Antioxidant capacity of anthocyanins from acerola genotypes

Anthocyanins from 12 acerola genotypes cultivated at the Active Germplasm Bank at Federal Rural University of Pernambuco were isolated for antioxidant potential evaluation. The antioxidant activity and radical scavenging capacity of the anthocyanin isolates were measured according to the β-carotene bleaching method and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, respectively. The antioxidant activity varied from 25.58 to 47.04% at 0.2 mg.mL-1, and it was measured using the β-carotene bleaching method. The free radical scavenging capacity increased according to the increase in concentration and reaction time by the DPPH assay. At 16.7 μg.mL-1 concentration and after 5 minutes and 2 hours reaction time, the percentage of scavenged radicals varied from 36.97 to 63.92% and 73.27 to 94.54%, respectively. Therefore, the antioxidant capacity of acerola anthocyanins varied amongst acerola genotypes and methods used. The anthocyanins present in this fruit may supply substantial dietary source of antioxidant which may promote health and produce disease prevention effects.

Chemical characterization of leaves of organically grown carrot Dacus carota L.) in various stages of development for use as food

In Brazil, street markets and vegetable distributors discard vegetable leaves and stems, including those of carrot (Dacus carota L.). Seeking to reduce the waste of vegetable parts, this study characterized chemically the leaves of organically grown carrot in three stages of development to determine the best time for their removal and consumption as food. The leaves were dehydrated in an oven at 70 °C for 43 hours and analyzed for chemical composition, antioxidant activity, chlorophyll content, fatty acid composition, and also calcium (Ca), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), zinc (Zn), and copper (Cu) contents. The analyses indicated 100 days of development as the ideal stage for the removal and consumption of carrot leaves with good antioxidant activity requiring only 63.78 ± 0.5 mg.L-1 methanol leaf extract to inhibit 50% of the concentration of the free radical DPPH (2,2-diphenyl-1picrilidrazil), and total protein and alpha-linolenic acid (18:3 n-3/LNA) contents of 18.23% ± 2.8 and 876.55 ± 20.62 mg.100 g-1 of dry matter, respectively.

Evaluation of antioxidant activity of agro-industrial waste of acerola (Malpighia emarginata D.C.) fruit extracts

This study was carried out to evaluate the antioxidant capacity of the agro-industrial waste from acerola. Hydroacetone, hydroethanolic, and hydromethanolic extracts were obtained using the sequential extraction process, and they were screened for their free radical DPPH• (1,1-diphenyl-2-picrilhidrazil) and ABTS•+ (2,2'-azino-bis-(3-etilbenzotiazolin 6-sulfonic acid) scavenging activity and their effect on the linoleic acid peroxidation by the ferric thiocyanate method. Soybean oil with the addition of the extracts (200 ppm) was submitted to Schaal oven test (60 °C, 28 days), in which the samples were analyzed for peroxide value and conjugated dienes. Hydroethanolic and hydromethanolic extracts exhibited good DPPH scavenging activity (low value of EC50 and TEC50 and high value of AE), good ABTS scavenging capacity (1445.1 and 1145.5 µMol TEAC.g-1, respectively), and high percentage inhibition of peroxidation of linoleic acid (96.12 and 91.84%, respectively) and showed the ability to retard the formation of peroxides and conjugated dienes.

Phenolic compounds and antioxidant activity in fermented rice (Oryza sativa) bran

This study investigated the content of total phenolic compounds and antioxidant activity in fermented rice bran in order to evaluate the effect of solid state fermentation on these properties. The process was performed with the fungus Rhizopus oryzae CTT 1217 in tray reactors at 30 °C for 120 hours. Samples of fermented rice bran were collected every 24 hours. Antioxidant property was evaluated by the diphenyl-1-picrylhydrazyl radical scavenging method and through the inhibition of enzymatic oxidation and lipid peroxidation of olive oil. The methanol extract of the biomass obtained at 96 hours of fermentation inactivated 50% of free radical in 15 minutes. The same extract reduced the peroxide value in the olive oil by 57% after 30 days of storage. The aqueous extract of the biomass obtained at 120 hours was the most efficient inhibitor of the darkening reaction catalyzed by peroxidase.

Phenols, flavonoids and antioxidant activity of aqueous and methanolic extracts of propolis (Apis mellifera L.) from Algarve, South Portugal

Propolis is a resinous substance collected by honeybees to seal honeycomb, which has been used in folk medicine due to its antimicrobial and antioxidant properties. In the present study, water and methanol were used to extract phenols and flavonoids from propolis collected in thirteen different areas in the Algarve region during the winter and spring. The ABTS•+, DPPH•, and O2•- scavenging capacity, and metal chelating activity were also evaluated in the propolis samples. Methanol was more effective than water in extracting total phenols (2.93-8.76 mg/mL) (0.93-2.81 mg/mL). Flavones and flavonols were also better extracted with methanol (1.28-2.76 mg/mL) than with water (0.031-0.019 mg/mL). The free radical scavenging activity, ABTS (IC50=0.006-0.036 mg/mL), DPPH (IC50=0.007-0.069 mg/mL) and superoxide (IC50=0.001-0.053 mg/mL), of the samples was also higher in methanolic extracts. The capacity for chelating metal ions was higher in aqueous extracts (41.11-82.35%) than in the methanolic ones (4.33-29.68%). Propolis from three locations of Algarve region were richer in phenols and had better capacity for scavenging free ABTS and DPPH radicals than the remaining samples. These places are part of a specific zone of Algarve known as Barrocal.

