Biological-chemical characterization of species of genus Hypericum L. (Hypericaceae) from central part of Balkan Peninsula and typification of teas based on St. John’s wort

Rod Hypericum obuhvata oko 500 različitih vrsta klasifikovanih u 36 sekcija. Najpoznatiji predstavnik roda je kantarion (Hypericum perforatum, Hypericaceae). Hemijska karakterizacija kantariona je bila predmet mnogobrojnih istraživanja koja su pokazala prisustvo različitih klasa jedinjenja, kao i širok spektar biološkog potencijala. Međutim, ispitivanja su otkrila prisustvo istih klasa jedinjenja i u drugim predstavnicima roda Hypericum, opravdavajući hemijska istraživanja i određivanje bioloških aktivnosti. S obzirom da se kantarion retko plantažno uzgaja, već uglavnom sakuplja iz prirode, neretko usled nedovoljne obučenosti sakupljača lekovitog bilja dolazi do zamene propisanog biološkog izvora droge Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) morfološki sličnim predstavnicima roda, što posledično utiče na sadržaj aktivnih principa i biološki potencijal. Zbog toga su ciljevi ove doktorske disertacije: utvrđivanje uticaja geografskog porekla i stadijuma ontogenetskog razvoja biološkog izvora na kvalitativni i kvantitativni hemijski sastav, biološki potencijal vodeno-alkoholnog ekstrakta taksona roda Hypericum, kao i utvrđivanje kvaliteta (stepen usitnjenosti, biološki izvor, hemijski sastav i biološki potencijal) komercijalno dostupnih čajeva na bazi kantariona koji se nalaze u slobodnoj prodaji. Biljni materijal je obuhvatio uzorke 32 taksona roda Hypericum kao i 51 uzorak monokomponentnih čajeva na bazi kantariona prikupljenih na teritoriji centralnog dela Balkanskog poluostrva, centralne Evrope, Rusije i Turske tokom 2011-2016. godine. U većini ispitanih ekstrakta kvantifikovan je visok sadržaj ukupnih fenola i flavonoida. Rezultati određivanja sadržaja hipericina u ispitivanim ekstraktima pokazali su njegovo prisustvo kod uzoraka svih taksona prikupljenih za vreme cvetanja, pri čemu je to bila i fenofaza u kojoj je dostignut maksimalan sadržaj. Hiperforin je takođe detektovan u većini uzoraka prikupljenih za vreme cvetanja, prateći dinamiku akumulacije sličnu hipericinu. Sa druge strane apigenin i epikatehin nisu detektovani u velikom broju ispitanih ekstrakta, dok je prisustvo naringenina kvantifikovano u manje od 50% uzoraka. Amentoflavon je bio prisutan u manje od 30% ispitanih uzoraka. Visok sadržaj kvercetina i rutina je određen u svim ispitanim ekstraktima, pri čemu u slučaju kvercetina nije zabeleženo značajnije variranje tokom ontogenetskog razvoja, dok je maksimalna koncentracija rutina određena u uzorcima prikupljenim pre, ili za vreme cvetanja. U većini uzoraka detektovane su galna, hlorogenska, kafena i p-hidroksibenzojeva kiselina (naročito u periodu koji prethodi cvetanju), dok ferulna kiselina nije kvantifkovana kod više od 80% ispitanih ekstrakta. Rezultati su pokazali snažnu antioksidantnu sposobnost ispitivanih ekstrakata. Uočena je snažnija inhibicija monoaminooksidaze A u odnosu na monoaminooksidazu B, kao i viši anti-α-glukozidazni od anti-α-amilaznog potencijala. Sposobnost inhibicije acetilholinesteraze je ocenjena kao umerena. Ispitivanje antiproliferativnog potencijala ekstrakata vrsta roda Hypericum, je pokazalo izrazit sinergistički efekat sa antineoplastičnim lekom bleomicinom (radiomimetik) kao i visoku selektivnost prema ćelijama karcinoma cerviksa i melanoma, za razliku od umerenog antiproliferativnog potencijala i niske selektivnosti samih ekstrakata prema malignim ćelijama. Zabeležen je značajan broj neusitnjenih (in toto) komercijalno dostupnih uzoraka čajeva na bazi kantariona, dok su kao biološki izvor ispitanih uzoraka čajeva identifikovane različite podvrste H. perforatum. Sličnost hemijskog profila i biološkog potencijala velikog broja ispitanih taksona sa H. perforatum ukazuju na mogućnost njihove eksploatacije. Međutim, zavisnost navedenih parametara od geografskog porekla biljnog materijala ističe značajan uticaj abiotičkih ekoloških faktora na kvalitet droge. Hemijski sastav i morfološko ispitivanje uzoraka monokomponentnih čajeva na bazi kantariona ukazuju na neophodnost kontrole njihovog kvaliteta.The genus Hypericum includes more than 