Arthrospira platensis Preserves Uterine Function by Modulating Electromechanical Coupling and Redox Pathways During Resistance Training in Female Rats

Algae-derived bioactives have emerged as promising nutraceuticals due to their ability to modulate key molecular pathways under physiological stress. <i>Arthrospira platensis</i> (Spirulina), a cyanobacterium widely recognized for its antioxidant and anti-inflammatory properties, is proposed as a functional supplement to preserve smooth muscle physiology. Progressive strength training (PST) can induce oxidative stress and disrupt electromechanical coupling in the uterus, potentially impairing female reproductive function. This study investigated whether supplementation with <i>A. platensis</i> prevents PST-induced uterine dysfunction and elucidated the molecular mechanisms involved. Virgin Wistar rats were divided into five groups: sedentary with saline (GS), sedentary with <i>A. platensis</i> (GAP100), adapted control (GC), PST-trained (GT), and PST-trained with <i>A. platensis</i> (GTAP100). An eight-week water-jump PST protocol was applied. Uterine contractile responses were recorded in isolated organ baths after cumulative KCl stimulation, in the absence or presence of pathway-specific inhibitors targeting nitric oxide synthase, cyclooxygenase, NADPH oxidase, or superoxide dismutase. Histological evaluations of uterine and ovarian tissues were also performed. PST increased contractile efficacy and myometrial thickness, associated with oxidative stress and activation of NO, COX, and NADPH oxidase pathways. Supplementation with <i>A. platensis</i> attenuated these alterations by enhancing NO signaling, stimulating relaxant prostanoids, and reducing superoxide production. These protective effects were abolished by inhibitors, confirming mechanistic involvement. Overall, our findings provide molecular evidence that <i>A. platensis</i> supplementation preserves uterine smooth muscle physiology under high-intensity resistance training, supporting its potential as a nutraceutical strategy for female reproductive health.