusarium oxysporum growth and spore development of Aspergillus niger. The antifungal activity of extracts were better than antibacterial activity. As a conclusion, these plants have allelopathic potential for natural weed control and antimicrobial potential for medicinal uses.

Candida parapsilosis culture extracts: in vitro, antagonistic action against Candida albicans, Candida auris and Candida parapsilosis

Fungal infections caused by Candida species has increased significantly in recent years. Additionally, resistance to conventional therapy is an aggravating factor causing high morbidity and mortality, especially in immunocompromised patients or those undergoing treatment with another antimicrobials. During the infection process, Candida species produces metabolites which can self-regulate population density, in addition to controlling several virulence factors and exerting action on other microorganisms. In view of this fact, the present study evaluated the in vitro antifungal activity of the pure culture extract of Candida parapsilosis against Candida albicans, Candida auris and Candida parapsilosis. Fungal culture extracts of C. parapsilosis were prepared in Sabouraud Dextrose Broth, extracted with ethyl acetate and dried in a rotary evaporator. Subsequently, tests were performed to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). The antifungal activity of the extracts against Candida species showed values of MIC ranging between 500 - 2000 µg/mL and a MFC range of 1414 µg/mL - 2000 µg/mL. Future investigations for the identification and composition of this fungal culture extract will provide insights about metabolites are present and involved in the antifungal activity shown here, contributing for the future to new therapeutic approaches in the control of infections caused by Candida.

Antifungal and antibacterial activity of marine sponges from Ratnagiri coast of India.

Marine sponges have proved to be a rich source of bioactive metabolites with multiple pharmacological properties. In this study, we have investigated the antifungal and antibacterial activities of methanol extracts of Cliona, Haliclona cratera, Hyrtios cavernosus, Spongia obscura, Sarcotragus foetidus, and Xestospongia carbonaria and fractions from X. carbonaria S. obscura and H. cratera. The antibacterial activity was determined by agar disc diffusion method against clinical gram-positive- Staphylococcus aureus, Bacillus subtilis and gram negative- Escherichia coli, Pseudomonas aeruginosa bacteria. The antifungal activity of the extracts and fractions was determined against Candida albicans and Aspergillus niger. S. obscura, X. carbonaria, H. cavernosus, and H. cratera exhibited good antibacterial activity against the tested gram-positive bacteria with larger zones of inhibition at 19±6 mm, 19.5±5.5mm, 20±0 mm and 23±0 mm. S. foetidus gave good inhibition of gram-negative bacteria at 19±0 mm. They showed moderate antifungal activities against C. albicans and A. niger. Cliona, H. cratera and H. cavernosus gave inhibition with 20±5 mm, 15.5±0.5 mm and 25.5±14.5 mm for A. niger. The MIC for Xc_PE_2, Sob_n but_1 and Hc_n but_3 was determined. H. cavernosus, S. foetidus, S. obscura and X. carbonaria showed presence of fatty acids and sterol type of compounds. The mass of molecular ions in purified fractions helped in characterization of known compounds in H. cratera, X. carbonaria and S. obscura which exhibited good antimicrobial activity.

Bio-Functional Potential and Biochemical Properties of Propolis Collected from Different Regions of Balochistan Province of Pakistan

