Estrone-mediated lowering of ROS and NOX4 improves endothelial function in ovariectomized wistar rats

Estrone (E1) constitutes the primary component in oral conjugated equine estrogens (CEEs) and serves as the principal estrogen precursor in the female circulation in the post-menopause. E1 induces endothelium-dependent vasodilation and activate PI3K/NO/cGMP signaling. To assess whether E1 mitigates vascular dysfunction associated with postmenopause and explore the underlying mechanisms, we examined the vascular effects of E1 in ovariectomized (OVX) rats, a postmenopausal experimental model. Blood pressure was measured using tail-cuff plethysmography, and aortic rings were isolated to assess responses to phenylephrine, acetylcholine (ACh), and sodium nitroprusside. Responses to ACh in rings pre-incubated with superoxide dismutase (SOD), catalase (CAT), or apocynin were also evaluated. Protein expression of SOD, CAT, NOX1, NOX2, and NOX4 was determined by Western blotting. E1 treatment resulted in decreased body weight and retroperitoneal fat, increased uterine weight, and prevented elevated blood pressure in the OVX group. Furthermore, E1 improved endothelium-dependent ACh vasodilation, activated compensatory antioxidant mechanisms - i.e. increased SOD and CAT antioxidant enzymes activity, and decreased NOX4 expression. This, in turn, helped prevent oxidative stress and endothelial dysfunction in OVX rats. Additionally, E1 treatment reversed the increased total LDL cholesterol observed in the OVX group. The findings underscore protective effects of E1 on the cardiovascular system, counteracting OVX-related oxidative stress and endothelial dysfunction in Wistar rats. E1 exhibits promising therapeutic benefits for managing cardiovascular health, particularly in postmenopausal conditions.

Efficacy of flavonoids in the management of high blood pressure

Plant compounds such as flavonoids have been reported to exert beneficial effects in cardiovascular disease, including hypertension. Information on the effects of isolated individual flavonoids for management of high blood pressure, however, is more limited. This review is focused on the flavonoids, as isolated outside of the food matrix, from the 5 main subgroups consumed in the Western diet (flavones, flavonols, flavanones, flavan-3-ols, and anthocyanins), along with their effects on hypertension, including the potential mechanisms for regulating blood pressure. Flavonoids from all 5 subgroups have been shown to attenuate a rise in or to reduce blood pressure during several pathological conditions (hypertension, metabolic syndrome, and diabetes mellitus). Flavones, flavonols, flavanones, and flavanols were able to modulate blood pressure by restoring endothelial function, either directly, by affecting nitric oxide levels, or indirectly, through other pathways. Quercetin had the most consistent blood pressure-lowering effect in animal and human studies, irrespective of dose, duration, or disease status. However, further research on the safety and efficacy of the flavonoids is required before any of them can be used by humans, presumably in supplement form, at the doses required for therapeutic benefit.

Maternal salt and fat intake causes hypertension and sustained endothelial dysfunction in fetal, weanling and adult male resistance vessels

Maternal salt and fat intake can independently programme adult cardiovascular status, increasing risk of cardiovascular disease in offspring. Despite its relevance to modern western-style dietary habits, the interaction between increased maternal salt and fat intake has not been examined. Female virgin Sprague-Dawley rats were fed, a standard control diet (CD) (10% kcal fat, 1% NaCl), High-fat diet (HF) (45% kcal fat, 1% NaCl), High-salt diet (SD) (10% kcal fat, 4% NaCl), High-fat high-salt diet (HFSD) (45% kcal fat, 4% NaCl) prior to pregnancy, during pregnancy and throughout lactation. Fetal, weanling and adult vessels were mounted on a pressure myograph at fetal day 18, weaning day 21 and day 135 of adulthood. Increased blood pressure in SD, HFD and HFSD male offspring at day 80 and 135 of age was consistent with perturbed vascular function in fetal, weanling and adult vessels. Maternal salt intake reduced EDHF and calcium-mediated vasodilation, maternal fat reduced NO pathways and maternal fat and salt intake, a combination of the two pathways. Adult offspring cardiovascular disease risk may, in part, relate to vascular adaptations caused by maternal salt and/or fat intake during pregnancy, leading to persistent vascular dysfunction and sustained higher resting blood pressure throughout life.