Antioxidant activities of kombucha prepared from three different substrates and changes in content of probiotics during storage

Kombucha is a health-promoting fermented beverage worldwide. The present study compared the free-radical scavenging abilities and total reducing power (TRP) of kombucha prepared from low-cost green tea (LGTK), black tea (BTK), and tea powder (TPK). LGTK had the highest scavenging abilities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radicals, while BTK showed the highest TRP. Changes in content of probiotics in LGTK were investigated during storage as well. The number of acetic acid bacteria decreased moderately up to 10 days of storage. The number of lactic acid bacteria (LAB) decreased significantly, and their survival rate was only 0.98% at the 8th day of storage.

Physicochemical properties and antioxidant activity of Tunisian date palm (Phoenix dactylifera L.) oil as affected by different extraction methods

The chemical analysis of flesh and seed of date palm fruit (Kentichi) was evaluated. Carbohydrates were the predominant component in all studied date cultivars (~78.69-83.46 g/100g dry matter), followed by moisture content (~9.23-11.17%), along with moderate amount of fat (~0.56-7.10 g/100g dry matter), protein (~2.16-2.80 g/100g dry matter), and ash (~1.18-1.64 g/100 g dry matter). Some antioxidants (Ascorbic acid, total phenolic, total flavonoid, chlorophyll and carotenoids) were found in different values in both date fruit and seed. The physicochemical properties and antioxidant activity of both flesh and seed oil which was extracted using Hexane, Soxhlet and Modified Bligh - Dyer extraction methods were determined. The experimental results showed that temperature, different solvents and extraction time had significant effect on the yield of the date palm oil and physicochemical properties. Date Flesh oil showed an important free radical scavenging activity towards 1-1-diphenyl-2-picrylhydrazyl (DPPH) free radical.

Influence of agro-ecological production areas on antioxidant activity, reducing sugar content, and selected phytonutrients of orange-fleshed sweet potato cultivars

Sweet potato is an important staple, and it is mainly known for its contribution of β-carotene in human diet. The effects of cultivar and habitat on this pigment and other nutritional characteristics of the crop still require investigation. In this study, three locally bred cultivars of sweet potato, two of which are orange-fleshed, were grown in three different agro-ecological areas to determine soluble sugar content, β-carotene, and total antioxidants of roots. In addition antioxidant activity, total carotenoids, and chlorophyll content were determined in edible leaves. Reducing sugars, β-carotene, total antioxidants capacity, total carotenoids, and chlorophyll content were significantly affected by environmental conditions. The location at lower altitude and closer to the coastline showed high evapotranspiration, thus reducing sugar content, antioxidant activity, and phytonutrients in both storage roots and leaves. Absence of water stress in agro-ecological locations further inland and at higher altitudes was associated with an increase in these compounds. Free radical scavenging activity of DPPH was higher in the storage roots (610.49 µmoles TE/100g) than in the leaves (426.06 µmoles TE/100g); nevertheless, opposite results were found for the ferric ion reducing activity (FRAP). The deep orange-fleshed cultivar A45 contained high β-carotene (15 mg/100g), which is enough to meet RDA for vitamin A. There is evidence of agro-ecological effect on sweet potato nutritional value.

Physicochemical and antioxidative properties of black, brown and red rice varieties of northern Thailand

Rice, the seed of Oryza species, is the major cereal crop in most of the developing countries. Nearly 95% of global rice production is done in Asian countries, and about half of the world’s population consumes it. Some speciality rices are not commonly consumed. Colored rice is one of such variety. In these varieties, high amounts of anthocyanin pigment are deposited in the rice coat to form its black (also known as purple), brown and red colors. Minimum studies are there to explain the properties of these rice varieties of Thailand. Thus, the current study was aimed to assess the physicochemical and antioxidative properties of three rice varieties (Chiang Mai Black rice, Mali Red rice and Suphanburi-1 Brown rice) of different cultivars of northern Thailand. Rice bran extracts of these three cultivars were prepared with different solvents (polar and non-polar) for the evaluation of total phytochemical content and anti-oxidant free-radical-scavenging properties. Chiang Mai Black rice contained higher concentration of phenolic acid, flavonoids, and anthocyanins (Cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin chloride). Chiang Mai Black rice is richer in free-radical-scavenging compounds and activities than the other tested varieties. Polar extractions of rice bran are high in anti-oxidative compounds and activities than non-polar extractions.

