Author(s): TSUJI, S., KOTANI, R., KOJI, S., Institution: KOBE UNIVERSITY, Country: JAPAN, Abstract-ID: 495

INTRODUCTION:
Dioscorea esculenta (D. esculenta) is a wild yam that contains high levels of diosgenin, a steroid sapogenin with a molecular structure similar to that of dehydroepiandrosterone (DHEA). Previous studies using cultured cells and rodents have reported that diosgenin exhibits anti-inflammatory effects, improves immune function, maintains muscle function, ameliorates hyperglycemia, and inhibits muscle atrophy¹; moreover, its intake has been shown to promote estrogen production in postmenopausal women and to contribute to the improvement of hyperglycemia². However, it is still unclear the effect of combination of D. esculenta and resistance exercise training on sex steroid hormone levels and the biomarker of lifestyle-related diseases and metabolic syndrome in individuals with middle and older age. The purpose of this study was to investigate the effects of combined treatment of D.esculenta intake and resistance exercise training lifestyle-related diseases and metabolic syndrome biomarkers in middle-aged and elderly individuals.
METHODS:
The participants were 12 middle-aged men and women aged 64 ± 8 years, who were randomly divided into two groups: (1) D. esculenta intake group and (2) D. esculenta intake plus home-based low- to moderate-intensity resistance exercise training group (n = 6 each). The index of measurements included body composition, fasting blood glucose, and blood pressure and pulse wave velocity before and after the intervention. lifestyle-related disease and metabolic syndrome biomarkers were measured from plasma sample. Tablets were prepared from D. esculenta powder, and three tablets (500 mg) were taken daily for 8-week.
Home-based resistance exercise training consisted 10 types of exercise and conducted 2 sets of 10 reps each exercise three times a week for 8-week according to British Heart Foundation.
RESULTS:
In both D and D+RE groups tend to be lower fasting blood glucose level after 8-week intervention compared to baseline. Estradiol concentration was significantly increased by D+RE after interventions compared to baseline. Oncostatin M (OSM) is a cytokine belonging to the interleukin-6 (IL-6) family and is involved in various biological processes, including cell proliferation and inflammatory responses. Plasma OSM and IL-6 levels tended to decrease after the intervention; however, no significant differences were observed between groups or between pre- and post-intervention. In addition, there was a significant negative correlation between the changes in estradiol and OSM levels.
CONCLUSION:
The D+RE intervention increased estradiol levels, leading to a decrease in inflammatory cytokines including OSM, and it may be one of the mechanisms that decreased blood glucose level by D. esculenta intake.
1．Yan et al., Chinese Journal of Natural Medicines. 13(8): 578-587, 2015.
2．Sun et al., Target and Therapy. 14:4015-4030, 2021