BRINGING PHARMACY KNOWLEDGE · determination of resveratrol in food supplements, as well as evaluation of their antioxidant activity. Dietary supplements used in the project were

BRINGING PHARMACY

KNOWLEDGE AND STUDENTS

TOGETHER

Volume 1 | Edition 1 | October 2013www.epsa-online.org

EPSA Students' Science Publication

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INTRODUCTION

Dear friends,

The purpose of the European Pharmaceutical Students' Association (EPSA) is to bring pharmacy, knowledge and students together. A way of bringing students' knowledge together, on a scientific level, is this new project which is a coalition between two departments: Education and Public Relations.

In other words, Students + Science + Publications = EPSA Students' Science Publication (ESSP). We are proud to finally be able to collect abstracts of student research projects and compile them in a publication that students all over Europe can read and gain inspiration from. Additionally, authors get the opportunity to share their research, hypothesis, ways of tackling scientific obstacles, results and thoughts on the outcome of each scientific project. This publication will also contain some personal comments on the authors’ research experience alongside the abstracts.

In order to ensure quality in the publication, we have been very lucky to be assisted by professional holds - with the help from Professor and Head of DrugTransport and Delivery Research Group, Natsa Skalko-Basnet, Department of Pharmacy (Dep. Phar) and Associate Professor at the Molecular Pharmacology Research Group (Dep. Phar), Yury Kiselev, both from the University of Tromsoe, Norway. We want, once again, to thank both of them for the energy put in this project and also thank all the students who have submitted their abstracts - because without them, this journal wouldn't exist!

We hope you enjoy reading this publication, and we hereby invite and encourage you to send in your abstracts for the next editions!

Yours in EPSA,Science Coordinator and Publications Coordinator 2013/2014Rebwar Saleh and Mara Lefter

EPSA Students' Science Publication Volume 1 | Edition 1 | October 2013

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TABLE OF CONTENT

Determination of nitrogen and organophosphorous pesticide residues in foods of plant origin – method validation, Srđan Radak ........................................................................................ 4

Figures and tables ......................................................................... 5Q&A of the authors ........................................................................ 6

Determination of resveratrol in dietary supplements and

assessment of their antioxidant activity, Karolina Podoga and Aleksandra Polak ..................................................................... 8

Figures and tables ......................................................................... 9Q&A of the authors ...................................................................... 10

Quantification of polyphenolic compounds with antioxidant action from various plant species, Carmen Sultan ................ 12

Figures and tables ....................................................................... 13Q&A of the authors ...................................................................... 14

Afterword ..................................................................................... 15


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DETERMINATION OF NITROGEN AND ORGANOPHOSPHOROUS PESTICIDE RESIDUES IN FOODS OF PLANT ORIGIN – METHOD VALIDATION Radak, Srđan. Medical Faculty, Department of Pharmacy, Novi Sad, Serbia

Combination of QuEChERS method and gas or liquid chromatography with mass spectrometry has enabled pesticide residue analysis in a wide analytical range with high selectivity and sensitivity. These analytical tools have become a mainstay in most laboratories for pesticide monitoring in order to meet global standards.

The aim of the study consisted in the validation of QuEChERS/GC-MS method for analysis of selected nitrogen and organophosphorous pesticide residues and evaluation of measurement uncertainty. The validation study was conducted on organically grown potato and carrot, fortified with standard mixture of nitrogen and organophosphorous pesticides, at two concentration levels, prepared by QuEChERS method and analysed by GC-MS.

The results of the study showed that the limit of quantification for the analytical method of 10μg/kg reached 63% of target compounds in both examined matrices, and additional 21% compound in just one. Estimated limit of quantification of instrumental method was below or at the level of 10μg/kg for 89% of analytes in both matrices. Matrix-matched calibration curves were constructed in the range defined by the limit of quantification at lower level and 500μg/kg as the upper one. At 10μg/kg fortification level, 63% and 76% of analytes showed acceptable recovery values in potato and carrot matrix, respectively. At 100μg/kg fortification level, those values were 76% and 74%. Pesticides with good recovery values were also characterized with good precision. Evaluation of expanded measurement uncertainty showed that this parameter was below 50% for all pesticides meeting the validation criteria.

Conclusion: Validation study and evaluation of measurement uncertainty confirmed the quality of multi residual QuEChERS/GC-MS method for the analysis of selected nitrogen and organophosphorous pesticides.


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FIGURES AND TABLES


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Q&A OF THE AUTHORS

1. Why did you select this topic for your research / master thesis?Analytical chemistry is my favorite field of pharmacy. I have had the opportunity to use analytical instruments such as high performance liquid chromatography (HPLC) and gas chromatography (GC) since 2nd year of studies.

