PepSAVI-MS reveals anticancer and antifungal cycloviolacins in Viola odorata

Parsley, Nicole C.; Kirkpatrick, Christine L.; Crittenden, Christopher M.; Rad, Javad Ghassemi; Hoskin, David W.; Brodbelt, Jennifer S.; Hicks, Leslie M.

doi:10.1016/j.phytochem.2018.04.014

Cited by 53 publications

(35 citation statements)

References 59 publications

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“…Many cysteine-rich knotted plant peptides other than cyclotides (e.g., defensins) play roles in antifungal host defense ( van der weerden et al, 2013 ; Goyal and Mattoo, 2014 ). However, so far, only one cyclotide (cyO8) has been tested recently for activity against F. gramineum ( Parsley et al, 2018 ). The assayed peptides were generally more potent against the two fungal pathogens ( C. utrechtense and A. alternata ) isolated from violets and B. cinerea than against F. oxysporum .…”

Section: Discussionmentioning

confidence: 99%

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

et al. 2018

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Cyclotides are cyclic plant polypeptides of 27–37 amino acid residues. They have been extensively studied in bioengineering and drug development contexts. However, less is known about the relevance of cyclotides for the plants producing them. The anti-insect larvae effects of kB1 and antibacterial activity of cyO2 suggest that cyclotides are a part of plant host defense. The sweet violet (Viola odorata L.) produces a wide array of cyclotides, including kB1 (kalata B1) and cyO2 (cycloviolacin O2), with distinct presumed biological roles. Here, we evaluate V. odorata cyclotides’ potency against plant pathogens and their mode of action using bioassays, liposome experiments and immunogold labeling for transmission electron microscopy (TEM). We explore the link between the biological activity and distribution in plant generative, vegetative tissues and seeds, depicted by immunohistochemistry and matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Cyclotides cyO2, cyO3, cyO13, and cyO19 are shown to have potent activity against model fungal plant pathogens (Fusarium oxysporum, F. graminearum, F. culmorum, Mycosphaerella fragariae, Botrytis cinerea) and fungi isolated from violets (Colletotrichum utrechtense and Alternaria alternata), with minimal inhibitory concentrations (MICs) ranging from 0.8 μM to 25 μM. Inhibition of phytopathogenic bacteria – Pseudomonas syringae pv. syringae, Dickeya dadantii and Pectobacterium atrosepticum – is also observed with MIC = 25–100 μM. A membrane-disrupting antifungal mode of action is shown. Finding cyO2 inside the fungal spore cells in TEM images may indicate that other, intracellular targets may be involved in the mechanism of toxicity. Fungi can not break down cyclotides in the course of days. varv A (kalata S) and kB1 show little potency against pathogenic fungi when compared with the tested cycloviolacins. cyO2, cyO3, cyO19 and kB1 are differentially distributed and found in tissues vulnerable to pathogen (epidermis, rizodermis, vascular bundles, protodermis, procambium, ovary walls, outer integuments) and pest (ground tissues of leaf and petiole) attacks, respectively, indicating a link between the cyclotides’ sites of accumulation and biological role. Cyclotides emerge as a comprehensive defense system in V. odorata, in which different types of peptides have specific targets that determine their distribution in plant tissues.

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Section: Discussionmentioning

confidence: 99%

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

et al. 2018

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“…V. inconspicua library fraction activity was assessed with a simple 8 straight-channel microfluidic chip ( Figure 1 ) to explore the merits of a microfluidic bioassay format. Whereas traditional “bulk” assays (e.g., 96-well plate) often require a minimum of 50 μL of sample mixture in each well (Sarker et al, 2007 ; Teh et al, 2017 ; Fowler et al, 2018 ) (10 μL extract, 40 μL of media and cells for each replicate) (Kirkpatrick et al, 2017 ; Parsley et al, 2018 , 2019 ; Moyer et al, 2019 ), microfluidic devices utilize sample sizes in the nanoliter/picoliter range. However, connectors and interfaces between microfluidic channels/chambers and injection sites can generate significant dead volume, requiring excess sample to ensure complete filling of microfluidic compartments.…”

Section: Resultsmentioning

confidence: 99%

Implementation of Microfluidics for Antimicrobial Susceptibility Assays: Issues and Optimization Requirements

Parsley

Smythers

Hicks

2020

Front. Cell. Infect. Microbiol.

