Antioxidant Evaluation of Coriander Extract and Ascorbyl Palmitate in Sunflower Oil Under Thermoxidation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Artemia enriched with unsaturated fatty acids and vitamin C on growth, survival and resistance Salmo trutta caspius larvae

This experiment was conducted to investigate the effect of using n-3 HUFA and Vitamin C enriched Artemia urmiana Nauplii Five difference treament were tested: for Caspian salmon (Salmo trutta caspius) larvae compare with artificial food in five treatment: (1) Artificial food, (2) Newly hatched Artemia (3) n-3 HUFA enriched Artemia (4) n-3 HUFA + 10% Ascorbyl Palmitate enriched Artemia (5) n-3 HUFA+20% Ascorbyl palmitate enriched Artemia during 15 days then all treatment were fed with artificial food during 20 days. In days of 15, larvae fed with newly hatched Artemia didn’t show significant difference of growth rate and survival compared to larvae fed with n-3 HUFA and Vitamn C enriched live food (p<0.05), However all treatment which fed live food have better growth rate and survival compred to larvae fed artificial food. Larvae fed with enriched Artemia with n-3 HUFA + 20% Ascorbyl palmitate has best result of temperature resistance at 26'C and 28'C. There is not significant difference between treatment (1) and (2), (3) and in this manner between (2), (3) and (4), (5) (P>0.05). In days of 35, larvae fed n-3 HUFA + 10% and 20% Ascorbyl pamlitate show better wet weight and dry weight compared to other treatment (P<0.05). Larvae fed n-3 HUFA Artemia showed significant difference compared to treatment (1) and (2), However there is not significant difference between treatment (1) and (2). Larvae fed artificial food show less and significant difference of survival compared to other treatment (P<0.05). Larvae fed artificial food show least of temperature resistance at 26'C and 28'C , However, there is not significant difference between all treatment (P<0.05).

The study of Indian shrimp larvae feeding by enriched rotifer with vitamin C and unsaturated fatty acid (epa, dha) and its effects on growth factors, survival rate and environmental stresses

In this experiment, the feeding of Indian white shrimp larvae by unenriched rotifers (treatment 1) and enriched with highly unsaturated fatty acid (treatment 2) and highly unsaturated fatty acid along with vitamin C (treatment 3) on the growth factors, survival and resistance against salinity and formalin stress tests were studied and their differences with control treatment including newly hatched Artemia nauplii is compared. In this the study four treatments in a completely randomized design with 3 replicates per treatment were used. Farming of shrimp larvae of Zoea II to postlarvae 5 was done in 20 liter plastic bucket. Present results indicated that growth factors and survival rate of stage Zoea II to postlarvae 1 in treatments 1, 2 and 3 improve rather than control in which this case was due to optimal size rotifer rather than Artemia nauplii. Also, treatments 2 and 3 feeding with oil liver cod emulsion enriched rotifer have the highest concentration of DHA (mg/g DW) and the ratio DHA/EPA in which due to have shown the highest growth factors and a significant difference (P<0.05) with treatments 1 and control. The highest survival at stage PL1 were observed in treatment 3 that was enriched with ascorbyl palmitate in which have to the synergistic properties of vitamin C rather than treatments 2, 1 and control and showed a significant difference (P<0.05). But in stage PL5 the highest amount of growth and survival rates were related to control treatment which showed a significant difference (P<0.05) with other treatments that control has higher size rather than treatments 1, 2 and 3. Also, among experiment treatments that the two treatments 2 and 3 due to enrichment had higher growth and survival rates compared with treatment 1 in which their differences have also been significant (P<0.05). In the case of stress tests, results indicated that the highest survival rate has been reported when specimens were offered a diet containing high levels of highly unsaturated fatty acids with vitamin C. So that in stage PL1 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3. As for the second, treatment 2 showed a significant difference (P<0.05) with treatment 3. It is worth mentioning that treatment 3 showed a higher survival rate compared to treatment 2 due to the synergistic properties of vitamin C. The difference between these two treatments with treatment 1 and control was also significant. No significant difference was observed in formalin stress test 100 ppm in this stage between treatments 3 and 2 which shows the highest survival rate. But their difference with treatments 1 and control was significant (P<0.05). Also, in stage PL5 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3 which showed no significant difference (P<0.05) with control treatment. While their difference in the amount of survival rate with treatment 1 and 2 was significant (P<0.05). In this stage, the highest observed survival rate in formalin stress test 100 ppm included treatments control, 3 and 2 among which there were no significant differences (P<0.05). While the difference between these three treatments with treatment 1 was significant.

