L-Arginine Ameliorates Arylesterase/Paraoxonase Activity of Paraoxonase-1 in Hypercholesterolemic Rats

Alterations in the liver histology and markers of metabolic syndrome associated with inflammation and liver damage in L-arginine exposed female Wistar albino rats

Metabolic Syndrome (MES), a cluster of metabolic disorders, is pandemic and more prevalent in females. It was associated with inflammation, liver damage and reduced nitric oxide concentration. Since L-arginine (ARG) may enhance nitric oxide synthesis, this study investigated the effect of ARG on the liver histology and selected serum markers of MES related to inflammation and liver damage. Two groups (n = 8) of female Wistar albino rats were exposed to 60 mg kg(-1) b. wt. of ARG and 3 mL kg(-1) b.wt. of distilled water, respectively as treated and control groups. Per oral exposure to ARG for twenty eight days caused a non-significant increase (p > 0.05) in the neutrophils count (22.50 +/- 10.35%, representing 38.46%) but a decrease (p > 0.05) in the lymphocytes count (77.50 +/- 10.35%, representing 8.82%) and in the total bilirubin concentration (0.40 +/- 0.19 mg/100 mL, representing 52.38%) of the rats, suggesting non-treatment related influence on these parameters. However, the exposure elicited a significant decrease (p < 0.01) in the serum alanine aminotransferase (ALT) activity (66.47 +/- 0.37 IU L(-1), representing 18.55%) and in the total White Blood Cell (WBC) count (2.73 +/- 0.75 x 10(9) L(-1), representing 43.24%), suggesting absence of inflammation and liver damage. ALT had a significant positive correlation with WBC (r = 0.01), while the liver histology revealed possible benefit in the ARG-fed rats, seeminlgly confirming benefit on these markers of inflammation and liver damage that could improve related MES features in the rats. Further studies using ARG rich nuts are required to harness insight gained from this study.

Effects of nutritional and excessive levels of selenium on red blood cells of rats fed a high cholesterol diet

In this study, we investigated the effects of selenium (Se) on the properties of erythrocytes and atherogenic index in the presence and absence of high cholesterol diet (HCD). The effect of selected two different doses (1 μg and 50 μg Se/kg/body weight) on HCD-induced oxidative stress was investigated. The hemolysis of the erythrocytes of the HCD rats as well as by high levels of selenium or their combination was markedly increased. Likewise, atherogenic index and plasma glutathione peroxidase (GPx) activity were significantly increased in the same groups of rats compared to control ones. In contrast, paraoxonase activity, glutathione levels and protein thiol levels, catalase, GPx, and superoxide dismutase activities were significantly decreased in rats that received the HCD, high selenium dose, or their combination. Malondialdehyde and protein carbonyl levels in the plasma and red blood cells were significantly increased by HCD and high selenium dose administration. Co-administration of selenium at low dose with or without an HCD restored all of the investigated parameters to near-normal values. The results of this study suggest that excess selenium administration with HCD worsens the atherogenic index and enhances formation of oxidized red blood cells. At dosage levels in the nutritional range such as 1 μg Se/kg body weight, selenium ameliorates the atherogenic index and preserves the antioxidant capacity of the erythrocytes.

Sub-chronic concomitant ingestion of L-arginine and monosodium glutamate improves feed efficiency, lipid metabolism and antioxidant capacity in male Wistar rats

The use of L-arginine (ARG) is common in supplements, whereas, Monosodium Glutamate (MSG) is widely used as flavor enhancing food additive. Thus, ARG and MSG may be present together in human diets, warranting this study aimed at investigating the effect of concomitant ingestion of ARG and MSG on some biochemical indices in male rats. Twelve male albino rats were grouped into three (n = 4) and concomitantly exposed to 0:0, 20:5 and 60:15 mg kg(-1) of ARG:MSG. Exposure was peroral and every twenty four h for 28 days. ARG plus MSG treatment caused a significant (p < or = 0.05) increase in Feed Efficiency (FE) (Low dose: 5.23 +/- 22%; High dose: 5.60 +/- 11%), whereas, it decreased (p < or = 0.05) the serum Total Cholesterol (T-Chol) (low dose: 80.83 +/- 0.11 mg/100 mL, high dose: 92.55 +/- 0.14 mg/100 mL), triacylglycerol (TAG) (low dose: 179.91 +/- 0.09 mg/100 mL, high dose: 119.77 +/- 0.32 mg/100 mL) and malondialdehyde (MDA) (low dose: 5.00 +/- 0.07 mg/100 mL, high dose: 24.36 +/- 0.10 mg/100 mL) concentrations of the rats in a dose dependent manner. However, (at the high dose) the increase in Body Weight (BW) (0.08 +/- 0.07 kg), Feed Intake (FI) (0.40 +/- 0.03 kg) and Water Intake (WI) (0.65 +/- 0.18 L) induced by ARG plus MSG exposure was not significant (p < or = 0.05), suggesting non treatment related effect on these routine parameters. However, exposure to ARG plus MSG may significantly improve feed efficiency, lipid metabolism and antioxidant capacity in the male rats.