PTS and PTSO, two organosulfur compounds from onion by‑products as a novel solution for plant disease and pest management

This research has been carried out within the project GRUPO OPERATIVO SALUD-OLIVAR from the Spanish Rural Development Program (2014-2020) funded by the Spanish Ministry of Agriculture, Fisheries and Food and co-financed by 80% by the European Agricultural Fund for Rural Development (FEADER) (Total investment 384.830,96 EUR). It has also received funding from European Union's Horizon 2020 research and innovation program under Grant agreement no. 887281 (BIOVEXO).This study is part of the Industrial Doctorate of the doctoral student Ana Falcon Pineiro, granted by the State Research Agency of the Spanish Government, with the following reference: DIN2019-010792.Background Over the past decade, the great impact of agricultural crop diseases has generated considerable economic losses and has compromised the production of edible crops at a time when the world population is only expected to rise, leading to the search for new pest management strategies. Besides that, the environmental impact resulting from the continued use of chemical pesticides has led to the search for natural and sustainable alternatives. One of the existing solutions that currently stands out for its effectiveness is the use of bioactive plant extracts. This study aims to evaluate the antimicrobial activity of propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO), two organosulfur compounds (OSCs) derived from Allium cepa, against a wide range of target bacteria and fungi. To this end, various in vitro procedures were conducted as well as soil sanitization tests using sterile substrate inoculated with soil-borne pathogens. In addition, this study also evaluates the pesticidal activity of both compounds through in vitro mortality and repellence tests. Results PTS and PTSO revealed inhibition activity on all the pathogens tested, belonging to different taxonomic groups. Moreover, both significatively reduced the population of bacteria and fungi in soil. The quantification of active substances in soil carried out in parallel to the microbial quantification showed that their use reduces the risk of residue accumulation since they break down quickly when applied. The set of antimicrobial tests performed demonstrated that the antifungal effect of both compounds is higher than the bactericidal effect. Lastly, PTS and PTSO showed a concentration-dependent significant biocidal and repellent effect against aphids. Conclusions The results presented in this work demonstrate that both PTS and PTSO have a significant antimicrobial and pesticidal activity against the great majority of phytopathogens tested, being a promising tool to improve pest management in crops.Spanish Ministry of Agriculture, Fisheries and FoodEuropean Agricultural Fund for Rural Development (FEADER)European Union’s Horizon 2020 research and innovation program 887281State Research Agency of the Spanish Government DIN2019‑01079

Activity of propyl-propane-thiosulfinate and propyl-propane-thiosulfonate against carbapenemresistant Gram-negative bacteria

Organosulfur compounds derived from plants of the Allium genus, such as propyl-propane-thiosulfinate (PTS) and propyl-propane-thiosulfonate (PTSO), have been proposed as an alternative in antibiotic resistance. The aim of this study was to compare the activity of these substances with other antibiotics against clinical isolates of carbapenem-resistant (CAR-R) and carbapenem-susceptible (CAR-S) Gram-negative bacteria. A total of 126 clinical isolates of CAR-R and 155 CAR-S bacteria were selected, including Enterobacterales, A. baumannii and P. aeruginosa. The antibiotic susceptibility of all isolates was assessed using the microdilution and Kirby–Bauer methods for PTS, PTSO, amoxicillin/clavulanate, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, ciprofloxacin, and amikacin. Both PTS and PTSO demonstrated in vitro bactericidal activity against CAR-R Enterobacteriaceae and A. baumannii, with no significant difference in activity compared to their response against CAR-S isolates. However, both compounds were less active against P. aeruginosa than against any of the other bacteria, regardless of their resistance to carbapenems. In all cases, the minimum inhibitory concentration values of PTSO were significantly lower than those of PTS. These findings offer valuable information about the potential antibacterial use of these substances, particularly against infections that currently have limited therapeutic options

Effect of Allium Extract Supplementation on Egg Quality, Productivity, and Intestinal Microbiota of Laying Hens

