Methods for the determination of antioxidant activity of plant extracts in vitro

Plants are rich sources of secondary metabolites that exhibit diverse biological and pharmacological effects. Some plant ingredients, primarily phenolics, have significant in vitro antioxidant activity, which implies their contribution to the maintenance of redox balance in the body. These potential antioxidant agents are structurally very diverse, having different mechanisms of antioxidant activity. Since there is a growing necessity to detect, develop and understand effective antioxidant compounds, interest in the identification and the measurement of antioxidants in various plant isolates is persistently growing and many methods are being established. Most of the available in vitro tests are affordable and easy to perform, but due to the complex composition of plant extracts, different kinetics, mechanisms and specificity of the chemical reactions underlying these tests, there is no universal parameter for the assessment of antioxidant activity. In this paper, some of the currently most used in vitro methods for investigating and evaluating antioxidant activity of plant extracts are presented, emphasizing their advantages and weaknesses

Natural products: chemistry, bioactivity and application

The focus of research group from Department of Pharmacognosy at the Faculty of Pharmacy in Belgrade is on natural products, their chemistry and application. Main subjects of research are analysis of composition and bioactivities of various plant isolates (extracts, essential oils), isolation and structural analysis of active specialized plant metabolites, optimization of extraction procedures involving new techniques, and green chemistry principles. Since the Balkan Peninsula is one of the centers of plant biodiversity, our main objective is to explore the autochthonous taxa, especially endemic and rare ones, in terms of their distribution, conservation, morphology, chemistry, pharmacology and potential utilization. The main outcomes of these studies are the identification of new herbal raw materials and isolates, their pharmacognostic and pharmacological characterization, and the development of methods of quality assessment and evaluation of safe use of natural products, along with exploring other ways of their use. Important segment of research focuses on identifying natural principles and influences on secondary plant metabolism and studying the chemotaxonomic potential of certain plant metabolites. Basic research interest of this group is constantly upgraded trough scientific collaboration with colleagues from other research institution from Serbia, neighboring regions and abroad, resulting in many scientific and professional publications, and PhD theses.Oral presentation at "Training Program of Natural Products and Drug Discovery" jointly organized by Shanghai Institute of Materia Medica（SIMM), Chinese Academy of Sciences and Institute for Biological Research “Sinisa Stankovic”, National Institute of Republic of Serbia, University of Belgrade (IBISS) - 24-25 May, 2023, Belgrade

Biljni i tradicionalni lekovi u terapiji oboljenja srca i krvnih sudova

In the market there are various herbal medicinal products for supportive therapy of cardiovascular disorders. However, there are only few of such products, for which safety and efficacy have been adequately proven trough clinical studies. These are herbal medicinal products based on: standardized extracts of hawthorn leaf with flower, Crataegi folium cum flore (heart insufficiency: NYHA Stage II); standardized powdered garlic, Allii sativi bulbus (atherosclerosis); standardized extract of ginkgo leaf, Ginkgo bilobae folium (peripheral arterial occlusive disease: intermittent claudication), and standardized extract of horse chestnut seed, Hippocastani semen (chronic venous insufficiency). Other herbal medicinal products are mostly used based on their longstanding use and experience (traditional herbal medicinal products).Na tržištu se može naći veliki broj biljnih lekovitih proizvoda namenjenih za dopunsku terapiju različitih oboljenja kardiovaskularnog sistema. Međutim, mali je broj onih čije su efikasnost i bezbednost potvrđene odgovarajućim kliničkim studijama. U ovu grupu spadaju biljni lekovi na bazi standardizovanih ekstrakata lista sa cvetom gloga, Crataegi folium cum flore, koji se primenjuju kod blažih oblika srčane insuficijencije (NYHA klasa II), na bazi standardizovanog praška lukovice belog luka, Allii sativi bulbus, koji se koriste za prevenciju ateroskleroze, na bazi standardizovanog ekstrakta lista ginka, Ginkgo bilobae folium, namenjeni za simptomatsku terapiju okluzivne bolesti perifernih arterija (intermitentna klaudikacija) i na bazi standardizovanog ekstrakta semena divljeg kestena, Hippocastani semen, namenjeni za simptomatsku terapiji hronične venske insuficijencije. Primena ostalih biljnih lekovitih proizvoda uglavnom je zasnovana na dugoj tradiciji i iskustvu (spadaju u kategoriju tradicionalnih biljnih lekova)

