Higher Levels Of Total Flavonoids Research Articles

Flavonoid compositions and antioxidant activity of calamondin extracts prepared using different solvents

Calamondin has been demonstrated to exhibit antioxidant function and tyrosinase inhibitory activity, which might be attributed to its flavonoid compounds. To improve their application, the flavonoid compositions and antioxidant activity of calamondin extracts, prepared by different solvents, were investigated. The results showed that total phenolic and flavonoid contents of extracts from peel of calamondin were higher than that from pulp, except the flavonoid content in hot water extract. The flavonoids found in extracts of calamondin were 3′,5′-di-C-β-glucopyranosylphloretin (DGPP), naringin, hesperidin, nobiletin, tangeretin, and diosmin. DGPP exhibited the highest quantity, while naringin and hesperidin were the other two major flavonoids. The content of DGPP in hot water extract of peel was higher than in extracts of organic solvents, however, the contents of nobiletin and tangeretin were found only in extracts of organic solvents. The highest levels of total flavonoids and DGPP were obtained in hot water extract from peel at 90°C. The extracts of hot water and ethyl acetate showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging potency than that of ethanol and methanol. A positive relationship existed between total phenolic contents and DPPH scavenging potency (p < 0.01), while total flavonoid compositions also showed correlation (p < 0.05). Thus, DGPP, naringin, and hesperidin might contribute to antioxidant activity. Collectively, the hot water extract of calamondin peel might have potential for health food and cosmetic applications due to its good antioxidant activity and high level of DGPP.

Fortification of the Health Benefit of Buckwheat (F agopyrum tataricum ) Tea

Three extracts from Zijuan (Camellia sinensis), Kudingcha (Ilex kudingcha) and Mingri (Angelica keiskei) leaves were used to fortify the health promoting function of traditional buckwheat tea. Three fortified teas with similar sensory property to the original tea and higher level of total flavonoids and catechin were chosen to evaluate their capability in lowering hyperglycemic and hyperlipidemic stress using mouse models. The blood glucose level in the hyperglycemic mice was significantly reduced by 10.84 to 34.12% after oral gavage of the three fortified teas (0.4 mL of 20% in solution) each day for 7 days, while it only lowered 4.56% in the original buckwheat tea treatment (P < 0.05). Also, the three fortified teas had effective response to lower the boosted blood glucose level in fasted mice. In the hyperlipidemic mouse model, the mice fed with the fortified teas for 30 days had lower serum total cholesterol and triglyceride levels and higher high-density lipoprotein-cholesterol level. Practical Applications This study demonstrated a potential method to enhance the health benefit of buckwheat tea without loss of its sensory properties. The information would be valuable in developing various health-promoting food products from buckwheat and other grains.

Cultivation characteristics and flavonoid contents of wormwood (Artemisia montana Pamp.)

The aim of this study was to establish the optimum harvesting time and the content of flavonoids in the leaves, stems, and roots of Artemisia montana Pamp. A. montana was monitored from June to October in 2012. The yield of A. montana at high density (30 × 10 cm) was higher than that of A. montana at low density (30 × 20 and 30 cm). Yield in terms of dry weight was increased with an extended growth period and development stage. High yield achieved at 2580 and 2757 kg?10 a?1 in September and October, respectively. Among the leaves, stems, and underground plant organs, jaceosidin and eupatilin were mainly detected in the leaves, and the highest levels were observed in June, at values of 66.6 and 158.2 mg?100 g?1, respectively. In contrast, apigenin was the major compound detected in the underground plant organs, with levels ranging from 21.2 to 29.5 mg?100 g?1 until September. Therefore, optimal harvest times were between September and October, generating a high yield and adding economic value although a higher level of total flavonoids was observed in crops harvested in June.

Characterization of phenolic compounds in flowers of wild medicinal plants from Northeastern Portugal

Crataegus monogyna, Cytisus multiflorus, Malva sylvestris and Sambucus nigra have been used as important medicinal plants in the Iberian Peninsula since a long time ago, and are claimed to have various health benefits. This study aimed to determine the phenolic profile and composition of wild medicinal flowers of those species. The analysis was performed by HPLC–DAD–ESI/MS. Flavonoids, and particularly flavonols and flavones, were the main groups in almost all the studied samples. C. multiflorus sample gave the highest levels of total flavonoids (54.5mg/gdw), being a chrysin derivative the most abundant flavone found (22.3mg/gdw). C. monogyna revealed the highest concentration in phenolic acids (5.5mg/gdw) that were not found in C. multiflorus sample; 5-O-caffeoylquinic acid was the most abundant phenolic acid found in the first species, being a procyanidin trimer also found (1.4mg/gdw). Kaempferol-3-O-rutinoside (0.84mg/gdw) and quercetin-3-O-rutinoside (14.9mg/gdw) were the main flavonols present in M. sylvestris and S. nigra, respectively. Due to the well established antioxidant activity of phenolic compounds, the studied wild medicinal flowers could be selected for processing extracts with health-promoting properties or to be incorporate into functional beverages or products with bioactive properties related to oxidative stress.

