Effects of Oolong Tea on Plasma Antioxidative Capacity in Mice Loaded with Restraint Stress Assessed Using the Oxygen Radical Absorbance Capacity (ORAC) Assay

Abstract

In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.

Antioxidant activity of fish sauces including puffer (Lagocephalus wheeleri) fish sauce measured by the oxygen radical absorbance capacity method

“…The measurement of oxygen radical absorbance capacity (ORAC) using fluorescence intensity for the determination of antioxidant activity (in the form of peroxyl radical elimination capacity) has been approved by the USDA (United States department of agriculture). Since cao et al first developed the method in 1993 (19), various studies have applied the orac assay in both the US (20-26) and Japan (27)(28)(29)(30)(31). Though Yamada et al reported the ORAC value of dried bonito stock (Katsuo-dashi) (32,33), no studies have determined the ORAC value of fish sauce.…”

Two new c-glucosyl benzoic acids and flavonoids from Mallotus nanus and their antioxidant activity

“…The antioxidant capacity of seven compounds isolated from the leaves of M. nanus was measured by ORAC, which has been recently accepted as a standard method to analyze the antioxidant potential of active substances of plants (Cao et al, 1997;Kurihara et al, 2004). Mallonanoside A (1) showed higher peroxyl radical-scavenging activity than mallonanoside B (2) (Fig.…”

“…In the final assay mixture, 40 nM fluorescein was used as a target of free radical attack with either 20 mM 2,2-azobis dihydrochloride (AAPH) as a peroxyl radical generator in a peroxyl radical-scavenging capacity (ORAC ROO• ) assay (Kurihara et al, 2004) or H 2 O 2 -CuSO 4 (H 2 O 2 , 0.75%; CuSO 4 , 5 µM) as mainly a hydroxyl radical generator in a hydroxyl radical-scavenging capacity (ORAC OH• ) assay (Cao et al, 1997). Trolox (1 µM) was used as a control standard and prepared fresh daily.…”

Total antioxidant capacity of the Korean diet

“…In the final assay mixture, 40 nM fluorescein was used as the target of free radical attack with either 20 mM 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as the peroxyl radical generator in a peroxyl radical scavenging capacity (ORACROO·) assay [20] or H2O2-CuSO4 (0.75% H2O2; 5 μM CuSO4) as the hydroxyl radical generator in a hydroxyl radical scavenging capacity (ORACOH·) assay [21]. Trolox (1 μM) was used as the standard control and prepared fresh daily.…”