The major objectives of this research were to produce a phenolic rich isolate from two locally grown Saskatchewan fruits, chokecherries and saskatoons, develop an encapsulation system for the phenolic isolate, and test this system for the delivery of the phenolic isolate in an animal (rat) model. Natural phenolic compounds present in plants such as fruits have antioxidant and free radical scavenging activities, which have been proposed to have health benefits. The extraction of these compounds from plants is commonly performed using methanol despite being toxic to both humans and animals. As such, ethanol was investigated for its ability to extract phenolics from plants as a food safe alternative to methanol. Phenolic extraction from chokecherries with ethanol:formic acid:water (EFW) resulted in higher concentrations (9.83 mg gallic acid equivalents (GAE)/g fresh weight) than with methanol:formic acid:water (MFW) (7.97 mg GAE/g fresh weight). Results from saskatoons showed similar phenolic levels of 4.26 and 4.21 mg GAE/g fresh weight with MFW and ethanol (EFW), respectively. These results showed that EFW was a suitable substitute for MFW in phenolic compound isolation from chokecherries and saskatoons, and could be used to produce extracts that were safe for use in foods and feeds. High performance liquid chromatography with photodiode array detection (HPLC-PDA) was used to determine the phenolic compound composition of the raw fruits and their phenolic rich isolates. Chlorogenic acid was identified in both chokecherry and saskatoon samples, and rutin was also shown to be present in saskatoons. These identifications were based on the relative retention time and ultra violet-visual spectra comparisons to standards. Solid phase extraction (SPE) using Amberlite XAD-16 was employed to produce phenolic isolates from chokecherries and saskatoons. HPLC-PDA results determined that there was a ~2.7x and ~1.6x increase in peak area for chokecherries and saskatoons, respectively when SPE was employed. The antioxidant activity of the extracts and isolates was determined using in vitro radical scavenging tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethylbenzthiazoline-sulphonic acid (ABTS). The EFW chokecherry extract and isolate had the highest overall free radical scavenging activity. Crude fruit extracts exhibited lower free radical scavenging values compared to the isolate samples in both of the assays performed. The fruit phenolic isolates were encapsulated in chitosan (CH) sodium tripolyphosphate (TPP) nanoparticles at a ratio of 4.0:1.0 (CH:TPP). HPLC-PDA was used to determine the entrapment efficiency of phenolic isolates to be 15.9 ± 2.7% and 23.0 ± 7.1% for chokecherries and saskatoons, respectively. Characteristics such as the size, surface potential and phenolic release were determined for the two fruit isolate containing nanoparticles. The size of the nanoparticles were 527.90 ± 74.57 nm and 443.03 ± 15.79 nm for chokecherries and saskatoons, respectively. Both of the nanoparticle systems had positive surface charges at 52.70 ± 2.93 mV and 54.43 ± 1.27 mV for chokecherries and saskatoons, respectively. The release properties of the CH:TPP nanoparticles containing fruit phenolics were examined in enzymatic simulated intestinal fluid and resulted in ~23% and ~28% release of chokecherry and saskatoon phenolics, respectively. Saskatoon phenolic isolates and isolates encapsulated in CH:TPP were gavage fed to rats (six animals in each of the two groups) at a dosage rate of 276.36 ± 9.74 mg/kg body weight. The saskatoon isolate contained 12.44 ± 0.44 mg/kg body weight anthocyanins (~3.30 mg anthocyanin per rat). These animals were sacrificed after 1 h and all stomach tissue samples in each of the treatment groups contained detectable levels of anthocyanins. In the small intestine tissues all six of the saskatoon isolate and three of the encapsulated isolate groups had detectable amounts of anthocyanins, while in the large intestine tissue, only one sample from the isolate group showed detectable amounts of anthocyanins. Although other tissues were tested (brain, heart, kidney and liver), anthocyanins were not detected. Therefore anthocyanins were detected in the gastrointestinal tract of both of the treatment groups. The research performed therefore illustrated that phenolic compounds can be extracted from fruit sources using EFW and can be successfully encapsulated in chitosan tripolyphosphate capsules allowing for targeted delivery in an animal model.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 78-86). Also available on the Internet.

