25 research outputs found
Dracocephalum moldavica L. and Melissa officinalis L. : Chemistry and Bioactivities Relevant in Alzheimer’s Disease Therapy
Oksidatiivisen stressin eli liiallisen reaktiivisten happiyhdisteiden määrän soluissa on jo pitkään arveltu olevan tärkeä Alzheimerin taudin kehittymiseen ja etenemiseen vaikuttava tekijä. Tämän vuoksi kiinnostus erilaisten antioksidanttien (yhdisteitä, jotka neutraloivat näitä happiradikaaleja soluissa) mahdollisia terapeuttisia ominaisuuksia Alzheimerin taudin hoidossa on tutkittu laajalti. Tähän mennessä ei kuitenkaan ole vielä onnistuttu löytämään antioksidanttia, joka olisi hyödyksi Alzheimerin taudin hoidossa. Tämän vuoksi on tärkeää pyrkiä löytämään uusia antioksidanttien lähteitä sekä tutkia niistä löytyviä aktiivisia yhdisteitä.
Kiinnostus luonnon antioksidantteja kohtaan on kasvanut voimakkaasti viime aikoina. Huomio on kiinnittynyt erityisesti aromaattisista sekä lääkekasveista löytyviin antioksidantteihin. Lamiaceae- perheeseen kuuluvia tuoksuampiaisyrttiä (Dracocephalum moldavica L.) ja sitruunamelissaa (Melissa officinalis L.) on käytetty Iranissa pitkään sekä ruoanlaitossa että lääkinnässä, minkä vuoksi näiden kasvien uutteiden antioksidanttisisältöä päätettiin analysoida käyttäen useaa erilaista in vitro- menetelmää. Näissä kokeissa ilmeni, että uutteilla oli useita antioksidanttisia vaikutuksia. Näistä antioksidanttisista vaikutuksista vastaavia yhdisteitä pyrittiin tunnistamaan käyttäen HPLC-PDA- tekniikkaa, minkä seurauksena niiden havaittiin sisältävän erilaisia polyfenoleita, kuten hydroksyloituneita bentsoeeni- ja cinnamamidihapon johdannaisia sekä flavonoideja. Kummankin kasvin uutteissa runsaimmin esiintynyt yhdiste oli rosmariinihappo.
Sitruunamelissaa (M. officinalis) on käytetty antiikin ajoista alkaen kognitiivisten toimintojen häiriöiden hoidossa. Perustuen tietoon kasvin käytöstä perinteisessä lääkinnässä, sen tehoa Alzheimerin taudin hoidossa on tutkittu viime aikoina kliinisin kokein. Sitruunamelissan todettiinkin olevan hyödyksi lievää ja keskivaikeaa Alzheimeimerin tautia sairastavien potilaiden hoidossa. Väitöskirjan osanan olevasta kooste-artikkelista käy ilmi, että tutkimalla lääkekasvien ominaisuuksia voidaan saada arvokkaita suuntaa-antavia vihjeitä Alzheimerin taudin lääkehoidon kehittämiseen. Tämän perusteella päätettiinkin testatata myös sitruunamelissauutteen kykyä estää asetyylikoliiniesteraasin (AChE) toimintaa, koska tämän entsyymin toiminna estämisen tiedetään olevan hyödyksi Alzheimerin taudin hoidossa. Uute kykeni estämään AChE:n toimintaa, minkä vuoksi uutteen sisältämiä komponentteja päätettiin tutkia terkemmin.
Uute jaettiin erilaisiin fraktioihin käyttäen HPLC-menetelmää, minkä jälkeen testattiin jokaisen fraktion kykyä inhiboida AchE. Suurin osa fraktioista kykeni inhiboimaan AChE:n toimintaa selkeästi tehokkaammin, kuin raakauute. Kaikista tehokkainta fraktiota analysoitiin tarkemmin sen aktiivisten yhdisteiden tunnistamiseksi, minkä seurauksena sen sisältämät yhdisteet tunnistettiin cis ja trans-rosmariinihapoiksi.
Tässä tutkimuksessa tunnistettujen yhdisteiden hyödyllisyyttä Alzheimerin taudin hoidossa tulisi seuraavaksi tutkia erilaisissa in vivo-malleissa. Lisäksi jäljellä olevien fraktioiden kemiallinen koostumus tulisi selvittää sekä antioksidanttiaktiivisuuden ja AChE:n toiminnan inhiboinnin välistä mahdollista yhteyttä tulisi tutkia tarkemmin.
