Effects of Pu-erh Tea on Oxidative Damage and Nitric Oxide Scavenging

Abstract

The effects of pu-erh tea, which is prepared by fermentation of tea, on oxidative damage and nitric oxide scavenging, compared with various other brands of tea were investigated. The total antioxidant activity was determined using the Trolox equivalent antioxidant capacity (TEAC) assay. The results showed that TEAC values of the 200 microg/mL water extracts of pu-erh tea (WEPT), green tea, oolong tea, and black tea were 86.3, 85.3, 87.4, and 80.3 (microg/mL), respectively, indicating that WEPT showed a significant antioxidant activity. WEPT, like green tea extract, oolong tea extract, and black tea extract, exhibited a remarkable protective effect in lipid (liposome) and nonlipid (protein and deoxyribose) model systems, implying that it is an inhibitor of lipid and nonlipid oxidative damage. It also exhibited metal-binding ability, reducing power, and scavenging effect for free radicals. Moreover, WEPT showed a decreasing effect on nitric oxide production of lipopolysaccharide-induced RAW 264.7 macrophages. In addition, the results revealed that epicatechin (EC), flavonoid, ascorbic acid, and polyphenolic compounds are present in WEPT, which may partially account for the protective effect on oxidative damage. Thus, WEPT may have potential as an antioxidant and as a nitric oxide scavenging agent.

Polyphenol Content and Antioxidant Effects in Herb Teas

“…given diet including some common fruits, vegetables and beverages [12]. The presented herb teas have various effects [13][14][15][16][17][18][19][20][21][22]. Tables 1 and 2 show that some of them, Arabian jasmine, Guava, Hardy rubber tree, Japanese persimmon, Oolong tea and Puerh tea, have high total polyphenol content and antioxidant activities.…”

Oxidized tea polyphenols prevent lipid accumulation in liver and visceral white adipose tissue in rats

“…Pu-erh tea is a Chinese tea made from green tea leaves that have been oxidized and fermented using micro-organisms such as Aspergillus species. Several studies have reported that Pu-erh tea has the ability to reduce body weight, fatty acid synthesis, hyperlipidaemia, NAFLD and oxidative stress [6][7][8][9][10][11][12][13]. However, the mechanisms underlying Pu-erh tea's alleviation of these metabolic processes and symptoms are not clear.…”

A new catechin oxidation product and polymeric polyphenols of post-fermented tea

“…Owing to the much lower consumption of post-fermented tea, the chemical composition of this tea has not been characterized in detail. However, recent studies suggest some beneficial effects of post-fermented tea (Chiang, Weng, Lin-Shiau, Kuo, Tsai, & Lin, 2006;Duh, Yen, Yen, Wang, & Chang, 2004;Kuo, Weng, Chang, Tsai, Lin-Shiau, & Lin, 2005;Noguchi, Hamauzu, & Yasui, 2008;Oyaizu, Hotsumi, Takagi, Matsumoto, Fujita, Matsuzaki, & Yamashita, 2005;Oyaizu, Hotsumi, Takagi, Matsuzaki, Yamashita, Takenaga, & Itho, 2006). Black and oolong tea production includes a process called "tea fermentation", in which constituents of fresh tea leaves are chemically altered by enzymes originally contained in the leaves (Roberts, 1962;Tanaka, Matsuo, & Kouno, 2010).…”