Sex differences in cardiac and renal responses to a high salt diet in Sprague-Dawley rats

A high salt intake in early life affects stress-coping response in males but not in female rats

Eating diets high in salt has been associated with alterations in the immune system and the potential development of neuropsychiatric disorders. This area of research shows promise, but there is currently a limited amount of research on this topic. The present study investigated whether a high salt diet (HSD) affects anhedonia and stress-coping response behaviors in young male and female Wistar rats. In this study, male and female Wistar rats were fed an HSD (8 % NaCl w/w) from weaning to post-natal day (PND) 64. From PND 60 to 64, the rats underwent a spontaneous locomotor activity test (SLA), sucrose splash test (SST), sucrose preference test (SPT), and forced swim test (FST), followed by euthanasia at PND 65. Male and female rats consuming the HSD exhibited an increase in water intake compared to the corresponding control diet (CD) groups. Male rats had lower body weight despite having similar food intakes compared to the CD group. Male rats displayed an active stress-coping behavior in the FST, characterized by increased mobility. Additionally, HSD-fed males exhibited a greater preference for sucrose solution in the SPT. However, no effect of diet and sex were detected in the SST and the SLA, and hypothalamic levels of leptin and ghrelin receptors. On the other hand, female rats were less susceptible to the experimental conditions applied in this protocol than males.

Phyllanthus amarus attenuated derangement in renal-cardiac function, redox status, lipid profile and reduced TNF-α, interleukins-2, 6 and 8 in high salt diet fed rats

High salt diet (HSD) has been implicated in the etiopathogenesis of immune derangement, cardiovascular disorders and, metabolic syndromes. This study investigated the protective effect of ethanol extract of Phyllanthus amarus (EEPA) against high salt diet (HSD) induced biochemical and metabolic derangement in male Wistar rats. The rats were divided into 5 groups of 6 animals each as follows; control group fed with normal rat chow, negative control group, fed HSD only, animals on HSD treated orally with 75 mg/kg, 100 mg/kg, and, 150 mg/kg EEPA once daily. At the end of 8 weeks treatment, lipid profile (TG, TC, LDL, and VLDL), oxidative stress (catalase, reduced glutathione, and malondialdehyde), inflammatory (TNF-a, interleukins 2, 6, and 8), cardiac (lactate dehydrogenase, creatine kinase) and kidney function markers (urea, uric acid, creatinine) were assessed. Serum TG, TC, LDL, and VLDL content were significantly (p < 0.05) elevated in HSD-only fed rats, while HDL was significantly elevated in a concentration-dependent manner in EEPA treated animals. The extract produced a significant (p < 0.05) and dose-dependent increase in the antioxidant enzymes activities and a significant reduction in the malondialdehyde level. A significant (p < 0.05) dose-dependent reduction in serum TNF-alpha, IL-2, 6, and 8 of EEPA treated rats compared with HSD-fed rats was observed. More so, reduction in serum LDH, creatine kinase, creatinine, urea, and uric acid activity of extract-treated animals were noted. EEPA attenuated high salt diet-induced oxidative stress, inflammation, and dyslipidemia in rats.

Effects of Doenjang, a Traditional Korean Soybean Paste, with High-Salt Diet on Blood Pressure in Sprague-Dawley Rats

Fermented foods in Korea contain a lot of salt. Although salt is reported to exacerbate health trouble, fermented foods have beneficial effects. We hypothesized that doenjang could reduce blood pressure in Sprague-Dawley (SD) rats fed a high-salt diet. Eighteen SD rats were divided into three groups: normal-salt (NS) group, high-salt (HS) group, and high-salt with doenjang (HSD) group. The salinity of doenjang and saltwater was adjusted to 8% using Mohr's method. Blood pressure was significantly reduced in the HSD group compared with the HS group. Water intake and urine excretion volume has significantly increased in the HS group compared with the HSD group. The excreted concentrations of urine sodium, urine potassium, and feces potassium significantly increased in the HSD group compared with the HS and NS groups. Renin level was significantly decreased in the HSD group compared to the other groups. These results indicate that eating traditional salty fermented food is not a direct cause of hypertension, and the intake of doenjang in normal healthy animals improved blood pressure.