500 different species classified in 36 sections. The most known representative of genus is St. John's wort (Hypericum perforatum, Hypericaceae). Chemical characterization of St. John's wort was the subject of many conducted researches which demonstrated the presence of different classes of compounds, as well as a wide spectrum of biological potential. However, the studies have also shown the presence of the same compounds in other representative of the genus Hypericum, justifying the evaluation of their chemical composition and biological potential. Considering the fact that St. John's wort is rarely being cultivated, rather collected from nature, unqualified collectors may substitute the official biological source of Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) for morphologically similar representatives of the genus, consequently affecting the quantities of active principles and biological potential of the drug. The aims of this PhD thesis were to evaluate the influence of geographical origin and stage of ontogenetic development of biological source on qualitative and quantitative chemical composition and biological potential of water - alcoholic extract of different Hypericum taxa, as well as to determine the quality (grinding degree, biological source, chemical composition and biological potential) of commercially available St. John’s wort teas on the market. The plant material included samples of 32 taxa of genus Hypericum, as well as 51 commercially available sample of monocomponent teas based on St. John's wort collected at territory of central part of Balkan Peninsula, central Europe, Russia and Turkey, during period 2011 - 2016. High amounts of total phenolics and flavonoids were quantified in the most of the examined extracts. Quantification of hypericin showed its presence in all of the samples collected during flowering period, while that was also the ontogenetic stage of its maximum accumulation. Hyperforin was also quantified in most of the samples collected during flowering period, following the hypericin trend of accumulation. On the other hand, apigenin and epicatechin were not detected in large number of the examined extracts, while naringenin was detected in less than 50% of samples. Amentoflavone was present in less than 30% of the examined samples. High amounts of quercetin and rutin were determined in all of the examined samples. No significant changes in the amounts of quercetin during ontogenetic development were noticed, while the highest amounts of rutin were determined in samples collected before, or during flowering. Gallic, chlorogenic, caffeic and p-hydroxybenzoic acid were detected in most of the examined samples (especially in period before opening of the flowers), while ferulic acid was not quantified in more than 80% of samples. The results have demonstrated strong antioxidant potential of the examined extracts. Stronger potential of the examined extracts to inhibit monoamine oxidase A than monoamine oxidase B, as well as stronger anti-α-glucosidase than anti-α-amylase potential were recorded. The obtained anticholinesterase activity of the examined extracts was moderate. The examination of antiproliferative potential of different Hypericum species extracts has shown additive effects in combination with bleomycin (radiomimetic), as well as high selectivity toward cervix and melanoma cancer cells. On the other hand, moderate antiproliferative potential and low selectivity during treatment of cancer cells only with the examined extracts was recorded. Significant share of in toto commercially available tea samples based on St. John's wort was noticed, while different subspecies of H. perforatum were identified as biological sources of the examined teas. Chemical profile and biological potential resemblance between a large number of investigated taxa and H. perforatum point to possibilities of their exploitation. However, the dependence of listed parameters from geographical origin of plant material emphasizes the importance of abiotic ecological factors for the quality of herbal drug. Chemical composition and morphological examination of monocomponent teas based on St. John’s wort stress the importance of their quality control

