4-Deoxypyridoxine inhibits chronic granuloma formation induced by potassium permanganate in vivo

4-Deoxypyridoxine (4-DPD) is a potent antagonist of Vitamin B6 coenzyme which inhibits IL-1, lymphocyte proliferation and has demonstrated that tolerance to skin grafts can be induced by administering splenic cells to pyridoxine-deficient mice. Chronic inflammation induced by dorsal injections of 200 microliters of a 1:40 saturated crystal solution of potassium permanganate (KMnO4) in mice treated or untreated with 4-DPD (400 micrograms/dose), has been investigated. After 7 days all mice developed a subcutaneous granulomatous tissue indicative of a chronic inflammatory response, at the site of injection. KMnO4-treated mice injected intraperitoneally with 4-DPD (400 micrograms/dose) on 5 consecutive days (the first at the same time of induction of the granuloma) show a significant decrease in size and weight of granuloma when compared to mice not treated with 4-DPD (Controls). In addition, in all mice treated with 4-DPD there was a strong inhibition of TNF alpha in serum (P < 0.01) and in supernatant fluids (P < 0.05) from minced granuloma, while IL-6 was inhibited in the supernatant fluids (P < 0.05) of minced granulomas but was not detected in the serum of treated and untreated mice. In this study we show for the first time the antiinflammatory effect of 4-DPD on chronic inflammation and the inhibitory effect of TNF and IL-6 generation in supernatant fluids from minced granulomas.

Inhibition of granuloma formation induced by potassium permanganate in the mouse by a specific human recombinant receptor antagonist for interleukin-1 (hrIL-1ra)

Interleukin-1 (IL-1) is a polypeptide which mediates several systemic changes associated with infection, inflammation and injury, such as fever, neutrophilia, increased acute phase protein synthesis, and arachidonic acid metabolites. Recently, a natural inhibitor of IL-1 has been cloned, called IL-1 receptor antagonist (IL-1ra), which prevents Escherichia coli-induced shock in rabbits and blocks PGE2 induced by IL-1. In this report we study the effect of human recombinant (hr) IL-1ra on chronic inflammation induced by dorsal injections of 200 microliters of a 1:40 saturated crystal solution of potassium permanganate (KMnO4) in mice. After 7 days, all mice developed a subcutaneous granulomatous tissue indicative of a chronic inflammatory response, at the site of injection. KMnO4-treated mice, injected intraperitoneally twice with hrIL-1ra, 20 micrograms/dose (the first at the same time of induction of the granuloma and the second 24 hr later), show significant decreases in size and weight of the granuloma when compared to mice not treated with hrIL-1ra (controls); the inhibitory effect was approximately 32-46 and 25-51%, respectively. In addition, in all mice treated with hrIL-1ra, there was a strong inhibition of PGE2 and LTB4 on assay of freshly minced granuloma tissue. Moreover, when hrIL-1 beta (1.0 ng/ml) or LPS (100 ng/ml) were added overnight to the minced granuloma tissue cultures, these compounds enhanced the production of LTB4 and PGE2 from the untreated mice, whereas in IL-1ra-treated mice they failed. In the histological studies of the granuloma, animals treated with hrIL-1ra show a lesser degree of mononuclear cell (MC) accumulation. The inhibitory effect of hrIL-1ra on PGE2 production was also confirmed on peritoneal macrophages from untreated mice, stimulated overnight with hrIL-1 beta or LPS in vitro. The resulting inhibition was dose-dependent. In these studies we show, for the first time, the anti-inflammatory effect of hrIL-1ra on chronic inflammation as assessed by the inhibition of granuloma formation, PGE2, LTB4, and white cell accumulation in inflamed tissue.

Interleukin-1 receptor antagonist inhibits calcium accumulation in in vivo chronic granuloma induced by potassium permanganate

Interleukin-1 (IL-1) is a monokine that exerts multiple biological activity, including immunity and inflammation. Moreover, IL-1 is involved in Ca2+ release causing hypercalcemia and bone resorption. Recently, a 22 kDa natural inhibitor to IL-1 called interleukin-1 receptor antagonist (IL-1ra) has been described in human fluids, which specifically binds IL-1 alpha or IL-1 beta receptors. In this study, we found that experimental granuloma induced by subcutaneous injections (0.2 ml) of potassium permanganate (KMnO4) 1:40 saturated crystal solution, after 7 days was strongly inhibited in size, weight and calcium content (measured as dry ash weight by incineration of granuloma tissue) compared with untreated controls, in mice treated intraperitoneally with IL-1ra (20 micrograms/bolus) given twice; the first at the same time of the induction of the granuloma and the second 24 hours later. In addition, leukotriene B4 and prostaglandin E2 were also inhibited in fresh granuloma of mice treated with IL-1ra. Taken together, these findings conclude for the first time, that the accumulation of calcium in chronic inflammatory states is strongly inhibited by IL-1ra, which decreases tissue calcergy and can potentially be useful for the treatment of calcium-related inflammatory diseases and malignancy-associated hypercalcemia.

Human recombinant interleukin-1 receptor antagonist (hrIL-1ra) enhances the stimulatory effect of interleukin-2 on natural killer cell activity against MOLT-4 target cells

Interleukin-1 (IL-1) is considered an enhancer of host defence against malignancies. Patients with different diseases, including cancer patients with large tumour burdens, have demonstrated a reduced production of IL-1 from circulating leukocytes, in vitro. There are many naturally occurring substances which inhibit IL-1 activity aspecifically. Recently an interleukin-1 receptor antagonist (IL-1ra) has been discovered, which is secreted by human macrophages and is structurally similar to IL-1 beta (26% homology). The pretreatment of human peripheral blood mononuclear cells (PBMC) with hrIL-1ra (0.25-250 ng/ml) inhibits IL-1 alpha or IL-1 beta and enhances, in a dose-dependent manner, the stimulatory effect of IL-2 on their natural killer (NK) activity against a lymphoid cell line MOLT-4. The enhancing effect of IL-1ra on IL-2 activity was similar to that provoked by IL-1 beta. However, when IL-1ra was used alone without IL-2, no stimulatory effect was found compared with the control. In our data we show that a member of the IL-1 family, IL-1ra, has a significant effect on IL-2-stimulated NK activity against the MOLT-4 cell line. These studies provide new evidence of the biological potential of IL-1ra since this new protein enhances IL-2 activity on NK cells.