Downloaded from http://journals.lww.com/nsca-jscr by BhDMf5ePHKbH4TTImqenVIukvCljlO2s5/r/M6IR55mvKKUJ2QjS+i425h/xKyUN80GBl3A7iUk= on 09/01/2020 Original Research Ergogenic Effects of 8 Days of Sceletium Tortuosum Supplementation on Mood, Visual Tracking, and Reaction in Recreationally Trained Men and Women Jay R. Hoffman, 1 Irit Markus, 2 Gal Dubnov-Raz, 3 and Yftach Gepner 2 1 Department of Molecular Biology, Ariel University, Ariel, Israel; 2 Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel; and 3 The Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Abstract Hoffman, JR, Marcus, I, Dubnov-Raz, G, and Gepner, Y. Ergogenic effects of 8 days of Sceletium tortuosum supplementation on mood, visual tracking, and reaction in recreationally trained men and women. J Strength Cond Res 34(9): 2476–2481, 2020— Sceletium tortuosum (ST) is a South African plant that has been reported to promote a sense of well-being in healthy individuals and used in treating people with anxiety, stress, or depression. These studies have been conducted in middle-aged and older adults, but no investigations have been performed in a healthy, young adult population. Thus, the purpose of this study was to examine the effect of 8 days of ST extract (25-mg) supplementation on changes in reactive agility, visual tracking, and mood. Sixty recreationally trained men (n 5 48) and women (n 5 12), between 20 and 35 years, were randomly assigned to 1 of 2 groups: ST or placebo (PL). Subjects were tested on 2 occasions: before supplementation and 2-hours after supplementation on day 8. Subjects completed a subjective questionnaire to assess alertness and energy using a visual analog scale (VAS). In addition, subjects completed the Profile of Mood States questionnaire and performed reactive agility and visual tracking assessments. Significant improvements were noted for ST in complex reactive performance that required subjects to respond to repeated visual stimuli with a cognitive load compared with PL. However, no significant changes were noted between the groups in either VAS or total mood score. In addition, no differences were observed in simple reaction assessments. The results of this study demonstrate an ergogenic benefit in complex reactive tasks that include a cognitive load. However, in this subject population studied, no benefits in mood were observed. Key Words: dietary intervention, cognitive enhancer, reactive agility, performance, nutrition Introduction Sceletium tortuosum (ST) is a South African plant that has been reported to promote a sense of well-being in healthy individuals and used in treating people with anxiety, stress, or depression (7). The physiological mechanism linked to its potential benefits seems to be related to its role as a potent blocker of the serotonin (5-HT) transporter and specifically act as an inhibitor of phosphodiesterase-4 (PDE4) (10). Serotonin reuptake inhibitors are generally used to treat depression, and recent evidence sug- gests that PDE4 inhibitors can also be used as a potential treat- ment option for depression (8). PDE4 inhibitors have also been reported to attenuate proinflammatory cytokines (8). The po- tential therapeutic benefit in the use of ST is that it may inhibit both 5-HT and PDE4, potentially requiring a lower dose to achieve desired efficacy, reducing the incidents of adverse events. Serotonin is a neurotransmitter found in the brain that has an important role in neuroplasticity (13). Dysfunction in neuro- plasticity can result in learning and memory deficits, and it can contribute to the pathophysiology of depression (13). Decreases in serotonin as a result of an attenuated synthesis is thought to be a cause of depression (16). Blocking the reuptake of 5-HT, thus maintaining 5-HT concentrations, has been used as therapeutic treatment for depression (17). Phosphodiesterases (PDE) are a group of enzymes that catalyze the hydrolysis of cyclic adenosine monophosphate (cAMP) (15). Of the 11 PDEs, PDE4 has received much focus in neuro- dysfunction because of its strong expression in the brain (9). The immediate downstream effector of cAMP is protein kinase A (PKA), which is activated upon cAMP binding and translocates to the nucleus where it phosphorylates cAMP response element binding protein (CREB). cAMP response element binding protein is a transcription factor that binds to cAMP response element promoter sites (2) located on specific CREB-mediated genes such as brain-derived neurotrophic factor (BDNF), which can alter synaptic function (6). Altered PDE4 signaling directly results in cAMP alterations (9). The use of PDE4 inhibition as a therapeutic option is to maintain the cAMP intracellular cascade. Others have reported that PDE4 inhibition can also attenuate inflammatory cytokines (12). Terburg et al. (21) reported that a single administration of ST extract (25 mg) can reduce anxiety-related amygdala reactivity and attenuate amygdala-hypothalamus coupling, providing the initial evidence that this plant is a dual PDE4 and 5-HT reuptake inhibitor for the treatment of anxiety disorders and depression. A subsequent investigation examined a 25-mg dose consumed for 3 weeks in middle-aged healthy men and women (4). Results from this investigation demonstrated improvements in mood and in Address correspondence to Dr. Jay R. Hoffman, jayho@ariel.ac.il. Journal of Strength and Conditioning Research 34(9)/2476–2481 ª 2020 National Strength and Conditioning Association 2476 Copyright © 2020 National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.