Natural Products as Antibacterial Agents — Antibacterial Potential and Safety of Post-distillation and Waste Material from Thymus vulgaris L., Lamiaceae

Medicinal plants have a long tradition of use in folk and conventional medicine. In recent years numerous studies confirm various bioactivities of natural products, among them antibacterial activity. Natural antibacterial agents such are essential oils and isolated compounds now represent a notable source for pharmaceutical and food industry and are widely used in cosmetology. They meet standards of \u27green consumerism\u27 together with excellent antibacterial activity. Aromatic plants such is Thymus vulgaris L. are the major sources of essential oils. Thyme essential oil, as well as dominant compounds thymol and carvacrol are generally recognised as safe and have been registered by European Commission for use as flavouring agents in foodstuffs. However, essential oil is present in very low amount (0,8-2,6%) in thyme leaves. Thus, the majority of plant material remains unused after the isolation. Nowadays, the biological potential of various plant waste materials are in focus of numerous studies. These investigations also include the antimicrobial activity considering the fact that waste material extracts represent the valuable source of different phenolic compounds. Regarding all this, the aim of the present study was to determine antibacterial potential of chemically characterised extracts obtained from waste material remaining after the preparation of drug (stems) and isolation of thyme essential oil (deodorised leaves, postdistillation decoction) on selected bacterial strains. Also, in order to determine safety of waste extracts their cytotoxicity was investigated. All extracts were prepared with maceration using 45% or 75% ethanol (EtOH) for 24 h at room temperature (1:10 w/v). Total phenolic compounds and flavonoids were determined spectrophotometrically. Extracts were chemically characterized by HPLC/DAD analysis. Antibacerial testing was done with broth dilution method against several bacterial strains (Staphylococcus aureus, Bacillus cereus, Salmonella infantis, Escherichia coli and Campylobacter jejuni). Cytotoxicity and cytoprotection studies were performed by XTT assay. Result of HPLC analysis showed that investigated extracts, especially those obtained from deodorised leaves represent a valuable source of rosmarinic acid and luteolin 7-O-glucuronide. Antibacterial testing indicated that all waste material extracts, except the extract T2, possess similar or even stronger bacteriostatic activity than T1. No cytotoxicity nor cytoprotection were determined. In conclusion, results of this study confirmed antibacterial potential investigated thyme extracts. High concentrations of rosmarinic acid and luteolin 7-O-glucuronide, which both have numerous pharmacological activities, were determined. This indicates that thyme postdistillation waste material extracts could be used for isolation of dominant compounds or as addities in pharmaceutical and food industry

Environmental Bovine Mastitis Pathogens: Prevalence, Antimicrobial Susceptibility, and Sensitivity to Thymus vulgaris L., Thymus serpyllum L., and Origanum vulgare L. Essential Oils

Mastitis is considered to be one of the most important diseases of dairy cows in terms of health, production, and economy. Being the most common cause of antibiotic consumption in dairy cows, treatment of this disease is one of the biggest challenges in the veterinary profession as an increasing number of pathogens develop resistance to antibiotics used in the treatment. Therefore, new alternative approaches for limiting the use of antibiotics in livestock are required. For this reason, our study aimed to investigate prevalence of environmental mastitis associated bacterial strains, as well as the sensitivity of isolated strains to different antibiotics. Additionally, the therapeutic potential of three essential oils (EOs) was tested against bovine Serratia spp. and Proteus spp. mastitis pathogens, based on their chemical composition, as well as antibacterial potential. The study was carried out on 81 milk samples collected from dairy cows with mastitis. In order to determine prevalence of S. marcescens and P. mirabilis, microbiological isolation and identification were performed. Antimicrobial susceptibility testing was performed by disk diffusion method and the microdilution method was used to determine the antibacterial activity of selected EOs. In the oregano EO, a total of 23 compounds were detected, with carvacrol as a dominant component (78.94%). A total of 26 components were present in the EO of common thyme, where thymol was the most abundant compound (46.37%). Thymol also dominated (55.11%) the wild thyme EO. All tested EOs displayed antibacterial activity against all strains to different extents, while wild and common thyme EOs were the most effective. It could be concluded that the tested EOs represent promising therapeutic candidates for effective non-antibiotic treatment of mastitis

