Maria Touraki | Aristotle University of Thessaloniki (original) (raw)

Papers by Maria Touraki

Blood cells, molecules, & diseases/Blood cells, molecules & diseases, Jul 1, 2024

Journal of Chromatography B: Biomedical Sciences and Applications, Feb 1, 2001

A high-performance liquid chromatography (HPLC) analytical method for the determination of oxolin... more A high-performance liquid chromatography (HPLC) analytical method for the determination of oxolinic acid and flumequine in Artemia nauplii is described. The samples were extracted and cleaned up by a solid-phase extraction (SPE) procedure using SPE C cartridges. Oxolinic acid and flumequine were determined by reversed-phase HPLC using a mobile 18 phase of methanol-0.1 M phosphate buffer, pH 3 (45:55, v / v) and a UV detection wavelength of 254 nm. Calibration curves 2 were linear for oxolinic acid in the range of 0.2-50 mg/g (r 50.9998) and for flumequine in the range of 0.3-50 mg/g 2 (r 50.9994). Mean recoveries amounted to 100.8% and 98.4% for oxolinic acid and flumequine, respectively. The quantification limit was 0.2 mg / g for oxolinic acid and 0.3 mg / g for flumequine. Quantitative data from an in vivo feeding study indicated excellent uptake of both drugs by Artemia nauplii.

World Journal of Microbiology & Biotechnology, Apr 15, 2012

Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in ... more Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in aquaculture as preventive measures against vibriosis. In vitro evaluation of the probiotics using co-culture assays with the pathogen Vibrio anguillarum and testing for the production of antibacterial substances showed the presence of antagonism and confirmed the production of antibacterial substances. Both potential probiotics were administered to the live fish feed Artemia franciscana nauplii, offering protection against a subsequent challenge of the nauplii with the fish pathogen V. anguillarum, with best survival rates of the nauplii and the most efficient protection offered by B. subtilis. Nauplii enriched with B. subtilis were further used to evaluate the protection of sea bass larvae against vibriosis. The untreated group of fish challenged with V. anguillarum presented low survival of 36.7 %, while the fish treated with nauplii enriched with the probiotic B. subtilis showed significantly increased survival rates of 86.7 % after challenge with the pathogen. The survival of healthy unchallenged fish treated with the probiotic was not significantly different from control unchallenged fish (90-94 %). Our results indicate that B. subtilis is a probiotic suitable to be used for the prevention of vibriosis in fish larvae and can be safely administered through their live feed Artemia nauplii.

Microorganisms, Jul 27, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied sciences, Apr 9, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Vlaams Instituut voor de Zee. VLIZ. Informatie over marien en kustgebonden onderzoek & beleid... more Vlaams Instituut voor de Zee. VLIZ. Informatie over marien en kustgebonden onderzoek & beleid in Vlaanderen.

Journal of the Hellenic Veterinary Medical Society, Jan 31, 2018

The journal of experimental zoology, Sep 1, 1991

The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examin... more The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examined. Addition of the divalent cations of manganese, cobalt, nickel, or barium during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that in the control paradox in the absence of divalent cations, there is an efflux of calcium from myocardial cells during calcium depletion and a massive influx of calcium during the following reperfusion, leading to a calcium overload. Divalent cations protected frog myocardial cells, when present in the calcium-free perfusion medium, by reducing both calcium efflux during calcium depletion and the massive calcium influx during reperfusion. The effectiveness of the added divalent cations showed a strong dependence upon their ionic radius. The most potent inhibitors of the calcium paradox in the frog heart were the divalent cations having an ionic radius closer to the ionic radius of calcium. These results are discussed in terms of the possible mechanism involved in the protective effect of manganese, cobalt, nickel, and barium. Readmission of calcium-containing buffers to mammalian hearts that have been deprived of calcium triggers a sequence of events known as the "calcium paradox" (Zimmerman and Hulsmann, '66; Rich and Langer, '82; Hearse et al., '78). This phenomenon is characterized by enzyme and protein release, development of contracture, loss of electrical excitability, uncontrolled entry of calcium, and severe ultrastructural damage. Calcium overload is thought to play the key role to the initiation of the cascade of events that leads t o cell death upon calcium repletion (Grinwald and Nayler, '81; Ganote and Nayler, '85; Ruigrok, '85). Calcium influx in the myocardial cells occurs mainly through the Na +-Ca2 + electrogenic exchange (Horackova and Vassort, '79) and through the Ca2 +-selective sarcolemmal slow channels (Trautwein and Cavalie, '85). It has also been re

