Supplementation with a Natural Source of Amino Acids, Sil-Q1 (Silk Peptide), Enhances Natural Killer Cell Activity: A Redesigned Clinical Trial with a Reduced Supplementation Dose and Minimized Seasonal Effects in a Larger Population.

The aim of this study was to re-validate the changes in natural killer (NK) cell cytotoxicity and cytokines related to T cells after Sil-Q1 (SQ; silk peptide) supplementation in a larger pool of Korean adults with minimized daily dose of SQ and controlling seasonal influence compared to the previous study. A total of 130 subjects were randomly assigned (1:1) to consume either 7.5 g of SQ or placebo for 8 weeks. NK cell cytotoxicity and cytokines were measured at T0 (baseline) and T8 (follow-up). Comparing the NK cell cytotoxicity values at T0 and T8 within each group, the cytotoxicity at all effector cell (E) to target cell (T) ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was significantly increased in the SQ group at T8. Additionally, significant differences in the changed value (Δ, subtract baseline values from follow-up values) comparison between the groups at E:T = 10:1, 5:1, and 2.5:1 were found. As a secondary endpoint, the interleukin (IL)-12 level in the SQ group was significantly increased for 8 weeks, and Δ IL-12 in the SQ group was greater than in the placebo group. In conclusion, the present study showed considerable practical implications of SQ supplementation. Thus, SQ is an effective and safe functional food supplement for enhancing immune function.

Efficacy and Safety of Sesame Oil Cake Extract on Memory Function Improvement: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Pilot Study.

The goal of treatment for mild cognitive impairment (MCI) is to reduce the existing clinical symptoms, delay the progression of cognitive impairment and prevent the progression to Alzheimer's disease (AD). At present, there is no effective drug therapy for AD treatment. However, early intake of dietary supplements may be effective in alleviating and delaying the MCI. This study aims to evaluate the effects of sesame oil cake extract (SOCE) supplementation on cognitive function in aged 60 years or older adults with memory impairment. A total of 70 subjects received either SOCE (n = 35) or placebo (n = 35) for 12 weeks based on random 1:1 assignment to these two groups. Cognitive function was evaluated by a computerized neurocognitive function test (CNT), and changes in the concentrations of plasma amyloid ß (Aß) proteins and urine 8-OHdG (8-hydroxy-2'-deoxyguanosine) were investigated before and after the experiment. Verbal learning test index items of the CNT improved markedly in the SOCE group compared to the placebo group (p < 0.05). Furthermore, plasma amyloid-ß (1-40) and amyloid-ß (1-42) levels in the SOCE group decreased significantly compared to that in the placebo group (p < 0.05). There was no statistically significant difference in urine 8-OHdG between the two groups (p > 0.05). Collectively, intake of SOCE for 12 weeks appears to have a beneficial effect on the verbal memory abilities and plasma ß-amyloid levels of older adults with memory impairment.

Effects of Porphyra tenera Supplementation on the Immune System: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial.

OBJECTIVE: The purpose of this study was to determine if Porphyra tenera extract (PTE) has immune-enhancing effects and is safe in healthy adults. METHODS: Subjects who met the inclusion criteria (3 × 103 ≤ peripheral blood leukocyte level ≥ 8 × 103 cells/µL) were recruited for this study. Enrolled subjects (n = 120) were randomly assigned to either the PTE group (n = 60) and were given 2.5 g/day of PTE (as PTE) in capsule form or the placebo group (n = 60) and were given crystal cellulose capsules with the identical appearance, weight, and flavor as the PTE capsules for 8 weeks. Outcomes were assessed based on measuring natural killer (NK) cell activity, cytokines level, and upper respiratory infection (URI), and safety parameters were assessed at baseline and 8 weeks. RESULTS: Compared with baseline, NK cell activity (%) increased for all effector cell-to-target cell ratios in the PTE group after 8 weeks; however, changes were not observed in the placebo group (p < 0.10). Subgroup analysis of 101 subjects without URI showed that NK cell activity in the PTE group tended to increase for all effector cell/target cell (E:T) ratios (E:T = 12.5:1 p = 0.068; E:T = 25:1 p = 0.036; E:T = 50:1 p = 0.081) compared with the placebo group. A significant difference between the two groups was observed for the E:T = 25:1 ratio, which increased from 20.3 ± 12.0% at baseline to 23.2 ± 12.4% after 8 weeks in the PTE group (p = 0.036). A significant difference was not observed in cytokine between the two groups. CONCLUSION: PTE supplementation appears to enhance immune function by improving NK cell activity without adverse effects in healthy adults.

Silk peptide treatment potentiates natural killer cell activity in vitro and induces natural killer cell maturation and activation in mouse splenocytes.