Diss.--Basel. / Vita.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 78-86). Also available on the Internet.

Στόχος της παρούσας διατριβής είναι η προσέγγιση του ρόλου ή των ρόλων των ανθοκυανινών στα φύλλα. Σε πολλά φυτικά είδη παρατηρείται το φαινόμενο του παροδικού ερυθρού χρωματισμού των φύλλων. Υπεύθυνες για την ερυθρότητα αυτή είναι οι ανθοκυανίνες που συντίθενται στα φύλλα αυτά. Προκειμένου να ανακαλύψουμε το ρόλο των ανθοκυανινών πραγματοποιήσαμε συγκρίσεις διαφόρων παραμέτρων ανάμεσα σε πράσινα (χωρίς ανθοκυανίνες) και κόκκινα (με ανθοκυανίνες) φύλλα. Στο πρώτο πείραμα που έγινε σε εργαστηριακές συνθήκες, μετρήθηκε η επίδραση ενός οξειδωτικού παράγοντα, του μεθυλ-βιολογόνου, στη φωτοχημική απόδοση πράσινων και κόκκινων φύλλων τεσσάρων ειδών (Cistus creticus, Photinia  fraseri, Rosa sp. Ricinus communis). Τα δύο πρώτα είδη διαθέτουν τις ανθοκυανίνες στα φωτοσυνθετικά κύτταρα του μεσόφυλλου, ενώ τα δύο άλλα στα μη φωτοσυνθετικά κύτταρα της επιδερμίδας. Στο δεύτερο πείραμα που έγινε σε συνθήκες πεδίου, μετρήθηκε εποχιακά η φωτοχημική απόδοση πράσινων και κόκκινων φύλλων του C. creticus. Τέλος, στο τρίτο πείραμα που επίσης πραγματοποιήθηκε στο εργαστήριο, μελετήθηκε η επίδραση του κόκκινου φωτισμού στη σύνθεση ανθοκυανινών σε φύλλα από το είδος Coleus blumei. Το μεθυλ-βιολογόνο επηρεάζει αρνητικά τόσο τα κόκκινα όσο και τα πράσινα φύλλα. Βρέθηκε όμως ότι τα φύλλα με τις ανθοκυανίνες στο μεσόφυλλο είναι πιο ανθεκτικά απέναντι στην οξειδωτική καταπόνηση σε σχέση με τα φύλλα με τις ανθοκυανίνες στην επιδερμίδα, γεγονός που ενισχύει την άποψη σχετικά με τον αντιοξειδωτικό ρόλο των ανθοκυανινών, μια και οι οξειδωτικές ρίζες σχηματίζονται περισσότερο στα κύτταρα του μεσόφυλλου. Το πείραμα του πεδίου, έδειξε πως τα άτομα C. creticus που συνθέτουν ανθοκυανίνες στα φύλλα τους διαθέτουν μια εγγενή κατωτερότητα της φωτοσυνθετικής τους δραστηριότητας, που όμως αντισταθμίζεται μόλις ξεκινήσει η σύνθεση των ανθοκυανινών. Αυτό το εύρημα παραπέμπει σε φωτοπροστατευτικό ρόλο των ανθοκυανινών. Τέλος, ο κόκκινος φωτισμός που χρησιμοποιήθηκε για την ανάπτυξη φύλλων του C. blumei δεν έδειξε σαφή αποτελέσματα σε σχέση με το ρόλο των ανθοκυανινών. / The aim of this work is finding out the possible role or roles of anthocyanins in leaves. In many plant species leaves temporarily turn red. Anthocyanins produced in these leaves are responsible for this redness. In order to discover the role of anthocyanins we compared some parameters between green (without anthocyanins) and red (containing antocyanins) leaves. In the first experiment, carried out in the laboratory, we measured the effect of methyl-viologen, an oxidative factor, in the photochemical efficiency of green and red leaves of four species (Cistus creticus, Photinia  fraseri, Rosa sp. Ricinus communis). The first two of these species contain anthocyanins in the photosynthetic mesophyll cells. The other two contain anthocyanins in the non photosynthetic epidermal cells. In a second experiment, carried out in the field, we measured the photochemical efficiency of green and red leaves of C. creticus during the period of a year. Finally, in a third experiment, also carried out in the laboratory, we studied the effect of red light in anthocyanin synthesis of Coleus blumei leaves. Methyl-viologen affects both red and green leaves. However, leaves with anthocyanins in the mesophyll cells show less damage than leaves with anthocyanins in the epidermis. This fact is compatible with an antioxidant role of those pigments, since the oxidative species are mostly produced in the mesophyll cells. The field experiment showed that the individuals which temporarily produce anthocyanins have a photosynthetic “inferiority” compared with individuals that don’t produce these red pigments. This inferiority is compensated once the anthocyanin synthesis begins. This result points out the photoprotective role of anthocyanins. The results of the last experiment are rather confusing about the effect of red light in anthocyanin synthesis.

