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Cellular antioxidant activity ( CAA) and inhibition of hepato-cellular carcinoma (HepG2) proliferation were evaluated for the first time in the pulp and peel of mango cultivars. Comparatively, peel had high flavonoids and tocopherols content and showed significant antioxidant activity. Among all the studied cultivars, the Xiao Tainong peel was predominant with highest fistein, mangiferin and alpha-tocopherol content and significant cellular antioxidant activity value 2986 ± 380 μmol QE/100 g FW. The HepG2 cells antiproliferation was maximum in the peel of Da Tainong and pulp of Aozhou with lowest EC50 values, 2.35 ± 0.65 (peel) and 185.4 ± 10.9 (pulp) mg mL−1, in a dose-dependent manner. Negative associations of flavonoids and tocopherol compounds with CAA and antiproliferative activity in mango confirmed synergistic, additive or antagonistic actions of phytochemicals. The current study suggests that mango peel could be used as a value added ingredient or functional food and may contribute considerably to promote consumer health. [ABSTRACT FROM AUTHOR]

A comparative assessment of the phytochemical profiles and antioxidant activities of seven cultivars of Aloe was conducted to evaluate the potential health benefits of Aloe. Aloe arborescens contained the highest levels of phenolic content, total antioxidant capacity by the oxygen radical scavenging capacity assay and cellular antioxidant activity assay. Aloe vera showed the highest levels of flavonoid content and antioxidant capacity by the peroxyl radical scavenging capacity assay. Aloe greenii had the highest CAA value with a PBS wash before adding ABAP. There were no significant differences observed between Aloe arborescens and Aloe greenii. Aloin, aloe-emodin-8-O-beta-D-glucopyranoside, catechin, epicatechin, sinapic acid and chlorogenic acid were identified in Aloe samples by the HPLC analysis. Aloin, aloe-emodin-8-O-beta-D-glucopyranoside and catechin showed strong relationships with antioxidant activity. Significant levels of aloin, aloe-emodin-8-O-beta-D-glucopyranoside and catechin were determined in Aloe greenii, Aloe vera and Aloe saponaria, respectively. [ABSTRACT FROM AUTHOR]

Flaxseed (Linum usitatissimum L.) is well known for its health benefits and chemical composition. This study aimed to evaluate the dynamic changes caused by germination in vitamin C, phenolic compounds and antioxidant activities of flaxseed. It was observed that eight-day germination of flaxseed sprouts caused increases in phytochemical contents, that is 22.1-fold increase in vitamin C, 2.67-fold increase in phenolics and 5.48-fold increase in flavonoid contents as compare to initial concentration in flaxseeds on dry weight basis. The stimulation was also noted in the three identified phenolic acid ingredients including caffeic acid, p-coumaric acid and ferulic acid. Similarly, the total PSC and ORAC values of flax sprouts at day 8 increased by 3- to 4-folds compared to nongerminated flaxseeds. It is revealed that comparatively, 8-day germination of flax sprouts leads to a significant increase in vitamin C, phenolic constituents and total antioxidant activities than those of flaxseeds. [ABSTRACT FROM AUTHOR]

Phenolics are suggested to be the major bioactive compounds responsible for the health benefits of tea. Seven types of tea were extracted using boiling water. The extraction kinetics was investigated. To more fully characterise the antioxidant profiles and possible associated health benefits of these tea types, the total water-soluble solid content, phenolics, flavonoids, and antioxidant and antiproliferative activities were quantified. Green tea leaves ( GTL) were found to have the highest phenolic content (128.7 ± 1.7 mg g−1 , P < 0.05), followed by teas of decaffeinated green tea bag (d GTB), green tea bag ( GTB), black tea bag ( BTB), decaffeinated BTB, black tea leaves and oolong tea leaves ( OTL). Among the three leaf teas, GT displayed the greatest antioxidant activity (4850.2 ± 60.7 μmol g−1, P < 0.05), followed by black tea ( BT) and oolong tea ( OT). As for the four bag teas, decaffeinated GT possessed the strongest antioxidant activity (4431.1 ± 335.0 μmol g−1, P < 0.05), followed by GT, BT and decaffeinated BT. The results display that phenolic/flavonoid content well correlated with antioxidant activity. Proliferation of three human cancer cells was significantly inhibited in a dose-dependent manner after exposure to some tea extracts. This may influence consumers in selecting the type of tea and tea brewing times, exhibiting greater health benefits. [ABSTRACT FROM AUTHOR]