scholarly journals Phytophthora Antagonism of Endophytic Bacteria Isolated from Roots of Black Pepper (Piper nigrum L.)

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 286 ◽  
Author(s):  
Van Anh Ngo ◽  
San-Lang Wang ◽  
Van Bon Nguyen ◽  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
...  

In this study, 90 root samples were collected from 30 black pepper farms in three provinces in the Central Highlands of Vietnam. A total of 352 endophytic bacteria were isolated and their morphology described. An in vitro assay on the antifungal activity of these isolates was then conducted and 47 isolates were found to have antagonistic activity on Phytophthora fungi. The antifungal activity of the 47 isolates was evaluated in vivo by shoot assay. Among these 47 isolates, 6 were selected for further investigation. The six isolates were classified and identified by sequencing the 16S RNA gene and phylogeny. The results showed that all six endophytic bacteria belong to the following species of Bacillus genus: B. siamensis, B. amyloliquefaciens, B. velezenis, and B. methylotrophiycus. Enzymatic activity related to the antifungal activity of the six potent isolates was determined; it showed that they possessed high chitinase and protease activities. These isolates were applied for black pepper seedlings in greenhouse. The results showed three promising isolates: B. siamensis EB.CP6, B. velezensis EB.KN12, and B. methylotrophycus EB.KN13. Black pepper seedlings treated with the promising bacteria had the lowest rate of root disease (8.45–11.21%) and lower fatal rate (11.11–15.55%) compared to the control group (24.81% and 24.44%). In addition, the three promising isolates strongly affected the growth of the black pepper seedlings in greenhouse. The plant height, length of roots, and fresh biomass of the seedlings in the treated plots were higher than those in the control plots. Thus, the endophytic bacterial isolates have the potential to act as biocontrol agent for the sustainable production of black pepper.

2020 ◽  
Vol 13 (11) ◽  
pp. 384
Author(s):  
Hang Yeon Jeong ◽  
Tae Ho Lee ◽  
Ju Gyeong Kim ◽  
Sueun Lee ◽  
Changjong Moon ◽  
...  

We previously reported that 3-pentylcatechol (PC), a synthetic non-allergenic urushiol derivative, inhibited the growth of Helicobacter pylori in an in vitro assay using nutrient agar and broth. In this study, we aimed to investigate the in vivo antimicrobial activity of PC against H. pylori growing in the stomach mucous membrane. Four-week-old male C57BL/6 mice (n = 4) were orally inoculated with H. pylori Sydney Strain-1 (SS-1) for 8 weeks. Thereafter, the mice received PC (1, 5, and 15 mg/kg) and triple therapy (omeprazole, 0.7 mg/kg; metronidazole, 16.7 mg/kg; clarithromycin, 16.7 mg/kg, reference groups) once daily for 10 days. Infiltration of inflammatory cells in gastric tissue was greater in the H. pylori-infected group compared with the control group and lower in both the triple therapy- and PC-treated groups. In addition, upregulation of cytokine mRNA was reversed after infection, upon administration of triple therapy and PC. Interestingly, PC was more effective than triple therapy at all doses, even at 1/15th the dose of triple therapy. In addition, PC demonstrated synergism with triple therapy, even at low concentrations. The results suggest that PC may be more effective against H. pylori than established antibiotics.


2021 ◽  
Vol 36 (1) ◽  
pp. 23-34
Author(s):  
Milica Mihajlovic ◽  
Emil Rekanovic ◽  
Jovana Hrustic ◽  
Mila Grahovac ◽  
Brankica Tanovic

A survey of in vitro and in vivo sensitivity of Verticillium dahliae and Fusarium oxysporum to several commercial fungicides and biofungicides was undertaken. In in vitro assays, the tested isolate of V. dahliae proved to be very sensitive to difenoconazole (EC50 = 0.02 mg/l). However, under greenhouse conditions, the highest efficacy in V. dahliae control on inoculated pepper plants was recorded for a product based on thiophanate-methyl (83.10% compared to control). Among the tested fungicides, the lowest efficacy was recorded for a product based on azoxystrobin (23.10 %) with no significant difference compared to control (p > 0.05). In in vitro assays, the tested F. oxysporum isolate was the most sensitive to prochloraz (EC50 = 0.07 mg/l) and the least sensitive to fluopyram (EC50 = 1075.01 mg/l). In in vivo assay, the highest efficacy was achieved by products based on captan (95.60%), and the lowest by a product based on thiophanate-methyl (54.40%). Antagonistic activity of the bacterium B. subtilis under laboratory conditions was not satisfying. Also, the antifungal activity and spectrum of a tested product based on tee tree oil was not efficient in suppressing pepper wilting caused by V. dahliae and F. oxysporum.


Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 903
Author(s):  
Miklós Nagy ◽  
Gábor Szemán-Nagy ◽  
Alexandra Kiss ◽  
Zsolt László Nagy ◽  
László Tálas ◽  
...  

Multiple drug resistant fungi pose a serious threat to human health, therefore the development of completely new antimycotics is of paramount importance. The in vitro antifungal activity of the original, 1-amino-5-isocyanonaphthalenes (ICANs) was evaluated against reference strains of clinically important Candida species. Structure-activity studies revealed that the naphthalene core and the isocyano- together with the amino moieties are all necessary to exert antifungal activity. 1,1-N-dimethylamino-5-isocyanonaphthalene (DIMICAN), the most promising candidate, was tested further in vitro against clinical isolates of Candida species, yielding a minimum inhibitory concentration (MIC) of 0.04–1.25 µg/mL. DIMICAN was found to be effective against intrinsically fluconazole resistant Candida krusei isolates, too. In vivo experiments were performed in a severly neutropenic murine model inoculated with a clinical strain of Candida albicans. Daily administration of 5 mg/kg DIMICAN intraperitoneally resulted in 80% survival even at day 13, whereas 100% of the control group died within six days. Based on these results, ICANs may become an effective clinical lead compound family against fungal pathogens.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Laila Muñoz Castellanos ◽  
Nubia Amaya Olivas ◽  
Juan Ayala-Soto ◽  
Carmen Miriam De La O Contreras ◽  
Miriam Zermeño Ortega ◽  
...  

In this study, hydrodistillation was used to obtain essential oils (EOs) from pepper (Piper nigrum L.) and clove (Eugenia caryophyllata) and co-hydrodistillation (addition of fatty acid ethyl esters as extraction co-solvents) was used to obtain functional extracts (FEs). Antifungal activity of EOs and FEs was evaluated by determination of minimum inhibitory concentration (MIC) against Fusarium oxysporum and Aspergillus niger. The results showed that pepper (Piper nigrum) and clove (Eugenia caryophyllata) essential oils and their functional extracts are effective in vitro at concentrations from 400 to 500 ppm after 10 days of culturing. The essential oils and functional extracts were used on tomato fruit samples at three different concentrations: 350, 400, and 450 ppm5. Clove essential oil reduced the growth of Aspergillus niger from 50% to 70% and Fusarium oxysporum to 40%. The functional extracts (FEs) of clove and pepper, mixed with ethyl decanoate (FEs-C10), were the best combination for protecting the tomato fruit in vivo against both phytopathogenic fungi. Gas chromatography-mass spectrometry (GC-MS) was used to identify eugenol as the principal compound in clove oil and limonene, sabinene, and β-caryophyllene in pepper oil.


Biologia ◽  
2009 ◽  
Vol 64 (1) ◽  
Author(s):  
Fábio Maciel ◽  
Márcio Geihs ◽  
Marcelo Vargas ◽  
Bianca Ramos ◽  
Bruno Cruz ◽  
...  

AbstractN-acetyl-5-methoxytryptamine or melatonin is a multifunctional molecule. The main physiological function, at least in vertebrates, is to transduce to the animal the photoperiodic information and regulate rhythmic parameters. But studies have also observed the action of this molecule on pigment migration in ectothermic vertebrates. Thus the aim of this paper was to investigate in vivo and in vitro the influence of melatonin on the pigment migration in melanophores of the crab Neohelice granulate. Injections of melatonin (2 × 10−9 moles · crab−1) at 07:00 h or 19:00 h did not affect (p > 0.05) the circadian pigment migration of the melanophores in constant darkness. Additionally no significant pigment migration (p > 0.05) was verified in normal and eyestalkless crabs injected with melatonin (10−10–10−7 moles · crab−1) during the day or night. In the in vitro assay, the response of melanophores to the pigment-dispersing hormone in eyestalkless crabs injected with melatonin (2 × 10−9 moles · crab−1) 1 and 12 hours before the observations did not differ (p > 0.05) from the control group (injected with physiological solution). These results suggest that melatonin does not act as a signaling factor for pigment dispersion or aggregation in the melanophores of N. Granulate.


