The Effects of Glycyrrhiza glabra L. extract use with aerobic training on inflammatory factors and cognitive state in elderly with mild cognitive impairment

Introduction: This study was aimed to investigate the effect of a 12-week aerobic training protocol and treatment with Glycyrrhiza glabra extract on serum interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) levels and cognitive state in the elderly with mild cognitive impairment (MCI). Methods: Forty people who attained scores 21-25 on the Mini–Mental State Examination (MMSE) were selected by purposive and convenience sampling and randomly assigned to four groups of 10 each: training, G. glabra-treated, training+G. glabra-treated, and placebo. All interventions were conducted within 12 weeks. Aerobic training protocol consisted of an 8-minute running at an intensity of 75%-85% maximum heart rate in the first session. One minute was added to the duration of running per two sessions so that after 12 weeks, the duration of running in two last sessions was 26 minutes. G. glabra extract was orally administered in 200 mg/kg body weight capsules per day. Results: IL-1β and TNF-α levels significantly decreased in training and G. glabra-treated groups but their decrease were more marked in training+G. glabra-treated group (P < 0.05). Cognitive state in three intervention groups significantly improved compared to placebo group, and this improvement was more marked in training+G. glabra-treated group (P < 0.05). Conclusion: Consumption of G. glabra extract with aerobic training for 12 weeks can slow down or stop the progression of MCI in the elderly through improving their cognitive states probably via decreasing inflammatory factors.