Long term (five-year) survival following radical surgical treatment plus adjuvant chemotherapy (FAM) in advanced gastric cancer: a controlled study

Several drugs and their associations are being used for adjuvant or complementary chemotherapy with the aim of improving results of gastric cancer treatment. The objective of this study was to verify the impact of these drugs on nutrition and on survival rate after radical treatment of 53 patients with gastric cancer in stage III of the TNM classification. A control group including 28 patients who had only undergone radical resection was compared to a group of 25 patients who underwent the same operative technique followed by adjuvant polychemotherapy with FAM (5-fluorouracil, Adriamycin, and mitomycin C). In this latter group, chemotherapy toxicity in relation to hepatic, renal, cardiologic, neurological, hematologic, gastrointestinal, and dermatological functions was also studied. There was no significant difference on admission between both groups in relation to gender, race, macroscopic tumoral type of tumor according to the Borrmann classification, location of the tumor in the stomach, length of the gastric resection, or response to cutaneous tests on delayed sensitivity. Chemotherapy was started on average, 2.3 months following surgical treatment. Clinical and laboratory follow-up of all patients continued for 5 years. The following conclusions were reached: 1) The nutritional status and incidence of gastrointestinal manifestation were similar in both groups; 2) There was no occurrence of cardiac, renal, neurological, or hepatic toxicity or death due to the chemotherapeutic method per se; 3) Dermatological alterations and hematological toxicity occurred exclusively in patients who underwent polychemotherapy; 4) There was no significant difference between the rate and site of tumoral recurrence, the disease-free interval, or the survival rate of both study groups; 5) Therefore, we concluded, after a 5-year follow-up, chemotherapy with the FAM regimen did not increase the survival rate.

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51% increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57% increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Protective effect of N-acetylcysteine against oxygen radical-mediated coronary artery injury

The present study investigated the protective effect of N-acetylcysteine (NAC) against oxygen radical-mediated coronary artery injury. Vascular contraction and relaxation were determined in canine coronary arteries immersed in Kreb's solution (95% O2-5% CO2), incubated or not with NAC (10 mM), and exposed to free radicals (FR) generated by xanthine oxidase (100 mU/ml) plus xanthine (0.1 mM). Rings not exposed to FR or NAC were used as controls. The arteries were contracted with 2.5 µM prostaglandin F2alpha. Subsequently, concentration-response curves for acetylcholine, calcium ionophore and sodium fluoride were obtained in the presence of 20 µM indomethacin. Concentration-response curves for bradykinin, calcium ionophore, sodium nitroprusside, and pinacidil were obtained in the presence of indomethacin plus Nomega-nitro-L-arginine (0.2 mM). The oxidative stress reduced the vascular contraction of arteries not exposed to NAC (3.93 ± 3.42 g), compared to control (8.56 ± 3.16 g) and to NAC group (9.07 ± 4.0 g). Additionally, in arteries not exposed to NAC the endothelium-dependent nitric oxide (NO)-dependent relaxation promoted by acetylcholine (1 nM to 10 µM) was also reduced (maximal relaxation of 52.1 ± 43.2%), compared to control (100%) and NAC group (97.0 ± 4.3%), as well as the NO/cyclooxygenase-independent receptor-dependent relaxation provoked by bradykinin (1 nM to 10 µM; maximal relaxation of 20.0 ± 21.2%), compared to control (100%) and NAC group (70.8 ± 20.0%). The endothelium-independent relaxation elicited by sodium nitroprusside (1 nM to 1 µM) and pinacidil (1 nM to 10 µM) was not affected. In conclusion, the vascular dysfunction caused by the oxidative stress, expressed as reduction of the endothelium-dependent relaxation and of the vascular smooth muscle contraction, was prevented by NAC.

Multiple factor analysis of metachronous upper urinary tract transitional cell carcinoma after radical cystectomy

Transitional cell carcinoma (TCC) of the urothelium is often multifocal and subsequent tumors may occur anywhere in the urinary tract after the treatment of a primary carcinoma. Patients initially presenting a bladder cancer are at significant risk of developing metachronous tumors in the upper urinary tract (UUT). We evaluated the prognostic factors of primary invasive bladder cancer that may predict a metachronous UUT TCC after radical cystectomy. The records of 476 patients who underwent radical cystectomy for primary invasive bladder TCC from 1989 to 2001 were reviewed retrospectively. The prognostic factors of UUT TCC were determined by multivariate analysis using the COX proportional hazards regression model. Kaplan-Meier analysis was also used to assess the variable incidence of UUT TCC according to different risk factors. Twenty-two patients (4.6%). developed metachronous UUT TCC. Multiplicity, prostatic urethral involvement by the bladder cancer and the associated carcinoma in situ (CIS) were significant and independent factors affecting the occurrence of metachronous UUT TCC (P = 0.0425, 0.0082, and 0.0006, respectively). These results were supported, to some extent, by analysis of the UUT TCC disease-free rate by the Kaplan-Meier method, whereby patients with prostatic urethral involvement or with associated CIS demonstrated a significantly lower metachronous UUT TCC disease-free rate than patients without prostatic urethral involvement or without associated CIS (log-rank test, P = 0.0116 and 0.0075, respectively). Multiple tumors, prostatic urethral involvement and associated CIS were risk factors for metachronous UUT TCC, a conclusion that may be useful for designing follow-up strategies for primary invasive bladder cancer after radical cystectomy.