Hypericum perforatum

St. John’s wort is a widely used medicinal plant. The quality of herbal drug, which is in most of the cases collected from nature, varies. Therefore, the aim of the present study was detailed chemical characterization of Hypericum perforatum subsp. perforatum samples collected in close time intervals during flowering and fruitification with the purpose to state the phenological stage characterized by maximum levels of active principles. The antioxidant potential and potential to inhibit biologically important enzymes, as well as the cytotoxicity and genotoxicity of the sample collected during the full flowering period, were evaluated. Data showed that the optimal period for the achieving of maximum level of active principles is the phenophase between floral budding and flowering stage. Significant antioxidant potential and the ability to inhibit biologically important enzymes (especially α-glucosidase) were recorded. The extract exhibited no genotoxicity in subcytotoxic concentrations, while increased cytotoxicity recorded in cotreatment with bleomycin on malignant cell lines was especially significant

New Perspective of Origanum vulgare L. and Satureja montana L. Essential Oils as Bovine Mastitis Treatment Alternatives

Mastitis represents a heavy burden for the dairy sector worldwide with high economic and animal welfare impact. Antibiotic treatment is an important component of mastitis control programs. However, emergence and transfer of antimicrobial-resistant (AMR) bacteria is becoming a growing concern. Therefore, the development of novel agents is required for prevention and treatment of mastitis. Hence, our aim was to assess the antibacterial properties of two essential oils (EOs) obtained from oregano (Origanum vulgare L., Lamiaceae) and mountain savory (Satureja montana L., Lamiaceae) against mastitis-associated bacteria in Serbia. The chemical composition and antioxidant potential of these EOs were also evaluated. The present study was conducted on strains derived from aseptic milk samples collected from Holstein-Friesian cows with clinical or subclinical mastitis, during the morning milking. Clinical mastitis was assessed by clinical examination, while subclinical mastitis was confirmed using somatic cell count in the milk samples. The microdilution method was used to determine the antibacterial activity, while antioxidant potential of the EOs was evaluated in several in vitro assays. The values of minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) were used to quantitatively measure the antibacterial activity of each EO. MIC/MBC ranged from 0.78/6.25 and 0.39/0.78 mg/mL for oregano and mountain savory, respectively. A total of 25 compounds were identified in the oregano EO, while 47 were identified in winter savory EO, among which aromatic oxygenated monoterpenes were the most abundant compounds. The tested EOs have shown promising antimicrobial activity and could be considered as one of the treatment approaches in mastitis-affected cows

Biological-chemical characterization of species of genus Hypericum L. (Hypericaceae) from central part of Balkan Peninsula and typification of teas based on St. John’s wort

