BIOPROSPECTION OF FUCOIDAN AND OUABAIN: EFFECTS ON HUMAN SPERM MOTILITY AND VITALITY IN VITRO
Name: PAULA GABRIELLA PEDRAS SILVA
Publication date: 18/03/2025
Examining board:
Name |
Role |
|---|---|
| BRENO VALENTIM NOGUEIRA | Coorientador |
| CARLOS MAGNO DA COSTA MARANDUBA | Examinador Externo |
| DEBORA DUMMER MEIRA | Presidente |
| FLAVIA DE PAULA | Examinador Interno |
Summary: Oral hormonal contraceptives (OC) are widely used in family planning but pose significant health risks to women. Although effective, they can cause severe adverse effects, such as cardiovascular alterations that increase the risk of pulmonary
embolism, venous and arterial thrombosis, and metabolic diseases such as diabetes and dyslipidemia. Cardiovascular diseases (CVD) are the leading cause of death in Brazil and globally, and hormonal contraceptive methods are associated with an
increased risk of cerebrovascular accidents and other CVDs. Plant-based spermicides are alternatives to chemical spermicides like Nonoxynol-9 (N-9), which can cause vaginal mucosa damage and increase the risk of infections. Alternatives to N-9, such as Sodium Lauryl Sulfate (SLS), also present adverse effects, including skin and mucosal irritation. Fucoidan, a sulfated polysaccharide found in brown seaweeds, has beneficial biological activities and is investigated as a drug carrier due to its low toxicity. Ouabain, extracted from the plant Strophanthus gratus, acts on sperm capacitation and inhibits Na+/K+-ATPase, playing a significant role in various physiological and pathological processes. This study aimed to analyze the spermicidal activity of fucoidan, extracted from the seaweed Fucus vesiculosus, and ouabain on human sperm in vitro. The methodology involved collecting semen samples from volunteers aged 18 to 45 years, after approval from the Ethics and Research Committee under the Ethical Appreciation Presentation Certificate (CAAE) 79783124.5.0000.5060, which were subjected to treatments with negative control, positive control (SLS), fucoidan, ouabain, and a combination of both. Sperm motility and vitality were assessed at two different time points (0 and 15 minutes) using seminal analysis techniques standardized by the World Health Organization. The
treatments significantly reduced sperm motility and vitality compared to the positive control (SLS). The combination of fucoidan and ouabain showed the greatest reduction in sperm motility, with approximately a 28.3% decrease in progressive motility and a 28.1% decrease in vitality, suggesting a synergistic effect between the compounds. Statistical analysis using non-parametric tests of Kruskal-Wallis and Wilcoxon post hoc confirmed the significance of these reductions at times T0 and T15. Moreover, the interaction of the compounds with reactive oxygen species (ROS) suggests a mechanism of action that compromises cellular integrity and sperm function. These findings highlight the potential of fucoidan and ouabain as effective spermicidal agents, contributing to the development of safer and more efficient contraceptive methods. However, it is necessary to consider the costs associated with each treatment and conduct further research to confirm these hypotheses and explore their future biotechnological applications.
