An 8-week randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of red Platycodon grandiflorus root extract on enhancement of immune function.

BACKGROUND: The immune-enhancing effects of red Platycodon grandiflorus root extract (RPGE) has been reported in vitro and in vivo, but there are few studies on humans. Therefore, this study aimed to investigate the efficacy and safety of RPGE in enhancing immune function in healthy subjects. SUBJECTS AND METHODS: An 8-week randomized, double-blind, parallel, placebo-controlled clinical trial was conducted at the Gachon University Gil Medical Center, Incheon, South Korea. A total of 100 adults aged 20-75 years with white blood cell counts of 3000-10,000 cell/µL were randomly divided into two groups (RPGE group, 50 and placebo group, 50) using a computer-generated random list with a 1:1 allocation ratio. The subjects consumed RPGE (2 times/day, 2 tablets/time, 375 mg RPGE powder/tablet) or placebo for 8 weeks. All test foods for the human study were coded and administered under double-blind conditions. The primary outcome was a change in the NK cell activity after 8 weeks of treatment compared to the baseline. RESULTS: Among 100 subjects enrolled for the study, 87 completed the study. NK cell activity (p = 0.005) and IFN-γ level (p = 0.003) of the RPGE group (n = 41) were higher than those of the placebo group (n = 46). The findings of the safety assessment revealed absence of clinically significant changes in any test and serious adverse events throughout the study. CONCLUSION: In conclusion, these results demonstrate the efficacy and safety of RPGE, suggesting it to be a beneficial agent for enhancing immune function in humans. TRIAL REGISTRATION: CRIS Registration Number KCT0005945, https://cris.nih.go.kr.

Efficacy of black rice extract on obesity in obese postmenopausal women: a 12-week randomized, double-blind, placebo-controlled preliminary clinical trial.

OBJECTIVES: Postmenopausal obesity is a paramount health concern among older women. Black rice is a well-known pigmented rice variety with a higher anthocyanin content. Both in vitro and in vivo studies have demonstrated the effects of black rice on obesity. The present study aimed to investigate the effects of black rice extract (BRE) on obesity among obese postmenopausal women from Korea. METHODS: This was a 12-week, randomized, double-blind, placebo-controlled preliminary clinical trial. The participants were postmenopausal women who had stopped menstruating for more than a year. Specifically, 105 participants were randomly assigned to the BRE (1 g/d) or placebo (maltodextrin, 1 g/d) group. RESULTS: Eighty-eight participants completed the study, 47 in the intervention group and 41 in the placebo group. At the study endpoint, dual-energy x-ray absorptiometry assessment showed that the BRE group had a significantly lower trunk fat (P = 0.04), total fat (P = 0.04), and total body fat percentage (P = 0.04) than did the placebo group. The body fat percentage (P = 0.04) was lower in the BRE group with marginal significance, and there were no significant differences in anthropometric measures such as weight, body mass index, waist circumference, or waist-to-hip ratio estimated by bioelectrical impedance analysis. CONCLUSION: BRE supplementation for 12 weeks seems to be effective in reducing fat accumulation in postmenopausal women.