Active components, antimicrobial and antioxidant activities of extracts from Melicope patulinervia

Melicope patulinervia (Merr. and Chun) Huang is the rare and endangered plant in the Hainan Province, China. In the purpose of exploring the value of its exploitation and utilization, this study was conceived to evaluate the antimicrobial, antioxidant activities and the active ingredients of this plant. Spectrophotometry was the basis for the determinations of total phenol and total flavonoids. Meanwhile, the antioxidant activities of the different parts, different solvents extracts of M. patulinervia were measured by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. Seven plant pathogenic fungi species were used to assay for antimicrobial activity of the extracts of this plant. The results showed that 70% methanol extracts of the leaves had higher level of total flavonoids, with a content of 41.3194±0.071 mg·g-1. But it was strange that the contents of total phenol of the extracts of the plant were significantly less than that of total flavonoids. The antioxidant activities of the different parts, different solvents extracts of M. patulinervia were all weak. The leaf extract showed antimicrobial activity against 4 of the plant of pathogenic fungi species, especially Oxytetracycline hydrochloride. Key words: Melicope patulinervia (Merr. and Chun) Huang, active ingredients, antimicrobial activity, antioxidant activity.

Chemical composition and anti-proliferative and anti-inflammatory effects of the leaf and whole-plant samples of diploid and tetraploid Gynostemma pentaphyllum (Thunb.) Makino

Leaf and whole-plant samples of the diploid and tetraploid Gynostemma pentaphyllum (GP) were investigated and compared for their chemical compositions, and their potential anti-proliferative and anti-inflammatory effects. The highest levels of total flavonoids and phenolics were observed in the diploid leaf botanical (2L3) at 36.84mg rutin equiv/g and 41.15mg gallic acid equiv/g, respectively. The diploid leaf sample (2L2) had the highest amount of rutin and quercetin contents of 77.7μmol quercetin equiv/g. The tetraploid whole-plant botanical (4L3) had the highest total saponin content of 227.1mg gypenoside equiv/g. Extracts from all tested GP samples showed time- and dose-dependent antiproliferative effects in HT-29 cells, and the diploid leaf samples had the overall highest inhibitory activity. These extracts had different order of antiproliferative properties in the LNCaP cells, suggesting the potential selective inhibition of GP extracts against different types of cancer cells and the effect of the cell model in screening and evaluation of antiproliferative components. In addition, the diploid leaf extracts showed the strongest inhibitory effects on the expression of TNF-α, IL-6 and COX-2 mRNA at final concentrations of 0.2 and 1mg botanical equiv/ml media. The results from this study will be used to develop new nutraceutical products from G. pentaphyllum.

Chemical Composition of Five Commercial Gynostemma pentaphyllum Samples and Their Radical Scavenging, Antiproliferative, and Anti-inflammatory Properties

Five Gynostemma pentaphyllum (GP) samples were investigated and compared for their chemical compositions and their antioxidant, antiproliferative, and anti-inflammatory effects. Extracts (50% acetone, 75% ethanol, and 100% ethanol) of the five GP samples (GP1-5) differed in their total phenolic, saponin, and flavonoid contents and in their rutin and quercetin concentrations. The highest level of total flavonoids was 63.5 mg of rutin equiv/g in GP4, and the greatest total phenolic content was 44.3 mg of gallic acid equiv/g in GP1 with 50% acetone as the extraction solvent. GP2 had the highest total saponin content of 132.6 mg/g with 100% ethanol as the extraction solvent. These extracts also differed in their scavenging capacity against DPPH and hydroxyl radicals, although they all showed significant radical scavenging capacity. The 100% ethanol extracts also showed dose-dependently strong inhibition on IL-6 and Ptgs2 mRNA expression and weak inhibition on TNF-α mRNA expression. In addition, GP1 had the highest antiproliferative activity at 3.2 mg equiv/mL concentration in HT-29 human colon cancer cells. The results from this study will be used to promote the application of G. pentaphyllum for improving human health.