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Despite the continuous emergence of multi-drug resistant pathogens, the number of new antimicrobials reaching the market is critically low. Natural product peptides are a rich source of bioactive compounds, and advances in mass spectrometry have achieved unprecedented capabilities for the discovery and characterization of novel molecular species. However, traditional bioactivity assay formats hinder the discovery and biochemical characterization of natural product antimicrobial peptides (AMPs), necessitating large sample quantities and significant optimization of experimental parameters to achieve accurate/consistent activity measurements. Microfluidic devices offer a promising alternative to bulk assay systems. Herein, a microfluidics-based bioassay was compared to the traditional 96-well plate format in respective commercially-available hardware. Bioactivity in each assay type was compared using a Viola inconspicua peptide library screened against E. coli ATCC 25922. Brightfield microcopy was used to determine bioactivity in microfluidic channels while both common optical and fluorescence-based measurements of cell viability were critically assessed in plate-based assays. Exhibiting some variation in optical density and fluorescence-based measurements, all plate-based assays conferred bioactivity in late eluting V. inconspicua library fractions. However, significant differences in the bioactivity profiles of plate-based and microfluidic assays were found, and may be derived from the materials comprising each assay device or the growth/assay conditions utilized in each format. While new technologies are necessary to overcome the limitations of traditional bioactivity assays, we demonstrate that off-the-shelf implementation of microfluidic devices is non-trivial and significant method development/optimization is required before conventional use can be realized for sensitive and rapid detection of AMPs in natural product matrices.

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“…Banafsha Flowers Oral Anti-microbial, antifungal (Parsley et al, 2018; Journal Pre-proof J o u r n a l P r e -p r o o f Table 3 Drugs prescribed in Unani medicine for nazla-e-wabaiya (…”

Section: Violaceaementioning

confidence: 99%

Overview of Covid-19; its prevention and management in the light of Unani medicine

Nikhat

Fazil

2020

Science of The Total Environment

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Journal Pre-proof J o u r n a l P r e -p r o o f ABSTRACT Since December 2019, a respiratory pandemic, named as Coronavirus disease 2019 (Covid-19)caused by a new coronavirus named as SARS-CoV-2, has taken the world by storm. The symptoms are fever, malaise, and cough which resolve in a few days in most cases; but may progress to respiratory distress and organ failure. Transmission is through droplet infection or fomites, but other modes such as airborne transmission and oro-fecal transmission is also speculated. Research is underway to develop effective vaccines and medicines for the disease. In such a scenario, we present the measures described in Unani system of medicine for health protection during epidemics. Unani is a traditional system of medicine developed during the middle ages, which employs natural drugs of herbal, animal and mineral origin for treatment. In Unani medicine, during an epidemic, apart from isolation and quarantine, three measures are of utmost importance, (i) purification of surroundings using certain herbal drugs as fumigants or sprays, (ii) health promotion and immune-modulation, and (iii) use of health-protecting drugs and symptom-specific drugs. Drugs such as loban (Styrax benzoides W. G. Craib), sandroos (Hymenaea verrucosa Gaertn.) za'fran (Crocus sativus L.), vinegar etc. are prescribed in various forms. Scientific researches on these drugs reveal the presence of a number of pharmacologically active substances, which may provide a new insight into the management of infections and epidemics. Journal Pre-proof J o u r n a l P r e -p r o o f ABBREVIATIONS

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PepSAVI-MS reveals anticancer and antifungal cycloviolacins in Viola odorata

Cited by 53 publications

References 59 publications

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

Implementation of Microfluidics for Antimicrobial Susceptibility Assays: Issues and Optimization Requirements

Overview of Covid-19; its prevention and management in the light of Unani medicine

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