Influence of some Stachys taxa on carrageenan-induced paw edema in rats

This work investigates the anti- inflammatory activity of methanol extracts of four endemic Stachys ( Labiatae) taxa from the Balkans: S. beckeana Dorfler & Hayek, S. anisochila Vis. et Pancic, S. plumosa Griseb., and S. alpina L. subsp. dinarica Murb. As a model of acute inflammation, carrageenan- induced paw edema in rats was used. Extracts, applied at doses of 50, 100, and 200 mg/ kg p. o., exhibited dose- dependent activity. S. beckeana and S. anisochila extracts were the most active ones ( ED50 154.52 and 162.24 mg/ kg, respectively), with the activity comparable with indomethacin at doses of 2 and 4 mg/ kg. S. plumosa extract has shown less- pronounced anti- inflammatory effect ( ED50 220.81 mg= kg). Extract of S. alpina subsp. dinarica had the lowest efficiency, attenuating inflammation less than 50%

Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage) is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF), in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO) 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

Primena biljnih lekovitih proizvoda kod hronične venske bolesti

In treatment of chronic venous disease (CVD) venoactive drugs (VADs) are used. They represent a heterogeneous group of drugs of synthetic (ie. calcium dobesilate, naftazone, and benzarone) or natural origin. Venoactive drugs of herbal origin are usually prepared from isolated plant constituents (i.e. flavonoids) or their semisynthetic derivatives (i.e. hydroxyethylrutosides, diosmin), but also from various herbal drugs and their preparations (herbal medicinal products, HMPs). Herbal medicinal products used in these indications are usually prepared from: horsechestnut seed and bark (Hippocastani semen/cortex), butcher’s broom rhizome (Rusci rhizoma), melilot herb (Meliloti herba), grapevine leaf (Vitis viniferae folium), billberry fruit (Myrtilli fructus), French maritime pine bark (Pini pinasteris cortex), centella herb (Centellae asiaticae herba), and ginkgo leaf (Ginkgonis folium). Active compounds of these herbal drugs belong to groups of saponins, coumarines, flavonoids, anthocyanins, proanthocyanidins or terpenes. According to community herbal monographs prepared by Committee on Herbal Medicinal Products at the European Medicines Agency (EMA/HMPC), HMPs with well- established use are those prepared from dry standardized horsechestnut seed extract (with 16­28% of aescin) and dry standardized grapevine leaf water extract (DER 4-6:1), for oral use. Herbal medicinal products classified under traditional medicinal use provisions are products prepared from horsechestnut seed and bark, grapevine leaf, butcher’s broom rhizome, and melilot herb (for oral and/or cutaneous use).Za terapiju primarne hronične venske bolesti (HVB) koriste se venoaktivni lekovi. Predstavljaju heterogenu grupu lekova sintetskog (npr. Ca-dobesilat, naftazon, benzaron) ili prirodnog porekla. Venoaktivni lekovi biljnog porekla se uglavnom izrađuju od izolovanih biljnih sastojaka (najčešće flavonoida) ili njihovih polusintetskih derivata (npr. hidroksietilrutozidi, diosmin), ali i od različitih biljnih droga i njihovih preparata (biljni lekoviti proizvodi, BLP). Najznačajnije biljne droge od kojih se izrađuju BLP za primenu u ovom indikacionom području su: seme i kora divljeg kestena (Hippocastani semen/cortex), rizom kostrike (Rusci rhizoma), herba ždraljevine (Meliloti herba), list vinove loze (Vitis viniferae folium), plod borovnice (Myrtilli fructus), kora francuskog primorskog bora (Pini pinasteris cortex), herba centele (Centellae asiaticae herba), i list ginka (Ginkgonis folium). Aktivni sastojci ovih droga spadaju u grupu saponozida, kumarina, flavonoida, antocijana, proantocijanidina ili terpena. Prema monografijama biljnih droga koje je do sada pripremio Komitet za biljne lekovite proizvode Evropske agencije za lekove (EMA/HMPC), status biljnih lekova imaju oni BLP koji se izrađuju od suvog standardizovanog ekstrakta semena divljeg kestena (sadrži 16-28% escina) i suvog standardizovanog vodenog ekstrakta lista vinove loze (DER 4-6:1), i namenjeni su za oralnu primenu. Status tradicionalnih biljnih lekova imaju odgovarajući lekoviti proizvodi na bazi semena i kore divljeg kestena, lista vinove loze, rizoma kostrike i herbe ždraljevine (za oralnu i/ili dermalnu primenu)