Tämä tutkimus osoittaa tuoksuampiasyrtin (D. moldavica) sekä sitruunamelissan (M. officinalis) sisältävän monenlaisia aktiivisia antioksidantteja. Lisäksi sitruunamelissan sisältämät yhdisteet kykenivät estämään asetyylikoliiniesteraasin (AchE) toimintaa. Nämä tulokset tukevat osaltaan väitöskirjan osana olevan kooste-artikkelin johtopäätöksiä, joiden mukaan etnofarmakologinen kasvitutkimus voi osoittautua erittäin hyödylliseksi kehitettäessä uutta lääkehoitoa Alzheimerin tautiin. Lisäksi tässä väitöskirjassa kuvattu tutkimus osoittaakin, että perinteisesti lääkekasvina käytettyä sitruunamelissaa voidaan mahdollisesti hyödyntää uusien Alzheimerin taudin hoitoon käytettävien lääkkeiden kehityksessä.Oxidative stress has been proposed to play a cardinal role in the aetiology and pathogenesis of Alzheimer’s disease (AD). Therefore, antioxidants have been studied for their therapeutic potential in AD therapy. However, there is still a need for novel sources of antioxidants.
Recently, there has been an increased interest in aromatic and medicinal plants as sources of natural antioxidants. The plants Dracocephalum moldavica L. and Melissa officinalis L., which belong to the family Lamiaceae, have been used in Iran for their culinary usefulness and medicinal properties. Therefore, extracts of the plants were screened for antioxidant properties in a battery of in vitro assays. The plant extracts demonstrated a wide range of antioxidant activities.
Furthermore, because it was important to determine which constituents present within the extracts may contribute to the observed activity, compositional fingerprint analyses were carried out using HPLC-PDA techniques. The extracts were found to contain polyphenolic compounds such as hydroxylated benzoic and cinnamic acid derivatives and flavonoids. Rosmarinic acid was the most abundant constituent in both plants.
The plant M. officinalis has been used since antiquity in the treatment of cognitive dysfunction. The plant was recently assessed for its clinical efficacy against AD and was found to be effective in the management of mild to moderate AD patients. According to a review carried out by the author, screening of medicinal plants for bioactivities relevant in the treatment AD can provide useful leads in the discovery of drugs against AD. Therefore, in addition to antioxidant evaluation, M. officinalis was screened for another bioactivity relevant to AD therapy, viz. acetylcholinesterase (AChE) inhibition. The plant extract showed AChE inhibitory activity, which formed the basis for activity guided fractionation.
The extract was fractionated using semipreparative scale HPLC fractionation. Fractions were subsequently subjected to AChE inhibitory screening. Most of the fractions demonstrated inhibitory activity and were proved to be significantly (P < 0.05) more potent than the crude extract. This is an indication of the complex nature of potential interactions between various components within the extract. The contents of the most potent fraction were tentatively identified as a mixture of cis- and trans-rosmarinic acid using LC-DAD-MS and NMR techniques.
There is a need to further investigate the efficacy of these chemical constituents in in vivo AD models. The remaining potent fractions should be analysed further to determine the identity of their chemical constituents and the possibility of a correlation existing between antioxidant activity and AChE inhibition should be investigated.
The current study showed the multifaceted nature of antioxidant action of D. moldavica and M. officinalis. Furthermore, the latter demonstrated AChE inhibitory activity. A review of the potential benefits of ethnopharmacological screening of plants in AD therapy was made and the importance of bioactivity guided screening and fractionation of medicinal plants was highlighted. It can be concluded that M. officinalis is a potential source for discovery and development of drugs against AD
Metabolite Profiling of Jaboticaba (Myrciaria cauliflora) and Other Dark-Colored Fruit Juices
Many dark-colored fruit juices, rich in anthocyanins,
are thought
to be important for human health. Joboticaba (Myrciaria
cauliflora) fruits, native to Brazil, have phenolics
including anthocyanins and are processed into juice and other products.