2011 ◽  
Vol 340 ◽  
pp. 337-343
Author(s):  
Guo Lei

The aim of this study was to evaluate whether the positive effect of GH002 on high-density lipoprotein (HDL) cholesterol in vitro and in vivo. In vitro assay, effects of GH002 on apolipoprotein (apo) A-I was studied using stable-transfected HepG2 cells with recombinant vector including apoA-I promoter; Effects of GH002 on apoA-I, apoA-II and apoC-III production were determined using HepG2 cells. In vivo assay, Effects of GH002 on lipid profile were investigated in hyperlipidemic rats. The results showed that GH002 can effectively activate apoA-I promoter, enhance apoA-I and apoA-II secretion in vitro, whereas reduce apoC-III production significantly. Furthermore, after in vivo study that the hyperlipidemic rats were treated with GH002, HDL-cholesterol levels were increased significantly (P<0.01) at 2 weeks (100 mg/kg, 28.8%) and 3 weeks (30mg/kg, 19.8% and 100mg/kg, 36.4%, respectively) compared with control group. Triglyceride levels were reduced significantly at 2 and 3 weeks (19.5%, P<0.05 and 28.1%, P<0.01 respectively). Total cholesterol levels also were reduced at 3 weeks (19.1%, P<0.05) after 100mg/kg GH002 administration, but GH002 didn’t increase the ratio of liver/body weight compared with the control group at the end of the experiments. It is therefore reasonable to assume that GH002 is an effectively HDL-cholesterol enhancer by regulating apoA-I gene expression, consequently enhancing apoA-I, apoA-II secretion and reducing apoC-III production.


2021 ◽  
Vol 9 (3) ◽  
pp. 188-203
Author(s):  
Pérez-Pérez Ana Isabel ◽  
Quiroz-Guerra Kimberly Alexandra ◽  
Ruiz-Escalona Evelyn Victoria ◽  
Bonfante-Cabarcas Rafael Armando

Background: Medicinal plants represent a proven alternative strategy to treat cancer. Objective: To determine Curcuma longa (turmeric) and Piper nigrum (black pepper) effects in vitro and on the evolution of malignant melanoma B16F10 in C57BL/6 mice. Methods: 103 female mice divided in 4 groups: Control (n=44), Turmeric (n=20), Pepper (n=21), Turpepp (n=18). Turmeric 5% and/or pepper 0.5% were mixed with a dough made of pre-cooked cornmeal, eggs and coconut milkshake and given ad libitum to experimental groups as main diet; control received dough based diet. 200,000 melanoma cells were transplanted into right leg hind paw. Clinical, psychological, pathological and biochemical parameters were evaluated in vivo to measure melanoma progression. In vitro, metabolic activity was measured by quantifying anaerobic glycolysis and viability through MTT assay. Results: Combined preventive treatment with turmeric and pepper increased latency time for tumor onset, improved locomotor activity, preserved nociceptive response, decreased tumor volume and weight, reduced metastases and increased survival. These results were reproduced in the Pepper group, but with less statistical force; however, pepper showed greater potency in vitro experiments. Conclusion: Pepper showed an antineoplastic chemopreventive activity in B16F10 malignant melanoma, which was enhanced by the synergistic effect of turmeric.


2019 ◽  
Vol 15 (1) ◽  
pp. 36
Author(s):  
Nur Alfi Saryanah ◽  
Suryo Wiyono ◽  
Dadang Dadang