Microbial Pathogenesis, Dec 1, 2018

Interactions among yeast and probiotic bacteria enhance probiotic properties and metabolism offer... more Interactions among yeast and probiotic bacteria enhance probiotic properties and metabolism offering augmented protection to Artemia franciscana against Vibrio anguillarum

Microorganisms

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates ... more Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and ant...

Aquaculture Research, Jan 10, 2012

ABSTRACT The uptake of oxolinic acid by the rotifer Brachionus plicatilis, Artemia franciscana na... more ABSTRACT The uptake of oxolinic acid by the rotifer Brachionus plicatilis, Artemia franciscana nauplii and metanauplii was studied as a function of its concentration in the enrichment medium and the duration of the enrichment period. An emulsion containing 5, 10, 20 or 30% (w/w) oxolinic acid was administered and the enrichment period lasted 4, 8, 12 or 36 h. Highest incorporation of oxolinic acid was achieved using a 20% emulsion and a 12 h enrichment for rotifers (205.05 ± 17.1 μg g−1 dry weight), a 24 h enrichment for nauplii (2528.8 ± 254.6 μg g−1 dry weight), and an 8 h enrichment for metanauplii (1236.58 ± 22.9 μg g−1 dry weight). Higher concentrations of oxolinic acid in the enrichment emulsion or longer enrichment times resulted in decreased survival. Two hours post enrichment the contents of the drug appeared significantly decreased. The concentration data of oxolinic acid were best fit to a two phase exponential elimination model, the first phase elimination half‐life (t1/2α) being 1.86, 1.08 and 1.74 and the terminal phase elimination half‐life (t1/2β) 26.83, 29.67 and 17.48 in rotifers, nauplii and metanauplii correspondingly. Enrichment with an emulsion containing 20% oxolinic acid is recommended employing a duration of 12, 24, or 8 h enrichment for rotifers, nauplii and metanauplii respectively, while enriched carriers should be used shortly after enrichment.

Aquaculture, Aug 1, 2010

The uptake of flumequine by Artemia nauplii was studied as a function of its concentration in the... more The uptake of flumequine by Artemia nauplii was studied as a function of its concentration in the enrichment medium and of the duration of the enrichment period. An emulsion containing 20, 30, 40 or 50% (w/w) flumequine was administered to nauplii for 4, 8, 12, 24 or 32 h. Increased uptake of flumequine (450.4 ±15.8 μg/g dry weight) and good survival rates of the nauplii were observed with the 40% emulsion and 24 h enrichment. The concentration data of flumequine in nauplii were best fit to a two phase exponential elimination model with the first phase elimination half-life (t 1/2α) and the terminal phase elimination half-life (t 1/2β) to be 1 and 19.5 h, respectively. In the efficacy trial 1000 sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 × 10 7 CFU/ml for 1 h. Fish either received no treatment or oral treatment with flumequine bioencapsulated in nauplii or bath treatments with flumequine. Medication commenced two days following challenge, for bath treatments performed on day 2, 4 and 6 post challenge at a dosage of 20 mg/l for 2 h. Medication for oral treatments, commenced two days post challenge and two doses each of 700 nauplii per fish daily for five consecutive days. Cumulative mortality reached 96% for the unmedicated challenged group, 43% in the group receiving bath treatments and 29% in the group receiving medicated nauplii. Pharmacokinetic parameters of flumequine were calculated in sea bass larvae, after bath treatment with flumequine and oral treatment with flumequine bioencapsulated in nauplii. Steady state concentrations of flumequine (80.7 μg/g) in sea bass larvae were achieved after a 5-day oral treatment with medicated nauplii and the elimination half-life was found to be 19.5 h.

