Comparison of phytochemical profiles, antioxidant and antiproliferative activities in Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruits

Here, we examined the phytochemical profiles, antioxidant activity (AA), and antiproliferative activity (APA) of four Chinese bayberry (Myrica rubra Sieb. et Zucc.) pulp extracts. They were found to be rich in total phenolics content (TPC; 186.45 +/- 5.42 to 498.94 +/- 8.25 mg of gallic acid equiv./100 g FW) and total flavonoids content (TFC; 126.28 +/- 4.18 to 194.35 +/- 12.03 mg of catechin equiv./100 g FW). For all varieties, the free flavonoid/phenolic/anthocyanin contents were higher than that the bound fractions. Wild pink bayberry (WPB) displayed the highest values of TPC and TFC, and also showed the highest total antioxidant activity (TAA) as revealed by peroxyl radical scavenging capacity (PSC) (451.47 +/- 8.01 mu mol Vit. C equiv./100 g FW), and free cellular antioxidant activity (CAA) (184.99 +/- 6.11 mu mol quercetin equiv./100 g FW, no PBS wash; 117.78 +/- 2.34 mu mol quercetin equiv./100 g FW, PBS wash) assays. Bayberry extracts had a marked reduction in the APA of HepG2 cells, and WPB exhibited the lowest EC50 (8.50 +/- 0.83 mg/ml) value, which was probably associated with cell cycle arrest and apoptosis induction. Practical Application Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruit is rich in natural phenolic compounds, which might be a functional ingredient in food and nutraceutical products. Our findings would provide a logical strategy to promote the comprehensive utilization of phenolics in bayberry fruit with both health and economy benefits.