Rod Hypericum obuhvata oko 500 različitih vrsta klasifikovanih u 36 sekcija. Najpoznatiji predstavnik roda je kantarion (Hypericum perforatum, Hypericaceae). Hemijska karakterizacija kantariona je bila predmet mnogobrojnih istraživanja koja su pokazala prisustvo različitih klasa jedinjenja, kao i širok spektar biološkog potencijala. Međutim, ispitivanja su otkrila prisustvo istih klasa jedinjenja i u drugim predstavnicima roda Hypericum, opravdavajući hemijska istraživanja i određivanje bioloških aktivnosti. S obzirom da se kantarion retko plantažno uzgaja, već uglavnom sakuplja iz prirode, neretko usled nedovoljne obučenosti sakupljača lekovitog bilja dolazi do zamene propisanog biološkog izvora droge Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) morfološki sličnim predstavnicima roda, što posledično utiče na sadržaj aktivnih principa i biološki potencijal. Zbog toga su ciljevi ove doktorske disertacije: utvrđivanje uticaja geografskog porekla i stadijuma ontogenetskog razvoja biološkog izvora na kvalitativni i kvantitativni hemijski sastav, biološki potencijal vodeno-alkoholnog ekstrakta taksona roda Hypericum, kao i utvrđivanje kvaliteta (stepen usitnjenosti, biološki izvor, hemijski sastav i biološki potencijal) komercijalno dostupnih čajeva na bazi kantariona koji se nalaze u slobodnoj prodaji. Biljni materijal je obuhvatio uzorke 32 taksona roda Hypericum kao i 51 uzorak monokomponentnih čajeva na bazi kantariona prikupljenih na teritoriji centralnog dela Balkanskog poluostrva, centralne Evrope, Rusije i Turske tokom 2011-2016. godine. U većini ispitanih ekstrakta kvantifikovan je visok sadržaj ukupnih fenola i flavonoida. Rezultati određivanja sadržaja hipericina u ispitivanim ekstraktima pokazali su njegovo prisustvo kod uzoraka svih taksona prikupljenih za vreme cvetanja, pri čemu je to bila i fenofaza u kojoj je dostignut maksimalan sadržaj. Hiperforin je takođe detektovan u većini uzoraka prikupljenih za vreme cvetanja, prateći dinamiku akumulacije sličnu hipericinu. Sa druge strane apigenin i epikatehin nisu detektovani u velikom broju ispitanih ekstrakta, dok je prisustvo naringenina kvantifikovano u manje od 50% uzoraka. Amentoflavon je bio prisutan u manje od 30% ispitanih uzoraka. Visok sadržaj kvercetina i rutina je određen u svim ispitanim ekstraktima, pri čemu u slučaju kvercetina nije zabeleženo značajnije variranje tokom ontogenetskog razvoja, dok je maksimalna koncentracija rutina određena u uzorcima prikupljenim pre, ili za vreme cvetanja. U većini uzoraka detektovane su galna, hlorogenska, kafena i p-hidroksibenzojeva kiselina (naročito u periodu koji prethodi cvetanju), dok ferulna kiselina nije kvantifkovana kod više od 80% ispitanih ekstrakta. Rezultati su pokazali snažnu antioksidantnu sposobnost ispitivanih ekstrakata. Uočena je snažnija inhibicija monoaminooksidaze A u odnosu na monoaminooksidazu B, kao i viši anti-α-glukozidazni od anti-α-amilaznog potencijala. Sposobnost inhibicije acetilholinesteraze je ocenjena kao umerena. Ispitivanje antiproliferativnog potencijala ekstrakata vrsta roda Hypericum, je pokazalo izrazit sinergistički efekat sa antineoplastičnim lekom bleomicinom (radiomimetik) kao i visoku selektivnost prema ćelijama karcinoma cerviksa i melanoma, za razliku od umerenog antiproliferativnog potencijala i niske selektivnosti samih ekstrakata prema malignim ćelijama. Zabeležen je značajan broj neusitnjenih (in toto) komercijalno dostupnih uzoraka čajeva na bazi kantariona, dok su kao biološki izvor ispitanih uzoraka čajeva identifikovane različite podvrste H. perforatum. Sličnost hemijskog profila i biološkog potencijala velikog broja ispitanih taksona sa H. perforatum ukazuju na mogućnost njihove eksploatacije. Međutim, zavisnost navedenih parametara od geografskog porekla biljnog materijala ističe značajan uticaj abiotičkih ekoloških faktora na kvalitet droge. Hemijski sastav i morfološko ispitivanje uzoraka monokomponentnih čajeva na bazi kantariona ukazuju na neophodnost kontrole njihovog kvaliteta.The genus Hypericum includes more than 500 different species classified in 36 sections. The most known representative of genus is