Mg supplementation attenuates ritonavir-induced hyperlipidemia, oxidative stress, and cardiac dysfunction in rats

Abstract

Mak IT, Kramer JH, Chen X, Chmielinska JJ, Spurney CF, Weglicki WB. Mg supplementation attenuates ritonavir-induced hyperlipidemia, oxidative stress, and cardiac dysfunction in rats. Am J Physiol Regul Integr Comp Physiol 305: R1102-R1111, 2013. First published September 18, 2013 doi:10.1152/ajpregu.00268.2013.-Use of protease inhibitors (PI) in HIV patients is associated with hyperlipidemia and increased risk of coronary heart disease. Chronic systemic and cardiac effects of ritonavir (RTV), a universal PI booster, and Mg supplementation were examined. RTV was administered (75 mg·kg Ϫ1 ·day Ϫ1 po) to LewisϫBrown-Norway hybrid (LBNF1) rats for up to 8 wk; significant increases in plasma triglyceride and cholesterol occurred from 8 days to 8 wk. At 5 wk, the expression of selected hepatic genes (CYP7A1, CITED2, G6PC, and ME-1), which are key to lipid catabolism/synthesis, were altered toward lipogenesis. Dietary Mg supplementation (six-fold higher) completely reversed the altered expression of these genes and attenuated both hypertriglyceridemia and hypercholesterolemia. Neutrophils isolated from the RTV-treated rats displayed a three-fold higher basal and a twofold higher stimulated superoxide production; plasma isoprostane and red blood cell (RBC) GSSG levels were elevated twoto three-fold. All oxidative indices were normalized by Mg supplementation. After 5 wk, RTV caused significant decreases in cardiac left ventricular (LV) shortening fraction and LV ejection fraction; mitral valve early/late atrial ventricular filling (E/A) ratio was reduced accompanied by LV posterior wall thinning. Immunohistochemical staining revealed significant white blood cell (WBC) infiltration (5 wk) and prominent fibrosis (8 wk) in the RTV hearts. Mg supplementation attenuated RTV-induced declines in systolic and diastolic (improved mitral valve E/A ratio) function (Ͼ70%), lessened LV posterior wall thinning (by 75%), and substantially decreased the pathological markers. The known clinical hyperlipidemia effects of RTV can be mimicked in the LBNF1 rats; in association, systemic oxidative stress and progressive cardiac dysfunction occurred. Remarkably, Mg supplementation alone suppressed RTV-mediated hyperlipidemia, oxidative stress, and cardiac dysfunction.HIV-1 protease inhibitor ritonavir; hepatic metabolic gene regulation; hyperlipidemia; oxidative stress; cardiac dysfunction; dietary Mg supplementation ACCORDING TO A RECENT REPORT (47), there are 34 million people worldwide infected with HIV-1, and of these, 1.3 million are in the United States (7). Nucleoside/nucleotide analogs, with Zidovudine (AZT) as the prototype compound, were first introduced in the late 1980s and continue to play a significant role in HIV therapy (13). With the introduction of protein inhibitors (PIs) in the mid 1990s, HIV-1 replication in the patients was shown to be dramatically reduced, and currently, to the extent that HIV-1 infection has become a more manageable disease (20,23). However, along with the chronic use of PIs, significant metabolic si...

Combination ART-Induced Oxidative/Nitrosative Stress, Neurogenic Inflammation and Cardiac Dysfunction in HIV-1 Transgenic (Tg) Rats: Protection by Mg

“…Previously, we reported that dietary Mg-supplementation protected against cardiovascular toxicity in normal control rats receiving chronic monotherapy with either AZT, ritonavir (RTV) or efavirenz (EFV) [6,7,8]. In the current study, we found that Mg-supplementation effectively suppressed the systemic ROS/RNS stress in the cART treated HIV-1 Tg rats; in association, substantial attenuation of the induced renal and cardiac dysfunctions was observed.…”

EGFR-TKI, Erlotinib, Causes Hypomagnesemia, Oxidative Stress, and Cardiac Dysfunction

“…At periodic intervals, blood was collected (∼0.5 ml) aseptically from the tail tip of anaesthetized rats (2 % isoflurane, EZ Anesthesia Chamber with nose cone) (13, 14) in sterile microtainer plasma separator tubes containing heparin and the protease inhibitor, aprotinin (Sigma Chemicals, St. Louis MO) to yield final blood concentrations of 10.74 units/ml and 0.016 units/ml, respectively. For subsequent samplings, the scab was carefully removed, and the process was repeated.…”

“…Magnesium levels in 1:50 or 1:100 diluted, acidified (nitric acid) plasma samples were determined by atomic absorption flame emission spectroscopy (wavelength = 285.2 nm) using an AA-6200 Shimadzu spectrophotometer (Columbia, MD) as described (13). Values obtained from standard curves were mg/dl, and reported as % of control.…”

“…The alkalinized aliquots were then neutralized in 2N HCl, prior to centrifugation (at room temperature) for 5 min at 12,000 rpm in a microcentrifuge (Marathon Micro A, Fisher Scientific). The final supernatants were used for the determination of total 8-isoprostane content by an EIA kit (Cayman Chemical, MI) (13, 16). …”

“…At sacrifice, whole blood (3 ml) samples were obtained; neutrophils were isolated by a step-gradient centrifugation method (13-16). Superoxide anion production from neutrophils (0.5-0.75×10 6 /ml) with (stimulated) or without (basal) PMA (phorbol myristate acetate, 100 ng/ml) was assayed in a phosphate buffer (pH 7.6) containing 5 mM glucose, 1 mM CaCl 2 , 1 mM MgCl 2 , and 75 μM cytochrome c ± 50 μg SOD.…”