Simple Summary: The growing interest in phytogenic products for use in feed, especially in the poultry sector, is mainly due to the improvement in the productivity parameters and gut microbiota modulation properties. For this reason, phytogenic products are becoming excellent candidates as alternatives to the use of antibiotics in animal production to mitigate the negative effects derived from their use. The aim of this study is to explore the ability of allium extract (containing garlic and onion), used as an ingredient in laying hen feed, to improve performance. The promising results obtained in the present study suggest that Allium spp. extracts had the potential to be used in feeding laying hens to improve productivity, without affecting egg quality, and to modulate the gut microbiota. Abstract: The use of allium extract containing propyl propane thiosulfonate (PTSO) as hen feed supplement was evaluated to demonstrate its positive effect on egg production and intestinal microbiota modulation. The study was carried out on 90 laying hens whose feed was supplemented with allium extract for 28 days. Nutritional properties of eggs were not affected, whereas an improvement in productivity was observed based on the increase weight of eggs. In addition, a modulator effect on intestinal microbiota was confirmed by the increase in Lactobacillus spp. and Bifidobacterium spp., as well as by the reduction in Enterobacteriaceae populations. Finally, the preservation of egg composition was checked by monitoring the content of PTSO, using a new analytical method consisting of the use of solid phase extraction and ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Consequently, based on current results, Allium spp. extract rich in organosulfur compounds such as PTSO added to the diet had a beneficial effect on the microbiota and would seem to be a possible alternative to increase productivity, while not affecting the biochemical composition of egg. However, further studies on the effects of allium extract as feed supplement are necessary.DOMCA S.A.University of Granada FQM-302University of Murcia R-1418/201

In Vitro Antibacterial Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate Derived from Allium spp. against Gram-Negative and Gram-Positive Multidrug-Resistant Bacteria Isolated from Human Samples

Background: The aim of this study was to compare the in vitro antibacterial activity of two compounds derived from Alliaceae, PTS (propyl-propane-thiosulfinate), and PTSO (propyl-propane-thiosulfonate), with that of other antibiotics commonly used against bacteria isolated from humans. Materials and methods: A total of 212 gram-negative bacilli and 267 gram-positive cocci isolated from human clinical samples and resistant to at least one group of antibiotics were selected. In order to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) to various antibiotics as well as PTS and PTSO, all isolates underwent broth microdilution assay. Results: PTS showed moderate activity against Enterobacteriaceae with MIC50 (and MBC50) and MIC90 (and MBC90) values of 256-512 mg/L, while PTSO showed greater activity with MIC50 and MIC90 values of 64-128 mg/L and MBC50 and MBC90 values of 128-512 mg/L. These data show the bactericidal activity of both compounds and indicate that PTSO was more active than PTS against this group of bacteria. Both compounds showed lower activity against P. aeruginosa (MIC50 = 1024 mg/L, MIC90 = 2048 mg/L, MBC50 = 2048 mg/L, and MBC90 = 2048 mg/L, for PTS; MIC50 = 512 mg/L, MIC90 = 1024 mg/L, MBC50 = 512 mg/L, and MBC90 = 2048 mg/L, for PTSO) compared to those obtained in others nonfermenting gram-negative bacilli (MIC50 = 128 mg/L, MIC90 = 512 mg/L, MBC50 = 128 mg/L, and MBC90 = 512 mg/L, for PTS; MIC50 = 64 mg/L, MIC90 = 256 mg/L, MBC50 = 64 mg/L, and MBC90 = 256 mg/L, for PTSO) and also indicate the bactericidal activity of both compounds against these groups of bacteria. Finally, the activity against S. aureus, E. faecalis, and S. agalactiae was higher than that observed against enterobacteria, especially in the case of PTSO (MIC50 = 8 mg/L, MIC90 = 8 mg/L, MBC50 = 32 mg/L, and MBC90 = 64 mg/L, in S. aureus; MIC50 = 4 mg/L, MIC90 = 8 mg/L, MBC50 = 8 mg/L, and MBC90 = 16 mg/L, in E. faecalis and S. agalactiae). Conclusion: PTS and PTSO have a significant broad spectrum antibacterial activity against multiresistant bacteria isolated from human clinical samples. Preliminary results in present work provide basic and useful information for development and potential use of these compounds in the treatment of human infections

Optimization of an onion oil microemulsion by response surface methodology for enhanced physicochemical stability and biological activity

Onion oil (OO) containing propyl-propane thiosulfinate (PTS) and propyl-propane thiosulfonate (PTSO) is known for various therapeutic properties. However, its industrial use in hydrophilic matrices is challenging due to the lack of physicochemical stability. Applying Box-Behnken design (BBD), we developed an optimal OO microemulsion (OOME) with a minimum droplet size and maximum chemical stability. The OOME comprised 2 % w/w oily phase (high oleic acid sunflower oil), 120 mg/L of OO containing PTS+PTSO, 1.47 % w/w emulsifier (Diacetyl tartaric acid ester of mono-diglycerides, DATEM), 0.25 % stabilizer (xanthan gum) and 573 mM phosphate buffer. Turbidimetry as well as laser and dynamic light scattering over 30 days was used to characterize physical stability of the OOME, assessing chemical stability by HPLC. Cytotoxicity and quantification of cytokines (IL-4 and IL-8) were evaluated in colorectal cancer cells (HT-29, T-84 and SW-837) culture supernatants. After 30 days of storage, OOME remained stable, with no flocculation or coalescence phenomena. It achieved a PTS+PTSO amount of 98 mg/L, a droplet size of 329 nm, a particle size dispersal coefficient of 0.89, and Z-potential was −40.17 mV. The OOME improved the antitumor effect of OO in lines HT-29 and SW-837, as well as its influence on the inflammatory response.Grupo de Investigación TEP025 Tecnología de Procesos Químicos y Bioquímico