The phenolic constituents in the fruits of jaboticaba were studied
by high-performance liquid chromatography coupled with electrospray
ionization time-of-flight mass spectrometry. Twenty-two compounds
were identified or tentatively determined by detailed analysis of
their mass spectral fragmentation patterns; 11 compounds including
7 gallotannins, 2 ellagic acid derivatives, syringin, and its glucoside
were detected for the first time in the fruit. The compositional differences
among the fruit extracts and their commercial products were also compared
by principal component analysis; two anthocyanins, delphinidin 3-<i>O</i>-glucoside and cyanidin-3-<i>O</i>-glucoside,
as well as two depsides, jaboticabin and 2-<i>O</i>-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic
acid, present in the fruit extracts were not detected unexpectedly
in commercial jaboticaba juice or jam. Therefore, the stability of
anthocyanins in jaboticaba fresh fruits and products has been compared
directly with that of other dark-colored fruit products made from
blueberry and Concord grape, and the same trend of decreasing amounts
of anthocyanins was observed in all tested products. The antioxidant
activities (DPPH<sup>•</sup> and ABTS<sup>•+</sup>)
of jaboticaba fresh fruit extract and commercial samples were also
compared. Principal component analysis proved to be a useful way to
discern changes between fresh and processed fruits. Jaboticaba is
a promising fruit with antioxidant capacity similar to those of other
so-called superfruits; however, during processing the levels of some
of anthocyanins and other polyphenols decrease significantly, and
therefore the capacity of these products to affect human health may
vary significantly from that of the fresh fruit
Solving the Jigsaw Puzzle of Wound-Healing Potato Cultivars: Metabolite Profiling and Antioxidant Activity of Polar Extracts
Potato (<i>Solanum
tuberosum</i> L.) is a worldwide food
staple, but substantial waste accompanies the cultivation of this
crop due to wounding of the outer skin and subsequent unfavorable
healing conditions. Motivated by both economic and nutritional considerations,
this metabolite profiling study aims to improve understanding of closing
layer and wound periderm formation and guide the development of new
methods to ensure faster and more complete healing after skin breakage.
The polar metabolites of wound-healing tissues from four potato cultivars
with differing patterns of tuber skin russeting (Norkotah Russet,
Atlantic, Chipeta, and Yukon Gold) were analyzed at three and seven
days after wounding, during suberized closing layer formation and
nascent wound periderm development, respectively. The polar extracts
were assessed using LC-MS and NMR spectroscopic methods, including
multivariate analysis and tentative identification of 22 of the 24
biomarkers that discriminate among the cultivars at a given wound-healing
time point or between developmental stages. Differences among the
metabolites that could be identified from NMR- and MS-derived biomarkers
highlight the strengths and limitations of each method, also demonstrating
the complementarity of these approaches in terms of assembling a complete
molecular picture of the tissue extracts. Both methods revealed that
differences among the cultivar metabolite profiles diminish as healing
proceeds during the period following wounding. The biomarkers included
polyphenolic amines, flavonoid glycosides, phenolic acids and glycoalkaloids.
Because wound healing is associated with oxidative stress, the free
radical scavenging activities of the extracts from different cultivars
were measured at each wounding time point, revealing significantly
higher scavenging activity of the Yukon Gold periderm especially after
7 days of wounding
Potato native and wound periderms are differently affected by down-regulation of FHT, a suberin feruloyl transferase
Potato native and wound healing periderms contain an external multilayered phellem tissue (potato skin) consisting of dead cells whose cell walls are impregnated with suberin polymers. The phellem provides physical and chemical barriers to tuber dehydration, heat transfer, and pathogenic infection. Previous RNAi-mediated gene silencing studies in native periderm have demonstrated a role for a feruloyl transferase (FHT) in suberin biosynthesis and revealed how its down-regulation affects both chemical composition and physiology. To complement these prior analyses and to investigate the impact of FHT deficiency in wound periderms, a bottom-up methodology has been used to analyze soluble tissue extracts and solid polymers concurrently. Multivariate statistical analysis of LC-MS and GC-MS data, augmented by solid-state NMR and thioacidolysis, yields two types of new insights: the chemical compounds responsible for contrasting metabolic profiles of native and wound periderms, and the impact of FHT deficiency in each of these plant tissues. In the current report, we confirm a role for FHT in developing wound periderm and highlight its distinctive features as compared to the corresponding native potato periderm.This work was supported by grants from the U.S. National Science Foundation (NSF MCB-0843627, 1411984, and 0741914 to R.E.S.), from the Spanish Ministerio de Economía y Competitividad and FEDER funding (AGL2012-36725; AGL2015-67495-C2-1-R), and from the University of Guelph (MPCUdG2016/078). The NMR resources were operated by The City College of New York and the CUNY Institute for Macromolecular Assemblies. Infrastructural support for the NMR facilities was provided by the U.S. National Institutes of Health (5G12MD007603-30 from the National Institute on Minority Health and Health Disparities). The GC-MS instrument was supported by the U.S. NSF (CHE-0840498) and the GC-FID instrument by the University of Guelph (SING11/1).Peer reviewe
