Antioxidant and free radical-scavenging activities of black soybean peptides (BSP)

The antioxidant and free radical-scavenging activities of black soybean peptides(BSP)fractions(Fra-Ⅰ,Fra-Ⅱ,Fra-Ⅲ)were investigated using reducing power and DPPH·/superoxide/hydroxyl radical-scavenging assay.The reducing power activity of Fra-Ⅲwas closer to that of BHT but lower than that of ascorbic acid.Fra-Ⅲshowed the strongest scavenging activity against free radicals.The radical-scavenging effect was in a dose-dependent manner and the IC50 values for DPPH·,superoxide and hydroxyl radicals were found to be 1.873,1.684 and 1.735 mg/mL,respectively.Amino acid analysis showed that Fra-Ⅲhad high hydrophobic amino acids(HAA)content and hydrophobicity.The molecular weight distribution of Fra-Ⅲwas found to vary from 100 to 1,000 Da mainly.The antioxidant activity of Fra-Ⅲis clearly related to the amino acid composition,the content of HAA and the molecular mass.The present study suggests that BSP with low molecular weight are useful nutritional antioxidant and potential functional factor for anti-aging.

黑豆多肽对D-半乳糖衰老小鼠抗氧化能力的影响

采用蛋白酶复合水解黑豆分离蛋白制备黑大豆多肽(BSP),将50只昆明小鼠随机分为5组(对照组、模型组、VC阳性组和低、高剂量组),除对照组外,其余4组分别腹腔注射400mg/kg bw.d D-半乳糖建立氧化衰老模型;多肽组分别灌胃BSP(400、800mg/kg bw.d),实验周期56d。实验结束后,处死小鼠,取脾、肾、肝脏及胸腺称质量,计算脏器指数;测定血清及肝脏中丙二醛(MDA)含量和谷胱甘肽过氧化物酶(GSH-Px)活性以及肝脏脂褐质(LPF)含量。结果表明,BSP能使小鼠胸腺指数和脾脏指数升高,血清和肝脏MDA含量明显下降,GSH-Px活力显著提高;并且使肝组织中LPF含量明显下降。提示BSP能显著提高亚急性衰老小鼠的抗氧化能力,尤以高剂量组效果最好,具有一定延缓衰老的作用。