Spirulina platensis, an important source of bioactive compounds, is a multicellular, filamentous cyanobacterium rich in high-quality proteins, vitamins, minerals, and antioxidants. Due to its nutrient composition, the alga is considered a complete food and is recognized for its anti-inflammatory, antioxidant, antiobesity, and reproprotective effects. All of which are important for prevention and treatment of organic and metabolic disorders such as obesity and erectile dysfunction. The aim of this study was to investigate the modulatory role of Spirulina platensis food supplementation and the mechanisms of action involved in reversing the damage caused by a hypercaloric diet on the erectile function of rats. The animals were divided into a standard diet group (SD, n=5); a hypercaloric diet group (HCD, n=5); a hypercaloric diet group supplemented with S. platensis at doses of 25 (HCD+SP25, n=5), 50 (HCD+SP50, n=5), and 100 mg/kg (HCD+SP100, n=5); and a hypercaloric diet group subsequently fed a standard diet (HCD+SD, n=5). In the rats fed a hypercaloric diet, dietary supplementation with S. platensis effectively increased the number of erections while decreasing latency to initiate penile erection. Additionally, S. platensis increases NO bioavailability, reduces inflammation by reducing the release of contractile prostanoids, enhances the relaxation effect promoted by acetylcholine (ACh), restores contractile reactivity damage and cavernous relaxation, reduces reactive oxygen species (ROS), and increases cavernous total antioxidant capacity (TAC). Food supplementation with S. platensis thus restores erectile function in obese rats, reduces production of contractile prostanoids, reduces oxidative stress, and increases NO bioavailability. Food supplementation with S. platensis thus emerges as a promising new therapeutic alternative for the treatment of erectile dysfunction as induced by obesity.

Strength training increases systemic oxygen consumption, causing the excessive generation of reactive oxygen species, which in turn, provokes oxidative stress reactions and cellular processes that induce uterine contraction. The aim of this study was to evaluate the possible protective effect of Spirulina platensis (SP), an antioxidant blue algae, on the contractile and relaxation reactivity of rat uterus and the balance of oxidative stress/antioxidant defenses. Female Wistar rats were divided into sedentary (CG), trained (TG), and T + supplemented (TG50, TG100) groups. Reactivity was analyzed by AQCAD, oxidative stress was evaluated by the malondialdehyde (MDA) formation, and the antioxidant capacity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Strength training increased contractile reactivity and decreased the pharmaco-mechanical component of relaxing reactivity in rat uterus. In addition, training decreased oxidation inhibition in the plasma and exercise increased oxidative stress in the uterine tissue; however, supplementation with algae prevented this effect and potentiated the increase in antioxidant capacity. Therefore, this study demonstrated that food supplementation prevents changes in reactivity and oxidative stress induced by strength training in a rat uterus, showing for the first time, that the uterus is a target for this exercise modality and antioxidant supplementation with S. platensis is an alternative means of preventing uterine dysfunction.

The consumption of hypercaloric diets is related to the development of obesity, favoring the etiology of gastrointestinal disorders. In this context, Spirulina platensis (SP), some blue‐green algae with antioxidant action, appears as a potential therapeutic alternative to prevent obesity and associated intestinal disorders. Thus, the present study is aimed at evaluating the deleterious effects of the hypercaloric diet on the contractile and relaxing reactivity of the ileum of rats, as well as the possible preventive mechanisms of dietary supplementation with SP. Wistar rats were divided into three groups: fed a standard diet (SD), a hypercaloric diet (HCD), and/or supplemented with 25 mg/kg SP (HCD + SP25) for 8 weeks. The hypercaloric diet was effective in promoting obesity in rats, as well as decreasing potency and ileal relaxing and contractile efficacy. In contrast, dietary supplementation with SP was able to prevent some of the parameters of experimental obesity. In addition, SP prevented the reduction of intestinal reactivity, possibly due to a positive modulation of voltage‐gated calcium channels (Ca_V) and negative regulation of muscarinic receptors (M3). Thus, food supplementation with Spirulina platensis becomes a promising alternative in the prevention of gastrointestinal diseases induced and/or aggravated by obesity.