2. How do you feel you have coped with the challenges that research brings?The topic is quite complex, but I have had a great opportunity to learn and work with Ass. Prof. Ljilja Torović. She is an expert in this field and one of the greatest professors in our faculty. I think I just scratched the surface of analytical chemistry and I am seeking for more knowledge.

3. What personal skills have you developed as a researcher during your research period?I learned the importance of correct time management, patience and hardworking.

4. If you had the opportunities, would you specialize more in the field?Yes, I have been interested in PhD and I hope to continue doing this type of research in the future.

5. Any other comments you want to share with other students?Once again, I would like to thank Ass. Prof. Ljilja Torović for all the help she provided me during the research.

More information:[email protected]


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DETERMINATION OF RESVERATROL IN DIETARY SUPPLEMENTS AND ASSESSMENT OF THEIR ANTIOXIDANT ACTIVITYPodoga, Karolina and Polak, Aleksandra from Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Poland

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenolic compound found in the skin of red grape skins, red wine and Japanese knotweed (Polygonum cuspidatum). During the last decade, resveratrol became a subject of many clinical trials, due to its influence on multiple biochemical pathways , in particular as a strong antioxidant and chemopreventive agent. Resveratrol nutritional supplements are available over-the-counter on the pharmaceutical market and the sales are constantly increasing.

The aim of this study was to optimize chromatographic method for the determination of resveratrol in food supplements, as well as evaluation of their antioxidant activity. Dietary supplements used in the project were available on the Polish pharmaceutical market: one containing only resveratrol (e.g. Trans Resveratrol) and the other multicomponent supplements (Cellasene, LongaVit, Natursteron, Nutrof). Determination of resveratrol was performed using isocratic reversed-phase high performance liquid chromatography (RP-HPLC) with spectrophotometric detection (306 nm). The antioxidant properties of tested supplements were evaluated in vitro by determining the efficiency of the inactivation of the synthetic stable radicals (DPPH •). For each sample the IC50 value was calculated, which determines the concentration of the sample causing 50% inhibition of radicals. In the final stage of the experiment, all tested supplements were compared in terms of the amount of active substance they contained, and also their antioxidant potential.

Results show that the content of active substance in dietary supplements is not always the same as declared by the manufacturer. The differences in the concentration of active substance may have an influence over the expected effectiveness of dietary supplements. The study shows that preparations have various antioxidant activities. The strongest antioxidant is the multicomponent supplement – Nutrof, containing also, besides resveratrol, a number of other substances with antioxidant activity (selenium, zinc, vitamin C, vitamin E). Surprisingly, a low IC50 value (high activity) was obtained for Longavit containing only 390 mg of standardized extract from the black grape skins. This may be a result of the presence of additional natural polyphenolic compounds in grape skin extract . Dietary supplement – TransResveratrol – according to the manufacturer‘s assertion, containing 200 mg pure trans-resveratrol in capsule, has the lowest antioxidant activity. The real content of trans-resveratrol in 1 capsule is 4-fold less than declared.


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Graph 1: Determination of resveratrol antioxidant activity.

Graph 2: Relation/Nexus between radical activity inhibition (%) and the concentration of dietary supplement - Nutrof.

FIGURES AND TABLES


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Q&A OF THE AUTHORS

1. Why did you select this topic for your research / master thesis?The reason seems to be simple. It is due to the fact that the regulations for dietary supplements are different and less strict than those for prescription or over-the-counter drugs. Then, these studies in our opinion become extremely valuable. Obviously, dietary supplement companies affirm their products’ efficacy and good quality. The aim of our research was to check how far the companies’ declarations are from the research results.

2. How do you feel you have coped with the challenges that research brings?We’ve manage to test some of the dietary supplements which were available in the Polish Pharmaceutical market. The goal for the future is to test another part of these products and compare them among each other. This would allow to choose the best product, containing resveratrol, in the Pharmaceutical market.

3. What personal skills have you developed as a researcher during your research period?The first one would be assiduity, especially when at the beginning of the research some of our results weren’t reproducible. We have learnt that no matter how many difficulties will occur on your way, you should follow and fulfill your passion. The satisfaction at the end is the best prize you could imagine. The other personal skills that we have managed to obtain during the whole process of our research were definitely: being more accurate and focused.

4. If you had the opportunities, would you specialize more in the field?Yes, of course. If we were given such a chance, we would definitely like to specialize ourselves in this field of science.

5. Any other comments you want to share with other students?To all students - If there is something that you are really interested in, do not waste your time and go for it! Even if it seems to be impossible to achieve, don’t give up! Together, passion and joy for what you are doing connected with hard work, are the formula which make dreams come true!