Comprehensive MS and Solid-State NMR Metabolomic Profiling Reveals Molecular Variations in Native Periderms from Four <i>Solanum tuberosum</i> Potato Cultivars
The
potato (<i>Solanum tuberosum</i> L.) ranks third
in worldwide consumption among food crops. Whereas disposal of potato
peels poses significant challenges for the food industry, secondary
metabolites in these tissues are also bioactive and essential to crop
development. The diverse primary and secondary metabolites reported
in whole tubers and wound-healing tissues prompted a comprehensive
profiling study of native periderms from four cultivars with distinctive
skin morphologies and commercial food uses. Polar and nonpolar soluble
metabolites were extracted concurrently, analyzed chromatographically,
and characterized with mass spectrometry; the corresponding solid
interfacial polymeric residue was examined by solid-state <sup>13</sup>C NMR. In total, 112 secondary metabolites were found in the phellem
tissues; multivariate analysis identified 10 polar and 30 nonpolar
potential biomarkers that distinguish a single cultivar among Norkotah
Russet, Atlantic, Chipeta, and Yukon Gold cultivars which have contrasting
russeting features. Compositional trends are interpreted in the context
of periderm protective function
Sustainable fabrication of plant cuticle-like packaging films from tomato pomace agro-waste, beeswax, and alginate
Plant cuticles have been used as models to produce hydrophobic films composed of sodium alginate, the fatty acid fraction of tomato pomace agrowaste, and beeswax. The fabrication process consisted of the blending of components in green solvents (water and ethanol) and a subsequent thermal treatment (150 °C, 8 h) to polymerize unsaturated and polyhydroxylated fatty acids from tomato pomace. When sodium alginate and tomato pomace fatty acids were blended, free-standing films were obtained. These films were characterized to evaluate their morphological (SEM), chemical (solid-state NMR, ATR-FTIR), mechanical (tensile tests), thermal (TGA), and hydrodynamic (water contact angle, uptake, and permeability) properties. A comparison between nonpolymerized and polymerized samples was carried out, revealing that the thermal treatment represents a sustainable route to create structured, composite networks of both components. Finally, beeswax was added to the blend with the same amounts of sodium alginate and tomato pomace fatty acids. The presence of the wax improved the hydrophobicity and the mechanical and water barrier properties as well as decreased the water uptake. These results indicate that polymerized plant cuticle-like films have valuable potential for packaging applications
Defensive Armor of Potato Tubers: Nonpolar Metabolite Profiling, Antioxidant Assessment, and Solid-State NMR Compositional Analysis of Suberin-Enriched Wound-Healing Tissues
The
cultivation, storage, and distribution of potato tubers are
compromised by mechanical damage and suboptimal healing. To investigate
wound-healing progress in cultivars with contrasting russeting patterns,
metabolite profiles reported previously for polar tissue extracts
were complemented by GC/MS measurements for nonpolar extracts and
quantitative <sup>13</sup>C NMR of interfacial solid suspensions.
Potential marker compounds that distinguish cultivar type and wound-healing
time point included fatty acids, fatty alcohols, alkanes, glyceryl
esters, α,ω-fatty diacids, and hydroxyfatty acids. The
abundant long-chain fatty acids in nonpolar extracts and solids from
the smooth-skinned Yukon Gold cultivar suggested extensive suberin
biopolymer formation; this hypothesis was supported by high proportions
of arenes, alkenes, and carbonyl groups in the solid and among the
polar markers. The absence of many potential marker classes in nonpolar
Atlantic extracts and interfacial solids suggested a limited extent
of suberization. Modest scavenging activities of all nonpolar extracts
indicate that the majority of antioxidants produced in response to
wounding are polar
Antioxidant and Metabolite Profiling of North American and Neotropical Blueberries Using LC-TOF-MS and Multivariate Analyses
There are many neotropical blueberries,
and recent studies have
shown that some have even stronger antioxidant activity than the well-known
edible North American blueberries. Antioxidant marker compounds were
predicted by applying multivariate statistics to data from LC-TOF-MS
analysis and antioxidant assays of 3 North American blueberry species
(Vaccinium corymbosum, Vaccinium angustifolium, and a defined mixture of Vaccinium virgatum with <i>V. corymbosum</i>) and 12 neotropical blueberry species (Anthopterus
wardii, Cavendishia grandifolia, Cavendishia isernii, Ceratostema silvicola, Disterigma
rimbachii, Macleania coccoloboides, Macleania cordifolia, Macleania rupestris, Satyria boliviana, Sphyrospermum buxifolium, Sphyrospermum cordifolium, and Sphyrospermum
ellipticum). Fourteen antioxidant markers were detected,
and 12 of these, including 7 anthocyanins, 3 flavonols, 1 hydroxycinnamic
acid, and 1 iridoid glycoside, were identified. This application of
multivariate analysis to bioactivity and mass data can be used for
identification of pharmacologically active natural products and may
help to determine which neotropical blueberry species will be prioritized
for agricultural development. Also, the compositional differences
between North American and neotropical blueberries were determined
by chemometric analysis, and 44 marker compounds including 16 anthocyanins,
15 flavonoids, 7 hydroxycinnamic acid derivatives, 5 triterpene glycosides,
and 1 iridoid glycoside were identified