Phytochemicals Determination, and Antioxidant, Antimicrobial, Anti-Inflammatory and Anticancer Activities of Blackberry Fruits

The following supporting information can be downloaded at: https:// www.mdpi.com/article/10.3390/foods12071505/s1, Table S1: Calibration ranges, curves, regression coefficients and LOD and LOQ of the standard molecules.This study was supported by the Spanish Ministry of Science and Innovation within the project ACTIVE HONEY: Innovative formulations of main bee products using natural ingredients. 2019–2022. (EXP 00116482/INNO-20182004), funded by the Technological Center for the Industrial Development (CDTI).A comprehensive characterization of the phytochemicals present in a blackberry fruit extract by HPLC-TOF-MS has been carried out. The main compounds in the extract were ursane-type terpenoids which, along with phenolic compounds, may be responsible for the bioactivity of the extract. In vitro antioxidant capacity was assessed through Folin-Ciocalteu (31.05 +/- 4.9 mg GAE/g d.w.), FRAP (637.8 +/- 3.2 mu mol Fe2+/g d.w.), DPPH (IC50 97.1 +/- 2.4 mu g d.w./mL) and TEAC (576.6 +/- 8.3 mu mol TE/g d.w.) assays. Furthermore, the extract exerted remarkable effects on in vitro cellular antioxidant activity in HUVEC cells at a concentration of 5 mg/mL. Antimicrobial activity of the extract was also tested. Most sensible microorganisms were Gram-positive bacteria, such as E. faecalis, B. cereus and Gram-negative E. coli (MBC of 12.5 mg/mL). IC50 values against colon tumoral cells HT-29 (4.9 +/- 0.2 mg/mL), T-84 (5.9 +/- 0.3 mg/mL) and SW-837 (5.9 +/- 0.2 mg/mL) were also obtained. Furthermore, blackberry extract demonstrated anti-inflammatory activity inhibiting the secretion of pro-inflammatory IL-8 cytokines in two cellular models (HT-29 and T-84) in a concentration-dependent manner. These results support that blackberry fruits are an interesting source of bioactive compounds that may be useful in the prevention and treatment of different diseases, mainly related to oxidative stress.Spanish Ministry of Science and Innovation within the project ACTIVE HONEY: Innovative formulations of main bee products using natural ingredients. 2019-2022 - Technological Center for the Industrial Development (CDTI) EXP 00116482/INNO-2018200

Article Lactiplantibacillus paraplantarum BPF2 and Pediococcus acidilactici ST6, Two Bacteriocinogenic Isolated Strains from Andalusian Spontaneous Fermented Sausages

Traditional spontaneously fermented foods are well known for their sensory and safety properties, which is mainly due to their indigenous microflora. Within this group of food, Mediterranean dry-cured sausages stand out as a significant source of lactic-acid bacterial strains (LAB) with biotechnological properties, such as their antimicrobial activity. The aim of this study was to investigate the biodiversity of antagonistic LAB strains from different Andalusian traditional sausages, such as salchichón and chorizo. First, a screening was carried out focusing on the antimicrobial activity against foodborne pathogens, such as Listeria monocytogenes, Escherichia coli, Clostridium perfringens, and Staphylococcus aureus, selecting two strains due to their higher antibiosis properties, both in agar and liquid media. These bacteria were identified as Lactiplantibacillus paraplantarum BPF2 and Pediococcus acidilactici ST6. In addition, genomic studies confirmed the presence of certain structural genes related to the production of bacteriocins. Finally, the culture supernatants of both strains were purified and analyzed by LC-MS/MS, obtaining the relative molecular mass and the amino acid sequence and identifying the peptides as the bacteriocins Pediocin-PA and Leucocin K. In conclusion, genomes and antimicrobial substances of P. acidilactici ST6, a Pediocin-PA producer, and Lpb. paraplantarum BPF2, a Leucocin K producer, isolated from Andalusian salchichón and chorizo, respectively, are presented in this work. Although further studies are required, these strains could be used alone or in combination as starters or protective cultures for the food industryPRIMA program, under BioProMedFood project (Reference Number: 2019-SECTION2-4; CUP: J34I19004820005)PRIMA program is supported by the European Union H2020 program and innovation progra