Algae-derived bioactives have emerged as promising nutraceuticals due to their ability to modulate key molecular pathways under physiological stress. Arthrospira platensis (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 A. platensis 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 A. platensis (GAP100), adapted control (GC), PST-trained (GT), and PST-trained with A. platensis (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 A. platensis 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 A. platensis supplementation preserves uterine smooth muscle physiology under high-intensity resistance training, supporting its potential as a nutraceutical strategy for female reproductive health.

Background/Objectives: Primary dysmenorrhea (DysP) is a prevalent gynecological condition characterized by painful uterine contractions. However, the underlying mechanism of action of dysmenorrhea has not been fully elucidated. This study aimed to standardize an animal model of dysmenorrhea using diethylstilbestrol and oxytocin to mimic pathophysiological mechanisms in female Wistar rats. Methods: For the induction of dysmenorrhea, diethylstilbestrol (s.c.) and oxytocin (i.p.) were used. Results: The model effectively reproduced hypercontractility and impaired uterine relaxation. The in vivo evaluations demonstrated increased pain responses (DysP group = 119 ± 6.9; control group CG = 3.0 ± 1.0), which were partially attenuated by standard medications (scopolamine/dipyrone and ibuprofen). In vitro assays revealed greater contractile reactivity when compared to that in the control group, in the DysP group, using oxytocin (pEC₅₀ = 3.6 ± 0.2 and E_max = 145.1 ± 8.7; CG (pEC₅₀ = 3.1 ± 0.1 and E_max = 100%); KCl (DysP pEC₅₀ = 2.2 ± 0.1 and E_max = 164 ± 8.0); CG (pEC₅₀ = 1.8 ± 0.1) and PGF_2α (DysP pEC₅₀ = 7.4 ± 0.2 and E_max = 127.3 ± 15.6); CG (pEC₅₀ = 6.2 ± 0.1)), while the relaxation responses to isoprenaline and nifedipine were decreased compared to those in the CG. The model promoted an imbalance in oxidative stress by increasing malondialdehyde (MDA) levels and reducing the total antioxidant capacity (TAC) in the uterine tissue. Conclusions: These findings suggest that the new virgin rat model is capable of replicating key aspects of the clinical features of DysP in humans and offers a valuable tool for studying its pathogenetic mechanisms and testing potential therapeutic agents.

Arthrospira platensis (Oscillatoriaceae) (AP): commonly known as Spirulina, is a widely cultivated cyanobacterium used as both a dietary supplement and a functional food. Growing evidence suggests potential therapeutic effects in smooth muscle–related disorders; however, critical evaluations of the available data remain scarce. This narrative review critically examines preclinical and clinical evidence on Arthrospira platensis and its bioactive metabolites in conditions involving smooth muscle dysfunction, highlighting methodological strengths and limitations, and outlining future research needs. A structured literature search was conducted in PubMed, Scopus, and Web of Science using predefined inclusion criteria, and only studies with validated taxonomy and experimental or clinical data were included. The GA-online Best Practice checklist and the Four Pillars of Best Practice in Ethnopharmacology guided the analysis. Preclinical studies consistently demonstrate antioxidant, anti-inflammatory, and smooth muscle–modulating effects of A. platensis extracts and metabolites, including phycocyanin and polysaccharides. Experimental models in vascular, intestinal, uterine, and airway tissues reveal improved contractility and reduced oxidative damage. Although limited, clinical evidence suggests benefits on metabolic parameters and cardiovascular risk factors. Major limitations include the absence of standardized extract characterization, variable dosing, inconsistent controls, and the scarcity of randomized clinical trials. In conclusion, Arthrospira platensis shows promising pharmacological activities relevant to smooth muscle physiology, but current evidence remains largely preclinical and constrained by methodological weaknesses. Standardized extract characterization, rigorous experimental designs, and adequately powered clinical trials are essential to confirm its therapeutic potential.