Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by...Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by hot-water(115 ℃) or ethanol(70%; 40 ℃) extraction were determined by their minimum inhibitory concentration.To assess possible synergistic effects, minimum inhibitory concentrations of various combinations were evaluated.Results: By evaluating antifungal susceptibility of Trichophyton rubrum, which is a major causative fungus for several types of dermatophytosis, we confirmed that ethanol extracts were more active than hot-water extracts in 25 of the 36 TOMs, suggesting that the constituents with high hydrophobicity tend to contribute significantly to fungistatic activity.We selected four TOMs with high fungistatic activity, including Aucklandiae radix, Gentianae macrophyllae radix, Scutellariae radix, and Galla rhois, and their synergistic effects were investigated through the combination studies between TOMs or TOM-conventional drug terbinafine.In combinations between four TOMs, partial synergistic effects were observed in Aucklandiae radix–Galla rhois and Gentianae macrophyllae radix–Galla rhois combinations, as supported by the lowest fractional inhibitory concentration index value of 0.66 for both combinations.Furthermore, Galla rhois showed the strongest synergistic effect on growth inhibition of Trichophyton rubrumwith a fractional inhibitory concentration index value of 0.50 in combination with terbinafine.Conclusions: Our findings indicate that the combination of TOMs and TOM-terbinafine may be effective on treatment for chronic and recurrent dermatophytosis by improving fungistatic activity and led to decrease systemic toxicity in clinical practice.展开更多
Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude prote...Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.展开更多
The fungistatic activity of a lactic acid bacterium, which had been isolated from yellow pitahaya cultures, against fungi associated with basal rot(Fusarium oxysporum and Fusarium fujikuroi) was measured in the presen...The fungistatic activity of a lactic acid bacterium, which had been isolated from yellow pitahaya cultures, against fungi associated with basal rot(Fusarium oxysporum and Fusarium fujikuroi) was measured in the present study. Its activity was assessed in three fractions: fermented(S1), metabolic products(S2), and biomass(S3), using two fermentation substrates: Man Rogosa Sharpe agar(MRS) and potato dextrose agar(PDA). The bacterium was molecularly identified as Lactobacillus plantarum. S3 reduced F. fujikuroi growth by 100% over 48 h of fermentation, which occurred during the stationary phase of bacterial growth. The three fractions' fungistatic activity against F. fujikuroi depended on the substrate employed. The fermentation kinetic parameters for L. plantarum indicated that its specific growth rate was 0.46 h^–1, with 93.63% substrate consumption, 0.045 kg kg^–1 cell yield, and 0.54 kg kg^–1 product yield. The kinetic parameters calculated will allow for bacteria production scaling. These in-vitro trials reveal L. plantarum's possible application as a biocontrol agent for diseases associated with Fusarium. However, further ex-vivo and in-vivo researches are required to demonstrate its behavior in crops.展开更多
Permeability of wood preservative is one of the most significant factors for protection of wood construction.Ani-sotropic flow permeability was involved in different directions of wood with higher flow resistance in t...Permeability of wood preservative is one of the most significant factors for protection of wood construction.Ani-sotropic flow permeability was involved in different directions of wood with higher flow resistance in the trans-verse and lower longitudinal directions.In this study,boron acid solution was brushed onto the tangential section of air-dried wood cubes and boron penetration along wood transverse direction was investigated under free dif-fusion,vacuum and HVEF treatments.Multi-scale boron distribution,FTIR measurement,leaching property,mechanical properties and fungistatic characteristic were investigated for free diffusion,vacuum and HVEF trea-ted samples respectively.The results revealed that boron exhibited high permeability along the transverse direc-tion with the penetration depth of≈35 mm for HVEF treated samples and≈1 mm for free diffusion and vacuum treated samples.For HVEF treated samples,no significant decrease of hardness,compression modulus of elasti-city and strength were found in the treated samples.Better fungistatic characteristic was showcased in HVEF trea-ted samples exposed to white rot fungi.Thus,HVEF treatment has a positive effect on boron permeability and the improvement of penetration depth of preservatives hence playing a significant role in wood protection and prolonging the service life of wood construction.展开更多
Laboratory experiments have been carried out to determine the effects of lemon, cedar, pine and thyme oils as well as Citrocept on the growth of Fusarium solani Mart. (Sacc.) mycelium isolated from stored potato tuber...Laboratory experiments have been carried out to determine the effects of lemon, cedar, pine and thyme oils as well as Citrocept on the growth of Fusarium solani Mart. (Sacc.) mycelium isolated from stored potato tubers. The biotic property of essential oils and Citrocept in inhibiting the linear growth of F. solani was assessed with the use of poisoned culture media, whereas the fungistatic property was determined by calculating, with the use of Abbott formula, the percentage indicating how many fungal colonies were inhibited from growth. A complete inhibition of the pathogen’s growth was observed in the presence of thyme oil at a concentration of 0.2% to 2% as well as in the presence of lemon oil at a concentration of 5% and 15%. Citrosept only at high concentrations caused a slower growth of F. solani. No fungistatic effects of cedar and pine oils were observed.展开更多
Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound...Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound is known for several other biological activities such as antiparasitic, antispasmodic and antibacterial activity. The aim of the present study was to investigate the effect of KA on Aspergillus nidulans. KA (0.3 mM) showed fungistatic activity against A. nidulans with visible hyphal elongation and morphology damage. These effects were reverted by CaCl2 addition showing that KA interferes with intracellular Ca2+ gradient in A. nidulans. This is the first report on the mechanism of action of KA involving calcium levels by altering the elongation of fungi hyphae.展开更多
基金supported by the Grant K17281 from Korea Institute of Oriental Medicine(KIOM),provided by the Ministry of Science,ICT and Future Planning(MISP),Republic of Korea
文摘Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by hot-water(115 ℃) or ethanol(70%; 40 ℃) extraction were determined by their minimum inhibitory concentration.To assess possible synergistic effects, minimum inhibitory concentrations of various combinations were evaluated.Results: By evaluating antifungal susceptibility of Trichophyton rubrum, which is a major causative fungus for several types of dermatophytosis, we confirmed that ethanol extracts were more active than hot-water extracts in 25 of the 36 TOMs, suggesting that the constituents with high hydrophobicity tend to contribute significantly to fungistatic activity.We selected four TOMs with high fungistatic activity, including Aucklandiae radix, Gentianae macrophyllae radix, Scutellariae radix, and Galla rhois, and their synergistic effects were investigated through the combination studies between TOMs or TOM-conventional drug terbinafine.In combinations between four TOMs, partial synergistic effects were observed in Aucklandiae radix–Galla rhois and Gentianae macrophyllae radix–Galla rhois combinations, as supported by the lowest fractional inhibitory concentration index value of 0.66 for both combinations.Furthermore, Galla rhois showed the strongest synergistic effect on growth inhibition of Trichophyton rubrumwith a fractional inhibitory concentration index value of 0.50 in combination with terbinafine.Conclusions: Our findings indicate that the combination of TOMs and TOM-terbinafine may be effective on treatment for chronic and recurrent dermatophytosis by improving fungistatic activity and led to decrease systemic toxicity in clinical practice.