Xylella fastidiosa in Olive: A Review of Control Attempts and Current Management

Since 2013, Xylella fastidiosa Wells et al. has been reported to infect several hosts and to be present in different areas of Europe. The main damage has been inflicted on the olive orchards of southern Apulia (Italy), where a severe disease associated with X. fastidiosa subspecies pauca strain De Donno has led to the death of millions of trees. This dramatic and continuously evolving situation has led to European and national (Italian and Spanish) measures being implemented to reduce the spread of the pathogen and the associated olive quick decline syndrome (OQDS). Research has been also carried out to find solutions to better and directly fight the bacterium and its main insect vector, Philaenus spumarius L. In the course of this frantic effort, several treatments based on chemical or biological substances have been tested, in addition to plant breeding techniques and integrated pest management approaches. This review aims to summarize the attempts made so far and describe the prospects for better management of this serious threat, which poses alarming questions for the future of olive cultivation in the Mediterranean basin and beyond

Antibacterial and Antifungal Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate, Two Organosulfur Compounds from Allium cepa: In Vitro Antimicrobial Effect via the Gas Phase

Propyl-propane thiosulfinate (PTS) and propyl-propane thiosulfonate (PTSO) are two volatile compounds derived from Allium cepa with a widely documented antimicrobial activity. The aim of this study was to evaluate their anti-candidiasis activity and the ability of its gaseous phase to inhibit bacterial and yeast growth in vitro. The minimum inhibitory concentration of various antifungal products (including PTS and PTSO) was determined versus 203 clinical isolates of Candida spp. through broth microdilution assay. Additionally, the antimicrobial activity through aerial diffusion of PTS and PTSO was evaluated over the growth of a collection of bacteria and yeasts cultivated in agar plates. All yeasts were susceptible to the antifungals tested, except C. glabrata and C. krusei, that showed azole resistance. PTSO (MIC50 and MIC90 ranged from 4 to 16 mg/L and 8 to 32 mg/L, respectively) was significantly more active against yeasts than PTS (MIC50 and MIC90 ranged from 16 to 64 mg/L and 32 to 64 mg/L). Values were higher than those obtained for antifungal drugs. Gaseous phases of PTS and PTSO generated growth inhibition zones whose diameters were directly related to the substances concentration and inversely related to the microbial inoculum. The quantification of PTS and PTSO levels reached in the growth media through aerial diffusion displayed a concentration gradient from the central zone to the periphery. Only P. aeruginosa ATCC 27853 showed resistance, while yeasts (C. albicans ATCC 200955 and C. krusei ATCC 6258) presented the higher susceptibility to both compounds. These results suggest that PTS and PTSO display antibacterial and anti-candidiasis activity in vitro through aerial diffusion, having potential use in human therapy

Risk Assessment and Environmental Consequences of the Use of the Allium-derived Compound Propyl-propane Thiosulfonate (PTSO) in Agrifood Applications

The organosulfur compound propyl-propane thiosulfonate (PTSO), mainly found in Allium cepa, has a promising use in the agrifood industry. To confirm its safety for livestock, consumers, and environment, toxicological assessment is needed. In this regard, endocrine-disrupting chemicals (EDCs) are in the spotlight of research. Therefore, as part of the risk assessment of PTSO, in the present work, an in vivo study was performed in mice exposed to PTSO to investigate its potential reproductive toxicity considering fertility, genetic and endocrine endpoints. Five-weeks-old CD1 mice (80 males, 80 females) were exposed for 11 or 16 weeks (males or females, respectively) to different doses of PTSO (0, 14, 28 and 55 mg PTSO/kg b.w./day; 20 animals per group and sex) through the food pellets. No clinical observations or mortality and no changes in absolute organ weights and relative organ weights/body weight or brain ratios occurred during the study. The estrous cycle did not undergo any significant toxicologically relevant change. Most of the sex hormones displayed normal values. Some alterations in the expression of some genes related to reproduction is only observed in females, but they do not appear to have consequences in the development of sex organs. Docking results showed the impossibility of stable binding to estrogen and androgen receptors. Considering all the results obtained, the safe profile of PTSO can be confirmed for different agrifood applications at the conditions assayed.Junta de Andalucía P18-TP-2147Ministerio de Ciencia, Innovación y Universidades FPU2019-0124