Journal of Fish Diseases, Jun 6, 2012

European sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 • 1... more European sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 • 10 7 CFU mL)1 for 1 h. Fish either received no treatment or oral treatment with Artemia franciscana (Kellog) nauplii enriched with oxolinic acid, or bath treatments with oxolinic acid. Medication commenced 1 day following challenge and was performed on days 1, 3 and 5 post-challenge at a dosage of 20 mg L)1 for 2 h for bath treatments, while two doses each of 750 nauplii per fish were administered daily for five consecutive days in oral treatments. Cumulative mortality reached 96% for the unmedicated challenged group, 32% in the group receiving bath treatments and 17% in the group receiving medicated nauplii. Pharmacokinetic parameters of oxolinic acid were calculated in sea bass larvae, for both treatments. Steady-state concentrations of oxolinic acid of 48.0 and 75.2 lg g)1 were achieved for bath treatment and oral treatment, respectively, while the elimination half-life was calculated to be 25.1 h for bath treatment and 21.7 h for oral treatment.

Separations, Nov 17, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied sciences, Apr 9, 2023

Immune system modulation is an intriguing part of scientific research. It is well established tha... more Immune system modulation is an intriguing part of scientific research. It is well established that the immune system plays a crucial role in orchestrating cellular and molecular key mediators, thus establishing a powerful defense barrier against infectious pathogens. Gut microbiota represent a complex community of approximately a hundred trillion microorganisms that live in the mammalian gastrointestinal (GI) tract, contributing to the maintenance of gut homeostasis via regulation of the innate and adaptive immune responses. However, impairment in the crosstalk between intestinal immunity and gut microbiota may reflect on detrimental health issues. In this context, many studies have indicated that probiotics and their bioactive compounds, such as bacteriocins and short chain fatty acids (SCFAs), display distinct immunomodulatory properties through which they suppress inflammation and enhance the restoration of microbial diversity in pathological states. This review highlights the fundamental features of probiotics, bacteriocins, and SCFAs, which make them ideal therapeutic agents for the amelioration of inflammatory and autoimmune diseases. It also describes their underlying mechanisms on gut microbiota modulation and emphasizes how they influence the function of immune cells involved in regulating gut homeostasis. Finally, it discusses the future perspectives and challenges of their administration to individuals.

Blood cells, molecules, & diseases/Blood cells, molecules & diseases, Jul 1, 2024

Journal of Chromatography B: Biomedical Sciences and Applications, Feb 1, 2001

A high-performance liquid chromatography (HPLC) analytical method for the determination of oxolin... more A high-performance liquid chromatography (HPLC) analytical method for the determination of oxolinic acid and flumequine in Artemia nauplii is described. The samples were extracted and cleaned up by a solid-phase extraction (SPE) procedure using SPE C cartridges. Oxolinic acid and flumequine were determined by reversed-phase HPLC using a mobile 18 phase of methanol-0.1 M phosphate buffer, pH 3 (45:55, v / v) and a UV detection wavelength of 254 nm. Calibration curves 2 were linear for oxolinic acid in the range of 0.2-50 mg/g (r 50.9998) and for flumequine in the range of 0.3-50 mg/g 2 (r 50.9994). Mean recoveries amounted to 100.8% and 98.4% for oxolinic acid and flumequine, respectively. The quantification limit was 0.2 mg / g for oxolinic acid and 0.3 mg / g for flumequine. Quantitative data from an in vivo feeding study indicated excellent uptake of both drugs by Artemia nauplii.

World Journal of Microbiology & Biotechnology, Apr 15, 2012

Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in ... more Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in aquaculture as preventive measures against vibriosis. In vitro evaluation of the probiotics using co-culture assays with the pathogen Vibrio anguillarum and testing for the production of antibacterial substances showed the presence of antagonism and confirmed the production of antibacterial substances. Both potential probiotics were administered to the live fish feed Artemia franciscana nauplii, offering protection against a subsequent challenge of the nauplii with the fish pathogen V. anguillarum, with best survival rates of the nauplii and the most efficient protection offered by B. subtilis. Nauplii enriched with B. subtilis were further used to evaluate the protection of sea bass larvae against vibriosis. The untreated group of fish challenged with V. anguillarum presented low survival of 36.7 %, while the fish treated with nauplii enriched with the probiotic B. subtilis showed significantly increased survival rates of 86.7 % after challenge with the pathogen. The survival of healthy unchallenged fish treated with the probiotic was not significantly different from control unchallenged fish (90-94 %). Our results indicate that B. subtilis is a probiotic suitable to be used for the prevention of vibriosis in fish larvae and can be safely administered through their live feed Artemia nauplii.

