The Effect of the Rice Endosperm Protein Hydrolysate on the Subjective Negative Mood Status in Healthy Humans: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial.

The rice endosperm protein (REP) hydrolysate containing the following rice endosperm protein derived oligopeptides QQFLPEGQSQSQK, LPEGQSQSQK, and pEQFLPEGQSQSQK (a N-terminal pyroglutamate residue-modified peptide) reportedly showed an antidepressant-like effect in an animal model. We investigated the effect of the REP hydrolysate on healthy humans who self-reported mental fatigue with subjectively low vigor. Seventy-six participants (age: 20-64 years) were randomly allocated to two groups. The influence of the REP hydrolysate on the mood state was evaluated in two studies: single intake (Study 1) and repeated intake over 4 weeks (Study 2). A salivary stress marker, Chromogranin A (CgA), was measured in Study 1. The single intake of the REP hydrolysate significantly improved the Profile of Mood Status 2nd edition for adults (POMS 2) subscale of Tension-Anxiety. Additionally, the salivary CgA concentrations were remarkably reduced after the single intake of the REP hydrolysate. Though a single intake of the REP hydrolysate did not significantly influence the other subscales and the TMD of the POMS 2 and the Euthymia Scale, both the subjective and objective results supported the possible effect of the REP hydrolysate on reducing anxiety and nervousness. No significant positive effects on the subjective mood state (Euthymia Scale and POMS 2) and sleep quality (Insomnia Severity Index) were observed in the trial setting employed for Study 2. In conclusion, a single intake of REP hydrolysate might help relax the subjective feelings of tension and anxiety. The effectiveness of repeated REP hydrolysate intake needs to be tested in a different clinical setting.

Lacticaseibacillus paracasei K71 Alleviates UVB-Induced Skin Barrier Dysfunction by Attenuating Inflammation via Increased IL-10 Production in Mice.

SCOPE: Ultraviolet B (UVB) radiation causes skin barrier dysfunction, leading to decreased water-holding capacity, impaired epidermal barrier function, and increased skin thickness. This study investigates the protective effects of oral administration of Lacticaseibacillus paracasei K71 against skin barrier dysfunction in UVB-irradiated mice. METHODS AND RESULTS: Mice are fed diets with or without K71 and irradiated with UVB three times a week for 12 weeks. Oral administration of K71 suppresses UVB-induced decrease in stratum corneum water content, mitigates the increase of transepidermal water loss, and decreases epidermal thickness of the dorsal skin. Treatment with K71 reverses the upregulation of inflammatory cytokines and the activation of nuclear factor-κB induced by UVB irradiation and upregulates the expression of anti-inflammatory IL-10 in the dorsal skin. Notable upregulation of IL-10 is observed in the spleens of K71-treated mice. K71 treatment enhances IL-10 production in J774.1 macrophages; however, this enhancement is diminished by inhibiting K71 phagocytosis and TLR3. Furthermore, transfection using K71 RNAs significantly increases IL-10 production. CONCLUSION: These results indicate that K71 may alleviate UVB-induced skin barrier dysfunction by attenuating inflammation via increasing IL-10 production and that K71 RNAs may induce IL-10 production in macrophages. Therefore, K71 may be beneficial for preventing skin barrier dysfunction.

Rice Endoplasmic Protein-Derived Peptides, Rice-Ghretropins A and B, Stimulate Ghrelin Release in MGN3-1 Cells and Increase Plasma Acylated Ghrelin and Food Intake in Mice.

In this study, we demonstrated that novel rice-derived bioactive peptides promote the secretion of ghrelin, an endogenous orexigenic hormone secreted from the stomach. The enzymatic digest of rice endosperm protein with subtilisin, a microorganism-derived enzyme, stimulated acylated ghrelin secretion in the ghrelin-releasing cell line MGN3-1 and increased food intake after oral administration in mice. By performing a comprehensive analysis based on structure-activity relationships, we selected candidate peptides from over 30,000 peptides in the rice digest. Among them, we found that QAFEPIRSV and TNPWHSPRQGSF, corresponding to the amino acid sequence of the rice endoplasmic proteins glutelin A1 or A2(52-60) and B1 or B2(31-42), respectively, stimulated acylated ghrelin release in MGN3-1 cells. We named them rice-ghretropins A and B. Pyroglutamate formation of rice-ghretropin A, [pyr1]-rice-ghretropin A, also promoted ghrelin secretion. Furthermore, oral administration of rice-ghretropins increased food intake, plasma ghrelin concentration, and small intestinal transit in mice. In addition, the subtilisin digest of the rice protein significantly increased food intake for 4 h in 9 month-old (control: 0.61 ± 0.049 g; digest: 0.83 ± 0.059 g) and 24 month-old mice (control: 0.52 ± 0.067 g; digest: 1.01 ± 0.064 g). In summary, we found that novel bioactive peptides, namely, rice-ghretropins, from the enzymatic digest of rice endosperm stimulated acylated ghrelin secretion and increased food intake. This is the first report of rice-derived exogenous bioactive peptides that increase acylated ghrelin secretion.

Beneficial effect of a diet containing heat-killed Lactobacillus paracasei K71 on adult type atopic dermatitis.

The purpose of this study was to investigate the clinical effect of a supplementary diet containing heat-killed lactic acid bacterium Lactobacillus paracasei K71 (LAB diet) on adult patients with atopic dermatitis (AD). A randomized, double-blind, placebo-controlled study was conducted in 34 adult type AD subjects who were treated with conventional topical corticosteroid and tacrolimus. LAB diet or placebo was added over 12 weeks. The primary end-point was the clinical severity of AD which was evaluated by a severity scoring system proposed by the guideline of the Japanese Dermatological Association. The effect was also secondarily evaluated by itch scores of visual analog scales (VAS), quality-of-life (QOL) impairment scores of Skindex 16 and consumption amounts of topical therapeutics. Data on these four assessment variables were collected at baseline and at week 4, 8 and 12. Within the study population, the skin severity scores were significantly decreased from baseline at week 8 (P<0.05) and at week 12 (P<0.01) in the LAB diet group but not in the placebo group. Influence of LAB diet on itch scores or QOL impairment scores was not evident. The consumption of topical therapeutics in the placebo group was 1.9-times greater in total amount compared with the corresponding value in the LAB diet group during the intervention period, although there was no significant difference. No LAB diet- or placebo-related adverse events were observed. We concluded that the LAB diet may have some benefits as a complementary therapy for adult AD patients who are managed with the conventional treatment.