No description available.

Pastaruoju metu daug mokslinių tyrimų atliekama su flavonoidų klasei priskiriamais antocianinais – augaliniais pigmentais, kurie aptinkami uogose, vaisiuose ir daržovėse ir suteikia jiems mėlyną, raudoną ir violetinę spalvas. Literatūroje aprašytas antocianinų poveikis, apsaugantis nuo širdies ir kraujagyslių ligų, siejamas su antocianinų antioksidaciniu veikimu. Mes iškėlėme hipotezę, kad antocianinai gali apsaugoti širdį redukuodami citozolyje esantį citochromą c. Šio darbo tikslas yra ištirti antocianinų poveikį žiurkės širdies mitochondrijų oksidacinio fosforilinimo sistemos efektyvumui bei nustatyti, kokius už ląstelės žūtį atsakingus viduląstelinius signalinius kelius reguliuoja šie junginiai. Iškelti uždaviniai: 1. Ištirti tiesioginį penkių dažniausiai gamtoje sutinkamų antocianinų poveikį žiurkės širdies mitochondrijų kvėpavimui skirtingose metabolinėse būsenose. 2. Nustatyti įvairių antocianinų gebėjimą redukuoti citochromą c in vitro. 3. Nustatyti, ar antocianinai – citochromo c reduktoriai – apsaugo nuo išemijos sukeltų oksidacinio fosforilinimo sistemos pažeidimų ir kaspazių aktyvacijos bei nuo išemijos/reperfuzijos sukeltos kardiomiocitų apoptozės ir nekrozės. 4. Ištirti, ar stipriu citochromą c redukuojančiu aktyvumu pasižymintys antocianinai gali atstatyti mitochondrijų oksidacinio fosforilinimo sistemos efektyvumą po išemijos. 5. Patikrinti, ar tirtųjų antocianinų poveikis širdies mitochondrijų funkcijoms bei apsauginis nuo išemijos ir išemijos/reperfuzijos. / A lot of research is carried out with anthocyanins, which are widely prevalent among colored berries, fruits, and vegetables and give them blue, red, violet, and purple colors. It is known that consumption of dietary plants and products rich in anthocyanins can reduce the risk of cardiovascular diseases. This protective effect is related to the antioxidant properties of anthocyanins. We have raised the hypothesis that anthocyanins could protect cardiomyocytes from ischemia/reperfusion-induced cell death reducing cytosolic cytochrome c. The aim of this work was to investigate the effect of anthocyanins on heart mitochondrial oxidative phosphorylation and determine what intracellular signaling pathways responsible for cell death are regulated by these compounds. The tasks of the study were: 1. To investigate the direct effect of anthocyanins on rat heart mitochondrial respiration rates; 2. To determine the ability of anthocyanins to reduce cytochrome c in vitro; 3. To determine whether anthocyanins – cytochrome c-reducing compounds – protect heart mitochondria from ischemia-induced mitochondrial dysfunction and ischemia/reperfusion-induced cardiomyocyte apoptosis and necrosis; 4. To examine whether anthocyanins with high cytochrome-c reducing activity can restore the efficiency of mitochondrial oxidative phosphorylation after ischemia; 5. To verify whether the effect of the investigated anthocyanins on cardiac mitochondrial function and their protective effect on... [to full text]

Graduation date: 1992

Thesis (M.S.)--Michigan State University. Dept. of Horticulture, 2006. / Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 161-168). Also issued in print.

Diss.--Basel. / Vita.