Microorganisms, Jul 27, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied sciences, Apr 9, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Vlaams Instituut voor de Zee. VLIZ. Informatie over marien en kustgebonden onderzoek & beleid... more Vlaams Instituut voor de Zee. VLIZ. Informatie over marien en kustgebonden onderzoek & beleid in Vlaanderen.

Journal of the Hellenic Veterinary Medical Society, Jan 31, 2018

The journal of experimental zoology, Sep 1, 1991

The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examin... more The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examined. Addition of the divalent cations of manganese, cobalt, nickel, or barium during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that in the control paradox in the absence of divalent cations, there is an efflux of calcium from myocardial cells during calcium depletion and a massive influx of calcium during the following reperfusion, leading to a calcium overload. Divalent cations protected frog myocardial cells, when present in the calcium-free perfusion medium, by reducing both calcium efflux during calcium depletion and the massive calcium influx during reperfusion. The effectiveness of the added divalent cations showed a strong dependence upon their ionic radius. The most potent inhibitors of the calcium paradox in the frog heart were the divalent cations having an ionic radius closer to the ionic radius of calcium. These results are discussed in terms of the possible mechanism involved in the protective effect of manganese, cobalt, nickel, and barium. Readmission of calcium-containing buffers to mammalian hearts that have been deprived of calcium triggers a sequence of events known as the "calcium paradox" (Zimmerman and Hulsmann, '66; Rich and Langer, '82; Hearse et al., '78). This phenomenon is characterized by enzyme and protein release, development of contracture, loss of electrical excitability, uncontrolled entry of calcium, and severe ultrastructural damage. Calcium overload is thought to play the key role to the initiation of the cascade of events that leads t o cell death upon calcium repletion (Grinwald and Nayler, '81; Ganote and Nayler, '85; Ruigrok, '85). Calcium influx in the myocardial cells occurs mainly through the Na +-Ca2 + electrogenic exchange (Horackova and Vassort, '79) and through the Ca2 +-selective sarcolemmal slow channels (Trautwein and Cavalie, '85). It has also been re

Microbial Pathogenesis, Dec 1, 2018

Interactions among yeast and probiotic bacteria enhance probiotic properties and metabolism offer... more Interactions among yeast and probiotic bacteria enhance probiotic properties and metabolism offering augmented protection to Artemia franciscana against Vibrio anguillarum

Microorganisms

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates ... more Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and ant...

Aquaculture Research, Jan 10, 2012

ABSTRACT The uptake of oxolinic acid by the rotifer Brachionus plicatilis, Artemia franciscana na... more ABSTRACT The uptake of oxolinic acid by the rotifer Brachionus plicatilis, Artemia franciscana nauplii and metanauplii was studied as a function of its concentration in the enrichment medium and the duration of the enrichment period. An emulsion containing 5, 10, 20 or 30% (w/w) oxolinic acid was administered and the enrichment period lasted 4, 8, 12 or 36 h. Highest incorporation of oxolinic acid was achieved using a 20% emulsion and a 12 h enrichment for rotifers (205.05 ± 17.1 μg g−1 dry weight), a 24 h enrichment for nauplii (2528.8 ± 254.6 μg g−1 dry weight), and an 8 h enrichment for metanauplii (1236.58 ± 22.9 μg g−1 dry weight). Higher concentrations of oxolinic acid in the enrichment emulsion or longer enrichment times resulted in decreased survival. Two hours post enrichment the contents of the drug appeared significantly decreased. The concentration data of oxolinic acid were best fit to a two phase exponential elimination model, the first phase elimination half‐life (t1/2α) being 1.86, 1.08 and 1.74 and the terminal phase elimination half‐life (t1/2β) 26.83, 29.67 and 17.48 in rotifers, nauplii and metanauplii correspondingly. Enrichment with an emulsion containing 20% oxolinic acid is recommended employing a duration of 12, 24, or 8 h enrichment for rotifers, nauplii and metanauplii respectively, while enriched carriers should be used shortly after enrichment.

