Mariana Zanovello

Background: Cardiometabolic disorders such as hypertension and diabetes are major contributors to chronic kidney disease and often coexist, amplifying dysfunction and metabolic imbalance that favor renal injury and nephrolithiasis. Although pharmacological therapies exist for blood pressure and glycemic control, few target these mechanisms simultaneously. Rosmarinic acid (RA), a polyphenolic compound, exhibits antioxidant, anti-inflammatory, and nephroprotective effects, but its role in combined models of hypertension, diabetes, and nephrolithiasis remains unexplored. Objectives: This study investigated the therapeutic potential of RA in an experimental model combining hypertension, diabetes mellitus, and nephrolithiasis. Methods: Male Wistar spontaneously hypertensive (SHR) and normotensive rats were assigned to eight groups, including controls, comorbid groups, and treatments with RA (10 mg/kg) or hydrochlorothiazide (HCTZ; 5 mg/kg). Diabetes was induced by streptozotocin and nephrolithiasis by ethylene glycol plus ammonium chloride. Hemodynamic, biochemical, oxidative stress, and histological parameters were assessed. Results: SHR exhibited sustained hypertension, further aggravated by diabetes and nephrolithiasis. RA stabilized arterial pressure progression, whereas HCTZ significantly reduced blood pressure. RA and HCTZ treatments decreased urinary calcium oxalate crystal formation by 47.34 and 58.99%, respectively, and partially restored renal morphology. RA restored superoxide dismutase activity, preserved nitrite levels, and reduced lipid peroxidation, indicating antioxidant and endothelial protection. Neither treatment normalized glycemia or fully recovered renal function. Histological analysis showed attenuation of tubular and glomerular alterations in treated groups, particularly with RA. Conclusions: Overall, RA exerted antioxidant, nephroprotective, and antilithogenic effects in this complex comorbidity model, supporting its potential as a complementary therapeutic agent in chronic metabolic and renal disorders.

Background: Systemic arterial hypertension is one of the leading global health concerns, significantly increasing the risk of cardiovascular and kidney diseases, including nephrolithiasis. The treatment, still far from ideal, is constantly undergoing new alternatives. In this context, medicinal plants rich in flavonoids, such as naringenin—a compound found in citrus fruits—have gained attention for their potential diuretic, nephroprotective, and blood pressure-lowering effects. Objectives: This study aimed to evaluate the effects of naringenin (100 mg/kg, orally) over nine days on blood pressure, renal function, and calcium oxalate crystal formation in normotensive Wistar (NTR) and spontaneously hypertensive male rats (SHR). Methods: Key assessments included blood pressure and heart rate measurements in vivo, urine volume and electrolyte excretion in vivo, in vitro calcium oxalate crystallization, and in silico molecular docking analyses to investigate molecular interactions. Results: Naringenin treatment significantly reduced blood pressure and increased diuresis in both NTR and SHR groups, while a notable natriuretic effect was observed specifically in NTR. In vitro, naringenin reduced the formation of calcium oxalate crystals in urines from NTR. Molecular docking studies suggested that these effects may be mediated by interactions with SGLT1 and SGLT2 transporters, potentially explaining the diuretic and natriuretic outcomes. Additionally, interactions with MMP-9 and β2-adrenergic receptors may contribute to the reduction in crystal formation. Conclusions: Collectively, these findings indicate that repeated administration of naringenin exerts beneficial effects on both cardiovascular and renal parameters, and point to promising molecular targets that may underlie its protective actions.

Background: Cardiovascular diseases rank as the top global cause of mortality, particularly acute myocardial infarction (MI). MI arises from the blockage of a coronary artery, which disrupts blood flow and results in tissue death. Among therapeutic approaches, bioactives from medicinal plants emerge as promising for the development of new medicines. Objectives: This study explored the effects of naringenin (NAR 100 mg/kg), a flavonoid found in citrus fruits, in normotensive (NTR) and spontaneously hypertensive (SHR) rats, both subjected to isoproterenol (ISO 85 mg/kg)-induced MI. Results: Post-treatment assessments indicated that NAR reduced blood pressure and minimized clot formation, particularly notable in the SHR group, which helps mitigate damage related to hypertension and ISO exposure. Additionally, NAR effectively restored KCl-induced contractility in the aortas of both NTR and SHR groups. NAR treatment reduced reduced glutathione (GSH) and lipid hydroperoxides (LOOH) values and recovered the activity of the antioxidant enzymes catalase (CAT) and glutathione-s-transferase (GST) in NTR groups. Moreover, myocardial damage assessed through histological analyses was reduced in groups treated with NAR. Conclusions: The results highlight significant pathophysiological differences between the groups, suggesting that NAR has protective potential against ISO-induced cardiac damage, warranting further investigation into its protective effects and mechanisms.

This study aimed to assess the ability of rosmarinic acid (RA) to prevent kidney stone formation in an ethylene glycol and ammonium chloride (EG/AC) model. There was an increase in diuresis in the normotensive (NTRs) and hypertensive rats (SHRs) treated with hydrochlorothiazide (HCTZ) and exposed to EG/AC, while RA restored urine volume in NTRs. The EG/AC groups exhibited lower urine pH and electrolyte imbalance; these parameters were not affected by any of the treatments. Both HCTZ+EG/AC and RA+EG/AC reduced calcium oxalate crystal formation in NTR and SHR urine. Kidney tissue analysis revealed alterations in oxidative stress and inflammation parameters in all EG/AC-receiving groups, with RA enhancing antioxidant defenses in SHRs. Additionally, crystals were found in the kidney histology of all EG/AC-exposed groups, with reduced Bowman’s capsule areas in NTRs and SHRs. The NTR VEH+EG/AC group showed intense renal damage, while the others maintained their structures, where treatments with HCTZ and RA were fundamental for kidney protection in the NTRs. Docking analysis showed that RA exhibited good binding affinity with matrix metalloproteinase-9, phosphoethanolamine cytidylyltransferase, and human glycolate oxidase enzymes. The data disclosed herein underscore the importance of further research to understand the underlying mechanisms better and validate the potential of RA for clinical use.