Antioxidant properties of annatto carotenoids

The antioxidant effects of beta-carotene, oil-soluble (bixin) and water-soluble (norbixin) annatto preparations and mixtures of these carotenoids with virgin olive oil polar extract were assessed in bulk olive oil and oil-in-water emulsions stored at 60degreesC. Norbixin was the only carotenoid that inhibited the oxidative deterioration of lipids in both systems. Though bixin and beta-carotene did not retard autoxidation, their mixtures with the polar extract from virgin olive oil enhanced the antioxidant effect of the olive oil extract. Norbixin (2 mM) was of similar activity to delta-tocopherol (0.1 mM) in stored oil. The combination of norbixin with ascorbic acid or ascorbyl palmitate in oil showed a reduction in formation of volatile oxidation products but not in peroxide value, compared with the analogous sample lacking norbixin. In olive oil-in-water emulsions, norbixin (2 mM) reduced hydroperoxide formation to a similar extent as delta-tocopherol (0.1 mM), which in turn was a better antioxidant than alpha-tocopherol. A synergistic effect between norbixin and ascorbic acid or ascorbyl palmitate was observed in the emulsion systems. (C) 2003 Elsevier Ltd. All rights reserved.

Drug Excipient Interaction Study with Polymorphic Forms of Tibolone

Powder mixtures (1:1) of tibolone polymorphic forms I (monoclinic) and II (triclinic) and excipients have been prepared and compacted. The samples were stored at 50 degrees C and 90% RH for one month and subsequently were evaluated using differential scanning calorimetry (DSC) and high-performance liquid chromatography (HPLC). The results indicate that during the compaction, the applied pressure reduced the chemical stability of tibolone in both polymorph forms. The triclinic form was more chemically unstable, both pure and in contact with excipients, than the monoclinic form. Lactose monohydrate was shown to reduce chemical degradation for both forms. Ascorbyl palmitate was shown to affect the tibolone stability differently depending on the polymorphic form used.

Avaliação do óleo de girassol adicionado de antioxidantes sob estocagem

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da estabilidade oxidativa do óleo bruto de açaí (Euterpe oleracea) na presença de compostos fenólicos puros ou de extratos vegetais amazônicos

ABSTRACT: A final 241 µM of ascorbyl palmitate and 555 µM of the following antioxidants separately: BHA, myricetin and quercetin standards, and extracts of Byrsonima crassifolia, Inga edulis or Euterpe oleracea, were added to crude açai oil and submitted to the oxidation process at 60 ºC for 11 days. Among the antioxidants used, only the myricetin standard showed the ability to defer the oxidation process until the third day of treatment. B. crassifolia, I. edulis and E. oleracea extracts showed no preventive capacity against the oxidation process, despite their high concentration phenolic compounds and antioxidant activities.

Artifactual oxidation of cholesterol during the analysis of cholesterol oxidation products: protective effect of antioxidants

To study the influence of the addition of various antioxidants and their combinations on the artifactual oxidation of cholesterol during analysis, 2 factorial experiments were performed in duplicate. In the first experiment, 2 amounts of the following antioxidants were assayed: ethylenediaminetetraacetic acid (EDTA) disodium salt (0 and 1 mg), pyrogallol (0 and 600 microg), and butylated hydroxytoluene (BHT; 0 and 600 microg); in the second, EDTA disodium salt (0 and 1 mg), ascorbyl palmitate (0 and 600 microg), and BHT (0 and 600 microg). Under low oxidative conditions of dim light, evaporation of solvents at low temperatures, and cold saponification in darkness under nitrogen atmosphere, the addition of antioxidants showed no further protective effect. Furthermore, the presence of ascorbyl palmitate significantly increased the formation of cholesterol-5beta,6beta-epoxide, and 7beta-hydroxycholesterol.

Mechanistic studies of mouse skin tumor promotion by chrysarobin

Since the anthrone chrysarobin oxidizes and generates free radicals, investigations were conducted to assess a possible role for free radicals or reactive oxygen species (ROS) in skin tumor promotion by chrysarobin. Epidermal glutathione levels were not noticeably altered by chrysarobin, nor did a glutathione-depleting agent enhance promotion by chrysarobin. Multiple applications of chrysarobin increased lipid peroxide levels in mouse epidermis two-fold as compared with controls. The antioxidant $\alpha$-tocopherol and the lipoxygenase inhibitor nordihydroguaiaretic acid both inhibited production of lipid peroxides by chrysarobin. The antioxidants $\alpha$-tocopherol acetate and ascorbyl palmitate effectively inhibited promotion and promoter-related effects induced by chrysarobin. Since prooxidant states can lead to increases in intracellular Ca$\sp{2+}$, the effect of two Ca$\sp{2+}$ antagonists, verapamil and TMB-8, on chrysarobin-induced promotion and promoter-related effects were investigated. Both Ca$\sp{2+}$ antagonists inhibited promotion and promoter-related effects induced by chrysarobin, suggesting a possible role for intracellular Ca$\sp{2+}$ alterations in chrysarobin-tumor promotion. Since radical generating compounds are reported to possess the ability to enhance progression of papillomas to squamous cell carcinomas (SCCs), the effects of chrysarobin on papilloma development were tested. Growth kinetics and regression of papillomas generated with limited promotion with chrysarobin were similar to what was reported for the nonradical generating promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (Aldaz et al., 1991). To test the chrysarobin's ability to enhance progression of pre-existing papillomas to SCCs, tumors were generated by initiation with dimethylbenz (a) anthracene and promotion with TPA. Then mice were treated with chrysarobin, TPA or acetone for 45 weeks. When mice treated with chrysarobin were compared to mice treated continually with TPA with similar numbers of papillomas, the number of papillomas that progressed to SCCs was similar, suggesting that papilloma burden influences the progression of papillomas to SCCs, rather than radical production. In summary, the present study suggests that chrysarobin produces oxidative stress in mouse epidermis as indicated by the generation of lipid peroxides. Antioxidants inhibited production of lipid peroxides and tumor promotion by chrysarobin. Collectively, these data suggest a role for free radicals or ROS in tumor promotion by chrysarobin. ^

