Efficacy of Flavonoid Apigenin on Hemodynamic indices, Baroreflex Function, Cardiac and Kidney Remodeling and Vasoactive-Inflammatory Biomarkers in Experimental Renal Hypertension

Abstract

The hypothesis stated here that, the long-term prevention by natural flavonoid phenolic compound, for example apigenin (Apg), improves baroreflex sensitivity and vascular resistance and occurs beneficial action for attenuation the renal hypertension (RH). One-kidney, 1-clip rats (1K1C) were treated with Apg for 2 weeks after 1 week of surgical intervention. At the end of the study in the control RH group the blood pressure (BP) increased on average by 43.5%, decreased in heart period (HP) by 9.8%, cardiochronotropic (vagal) component of baroreflex sensitivity (BRS) by 50%, and adrenergic component by 34%. Thus, in 1K1C experimental model of hypertension, provides switching to parasympathetic component and accompanied with proportionally nearly two-fold increase in epinephrine (EPN) and norepinephrine (NE) without changes in EPN/NE ratio. Morphometric changes in the kidney and heart confirmed the development of kidney and cardiac hypertrophy and renal functioning disturbances (blood urea nitrogen (BUN) increased in more than two-fold) and markers of sodium reabsorption in proximal tubule, total trans-EETs, decreased in 1.6-fold. The pronounced increased proinflammatory cytokines, interleukin 1b (IL1 b), endothelin -1 (ET-1) and tumor necrosis factor (TNF)-a confirmed the formation of “sterile inflammation” which strengthening by the nearly two-fold decreasing in the level of anti-inflammatory (vasodilatory) mediators, prostaglandin E2 (PGE2). Preventive long-term regime treatment with Apg (5mg/kg i.p./daily) in RH rats significantly decreased BP by 18.6%, increased parasympathetic component of BRS by 38.5% without marked altered its sympathetic component. Such deremodeling in BRS sensitivity associated with significant decreased in heart and kidney hypertrophy and functional activity of kidney, normalization of BUN and total EETs, reducing in circulating plasma level of catecholamines, and markedly attenuated progression of inflammation, decreased of proinflammatory levels of cytokines. Thus, Apg provides preventive beneficial pluripotent action in RH rats by exerting antihypertensive, cardio- and renoprotective effects and attenuation of “sterile inflammation”.