Nutritional composition and flavonoids content of flour from different buckwheat cultivars

SummaryThirty nine buckwheat cultivars were collected from China, of which twenty one were tartary buckwheat and others were common buckwheat. Flour samples from these cultivars were analysed for colour properties, nutritional composition and flavonoid content. Buckwheat cultivars exhibited high variations for each of these parameters. The flour of common buckwheat showed a higher whiteness index than that of tartary buckwheat and contained very low levels of flavonoids. On average, the tartary buckwheat flour contained a higher level of ash (2.38%) and lower levels of total starch (70.22%), amylose (22.32%), resistant starch (17.66%) than the common buckwheat flour (2.17%, 73.69%, 23.01%, 18.69% respectively) (P &lt; 0.05) whereas the contents of proteins, fats and crude fibres of the tartary buckwheat flour were similar to those of common buckwheat flour. The Mei‐Hua‐Shan tartary buckwheat flour contained the highest level of total flavonoids and quercetin (22.74 mg g−1 and 2.38 mg g−1, respectively).

Antioxidant activities and phenolic contents of the methanol extracts of the stems of Acokanthera oppositifolia and Adenia gummifera.

BackgroundAcokanthera oppositifolia Lam (family: Apocynaceae) is a shrub or small tree with white latex, and the leaves of this plant are used in the form of a snuff to treat headaches and in infusions for abdominal pains and convulsions and septicaemia. Adenia gummifera Harv of the family Passifloraceae is a distinctive woody climber whose infusions are used as emetics and are said to help with some forms of depression. Lipid peroxidation has gained more importance today because of its involvement in pathogenesis of many diseases. Free radicals are the main agents in lipid peroxidation. Antioxidants thus play an important role of protecting the human body against damage by the free radicals. Plants containing phenolic compounds have been reported to possess strong antioxidant properties.MethodsThe antioxidant activities and phenolic contents of the methanol extracts of the stems of Acokanthera oppositifolia and Adenia gummifera were evaluated using in vitro standard procedures. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the stem extract of Acokanthera oppositifolia were determined by the 2,2'-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS), 1,1-Diphenyl-2-picrylhydrazyl (DPPH), and ferrous reducing antioxidant property (FRAP) methods.ResultsThe results from this study showed that the antioxidant activities of the stem extract of Acokanthera oppositifolia as determined by the 1,1-Diphenyl-2-picrylhydrazyl (DPPH), and ferrous reducing antioxidant property (FRAP) methods, were higher than that of Adenia gummifera. The levels of total phenols and flavonols for A. oppositifolia were also higher. On the other hand, the stem extract of Adenia gummifera had higher level of total flavonoids and proanthocyanidins than that of Acokanthera oppositifolia. The 2, 2'-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS) activities of the 2 plant extracts were similar and comparable to that of BHT.ConclusionThus, the present results indicate clearly that the extracts of Acokanthera oppositifolia and Adenia gummifera possess antioxidant properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants. This study has to some extent validated the medicinal potential of the stems of Acokanthera oppositifolia and Adenia gummifera.

Soy intake and breast cancer: elucidation of an unanswered question

Soy intake and breast cancer: elucidation of an unanswered question

The Role of Flavonol Glycosides and Carotenoids in Protecting Soybean from Ultraviolet-B Damage.

The increase in ultraviolet-B (UV-B; 0.290-0.320 [mu]m) radiation received by plants due to stratospheric ozone depletion heightens the importance of understanding UV-B tolerance. Photosynthetic tissue is believed to be protected from UV-B radiation by UV-B-absorbing compounds (e.g. flavonoids). Although synthesis of flavonoids is induced by UV-B radiation, its protective role on photosynthetic pigments has not been clearly demonstrated. This results in part from the design of UV-B experiments in which experimental UV-A irradiance has not been carefully controlled, since blue/UV-A radiation is involved in the biosynthesis of the photosynthetic pigments. The relationship of flavonoids to photosynthetic performance, photosynthetic pigments, and growth measures was examined in an experiment where UV-A control groups were included at two biologically effective daily UV-B irradiances, 14.1 and 10.7 kJ m-2. Normal, chlorophyll-deficient, and flavonoid-deficient pigment isolines of two soybean (Glycine max) cultivars that produced different flavonol glycosides (Harosoy produced kaempferol, Clark produced quercetin and kaempferol) were examined. Plants with higher levels of total flavonoids, not specific flavonol glycosides, were more UV-B tolerant as determined by growth, pigment, and gas-exchange variables. Regression analyses indicated no direct relationship between photosynthesis and leaf levels of UV-B-absorbing compounds. UV-B radiation increased photosynthetic pigment content, along with UV-B-absorbing compounds, but only the former (especially carotenoids) was related to total biomass (r2 = 0.61, linear) and to photosynthetic efficiency (negative, exponential relationship, r2 = 0.82). A reduction in photosynthesis was associated primarily with a stomatal limitation rather than photosystem II damage. This study suggests that both carotenoids and flavonoids may be involved in plant UV-B photoprotection, but only carotenoids are directly linked to photoprotection of photosynthetic function. These results additionally show the importance of UV-A control in UV-B experiments conducted using artificial lamps and filters.