St. John's wort (Hypericum perforatum, Hypericaceae). Chemical characterization of St. John's wort was the subject of many conducted researches which demonstrated the presence of different classes of compounds, as well as a wide spectrum of biological potential. However, the studies have also shown the presence of the same compounds in other representative of the genus Hypericum, justifying the evaluation of their chemical composition and biological potential. Considering the fact that St. John's wort is rarely being cultivated, rather collected from nature, unqualified collectors may substitute the official biological source of Hyperici herba (H. perforatum subsp. perforatum, Hypericaceae) for morphologically similar representatives of the genus, consequently affecting the quantities of active principles and biological potential of the drug. The aims of this PhD thesis were to evaluate the influence of geographical origin and stage of ontogenetic development of biological source on qualitative and quantitative chemical composition and biological potential of water - alcoholic extract of different Hypericum taxa, as well as to determine the quality (grinding degree, biological source, chemical composition and biological potential) of commercially available St. John’s wort teas on the market. The plant material included samples of 32 taxa of genus Hypericum, as well as 51 commercially available sample of monocomponent teas based on St. John's wort collected at territory of central part of Balkan Peninsula, central Europe, Russia and Turkey, during period 2011 - 2016. High amounts of total phenolics and flavonoids were quantified in the most of the examined extracts. Quantification of hypericin showed its presence in all of the samples collected during flowering period, while that was also the ontogenetic stage of its maximum accumulation. Hyperforin was also quantified in most of the samples collected during flowering period, following the hypericin trend of accumulation. On the other hand, apigenin and epicatechin were not detected in large number of the examined extracts, while naringenin was detected in less than 50% of samples. Amentoflavone was present in less than 30% of the examined samples. High amounts of quercetin and rutin were determined in all of the examined samples. No significant changes in the amounts of quercetin during ontogenetic development were noticed, while the highest amounts of rutin were determined in samples collected before, or during flowering. Gallic, chlorogenic, caffeic and p-hydroxybenzoic acid were detected in most of the examined samples (especially in period before opening of the flowers), while ferulic acid was not quantified in more than 80% of samples. The results have demonstrated strong antioxidant potential of the examined extracts. Stronger potential of the examined extracts to inhibit monoamine oxidase A than monoamine oxidase B, as well as stronger anti-α-glucosidase than anti-α-amylase potential were recorded. The obtained anticholinesterase activity of the examined extracts was moderate. The examination of antiproliferative potential of different Hypericum species extracts has shown additive effects in combination with bleomycin (radiomimetic), as well as high selectivity toward cervix and melanoma cancer cells. On the other hand, moderate antiproliferative potential and low selectivity during treatment of cancer cells only with the examined extracts was recorded. Significant share of in toto commercially available tea samples based on St. John's wort was noticed, while different subspecies of H. perforatum were identified as biological sources of the examined teas. Chemical profile and biological potential resemblance between a large number of investigated taxa and H. perforatum point to possibilities of their exploitation. However, the dependence of listed parameters from geographical origin of plant material emphasizes the importance of abiotic ecological factors for the quality of herbal drug. Chemical composition and morphological examination of monocomponent teas based on St. John’s wort stress the importance of their quality control