Propolis is a well-known resinous natural substance collected by honeybees (Apis mellifera L.) from plants exudations. Variations in chemical composition of propolis are due to different sources from which it is collected and change in climate and geographical location. In this study, different propolis samples were collected from different regions of Balochistan and examined for its chemical composition, total phenolics and total flavonoid contents, and antioxidant potential by using DPPH radical scavenging assay and antimicrobial activity. Bioactive components analysis revealed the presence of steroids, carbohydrates, flavonoids, coumarins, cardiac glycosides, quinones, anthraquinones, terpenoids, tannins, and phlobatannins at different levels. The total phenolics contents were ranged from 2.9343 ± 1.247 to 6.0216 ± 2.873 mg GAE g−1, and flavonoid contents were found to be 0.1546 ± 0.087 to 0.6586 ± 0.329 mg QE g-1, respectively. The antioxidant ability of each extract was analyzed by their concentration having 50% inhibition (IC50). The propolis sample P3 possessed lower IC5027.07 ± 0.73 mg mL−1 with higher % inhibition of DPPH radical, and P8 showed lower % inhibition by having IC5084.43 ± 2.07 mg mL−1. The antibacterial activity of all samples was analyzed against a wide group of bacteria including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumonia and propolis extract (P4) was highly active against Klebsiella pneumoniae with the maximum diameter of zone of inhibition 20.33 ± 1.52 mm, and propolis extract (P3) showed maximum zone of inhibition against Escherichia coli19.06 ± 1.90, while propolis extract (P2) was found less active with minimum diameter of zone of inhibition 7.46 ± 1.50 mm. The antifungal activity of extract was considered as active against the fungal species. Propolis extract (P3) showed 82% of zone of inhibition against Aspergillus Niger, and propolis extract (P1) was highly active against Aspergillus parasiticus with 80% of zone of inhibition. By comparing the vibration frequencies in wave numbers of the sample spectrograph acquired from an FTIR spectrophotometer, the functional groups present in the extracts were identified. The presence of seven elements (Fe, Zn, Mn, Ni, Pb, Cd, and Cr) was analyzed through atomic absorption spectrophotometer. The obtained concentrations were within the permissible ranges established by the World Health Organization. The GC-MS analysis revealed the presence of 80 different compounds belonged to different classes. The obtained results confirmed the imperative potential of propolis which can be used in various biological applications.

In vitro antibacterial and antifungal activities of extracts and fractions of leaves of Ricinus communis Linn against selected pathogens.

IntroductionInfectious disease impacts are reduced due to the development of antimicrobial agents. However, the effectiveness of antimicrobial agents is reduced over time because of the emergence of antimicrobial resistance. To overcome these problems, scholars have been searching for alternative medicines. Ricinus communis is used as a traditional treatment for bovine mastitis, wound infection, and other medicinal purposes.ObjectiveThe objective of the present study was to further evaluate the antimicrobial activities of R. communis leaf extracts and fractions.Methods R. communis leaves were macerated in methanol and acetone. The methanol extract showed better antimicrobial activity and subjected to further fractionation via increasing polarity of solvents (n‐hexane, chloroform, ethyl acetate, and aqueous). Test microorganisms included in the study were six laboratory reference bacteria (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Kleibsella pneumoniae, Pseudomonas aeruginosa and Streptococcus pyogenes), two clinical isolate bacteria (E. coli and S. aureus), and Candida albicans. The agar well diffusion method was employed to determine antimicrobial activity. The minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC) were determined through broth microdilution.ResultsThe results indicated that the best antimicrobial activity for ethyl acetate fraction ranged from 14.67 mm (clinical E. coli) to 20.33 mm (S. aureus) at 400 mg/ml, however, n‐hexane exhibited the lowest antimicrobial activity. Among the tested fractions, ethyl acetate fraction showed the lowest MIC values ranged from 1.5625 mg/ml (S. aureus) to 16.67 mg/ml (Candida albicans). The ethyl acetate fraction showed bactericidal activity against all tested microorganisms.ConclusionHence, ethyl acetate fraction of crude methanol extract exhibited the best antimicrobial activity.

Antifungal activity of extracts from the Antarctic plant Colobanthus quitensis Kunth. (Bartl) cultured in vitro against Botrytis cinerea Pers

Botrytis cinerea, a responsible for grey rot that mainly affects fruit and represent a problem in fruit-exporting countries. Synthetic antifungals are used for its control. However, it has developed a specific resistance towards them. Therefore, a search for new natural alternatives that are friendly to the environment has increased in the last decade. In this work, the activity of in vitro-cultured C. quitensis extracts was analysed. Extract was characterized using LC-MS/MS and evaluated in vitro, and in vivo using edible coatings in table grapes. The application of extracts inhibited the development of conidia and mycelium of B. cinerea, with EC50 values of 0.071 ± 0.008 g L−1 and 0.074 ± 0.09 g L−1, respectively, inducing oxidative stress in vitro; on the other hand, in vivo assays showed a protection and preservation of anthocyanins and sugars in table grapes. These results suggest that C. quitensis extracts represent a good alternative to control B. cinerea.