Chemical composition and anti‐DPPH activity of essential oil obtained from commercial sample of Cretan dittany herb, Origani dictamni herba

Kritski origano, Origanum dictamnus L. (Lamiaceae), je endemična biljka grčkog ostrva Krit. Komitet za biljne lekovite proizvode Evropske agencije za lekove (EMA/HMPC) izdao je EU monografiju za tradicionalnu primenu herbe kritskog origana, Origani dictamni herba. Prema ovoj monografiji usitnjena herba se koristi oralno u obliku čaja (infuza) za ublažavanje kašlja povezanog sa prehladom i za simptomatsko ublažavanje blagog gastrointestinalnog diskomfora, kao i dermalno u obliku infuza ili dekokta za tretman manjih inflamacija kože i modrica. U Evropskoj farmakopeji (Ph. Eur.) za sada ne postoje monografije za ovu biljnu drogu i njeno etarsko ulje. Cilj ovog rada bio je ispitivanje hemijskog sastava etarskog ulja izolovanog iz komercijalnog uzorka herbe kritskog origana poreklom iz Grčke, kao i procena njegove antiradikalske aktivnosti. Etarsko ulje je izolovano iz herbe destilacijom vodenom parom u aparaturi po Clevenger-u, prema postupku Ph. Eur. Prinos etarskog ulja iznosio je 1,51% V/m, tj. 1,46% m/m. Hemijski sastav etarskog ulja analiziran je gasnom hromatografijom sa FID i MS detekcijom (GC-FID i GC-MS). Identifikovane su 42 komponente, koje su činile 94,6% sastava etarskog ulja. Procentualno najveći udeo u etarskom ulju činili su oksidovani monoterpeni (58,8%; 9 jedinjenja), a sledili su monoterpenski ugljovodonici (27,4%; 12 jedinjenja), seskviterpenski ugljovodonici (5,6%; 12 jedinjenja) i oksidovani seskviterpeni (2,3%; 6 jedinjenja). Glavna komponenta etarskog ulja bio je monoterpenski fenol karvakrol (51,4%), dok su po količini sledili monoterpenski ugljovodonici p-cimen (14,3%) i γ-terpinen (9,3%). Dobijeni rezultati bili su u skladu sa literaturnim podacima, pri čemu je u slučaju uzorka analiziranog u ovom radu, prinos etarskog ulja bio veći od prethodno publikovanih vrednosti (1, 2). Antiradikalska aktivnost izolovanog etarskog ulja ispitana je spektrofotometrijskim DPPH testom. Stepen antiradikalske aktivnosti je rastao linearno sa povećanjem koncentracije etarskog ulja, pri čemu je koncentracija u kojoj je etarsko ulje inhibiralo 50% DPPH radikala (SC50) iznosila 141,77 μg/mL. Značajan anti-DPPH potencijal etarskog ulja herbe kritskog origana može se barem delom objasniti velikim udelom karvakrola, čiji je antiradikalski potencijal ranije pokazan (3). Rezultati sprovedenih hemijskih ispitivanja mogu biti od značaja za buduće definisanje parametara farmaceutskog kvaliteta droge Origani dictamni herba i njenog etarskog ulja.Cretan dittany, Origanum dictamnus L. (Lamiaceae), is an endemic species from the Greek island of Crete. The Committee on Herbal Medicinal Products of the European Medicines Agency (EMA/HMPC) adopted EU monograph on traditional use of Cretan dittany herb, Origani dictamni herba. According to this monograph, comminuted herb is used orally as herbal tea (infusion) for the relief of cough associated with cold and for mild gastrointestinal disorders, as well as cutaneously as infusion or decoction for the treatment of minor skin inflammations and bruises. European Pharmacopoeia (Ph. Eur.) monographs for this herbal drug and its essential oil do not exist for now. The aim of this work was to investigate chemical composition of the essential oil obtained from a commercial sample of Cretan dittany herb and to evaluate its antiradical activity. The essential oil was isolated from the herb by hydrodistillation in a Clevenger‐type apparatus, according to procedure given in Ph. Eur. The yield was 1.51% V/w, i.e. 1.46% w/w. Chemical composition of the essential oil was analyzed by gas chromatography with FID and MS detection (GC-FID and GC-MS). A total of 42 components were identified, comprising 94.6% of the composition of the essential oil. The dominant were oxygenated monoterpenes (58.8%; 9 compounds), followed by monoterpene hydrocarbons (27.4%; 12 compounds), sesquiterpene hydrocarbons (5.6%; 12 compounds) and oxygenated sesquiterpenes (2.3%; 6 compounds). The main component of the essential oil was monoterpene phenol carvacrol (51.4%), followed by monoterpene hydrocarbons p-cymene (14.3%) and γ-terpinene (9.3%). Obtained results were in accordance with the literature data; it should be noted that in the case of the sample analyzed in this work, the essential oil yield was higher than previously published values (1, 2). The antiradical activity of the essential oil was investigated by spectrophotometric DPPH test. The percentage of antiradical activity increased linearly with the increase of essential oil concentration. The concentration at which the essential oil inhibited 50% DPPH radicals (SC50) was 141.77 μg/mL. Significant anti-DPPH potential of the essential oil of Cretan dittany herb can be at least partly explained by the presence of high quantity of carvacrol, which antiradical potential was demonstrated previously (3). The results of performed chemical investigations may be important for defining pharmaceutical quality parameters of the herbal drug Origani dictamni herba and its essential oil in the future.Drugi naučni simpozijum Saveza farmaceutskih udruženja Srbije sa međunarodnim učešćem, 28. 10. 2021. Beogra

