Antioxidant activities of the extracts from chestnut flower, leaf, skins and fruit

Abstract

In this study, the antioxidant properties of chestnut (flowers, leaves, skins and fruits) extracts were evaluated through several biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, reducing power, inhibition of b-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,2 0 -azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of lipid peroxidation in pig brain tissue through the formation of thiobarbituric acid-reactive substances (TBARS). These assays have been extensively studied as models for the peroxidative damage in biomembranes. The EC 50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each chestnut extract. The phenol and flavonoid contents were also obtained. Chestnut skins revealed the best antioxidant properties, presenting much lower EC 50 values, particularly for lipid peroxidation inhibition in the TBARS assay. Furthermore, the highest antioxidant contents (polyphenols and flavonoids) were found for these extracts.

Flavonoid composition and antioxidant capacity of the edible flowers ofAgave durangensis(Agavaceae)

“…The flavonoid content of the entire flowers of A. durangensis was lower than that reported by Barreira, Ferreira, Oliveira, and Pereira (2008) for Castanea sativa (chestnut) flowers (160 mg/g extract), by Liu et al (2009) for Litchi chinensis (lychee) flowers (273 mg/g extract), and by Tai et al (2011) for Sophora viciifolia flowers (133.8 mg/g dry extract). The flavonoid content of the entire flowers of A. durangensis was also lower than the levels reported for Ginkgo biloba extracts (240 mg/g), a species considered to be rich in flavonoids (Mouren, Caillard, & Schwartz, 1994), but was higher than that reported by Zhang and Cui (2005) for Hippophae rhamnoides extracts (10-439 µg/g).…”

Antioxidant capacity and toxicological evaluation ofPterospartum tridentatumflower extracts

“…Total phenolic compounds in the water extracts (or in lyophilized extracts) were estimated by a colorimetric assay based on procedures described by Singleton and Rossi (Singleton & Rossi, 1965), with some modifications, accordingly to Barreira and colleges (Barreira, Ferreira, Oliveira, & Pereira, 2008), for lyophilized extracts: 0.5 g of extracts were mixed with ultrapure water or ethanol 50% and shaken until a clear solution was obtained. This step was repeated three times to increase the extraction yield.…”

“…Flavonoid contents in the extracts were determined by a colorimetric method described by Jia et al (Jia, Tang, & Wu, 1999), with some modifications (Barreira et al, 2008). P. tridentatum and R. officinalis extracts (250 mL of lyophilized extract reconstituted in ultrapure water or ethanol 50%) were mixed with 1.25 mL of distilled water and 75 mL of a 5% NaNO 2 solution.…”

Total antioxidant capacity of the Korean diet

“…In the Korean diet, the phenolics in fruit juices and nuts were the highest, followed by those in vegetables and fruits (Table 2). In a preliminary study in Korea, the phenolic content in Korean nuts was higher than that in vegetables, which might have been be due to the antioxidant capacity of the chestnut, which is the most popular nut in Korea [24,25]. Zamora-Ros et al [26] also have reported that the phenolic content in the nuts in the European diet is greater than the phenolics in oranges and other fruits.…”

“…Recently, several studies have evaluated the contribution of food items to the TDAC of a diet. Yang et al [15] have reported that teas, dietary supplements, and fruits and fruit juices were the major sources of the TDAC for the US population (28,25, and 17%, respectively), while the largest contributors to the TDAC were beverages (approximately 68% -the mean of FRAP and ABTS values) in the Spanish Mediterranean diet [4].…”