HPLC-DAD analysis, antifungal and antioxidant activity of Solanum dolichosepalum bitter extracts and fractions

Solanum dolichosepalum is a plant with anti-infective effects. It is a healing agent and has ethnopharmacological uses. In this study, the antifungal activity of extracts and fractions of this species on C. albicans and F. oxysporum was evaluated. The antioxidant activity was measured using the ABTS and DPPH methods, and by determining the total content of phenolic compounds. An HPLC-DAD qualitative analysis was carried out to identify phenolic compounds and alkaloids. Pearson’s correlation coefficients were calculated. Inhibitory effects were found in all the extracts and fractions on the analyzed microorganisms. F. oxysporum was the microorganism most sensitive to the action of S. dolichosepalum extracts. All extracts and fractions showed antioxidant activity, with the acetone extract and the acetone fraction being those that generated the best results. The content of total phenolic compounds showed that acetone has a greater affinity with the phenolic compounds present in S. dolichosepalum. In this plant, p-Hydroxybenzoic, vanillic, ferulic, trans-cinnamic, caffeic, p-coumaric, and rosmarinic acids were found, as well as theobromine, quercetin, and luteolin. The content of total phenolic compounds was determined to be directly proportional to the inhibition of the ABTS and DPPH radicals, and the inhibition of the analyzed microorganisms. It was determined that the extracts and fractions obtained from S. dolichosepalum show antioxidant and antifungal activity.

Ruta graveolens, Pelargonium graveolens E Hibiscus cannabinus COMO INIBIDORES NATURAIS DO CRESCIMENTO DE Candida albicans

Candidiasis is an infection caused by fungi of the genus Candida, Candida albicans being the species that most causes the disease in Brazil. The Fluconazole is the conventional medicine used as a treatment of these infections; however, it causes many adverse reactions in the patient and its continued use can induce the resistance of the pathogen. The medicinal plants can be very effective as an alternative treatment of diseases and have been used in folk medicine for years. In this study, it was evaluated the antifungal activity of extracts of Ruta graveolens, Pelargonium graveolens and Hibiscus cannabinus against the fungal development of Candida albicans, comparing the efficiency of these extracts to Fluconazole. The extracts were prepared in the concentration of 1g of the plant for each 5 mL of alcohol 70%. The data were obtained using the agar diffusion method. The minimum inhibitory concentration test (MIC) was performed, and showed that R. graveolens was able of inhibiting 100% of the pathogen when using 100 mg.ml-1 concentration. From the results obtained, it was possible to conclude that R. graveolens was the most effective extract when compared to Fluconazole, suggesting that this extract can be used as an alternative to conventional treatment to improve the efficiency of current treatments. The extracts of P. graveolens and H. cannabinus also presented antifungal activity but in smaller proportion than Fluconazole. The data from this study suggests that R. graveolens extract can be tested in future in vivo studies with the objective of proposing its use in alternative or simultaneous treatment of the synthetic drug used.

