Combination treatment of parenteral arginine and nitric oxide inhibitor NG-nitro-L-arginine methyl ester in rats with peritonitis

Effect of inositol -stabilized arginine silicate on arthritis in a rat model

The purpose of this study was to test the effects of arginine-silicate-inositol complex (ASI), compared to a combination of the individual ingredients (A+S+I) of the ASI, on inflammatory markers and joint health in a collagen-induced arthritis (CIA) rat model. A total of 28 Wistar rats were divided into four groups: (i) Control; (ii) Arthritic group, rats subjected to CIA induction by injection of bovine collagen type II (A); (iii) Arthritic group treated with equivalent doses of the separate components of the ASI complex (arginine hydrochloride, silicon, and inositol) (A+S+I); (iv) Arthritic group treated with the ASI complex. The ASI complex treatment showed improved inflammation scores and markers over the arthritic control and the A+S+I group. ASI group had also greater levels of serum and joint-tissue arginine and silicon than the A+S+I group. Joint tissue IL-6, NF-κB, COX-2, TNF-α, p38 MAPK, WISP-1, and β-Catenin levels were lower in the ASI group compared to the other groups (P < 0.05 for all). In conclusion, these results demonstrate that the ASI complex may be effective in reducing markers of inflammation associated with joint health and that the ASI complex is more effective than a combination of the individual ingredients.

The Nitric Oxide Synthase Inhibitor NG-Nitro-L-Arginine Methyl Ester Diminishes the Immunomodulatory Effects of Parental Arginine in Rats with Subacute Peritonitis

The combined treatment of parenteral arginine and the nitric oxide synthase inhibitor N^G-nitro-L-arginine methyl ester (L-NAME) have been shown to improve liver function and systemic inflammation in subacute peritonitic rats. Here, we investigated the effects of single and combined parenteral arginine and L-NAME treatments on leukocyte and splenocyte immunity. Male Wistar rats were subjected to cecal punctures and were intravenously given total parenteral nutrition solutions with or without arginine and/or L-NAME supplementations for 7 days. Non-surgical and sham-operated rats with no cecal puncture were given a chow diet and parenteral nutrition, respectively. Parenteral feeding elevated the white blood cell numbers and subacute peritonitis augmented the parenteral nutrition-induced alterations in the loss of body weight gain, splenomegaly, and splenocyte decreases. Parenteral arginine significantly increased the B-leukocyte level, decreased the natural killer T (NKT)-leukocyte and splenocyte levels, alleviated the loss in body weight gain and total and cytotoxic T-splenocyte levels, and attenuated the increases in plasma nitrate/nitrite and interferon-gamma production by T-splenocytes. L-NAME infusion significantly decreased NKT-leukocyte level, tumor-necrosis factor (TNF)-alpha production by T-splenocytes and macrophages, and interferon-gamma production by T-leukocytes, monocytes, and T-splenocytes, as well as increased interleukin-6 production by T-leukocytes and monocytes and nitrate/nitrite production by T-leukocytes. Combined treatment significantly decreased plasma nitrate/nitrite, the NKT-leukocyte level, and TNF-alpha production by T-splenocytes. Parenteral arginine may attenuate immune impairment and L-NAME infusion may augment leukocyte proinflammatory response, eliminate splenocyte proinflammatory and T-helper 1 responses, and diminish arginine-induced immunomodulation in combined treatment in subacute peritonitic rats.