Degradation, receptor binding, insulin secreting and antihyperglycaemic actions of palmitate-derivatised native and Ala(8)-substituted GLP-1 analogues

The hormone glucagonlike peptide-1(736)amide (GLP-1) is released in response to ingested nutrients and acts to promote glucosedependent insulin secretion ensuring efficient postprandial glucose homeostasis. Unfortunately, the beneficial actions of GLP-1 which give this hormone many of the desirable properties of an antidiabetic drug are short lived due to degradation by dipeptidylpeptidase IV (DPP IV) and rapid clearance by renal filtration. In this study we have attempted to extend GLP-1 action through the attachment of palmitoyl moieties to the epsilon-amino group in the side chain of the Lys(26) residue and to combine this modification with substitutions of the Ala(8) residue, namely Val or aminobutyric acid (Abu). In contrast to native GLP-1, which was rapidly degraded, [Lys(pal)(26)]GLP-1, [Abu(8),Lys(pal)(26)]GLP-1 and [Val(8),Lys(pal)(26)]GLP-1 all exhibited profound stability during 12 h incubations with DPP IV and human plasma. Receptor binding affinity and the ability to increase cyclic AMP in the clonal beta-cell line BRIN-BD11 were decreased by 86- to 167-fold and 15- to 62-fold, respectively compared with native GLP-1. However, insulin secretory potency tested using BRIN-BD11 cells was similar, or in the case of [Val(8),Lys(pal)(26)]GLP-1 enhanced. Furthermore, when administered in vivo together with glucose to diabetic (ob/ob) mice, [Lys(pal)(26)]GLP-1, [Abu(8),Lys(pal)(26)]GLP-1 and [Val8,Lys(pal)26]GLP-1 did not demonstrate acute glucoselowering or insulinotropic activity as observed with native GLP-1. These studies support the potential usefulness of fatty acid linked analogues of GLP-1 but indicate the importance of chain length for peptide kinetics and bioavailability.

Effets de plantes réputées antidiabétiques sur un modèle cellulaire hépatique de résistance à l’insuline induite par le palmitate

La pharmacopée Cris est riche en plantes médicinales et plusieurs d’entre elles sont étudiées par notre laboratoire pour leur potentiel antidiabétique. Certaines espèces ont démontré leur capacité à stimuler la protéine kinase activée par l’AMP (AMPK), une enzyme qui favorise la translocation de transporteurs de glucose à la membrane (effet hypoglycémiant). L’AMPK stimule également d’autres fonctions, telle l’oxydation des graisses, dans le but de rétablir l’énergie cellulaire. Ce projet a comme objectifs d’évaluer, premièrement, le stress métabolique induit par huit des extraits dans des cellules musculaires et des hépatocytes, effet qui serait responsable de l’activation de l’AMPK. Ce stress peut être déterminé en mesurant l’acidification du milieu extracellulaire ainsi que la déplétion du contenu en ATP des cellules suite aux traitements. Le deuxième objectif est de mesurer l’efficacité des extraits à réduire le contenu en gras (oxydation des graisses) et à ainsi normaliser la résistance à l’insuline dans des hépatocytes rendus insulino-résistants. Les hépatocytes sont rendus résistants à l’insuline (condition fortement lié à l’obésité) via traitement avec un acide gras saturé, le palmitate. Les résultats montrent que la majorité des extraits semble induire un stress métabolique de courte durée dans les cellules. Parmi les extraits, seul un a réussi à faire diminuer significativement le taux de triglycérides intracellulaire suite au traitement au palmitate sans toutefois améliorer la sensibilité à l’insuline. En conclusion, le potentiel hypoglycémiant des extraits serait du à leur capacité à affecter la respiration mitochondriale (stress métabolique). Toutefois, leur capacité à améliorer la sensibilité à l’insuline n’a pu être établie.