Context: Silk peptide from cocoons of silkworm (Bombyx mori L., Bombycidae) has been employed as a biomedical material and exhibits various bioactivities, including immune-modulating activity. Objective: We analyzed whether silk peptide exerts direct modulating effects on NK cells using an NK cell line in vitro and ex vivo splenocytes. We also attempted to delineate the mechanism underlying the modulation. Material and methods: In vitro activity of silk peptide on NK cells was determined by measurement of cytolytic activity against K562 cells at an effector-to-target ratio of 5:1 after incubation of NK-92MI cells with silk peptide (0-2000 µg/mL) for 48 and 72 h. Ex vivo activity of silk peptide on mouse splenic NK cells was determined similarly by using YAC-1 cells. Results: Treatment of NK-92MI NK cells with silk peptide (500-2000 µg/mL) significantly increased cytolytic activity on target cells by 2- to 4-fold. The same concentrations (500-2000 µg/mL) of silk peptide treatment also significantly enhanced the cytolytic activity of splenic NK cells against YAC-1 cells. Silk peptide treatment of IL-2-stimulated splenocytes induced enhanced expression of Th1, 2 and 17 cytokines including TNF-α, IFN-γ, IL-6, IL-4 and IL-17. Finally, ex vivo treatment with silk peptide on mouse splenocytes significantly enhanced the degree of NK cell maturation in a dose-dependent manner from 3.49 to 23.79%. Discussion and conclusions: These findings suggest that silk peptide stimulates NK cells, thereby influencing systemic immune functions and improving natural immunity. Thus, silk peptide could be useful as a complementary therapy in cancer patients.

Supplementation with extract of Gynostemma pentaphyllum leaves reduces anxiety in healthy subjects with chronic psychological stress: A randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: The ethanol extract of Gynostemma pentaphyllum Makino leaves (EGP) has been reported recently to have anxiolytic effects on chronically stressed mice models. PURPOSE: We aimed to investigate the efficacy and safety of EGP on anxiety level in healthy Korean subjects under chronic stressful conditions. STUDY DESIGN: Double-blind, placebo-controlled trial. METHODS: This study was conducted with 72 healthy adults who had perceived chronic stress and anxiety with a score on the State-Trait Anxiety Inventory (STAI) from 40 to 60. Participants were randomly assigned to receive either EGP (200 mg, twice a day, N = 36) or placebo (N = 36). All participants were exposed to repetitive loads of stress by performing the serial subtraction task for 5 min every second day during the 8-week intervention. Primary outcome of Trait-STAI and secondary outcomes of State-STAI, total score of STAI, Hamilton Anxiety Inventory (HAM-A), Beck Anxiety Inventory (BAI), blood norepinephrine and adrenocorticotropic hormone (ACTH), salivary cortisol and alpha-amylase, cardiovascular autonomic nervous system (ANS) functional test, and heart rate variability (HRV) test were measured before and after intervention. RESULTS: After the 8-week intervention, the EGP significantly lowered the score of the Trait Anxiety Scale of the STAI (T-STAI) by 16.8% compared to the placebo (p = 0.041). The total score on the STAI decreased by 17.8% in the EGP group and tended to improve compared with that of the placebo group (p = 0.067). There were no significant differences in the changes in score of S-STAI, HAM-A, BAI, and other parameters from baseline between the two groups. There was no causal relationship between the ingestion of EGP and adverse drug reactions. CONCLUSION: We found that supplementation with EGP reduced "anxiety proneness" in subjects under chronic psychological stress, as shown by a decrease in the score of T-STAI and the tendency for decrease in the total score of STAI. This result suggests that EGP supplementation can be used as a regimen to safely reduce stress and anxiety; however, more studies are needed to establish the long-term safety and effectiveness.

Randomized, double-blind, placebo-controlled trial of Ficus carica paste for the management of functional constipation.

BACKGROUND AND OBJECTIVES: Constipation affects up to 20% of the world's population. The aim of this study was to investigate whether supplementation with Ficus carica paste could be used to treat constipation in Korean subjects with functional constipation. METHODS AND STUDY DESIGN: We conducted a randomized, double-blind, placebo-controlled trial. Subjects with functional constipation were orally supplemented with either F. carica paste (n=40) or placebo (n=40) for 8 weeks. We measured the efficacy and safety of F. carica paste. Primary outcomes (colon transit time) and secondary outcomes (questionnaire related to defecation) were compared before and after the 8-week intervention period. RESULTS: F. carica paste supplementation was associated with a significant reduction in colon transit time and a significant improvement in stool type and abdominal discomfort compared with the placebo. Blood parameters and clinical findings for organ toxicity remained within normal ranges. CONCLUSION: These results suggest that F. carica paste may have beneficial effects in subjects suffering from constipation.