Machine learning approach for predicting the antifungal effect of gilaburu (Viburnum opulus) fruit extracts on Fusarium spp. isolated from diseased potato tubers

This work addresses the mathematical model building to detect the diameter of the inhibition zone of gilaburu (Viburnum opulus L.) extract against eight different Fusarium strains isolated from diseased potato tubers. Gilaburu extracts were obtained with acetone, ethanol or methanol. The isolated Fusarium strains were: F. solani, F. oxysporum, F. sambucinum, F. graminearum, F. coeruleum, F. sulphureum, F. auneaceum and F. culmorum. In general, it was observed that ethanolic extracts showed highest antifungal activity. The antifungal activity of extracts was evaluated with machine learning (ML) methods. Several ML methods (classification and regression trees (CART), support vector machines (SVM), k-Nearest Neighbors (k−NN), artificial neural network (ANN), ensemble algorithms (EA), AdaBoost (AB) algorithm, gradient boosting (GBM) algorithm, random forests (RF) bagging algorithm and extra trees (ET)) were applied and compared for modeling fungal growth. From this research, it is clear that ML methods have the lowest error level. As a result, ML methods are reliable, fast, and cheap tools for predicting the antifungal activity of gilaburu extracts. These encouraging results will attract more research efforts to implement ML into the field of food microbiology instead of traditional methods.

Antifungal Activity of Extracts, Fractions, and Constituents from Coccoloba cowellii Leaves.

Coccoloba cowellii Britton (Polygonaceae, order Caryophyllales) is an endemic and critically endangered plant species that only grows in the municipality of Camagüey, a province of Cuba. A preliminary investigation of its total methanolic extract led to the discovery of promising antifungal activity. In this study, a bioassay-guided fractionation allowed the isolation of quercetin and four methoxyflavonoids: 3-O-methylquercetin, myricetin 3,3′,4′-trimethyl ether, 6-methoxymyricetin 3,4′-dimethyl ether, and 6-methoxymyricetin 3,3′,4′-trimethyl ether. The leaf extract, fractions, and compounds were tested against various fungi and showed strong in vitro antifungal activity against Cryptococcus neoformans and various Candida spp. with no cytotoxicity (CC50 > 64.0 µg/mL) on MRC-5 SV2 cells, determined by a resazurin assay. A Candida albicans SC5314 antibiofilm assay indicated that the antifungal activity of C. cowellii extracts and constituents is mainly targeted to planktonic cells. The total methanolic extract showed higher and broader activity compared with the fractions and mixture of compounds.

Digera muricata (L.) Mart. mediated synthesis of antimicrobial and enzymatic inhibitory zinc oxide bionanoparticles

Abstract Herein, we report a simple and ecofriendly synthesis of ZnO nanoparticles (ZnO NPs) employing Digera muricata along with bioassay studies of synthesized NPs. The ZnO NPs obtained were indicated by a colour change from yellow to almost faint yellow giving whitish tinge and supported by the appearance of UV-Vis band at 373 nm and were characterized by using Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDX), and scanning electron microscopy (SEM). The FT-IR spectrum confirmed the presence of biomolecules fabricated on ZnO NPs as indicated by the absorption bands at 1,378 for C–O cm−1, and ZnO NPs were also evident from the absorption bands at 440 and 670 cm−1, the former being the result of symmetric vibration of hexagonal ZnO and the latter belonged to a very weak vibration of ZnO. Its surface morphology was confirmed by SEM, and the zinc and oxygen bonds were confirmed by EDX analysis giving sharp signals for Zn and oxygen with At% of 17.58 and 30.49, respectively. The antimicrobial activity of ZnO nanoparticles was determined by the agar well diffusion method against pathogenic bacterial and fungal strains using imipenem and miconazole as standards. The results reflected that ZnO NPs enhanced the activity of plant extracts against all employed algal (E. coli, S. faecalis, P. aeruginosa, K. pneumonia, S. aureus, and B. subtilis) and fungal (T. mentogrophytes, E. floccosum, A. niger, M. canis, and F. culmorum) strains. The antibacterial and antifungal activities of extracts were enhanced by the formation of ZnO NPs. The results indicated that Digera muricata extract contains effective reducing agents for green synthesis of Digera muricata fabricated ZnO NPs, which are more potent antimicrobial than the plant extract and showed almost similar inhibition against lipoxygenase, i.e., the IC50 value of 83.82 ± 1.15, comparable to the standard.