Tea regimen, a comprehensive assessment of antioxidant and antitumor activities of tea extract produced by Tie Guanyin hybridization

Abstract

A comprehensive assessment was conducted in this study to examine the antioxidant and antitumor activities of tea extract produced by Tie Guanyin hybridization. Two radical-scavenging systems of assay in vitro, namely ABTS and DPPH assays, were used to investigate the antioxidant activity of the summer tea and autumn tea extract (STE and ATE) derived from the Jin Guanyin. The results indicated that the major active ingredients were catechins, and the theaflavin is rare in the STE and ATE. Moreover, STE and ATE could significantly suppress the growth of human breast cancer cells MDA-MB-231 in a dosedependent manner, and wrecked the morphology of mitochondria, activated caspase families, leading to the cancer cell death by both apoptosis and cell cycle arrest pathways. Based on the results from an MDA-MB-231 xenograft nude mice model, STE could effectively prevent the tumor formation, and greatly improve the mice immunity and thus improve their living conditions. Taken together, ATE and STE could act as a healthy and prospective substitute for natural antioxidants and a promising prophylactic agent against cancer. This finding provides a great promising nutritional approach to treat diseases related with oxidative stress.

Structure–Activity Relationship Analysis on Antioxidant and Anticancer Actions of Theaflavins on Human Colon Cancer Cells

“…6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), as a standard antioxidant universally used, has been utilized as a positive control in many studies. The IC 50 value of Trolox was 76.3 μM as measured previously . As shown in Figure A, the IC 50 values of TFs on scavenging DPPH • radicals were 7.26, 5.93, 5.51, and 4.48 μM, respectively, indicating the remarkable scavenging effects of TFs on lipophilic free radical (DPPH • ) compared to Trolox.…”

“…As shown in Figure A, the IC 50 values of TFs on scavenging DPPH • radicals were 7.26, 5.93, 5.51, and 4.48 μM, respectively, indicating the remarkable scavenging effects of TFs on lipophilic free radical (DPPH • ) compared to Trolox. In the ABTS • + system, TFs exhibited more superior antioxidant activities, with the IC 50 values of 2.44, 2.11, 2.34, and 1.92 μM, respectively (Figure B), compared to Trolox, whose IC 50 value was 57.9 μM in a previous study . On the basis of the above results, it could be concluded that the TFs had excellent antioxidant activities, in which the inhibition of the hydrosoluble free radical (ABTS • + ) was remarkably stronger than that of the liposoluble free radical (DPPH • ), and TF4 exhibited the best antioxidant activities in both DPPH • and ABTS • + systems, which may result from the existence of the two galloyl groups.…”

Antioxidant Activity and Main Chemical Components of a Novel Fermented Tea

“…Tea is produced from the plant Camelia sinensis and is one of the most popular beverages worldwide, second only to water [1]. It contains as much as 30% soluble ingredients, which may vary with the cultivar, climate condition, genetic strain, production region, plucking season, position of the leaf as well as the processing operations [2]. Polyphenols, the main constituents of tea, is known to take up 20–35% of tea’s dry weight.…”

“…Among polyphenols, catechin was the predominant group, counting for 60–80% of tea polyphenols. In general, catechins largely include catechin, epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-O-gallate (EGCG) [2,3,4]. Tea is typically categorized into seven types based on processing methods: green tea, yellow tea, white tea, oolong tea, black tea, aged pu-erh tea, and ripened pu-erh tea [5].…”

Phoenix Dan Cong Tea: An Oolong Tea variety with promising antioxidant and in vitro anticancer activity

“…Caspases are closely associated with cellular apoptosis (37). Caspase-3 plays a key role in apoptosis; it acts as a central regulator, while caspase-8 and caspase-9 act as the initiators of the exogenous death receptor-mediated and endogenous mitochondria-mediated apoptotic pathways, respectively (38). To assess caspase activity in MDA-MB231 cells during PDCe-induced apoptosis, we measured the fluorescence intensity of substrates of caspase-3, -8, and -9, which indicate the activation of the corresponding enzymes after treatment with PDCe at 7.5, 15, or 30 μg/mL.…”