Aquaculture, Aug 1, 2010

The uptake of flumequine by Artemia nauplii was studied as a function of its concentration in the... more The uptake of flumequine by Artemia nauplii was studied as a function of its concentration in the enrichment medium and of the duration of the enrichment period. An emulsion containing 20, 30, 40 or 50% (w/w) flumequine was administered to nauplii for 4, 8, 12, 24 or 32 h. Increased uptake of flumequine (450.4 ±15.8 μg/g dry weight) and good survival rates of the nauplii were observed with the 40% emulsion and 24 h enrichment. The concentration data of flumequine in nauplii were best fit to a two phase exponential elimination model with the first phase elimination half-life (t 1/2α) and the terminal phase elimination half-life (t 1/2β) to be 1 and 19.5 h, respectively. In the efficacy trial 1000 sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 × 10 7 CFU/ml for 1 h. Fish either received no treatment or oral treatment with flumequine bioencapsulated in nauplii or bath treatments with flumequine. Medication commenced two days following challenge, for bath treatments performed on day 2, 4 and 6 post challenge at a dosage of 20 mg/l for 2 h. Medication for oral treatments, commenced two days post challenge and two doses each of 700 nauplii per fish daily for five consecutive days. Cumulative mortality reached 96% for the unmedicated challenged group, 43% in the group receiving bath treatments and 29% in the group receiving medicated nauplii. Pharmacokinetic parameters of flumequine were calculated in sea bass larvae, after bath treatment with flumequine and oral treatment with flumequine bioencapsulated in nauplii. Steady state concentrations of flumequine (80.7 μg/g) in sea bass larvae were achieved after a 5-day oral treatment with medicated nauplii and the elimination half-life was found to be 19.5 h.

Journal of Fish Diseases, Jun 6, 2012

European sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 • 1... more European sea bass larvae were challenged by bath with Listonella anguillarum strain 332A, 2.5 • 10 7 CFU mL)1 for 1 h. Fish either received no treatment or oral treatment with Artemia franciscana (Kellog) nauplii enriched with oxolinic acid, or bath treatments with oxolinic acid. Medication commenced 1 day following challenge and was performed on days 1, 3 and 5 post-challenge at a dosage of 20 mg L)1 for 2 h for bath treatments, while two doses each of 750 nauplii per fish were administered daily for five consecutive days in oral treatments. Cumulative mortality reached 96% for the unmedicated challenged group, 32% in the group receiving bath treatments and 17% in the group receiving medicated nauplii. Pharmacokinetic parameters of oxolinic acid were calculated in sea bass larvae, for both treatments. Steady-state concentrations of oxolinic acid of 48.0 and 75.2 lg g)1 were achieved for bath treatment and oral treatment, respectively, while the elimination half-life was calculated to be 25.1 h for bath treatment and 21.7 h for oral treatment.

Separations, Nov 17, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Applied sciences, Apr 9, 2023

Immune system modulation is an intriguing part of scientific research. It is well established tha... more Immune system modulation is an intriguing part of scientific research. It is well established that the immune system plays a crucial role in orchestrating cellular and molecular key mediators, thus establishing a powerful defense barrier against infectious pathogens. Gut microbiota represent a complex community of approximately a hundred trillion microorganisms that live in the mammalian gastrointestinal (GI) tract, contributing to the maintenance of gut homeostasis via regulation of the innate and adaptive immune responses. However, impairment in the crosstalk between intestinal immunity and gut microbiota may reflect on detrimental health issues. In this context, many studies have indicated that probiotics and their bioactive compounds, such as bacteriocins and short chain fatty acids (SCFAs), display distinct immunomodulatory properties through which they suppress inflammation and enhance the restoration of microbial diversity in pathological states. This review highlights the fundamental features of probiotics, bacteriocins, and SCFAs, which make them ideal therapeutic agents for the amelioration of inflammatory and autoimmune diseases. It also describes their underlying mechanisms on gut microbiota modulation and emphasizes how they influence the function of immune cells involved in regulating gut homeostasis. Finally, it discusses the future perspectives and challenges of their administration to individuals.