Quantification and analysis of anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors

Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.

Effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi on growth performance,meat quality and antioxidative ability of broilers

An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi（SBGFN） as SBGFN-zinc（SBGFN-Zn） on growth performance, meat quality, immune responses and antioxidation of broilers. A total of 450 one-d-old Arbor Acres male broilers were randomly allocated to 5 treatments with 6 replicates of 15 birds per replicate for each treatment in a completely randomized design. Birds were fed a SBGFN-unsupplemented cornsoybean meal basal diet（control） or the basal diet supplemented with 60, 120, 180 or 240 mg SBGFN kg-（–1） from SBGFN-Zn for 42 d. Dietary SBGFN supplementation affected（P〈0.03） drip loss in thigh muscle, total superoxide dismutase（T-SOD） and glutathione peroxidase（GSH-Px） activity in liver of broilers at 42 d of age. Chicks fed the diets supplemented with 120, 180 and 240 mg SBGFN kg-（–1） had lower（P〈0.03） drip loss of thigh muscle than those fed the control diet. Chicks fed the diet supplemented with 180 mg SBGFN kg-（–1） had higher（P〈0.03） liver T-SOD and GSH-Px activity than those fed the diets supplemented with 0, 60 and 120 mg SBGFN kg-（–1）. The results from the present study indicate that dietary supplementation with 180 mg SBGFN kg-（–1） as SBGFN-Zn improved both meat quality and antioxidative ability of broilers.

Association between heat stress and oxidative stress in poultry;mitochondrial dysfunction and dietary interventions with phytochemicals

Heat as a stressor of poultry has been studied extensively for many decades; it affects poultry production on a worldwide basis and has significant impact on well-being and production. More recently, the involvement of heat stress in inducing oxidative stress has received much interest. Oxidative stress is defined as the presence of reactive species in excess of the available antioxidant capacity of animal cells. Reactive species can modify several biologically cellular macromolecules and can interfere with cell signaling pathways. Furthermore, during the last decade, there has been an ever-increasing interest in the use of a wide array of natural feed-delivered phytochemicals that have potential antioxidant properties for poultry. In light of this, the current review aims to（1） summarize the mechanisms through which heat stress triggers excessive superoxide radical production in the mitochondrion and progresses into oxidative stress,（2） illustrate that this pathophysiology is dependent on the intensity and duration of heat stress,（3） present different nutritional strategies for mitigation of mitochondrial dysfunction, with particular focus on antioxidant phytochemicals.Oxidative stress that occurs with heat exposure can be manifest in all parts of the body; however, mitochondrial dysfunction underlies oxidative stress. In the initial phase of acute heat stress, mitochondrial substrate oxidation and electron transport chain activity are increased resulting in excessive superoxide production. During the later stage of acute heat stress, down-regulation of avian uncoupling protein worsens the oxidative stress situation causing mitochondrial dysfunction and tissue damage. Typically, antioxidant enzyme activities are upregulated. Chronic heat stress, however, leads to downsizing of mitochondrial metabolic oxidative capacity, up-regulation of avian uncoupling protein, a clear alteration in the pattern of antioxidant enzyme activities, and depletion of antioxidant reserves.Some phytochemicals, such as various types of flavonoids and related compounds, were shown to be beneficial in chronic heat-stressed poultry, but were less or not effective in non-heat-stressed counterparts. This supports the contention that antioxidant phytochemicals have potential under challenging conditions. Though substantial progress has been made in our understanding of the association between heat stress and oxidative stress, the means by which phytochemicals can alleviate oxidative stress have been sparsely explored.