Nicotinamide improves physiological outcomes in an arginine vasopressin rat model of pre-eclampsia

Pre-eclampsia (PE) is a hypertensive disorder of pregnancy that poses a substantial risk to both maternal and fetal health, especially in low-middle-income countries. Despite advancements in pregnancy-related research, effective treatment options for PE remain limited, emphasizing the need for innovative therapeutic strategies in regions that are under-resourced with the highest burden. In this light, there has been growing interest in the safety and efficacy of natural products, where nicotinamide (NAM) has emerged as a promising candidate for alternative PE management. This study aims to evaluate the therapeutic potential of NAM in a preclinical model of PE, specifically assessing its effects on blood pressure, placental and fetal development, and hematological parameters. Twenty-four pregnant female Sprague Dawley rats were subcutaneously administered arginine vasopressin (AVP) via mini osmotic pumps (infused at a rate of 200 ng/h). AVP-administered rodents received either NAM (p.o., 200 mg/kg body weight) or captopril (p.o., 40 mg/kg body weight (BW)) for two weeks. Our findings demonstrate that NAM effectively reduced both systolic and diastolic blood pressure in AVP-treated rats, reduced urinary protein levels and the urine protein-to-creatinine ratio (UPCR), alongside improvements in hematological parameters. Concerning pregnancy outcomes, NAM administrations significantly increased urine output and placental and individual pup weights. These findings highlight the preclinical efficacy of NAM in ameliorating the symptoms associated with hypertension in pregnancy, improving both maternal and fetal well-being, and paving the way for future research into the use of NAM. • Nicotinamide significantly reduced systolic and diastolic blood pressure in AVP-treated rats. • Nicotinamide lowered urinary protein levels and UPCR, indicating improved kidney function. • Nicotinamide increased urinary output, enhanced hematological indices, and supported placental and fetal growth. • These findings suggest nicotinamide as a potential cost-effective, non-invasive treatment for HDPs.