抑制黑色素合成的乳酸菌胞外多糖的筛选和性质研究

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

【目的】筛选可抑制黑色素合成的乳酸菌胞外多糖。【方法】通过观察凝乳拉丝外观筛选产胞外多糖的乳酸菌菌株,测量胞外多糖对B16黑色素瘤细胞黑色素合成和细胞活力的影响。对胞外多糖进行纯化,并通过PMP衍生-HPLC、红外光谱、抑制酪氨酸酶活性、抗氧化能力对其单糖组成和结构、作用机制进行研究。【结果】筛选到一株乳酸菌Lactobacillus rhamnosus HLAB122,发酵产生的胞外多糖在5 g/L浓度下可使B16细胞黑色素产量下降至空白对照的32.7%,且在96 h内对细胞活力无影响。纯化后的多糖由鼠李糖、葡萄糖、半乳糖构成,各单糖摩尔比为1?5.44?5.37。该胞外多糖不抑制酪氨酸酶活力且抗氧化性微弱。【结论】L.rhamnosus HLAB122产生的胞外多糖在个人护理产品中有潜在应用价值。

[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 LR122 EPS, cell viability was not changed within 96 hours. Purified LR122 EPS was composed of rhamnose, glucose, and galactose in a molar ratio of 1：5.44：5.37. LR122 EPS could not inhibit tyrosinase activity and its antioxidation was weak. [Conclusion] Exopolysaccharide LR122 EPS had the potential in products toinhibit melanin synthesis.