Ameliorative potential of D‐Ribose‐L‐Cysteine in male Wistar rats with metabolic syndrome

Abstract

Metabolic Syndrome (MS) refers to cluster of cardiometabolic risk factors which include obesity, insulin resistance, dyslipidaemia, hyperglycaemia and hypertension. Although, oxidative stress is implicated in its aetiology, protocols in MS management have not included the use of antioxidants. D‐ribose‐L‐cysteine (DRLC) is a potent antioxidant which has been suggested to be useful in the management of dyslipidaemia. This study was designed to investigate the effects of DRLC in rats with MS.Twenty male Wistar rats (190‐200g) were assigned into four groups (n=5). Groups I and II were fed with standard diet (SD) for eight weeks and were subsequently treated orally with: 10mL/kg distilled water and 250mg/kg DRLC daily for another eight weeks respectively. Groups III and IV were fed with a modified standard diet (MSD) consisting of 17% fructose and 20% lard with additional 10% fructose solution, given ad‐libitum for eight weeks to induce MS in rats. They were subsequently treated orally with: 10mL/kg distilled water (group III) and 250mg/kg DRLC (group IV) daily for another eight weeks respectively. Animals were weighed and Blood Pressure (BP) measured using rat tail cuff method. They were euthanized, and blood and heart were collected for biochemical analysis. Fasting Blood Glucose (FBG) was determined through glucose oxidase method. Serum C‐reactive Protein (CRP), Tumour Necrosis Factor alpha (TNFα) and insulin were determined through ELISA. Cardiac reduced Glutathione (GSH), Glutathione Peroxidase (GPx), Superoxide Dismutase (SOD), Xanthine Oxidase (XO), malondialdehyde; serum triglycerides, Total Antioxidants Capacity (TAC), High Density Lipoprotein (HDL) and Total Cholesterol (TC) were determined by spectrophotometry. Low Density Lipoprotein (LDL) was determined using Friedwald’s formula. Data were expressed as mean ± SEM and compared by ANOVA at p < 0.05.Body weight, systolic BP, FBG and TNFα of group IV (255.8±10.8g, 167.8±8.6mmHg, 84.3±6.0mg/dL, 433.0±54.8pg/mL, respectively) were significantly reduced compared to group III (318.9±12.7g, 219.0±9.8mmHg, 140.9±9.9mg/dL, 577.8±31.8pg/mL, respectively). Also, insulin, TC, LDL and heart XO of group IV were significantly reduced compared to group III. The serum levels of CRP, triglycerides and malondialdehyde in group II were significantly reduced compared to group I. There were significant increases in serum TAC, cardiac GPx, SOD, GSH; and serum HDL of group IV (1.2±0.3mmol/mL, 2.4±0.5U/L, 1.1±0.1U/L, 11.3±9.7mM, 13.4±1.6mg/dL, respectively) compared to group III (0.6±0.2mmol/mL, 1.1±0.2U/L, 0.7±0.1U/L, 0.8±0.2mM, 7.7±1.4mg/dL, respectively).The D‐ribose‐L‐cysteine ameliorated dyslipidaemia, hyperglycaemia and hypertension by decreasing oxidative stress and pro‐inflammatory cytokines in male rats with metabolic syndrome.