Inhibitory effect of proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves on the lipid oxidation in an emulsion system

- A cholesterol-linoleic acid emulsion model was used to simulate circulation system.
- BLP and its derivates strongly inhibited cholesterol oxidation in an emulsion model.
- BLPs were able to retain linoleic acid in an emulsion model.
- The ability against lipid oxidation of BLPs was comparable to synthetic antioxidants.
- BLPs could be developed as nature food additives for anti-lipid oxidation.

Three different Chinese bayberry leaves proanthocyanidins (BLPs) extracts were prepared by a normal extraction method, Sephadex LH-20 column purification (SPBLPs) and ultrasound degradation (UDBLPs). Their peroxyl radical scavenging capacity (PSC) and anti-lipid oxidation activity were evaluated. SPBLPs had a high PSC value at 23000.4 ± 398.5 mg of vitamin C equivalent/100 g. An emulsion model containing cholesterol and linoleic acid was used to evaluate the anti-lipid oxidation ability of BLPs. The inhibition rates of 7-ketocholesterol for the UDBLPs and SPBLPs at 40 μg/mL were 83.8 ± 0.6% and 88.5 ± 0.4% respectively, which were equivalent to that of artificial antioxidant BHT or TBHQ at 20 μg/mL. SPBLPs exhibited great antioxidant activity in prevention of lipid oxidation. The prevention of linoleic acid oxidation was highly correlated to the total phenolic contents (TPC), while the correlation of the inhibition of cholesterol oxidation and the proanthocyanidins contents was higher than that of the TPC. Overall, UDBLPs or SPBLPs could be a natural antioxidant applied for health promotion.