Screening and study on exopolysaccharide from lactic acid bacteria to inhibit melanin synthesis

Abstract:

[Objective] To screen exopolysaccharide from lactic acid bacteria for inhibiting melanin synthesis. [Methods] Exopolysaccharide-producing lactic acid bacteria were screened by observing the ropy appearance in skim milk media. Effects of exopolysaccharides on melanin synthesis and cell viability were measured on B16 melanoma cell. Exopolysaccharide was purified by chromatography columns of DEAE-52 cellulose and Sepahdex G100. Monosaccharide composition and basic structural information were studied by PMP-HPLC and FT-IR method. Tyrosinase inhibiting activity and antioxidant activity were studied. [Results] Exopolysaccharide form Lactobacillus rhamnosus HLAB122 (LR122EPS) could inhibit melanin synthesis of B16 melanoma cell. Compared with the control, melanin production decreased to 32.7% at 5 g/L of LR122EPS, cell viability was not changed within 96 hours. Purified LR122EPS was composed of rhamnose, glucose, and galactose in a molar ratio of 1:5.44:5.37. LR122EPS could not inhibit tyrosinase activity and its antioxidation was weak. [Conclusion] Exopolysaccharide LR122EPS had the potential in products toinhibit melanin synthesis.