Bone marrow effects of environmental degradation product MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine) and herbal supplement echinacea

Hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) is an environmental degradation product of munitions compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Acute oral exposures to RDX and MNX resulted in seizures in rats and humans. Earlier studies in our laboratory have reported hematotoxicity associated with acute exposure to MNX. However, the toxicity of long term exposures of MNX is not known. The objective of this study was to determine whether hematotoxicity continued with subchronic MNX exposure. Female SD rats were gavaged daily for 4 or 6 weeks with 47 mg/kg/d MNX (1/4 LD50) or vehicle and sacrificed 24 h after the last dose. Toxicological endpoints measured included clinical observations, body weights, hematology, clinical chemistry, organ weights, and tissue histopathology. The major toxicological effects observed were an increase in platelets and granulocytes in blood. In agreement, bone marrow exhibited an increased megakaryocyte number per area, but the cellularity was unchanged. Fibrosis was absent as evidenced by no MNX-induced change in silver stained reticulin fibers in iliac bone marrow. No changes in hemoglobin or hematocrit occurred with subchronic MNX. Clinical chemistry indicated an increase in potassium, a corresponding decrease in sodium, chloride, glucose, and creatinine levels in serum. Other changes were increased liver and spleen weights, but body weight gain was unaffected by MNX. In conclusion, our results indicated proliferation of megakaryocytes in the bone marrow and thrombocytosis and granulocytosis after subchronic MNX exposures which might mimic the myeloproliferative disorders prefibrotic myelofibrosis or essential thrombocythemia.;Echinacea is used for perceived beneficial effects on immune function and various prevalent phytochemicals have immunomodulatory effects. Using a commercial E. purpurea (L.) Moench product, we have evaluated the myelopoietic effects on bone marrow of rats treated with various extracts and correlated this with their chemical class composition. Granulocyte/macrophage-colony forming cells (CFU-GMs) from femurs of female SD rats were assessed 24 hr after 7 daily oral treatments. A 75% ethanolic extract of commercial E. purpurea at 50 mg dried weight (derived from 227 mg aerial parts) per kg body weight increased CFU-GMs by 70%, but at 100 mg/kg was without effect. The myelostimulation by commercial product was compared to ethanolic extracts from aerial parts of E. angustifolia (PI 649026 and PI 649029) and E. purpurea (PI 649040) obtained from the USDA North Central Regional Plant Introduction Station. PI 649026 was most active, yielding 3 times CFU-GMs of vehicle-treated rats with the highest tested dose (200 mg/kg, 1575 mg/kg plant material), while effect of PI 649040 plateaued at twice that of vehicle at 100 mg/kg. 1H, APT NMR, MS, and TLC indicated alkylamides and caffeic acid derivatives (CADs) in ethanolic extracts of both the commercial and USDA-derived material. Cichoric and caftaric acids were prominent in both sources of E. purpurea ethanolic extracts, but absent in E. angustifolia. Aqueous extract of the commercial material exhibited polysaccharides and CAD signatures and was without an effect on CFU-GMs. An inactive methanol-CHCl3 fraction of commercial source was almost exclusively 1:4 nonanoic: decanoic acids, which were also abundant in commercial ethanolic extract, but absent from the USDA material. In conclusion, we have demonstrated an ethanol-extractable myelostimulatory activity in Echinacea aerial parts that, when obtained from commercial herbal supplements, may be antagonized by medium-chain fatty acids presumably derived from non-plant additive.