More information: [email protected]


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QUANTIFICATION OF POLYPHENOLIC COMPOUNDS WITH ANTIOXIDANT ACTION FROM VARIOUS PLANT SPECIESSultan, Carmen., The university of Carol Davila, Bucharest, Romania

Nowadays many diseases are influenced and some are generated by oxidative stress which results from free radicals and reactive oxygen species. This is why research is oriented towards finding a natural solution: vegetable antioxidants. Poly-phenolic compounds (flavonoids, caffeic acid, chlorogenic acid) from plants are known to have antioxidant properties so that they may be used in therapy.

Crataegi fructus, Daucus carota tuber, Aurantii pericarpium and Myrtilli fructus extract were subject to pharmacognostic analysis and HPLC analysis to determine the free radical scavenging and antioxidant properties.

In Crataegi and Myrtilli fructus, there were identified poly-phenolic derivatives (flavonoids, anthocyanins, proanthocyanidins, catechol). In Daucus carota tuber, there were determined tetraterpenoid compounds such as carotenoids . Regarding Aurantii pericarpium there were found flavonoids, proanthocyanidins and catechol. HPLC analysis separated caffeic acid in Crataegi fructus and Aurantii pericarpium, ferulic acid in Aurantii pericarpium and Myrtilli fructus, quercetol in Daucus carota tuber and Crataegi fructus.

The analysed plants proved to be an important source of compounds with anti-radical activity thus justifying their use associated with treatment for different types of ailments (disorders caused by capillary fragility, angiopathy and diabetic retinopathy, hemeralopia, dermal diseases, cardiovascular disorders).


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FIGURES AND TABLES


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Q&A OF THE AUTHORS

1. Why did you select this topic for your research/master thesis?At first I chose the department in which I wanted to do the research and then decided to work on something that could answer a current issue. With the help of my coordinating teacher I settled on antioxidants, more specifically the quantification of antioxidant compounds from 4 different plant species.

2. How do you feel you have coped with the challenges that research brings?I was very enthusiastic about the research in the beginning and had a lot of ideas, then got a little less enthusiastic when I realised that not all of them could be applied. In order to get some results and after a great amount of work has been done, I had to change my initial plan because the results didn’t match with the hypothesis. I was really happy in the end when I realised the achievement.

3. What personal skills have you developed as a researcher during your research period?Patience, perseverance, hard work, desire and knowledge.

4. If you had the opportunities, would you specialize more in the field?Lab work is interesting and rather addictive: after finishing a research you want to continue with a different aspect of the same topic in order to have a complete view over the discussed issue. But working in this field only suits some of us - personally, talking with patients seems more challenging and fills me with the needed satisfaction.

5. Any other comments you want to share with other students?Don't hesitate to get involved in research papers during university! It is an experience that shall contribute to your professional development even if you decide to take a different career path after graduation. There's no bigger accomplishment than sending the message across to others that find your work interesting and want to know more about it.

More information: [email protected]


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AFTERWORD

The idea of this publication was born at the first Team Meeting in Novi Sad, Serbia where members of the Education Board discussed the possibility of creating a platform where students can share knowledge. Also, together with the Vice President of Public Relations (VPPR) Stefan Rack, the idea got more air under its wings. Later on in the process, the publication coordinator, Mara Lefter, got involved in the projects in those areas where the project touched her portfolio.

For this first publication, participants of the 5th EPSA Science day were called and asked for their interest in sharing their abstracts with the rest of the members of EPSA that did not have the opportunity to experience their awesome presentation in Catania, Italy. Luckily, we got enough responses to launch the project.

They sent in their abstracts and answered those questions that were prepared beforehand, and our two professional researchers, Prof. Skalko-Basnet and Ass. Prof. Kiselev, went through all the abstracts in order to ensure its quality. The authors got the recommendations from the researchers, edited some parts and it was all was compiled into what you have seen today.

Personally, I would like to grab my opportunity to once again direct a huge “Thank you” to all bodies involved. From our researchers, to our main involved VPs, Stefan Rack and Jorge Batista for their support. I would also thank specifically our Publication and Design coordinators, Mara Lefter and Svenja Laarhuis, for guiding through the, in my opinion, magical world of “how to make things look good”. Without their energy and effort, this would look like a regular word document (Black on white) with lots of text and without that real spice that they have managed to add.

Now it is time for me to invite all our members students to share their knowledge and research outcomes. I would like to encourage everyone to send in abstracts and take part in this project. This is your opportunity to practice your skills in writing summaries of your research that you may need in your future career. Also, this is your chance to inspire other students for their future research!

If you are interested, please send an e-mail to [email protected] and you will receive a list of requirements for documents that are needed for this publication!

Yours in EPSA, Rebwar Saleh EPSA Science Coordinator 2013/2014

Documents

BRINGING PHARMACY KNOWLEDGE · determination of resveratrol in food supplements, as well as evaluation of their antioxidant activity. Dietary supplements used in the project were