基金Supported by the natural science foundation of Hainan Province in 2015(20158304)
文摘Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.
基金the Administrative Department of Science, Technology, and Innovation, Colciencias, Asoppitayathe Inter-American Development Bank IDB for funding。
文摘The fungistatic activity of a lactic acid bacterium, which had been isolated from yellow pitahaya cultures, against fungi associated with basal rot(Fusarium oxysporum and Fusarium fujikuroi) was measured in the present study. Its activity was assessed in three fractions: fermented(S1), metabolic products(S2), and biomass(S3), using two fermentation substrates: Man Rogosa Sharpe agar(MRS) and potato dextrose agar(PDA). The bacterium was molecularly identified as Lactobacillus plantarum. S3 reduced F. fujikuroi growth by 100% over 48 h of fermentation, which occurred during the stationary phase of bacterial growth. The three fractions' fungistatic activity against F. fujikuroi depended on the substrate employed. The fermentation kinetic parameters for L. plantarum indicated that its specific growth rate was 0.46 h^–1, with 93.63% substrate consumption, 0.045 kg kg^–1 cell yield, and 0.54 kg kg^–1 product yield. The kinetic parameters calculated will allow for bacteria production scaling. These in-vitro trials reveal L. plantarum's possible application as a biocontrol agent for diseases associated with Fusarium. However, further ex-vivo and in-vivo researches are required to demonstrate its behavior in crops.
基金The authors would like to express their sincere appreciation for the funding from the National Natural Science Foundation of China(Grant Nos.32071700 and 31901252)the National Key R&D Program of China(Grant No.2018YFD1101002)+1 种基金This study was also supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20180276)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant Nos.18KJB220012 and 20KJB560010).
文摘Permeability of wood preservative is one of the most significant factors for protection of wood construction.Ani-sotropic flow permeability was involved in different directions of wood with higher flow resistance in the trans-verse and lower longitudinal directions.In this study,boron acid solution was brushed onto the tangential section of air-dried wood cubes and boron penetration along wood transverse direction was investigated under free dif-fusion,vacuum and HVEF treatments.Multi-scale boron distribution,FTIR measurement,leaching property,mechanical properties and fungistatic characteristic were investigated for free diffusion,vacuum and HVEF trea-ted samples respectively.The results revealed that boron exhibited high permeability along the transverse direc-tion with the penetration depth of≈35 mm for HVEF treated samples and≈1 mm for free diffusion and vacuum treated samples.For HVEF treated samples,no significant decrease of hardness,compression modulus of elasti-city and strength were found in the treated samples.Better fungistatic characteristic was showcased in HVEF trea-ted samples exposed to white rot fungi.Thus,HVEF treatment has a positive effect on boron permeability and the improvement of penetration depth of preservatives hence playing a significant role in wood protection and prolonging the service life of wood construction.
文摘Laboratory experiments have been carried out to determine the effects of lemon, cedar, pine and thyme oils as well as Citrocept on the growth of Fusarium solani Mart. (Sacc.) mycelium isolated from stored potato tubers. The biotic property of essential oils and Citrocept in inhibiting the linear growth of F. solani was assessed with the use of poisoned culture media, whereas the fungistatic property was determined by calculating, with the use of Abbott formula, the percentage indicating how many fungal colonies were inhibited from growth. A complete inhibition of the pathogen’s growth was observed in the presence of thyme oil at a concentration of 0.2% to 2% as well as in the presence of lemon oil at a concentration of 5% and 15%. Citrosept only at high concentrations caused a slower growth of F. solani. No fungistatic effects of cedar and pine oils were observed.
基金J.A.R.received a Doctoral Fellowship from Coorde-nacao de Apoio de Pessoal de Nível Superio(CAPES)N.S.A.would like to thank Universidade Estadual de Londrina and Fundacao Araucária.
文摘Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound is known for several other biological activities such as antiparasitic, antispasmodic and antibacterial activity. The aim of the present study was to investigate the effect of KA on Aspergillus nidulans. KA (0.3 mM) showed fungistatic activity against A. nidulans with visible hyphal elongation and morphology damage. These effects were reverted by CaCl2 addition showing that KA interferes with intracellular Ca2+ gradient in A. nidulans. This is the first report on the mechanism of action of KA involving calcium levels by altering the elongation of fungi hyphae.