Phytochemicals in the Prevention and Treatment of SARS-CoV-2—Clinical Evidence

The first case of SARS-CoV-2 infection was reported in December 2019. Due to the rapid spread of the disease and the lack of adequate therapy, the use of plants that have a long history in the treatment of viral infections has often been considered. The aim of this paper is to provide a brief review of the literature on the use of phytochemicals during the new pandemic. An extensive search of published works was performed through platforms Google Scholar, PubMed, Science Direct, Web of Science and Clinicaltrials.gov. Numerous preclinical studies on the use of phytochemicals (quercetin, curcumin, baicalin, kaempferol, resveratrol, glycyrrhizin, lycorine, colchicine) against SARS-CoV-2 have shown that these components can be effective in the prevention and treatment of this infection. Clinical research has proven that the use of black cumin and green propolis as well as quercetin has positive effects. As for other phytochemicals, in addition to preclinical testing which has already been carried out, it would be necessary to conduct clinical tests in order to assert their effectiveness. For those phytochemicals whose clinical efficacy has been proven, it would be necessary to conduct research on a larger number of patients, so that the conclusions are more representative

Plasma Concentrations of Rosmarinic Acid in Patients on Antiretroviral Therapy: In Silico Exploration Based on Clinical Data

Rosmarinic acid (RA) is a phenolic compound with antiviral properties, often encountered in dietary supplements and herbal drugs. Data on the pharmacokinetics of RA are lacking in cases of the chronic use of supplements containing this compound, and only limited data on the metabolism and distribution of RA are available. The aim of the study was to investigate the plasma levels of RA after 12 weeks of use and determine potential interactions of RA and selected antiretroviral drugs. Patients infected with human immunodeficiency virus took a supplement containing RA for 12 weeks, after which the RA concentrations in the plasma samples were analyzed. A detailed in silico analysis was conducted in order to elucidate the potential interactions between RA and the drugs efavirenz, darunavir and raltegravir. It was found that RA can be detected in patients’ plasma samples, mainly in the form of sulphoglucuronide. The potential interactions are suggested on the level of liver metabolizing enzymes and efflux P-glycoprotein, with RA competing with antiretroviral drugs as a substrate in metabolism and distribution systems. The present study suggests that the simultaneous use of RA and antiretroviral therapy (containing efavirenz, darunavir or raltegravir) may affect the plasma levels of RA after prolonged supplementation

Phytochemistry and Antihyperglycemic Potential of <i>Cistus salviifolius</i> L., Cistaceae

Cistus salviifolius has been previously reported as a traditional remedy for hyperglycemia. However, the plant has been scarcely investigated from scientific point of view. Thus, the aim was to examine the chemical composition and to evaluate its antioxidant and antihyperglycemic potential in vitro. Aqueous and ethanolic extracts were evaluated for total phenolic, tannin, and flavonoid content using spectrophotometric methods. Detailed chemical characterization was performed by high-performance liquid chromatography (HPLC-DAD). The volatile organic compounds (VOCs) profile was assessed by gas chromatography technique. The potential in diabetes treatment was evaluated through tests of free radicals neutralization, inhibition of lipid peroxidation process, and test of ferric ion reduction; activity in tests of inhibition of α-amylase, α-glucosidase and dipeptidyl peptidase-4 was also evaluated. High content of phenolics (majority being tannins) was detected; detailed HPLC analysis revealed high content of gallic acid, followed by rutin, chlorogenic and caffeic acids. The VOCs analysis determined sesquiterpene hydrocarbons and oxygenated sesquiterpenes as the main groups of compounds. The assays classified extracts as potent neutralizers of 2,2-diphenyl-1-picrylhydrazil and nitroso radicals formation and potent inhibitors of α-amylase and α-glucosidase. In conclusion, Cistus salviifolius represents a rich source of phenolics and essential oil with sesquiterpenes. The established results suggested its promising antioxidant and antihyperglycemic activities

Natural Agents against Bovine Mastitis Pathogens

Bovine mastitis is the most widespread and economically important disease worldwide. The present study aimed to determine bioactive compounds in two essential oils (EOs) from wild (Thymus serpyllum) and common thyme (Thymus vulgaris) and to assess the antioxidant potential as well as antibacterial efficacy of the EOs against mastitis-associated bacteria. The study also included antibiotic susceptibility tests. The strains were previously isolated from lactating animals with clinical and subclinical mastitis. The antioxidant potential of the commercial EOs of wild and common thyme was evaluated by five in vitro assays. The antibacterial activity was performed using the microdilution technique, while antibiotic susceptibility testing was performed by the Kirby–Bauer disc diffusion method. The dominant compound in wild thyme was thymol (45.22%), followed by p-cymene (23.83%) and γ-terpinene (3.12%), while in common thyme, it was thymol (54.17%), followed by γ-terpinene (22.18%) and p-cymene (16.66%). Among the fourteen mastitis-associated bacteria, strain IX Streptococcus spp. (β-hemolytic) was the most sensitive to the tested EOs (minimum inhibitory concentration (MIC)/minimal bactericidal concentration (MBC) were 0.78/1.56 and 0.39/0.78 mg/mL for T. serpyllum (TS) and T. vulgaris (TV), respectively). Regarding Streptococcus spp. β heamoliticus, MICs for TS ranged from 0.78 to 1.56 mg/mL, while for the same oil, MBCs ranged from 1.56 to 12.5 mg/mL. In the case of T. vulgaris, MICs ranged from 0.39 to 3.125 mg/ mL, while MBCs ranged from 3.125 to 6.25 mg/mL. TV is more active against E. coli, E. sakazakii, and Streptococcus spp., while it is less effective against Staphylococcus spp. than TS. The study revealed that the tested EOs possess remarkable antioxidative and antibacterial activities and could be used in the development of pharmaceutical formulation as an alternative to conventional mastitis therapy