Activity of Fungal Endophyte Secondary Metabolites against Colletotrichum acutatum on Chili PepperColletotrichum acutatum is one of anthracnose causal agents on chili pepper that has been reported to be predominant species in a some regions of Java Island. Secondary metabolites of endophytic fungi have been reported to have a potency as antifungal agents against plant pathogen. However, its antifungal activity against C. acutatum has not been reported yet. This study was aimed to evaluate the antifungal activity of fungal endophyte secondary metabolite against C. acutatum at in vitro and in vivo assay. In vitro assay was conducted to evaluate antifungal activity of fungal endophyte CBR1D14 isolate culture filtrate (FCBR) and mycelia extract (MCBR) in inhibiting conidial germination of C. acutatum. The results of in vitro assay showed that ethyl acetate extract of FCBR (EA FCBR) had the highest activity in inhibiting C. acutatum conidial germination. Methanol fraction from the partition of EA FCBR (FM FCBR) and from the partition of MCBR ethyl acetate extract (FM MCBR) showed the ability in inhibiting C. acutatum conidial germination. In vivo assay to chili pepper fruit showed that the treatment of FM FCBR (IC95 609.9 µg mL-1) and FM MCBR (IC95 1178.27 µg mL-1) decreased anthracnose disease incidence and lesion diameter. The efficacy rate of FM FCBR and FM MCBR treatments against anthracnose was 36.72 and 48.68%, respectively. Bioautography test was done on silica gel thin layer chromatogram. Methanol fraction of FCBR and MCBR were separated into 3 bioautographic spots respectively (Rf 0.04, 0.07, 0.7 for FM FCBR and Rf 0.06, 0.52, 0.7 for FM MCBR).


2022 ◽  
Vol 11 (1) ◽  
pp. 11-28
Author(s):  
Sami Bawazeer ◽  
Ibrahim Khan ◽  
Abdur Rauf ◽  
Abdullah S. M. Aljohani ◽  
Fahad A. Alhumaydhi ◽  
...  

Abstract As compared to conventional techniques, currently nanotechnology has gained significant attention of scientists for the development of plant-based natural nanoparticles (NPs) due to their safety, effectiveness, and environment friendly nature. The current study was aimed for development, characterization (energy-dispersive X-ray, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy), and evaluation of the biological efficiency of black pepper (BP; Piper nigrum) fruit-based gold NPs (BP-AuNPs) through different in vitro and in vivo assays. BP extract revealed maximum antibacterial and antifungal potential against Escherichia coli (24 mm) and Aspergillus flavus (47 mm), respectively. However, BP-AuNPs (200 µg·mL−1) inhibited the urease, xanthine oxidase, and carbonic acid-II activities with a percent inhibition of 83.11%, 91.28%, and 86.87%, respectively. Further, the anti-inflammatory effect of BP extract at the dose of 100 mg·kg−1 was 72.66%, whereas for BP-AuNPs it was noticed to be 91.93% at the dose of 10 mg·kg−1. Similarly, the extract of BP and prepared AuNPs demonstrated significant (p < 0.01) sedative effect at all tested doses. The BP-AuNPs catalytically reduced methyl orange dye. Results suggest that BP-AuNPs possess significant biological activities, and further studies must be conducted to identify the probable mechanism of action associated with these activities.


1992 ◽  
Vol 13 (8) ◽  
pp. 463-471 ◽  
Author(s):  
Shanta Modak ◽  
Lester Sampath ◽  
Harvey S.S. Miller ◽  
Irving Millman

AbstractObjective:Gloves containing chlorhexidine gluconate in an instant-release matrix on their inner surface (CHG gloves) were tested to determine their ability to rapidly inactivate infectious pathogens that may permeate or leak through the latex surface.Design:CHG gloves were exposed for 1 to 10 minutes to blood or media containing infectious pathogens (e.g., bacteria, fungi, parasites, and viruses) as well as to lymphocytes and macrophages that are known to be the primary carriers of human immunodeficiency virus (HIV). Inactivation of pathogens was determined either by in vitro assay or in vivo infectivity. Stressed control and CHG glove fingers were submerged in a viral pool (retrovirus or bacteriophage) and after a set time, the glove interiors were checked for presence of permeated viz-ions.Results:CHG gloves rapidly inactivate all the pathogens tested including retrovirus and hepatitis B virus (90% to 100%). In the stressed glove fingers, live virus was detected in 26% of the control group but not in any of the CHG group.Conclusions:The use of CHG gloves may reduce the risk of exposure to infectious fluidborne pathogens should the integrity of the latex barrier be compromised by overt failure or by permeation of viruses. Rapid destruction of lymphocytes and macrophages may facilitate inactivation of HIV associated with these cells. Tests have shown that CHG coating does not alter physical properties of the glove, and, furthermore, CHG gloves do not show potential for dermal irritation or sensitization.


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