Effects of oleuropein in rats with simultaneous type 2 diabetes and renal hypertension: a study of antihypertensive mechanisms

Abstract

The mechanism of oleuropein's antihypertensive effects was examined in rat model of simultaneous type 2 diabetes and renal hypertension (diabetic hypertensive). Five groups of male Sprague-Dawley rats including a control, a diabetic-hypertensive group receiving vehicle, and three diabetic-hypertensive groups receiving oleuropein at 20, 40, or 60 mg/kg/day were used. The duration of diabetes was 10 weeks; during the last 4 weeks of which, animals were hypertensive and received vehicle or oleuropein. Systolic blood pressure, glucose and malondialdehyde, heart rate, and maximal response to phenylephrine (PE) in the absence of nitro-L-arginine methyl ester (L-NAME) of oleuropein-treated groups were significantly lower than those of vehicle-treated group. Erythrocyte superoxide dismutase, maximal response to PE in the presence of L-NAME, and maximal response to acetylcholine (Ach) of oleuropein-treated groups were significantly higher than those of vehicle-treated group. The findings indicate that antihypertensive effects of oleuropein might be partly mediated by improving the release of nitric oxide, and antioxidant and sympathoplegic activities.

Effect of oleuropein on myocardial dysfunction and oxidative stress induced by ischemic-reperfusion injury in isolated rat heart

“…It has been reported that the antioxidant activity of oleuropein is comparable to that of hydrosoluble α-tocopherol [26], [42]. Thus, antioxidant and anti-inflammatory properties of oleuropein made it an adequate candidate to investigate its potential protective effects in the heart [27]. The findings of the present study suggest that perfusion of isolated rat hearts with oleuropein (before or after ischemia) had no effects on the physiological functional parameters of myocardium that was obvious by no significant changes in the heart rate, LVEDP, max and min dp/dt and contractility.…”

“…So far, few studies have been conducted on the effect of oleuropein on cardiovascular system in animal models to study cardioprotective effects [4], [23], [24], [25], [26], [27], [28]. However there is no study about the direct effect of oleuropein on myocardial dysfunction following ischemic – reperfusion injury.…”

“…They had no data on the effect of oleuropein on myocardial dysfunction, infarct size and the magnitude of arrhythmia [25]. Recently, Nekooian and colleagues (2014) indicated that pre-treatment of hypertensive rats with type 2 diabetes with oleuropein (20, 40 and 60 mg/kg) for 16 weeks attenuated cardiovascular complications [27].…”

Oleuropein attenuates the progression of heart failure in rats by antioxidant and antiinflammatory effects

“…We (Nekooeian et al 2014) and others (Romero et al 2016;Zarzuelo et al 1991) showed that oleuropein possessed hypotensive and vasodilatory effects. It is interesting that, nonetheless, treatment with oleuropein was associated with increased SBP in the present model of heart failure, which was associated with reduced SBP and increased AR.…”

Potential Health Benefits of Olive Leaf

“…41 Yapılan başka bir çalışmada, Tip 2 diyabetli ve renal hipertansiyonu olan ratlarda oleuropeinin 20 mg/kg, 40 mg/kg ve 60mg/kg/gün düzeylerinde alı-mının kan basıncını düşürdüğü belirtilmiştir. 42 Oleuropeinin kan basıncını nasıl düşürdüğü konusunda kesin bir bilgi yoktur. Ancak çalışmalar bunu, anjiotensin dönüştürücü enzimi (ACE) baskılayarak ve radikal temizleyici etki göstererek, endotel fonksiyonu restore ederek, kalsiyum kanalları aktivitesini bloke ederek ve vazodilatör etki gös-tererek gerçekleştirdiğini söylemektedir.…”