Biljni lekoviti proizvodi: Uslovi za bezbednu primenu

As the use of herbal medicinal products is constantly growing, their safety became an important public health issue. In spite of common belief that herbal medicinal products are safe and harmless because they are natural, it is not always so and their usage is not devoid of certain risks. The most common reasons for herbal adverse reactions (ADRs) are: improper use (overdose or prolonged use), interactions with conventional drugs and poor quality of herbal products. In this work were discussed the most important issues on their safe usage. Classification of herbal medicinal products (herbal medicine, traditional herbal medicine) and basic informations on their registration and marketing authorization according to current European and Serbian legislation were also given. Manufacturing of quality herbal medicinal products is highlighted as one of the most important requirements for their safety. Having in mind that most of these products are sold without prescription (OTC) and that they are mostly used in self-medication, the role of health professionals in consulting patients on choosing of herbal medicinal product and its usage was emphasized. The importance of patient's collaboration with health professionals on recognizing and monitoring herbal ADRs and avoiding possible interactions was also pointed out. Examples of the most frequent herbal medicinal products ADRs occurring in course of their recommended and improper use, on their interactions with drugs as well as on their poor quality were given. The importance of involving herbal medicinal products in international pharmacovigilance systems was also explained

Chemical Composition, Antimicrobial and Antiradical Properties of the Essential Oils of Seseli globiferum Fruits

The chemical composition and antimicrobial and antiradical activities of the essential oils isolated from unripe and ripe fruits of S. globiferum Vis. (Apiaceae) have been determined. The most abundant constituent in the essential oils of unripe and ripe fruits was sabinene (53.1% and 65.3%), followed by gamma-terpinene (7.7% and 6.6%), alpha-pinene (7.2% and 4.4%), and beta-phellandrene (5.0% and 4.9%). Antibacterial and antifungal properties of these oils were evaluated using a modified microdilution technique. Scavenging activity was determined by the DPPH radical assay. The essential oils exhibited significant antimicrobial, but low antiradical activity

MODIFICATION OF THE COBWEB MODEL INTO GENERALIZED LOGISTIC EQUATION FOR THE WHEAT PRICE ANALYSIS

In the paper we constructed the new wheat growth model, based on the generalized logistic equation. Starting from the theoretical framework of the cobweb model, we adapted generalized logistic equation to better fit the real data of wheat prices, according to the presented wheat growth model. The aim of the paper is to present how logistic and generalized logistic equations can be used for both prediction of wheat prices and for the wheat price stability analysis. Data analysis showed better performances of the generalized logistic map in comparation with the conventional logistic map as a main result of this paper. For estimated parameters of the model the bifurcation diagrams also have been presented to show stability of wheat price over time. The conclusion is that the proposed model can be useful in predicting future wheat prices in the short-run period, as well as for the analysis of stability in conditions of uncertainty, which is also a recommendation for the application of the model in the future research