Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources of protein with a high amino acid score and can provide bioactive peptides. This manuscript presents a review on legume-derived peptides, focusing on in vitro and in vivo studies on the potential antioxidative activities of protein hydrolysates and their characterization, amino acid sequences, or purified/novel peptides. The health implications of legume-derived antioxidative peptides in reducing the risks of cancer and cardiovascular diseases are linked with their potent action against oxidation and inflammation. The molecular weight profiles and amino acid sequences of purified and characterized legume-derived antioxidant peptides are not well established. Therefore, further exploration of legume protein hydrolysates is necessary for assessing the potential applications of antioxidant-derived peptides in the functional food industry.

This study aimed to assess the suppressive effect of long-term diet supplementation with Lactobacillus strains on cognitive decline in the senescence-accelerated mouse prone 8 (SAMP8) model. For 43 weeks, fourteen-week-old female SAMP8 mice were fed a standard diet containing 0.05% (w/w) Lactobacillus casei subsp. casei 327 (L. 327) or Lactobacillusparacasei K71 (L. K71) derived from rice grains and sake lees, respectively. SAMP8 mice that were fed a L. K71-supplemented diet had better cognitive performance compared with the control and L. 327 groups in the Barnes maze and passive avoidance tests. An ELISA analysis revealed that the levels of serotonin were elevated in the serum and brain tissue of L. K71-fed mice. The protein expression levels of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and phosphorylated CREB were evaluated using western blot. Long-term administration of L. K71 resulted in increased protein expression of BDNF and CREB phosphorylation in the hippocampus. These results suggest that prolonged intake of a diet supplemented with a Lactobacillus strain derived from sake lees may prevent age-dependent cognitive decline by upregulating BDNF expression in the hippocampus.