Amifostine loaded lipid-calcium carbonate nanoparticles as an oral drug delivery system for radiation protection.

Amifostine (AMF) as the first-line radiation protection drug, usually suffered from low compliance and short half-life upon clinical applications. The development of oral drug delivery system (DDS) for AMF is a promising solution. However, the inherent shortages of AMF present significant challenges in the design of suitable oral DDS. Here in this study, we utilized the ability of calcium ions to bind with AMF and prepared AMF loaded calcium carbonate (CC) core, CC/AMF, using phase transferred coprecipitation method. We further modified the CC/AMF using phospholipids to prepare AMF loaded lipid-calcium carbonate (LCC) hybrid nanoparticles (LCC/AMF) via a thin-film dispersion method. LCC/AMF combines the oral advantages of lipid nanoparticles with the drug-loading capabilities of CC, which was shown as uniform nano-sized formulation with decent stability in aqueous solution. With favorable intestinal transport and absorption effects, it effectively enhances the in vivo radiation protection efficacy of AMF through oral administration. More importantly, we further investigated the cellular accumulation profile and intracellular transport mechanism of LCC/AMF using MDCK and Caco-2 cell lines as models. This research not only alters the current administration method of AMF to enhance its convenience and compliance, but also provides insights and guidance for the development of more suitable oral DDS for AMF in the future.

Hepatoprotective effect of amifostine and WR-1065 on acetaminophen-induced liver toxicity on Wistar rats.

PURPOSE: The most important problem with acetaminophen is its hepatotoxicity. N-acetylcysteine (NAC) is used to treat the hepatotoxicity of acetaminophen. Due to the structural similarities of this compound with amifostine, we decided to test the effect of this substance and its metabolite, WR-1065, on the hepatotoxicity of acetaminophen. METHODS: The single-dose method contained 1. Control; 2. Acetaminophen (1 g/kg, gavage); 3-5. Acetaminophen + amifostine (100, 200, 400 mg/kg, i.p.); 6-8. Acetaminophen + WR-1065 (50, 100, 200 mg/kg, i.p.); and 9. Acetaminophen + NAC (100, 200 mg/kg, i.p.). The multiple-dose method included the same groups: amifostine (50, 100, 200 mg/kg), WR-1065 (25, 50, 100 mg/kg), and NAC (100 mg/kg). Then, animals were sacrificed, and blood samples were collected for measuring ALT, AST, ALP, and T-Bil, liver tissue for histopathological examination, MDA, and GSH amounts. RESULTS: Acetaminophen increased the levels of MDA, T-Bil, ALT, AST, and ALP, decreased GSH levels, and augmented necrosis, neutrophils, lymphocytes, and macrophages in the port space in single-dose and multiple-dose studies. Amifostine and WR-1065 significantly reduced the levels of MDA, T-Bil, ALT, AST, ALP, increased GSH content, and ameliorated histopathological alterations in a single-dose and multiple-dose method compared to the acetaminophen group. Moreover, NAC caused a significant decrease in the levels of MDA, T-Bil, ALT, AST, and ALP, and reduced GSH amounts in single-dose and multiple-dose studies. CONCLUSION: Amifostine and WR-1065 as antioxidant and hepatoprotective compounds are effective in reducing acetaminophen-induced hepatotoxicity with a similar effect to NAC and can be administered as an adjunct in the treatment of acetaminophen overdose.

The effect of amifostine on bacterial translocation after radiation induced acute enteritis

ABSTRACT PURPOSE: To investigate the effects of amifostine on bacterial translocation and overgrowth in colonic flora after acute radiation enteritis in a rat model. METHODS: Thirty-two female Wistar albino rats were divided into four groups: Group-1 (n=8): only normal saline was administered intraperitoneally. Group-2 (n=8): first serum saline was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. Group-3 (n=8): only amifostine 200 ml/kg was administered intraperitoneally and radiation was not applied. Group-4 (n=8): first amifostine 200 ml/kg was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. On the 5th day after radiation, samples of mesenteric lymph tissues and cecal contents were taken by laparotomy for microbiological culture. RESULTS: Intraperitoneal amifostine administration significantly decreased the bacterial overgrowth related to radiation in colon but did not significantly decrease the bacterial translocation. CONCLUSİON: Although not providing a full protection on the damaged mucosal barrier, amifostine significantly decreased the bacterial overgrowth in the cecal content after high dose radiation. There is a need to find out appropriate amifostine dose under different radiation applications avoiding bacterial translocation in gastrointestinal system.

Amifostine (WR-2721), a cytoprotective agent during high-dose cyclophosphamide treatment of non-Hodgkin's lymphomas: a phase II study

Clinical trials indicate that amifostine may confer protection on various normal tissues without attenuating anti-tumor response. When administered prior to chemotherapy or radiotherapy, it may provide a broad spectrum of cytoprotection including against alkylating drugs. The mechanism of protection resides in the metabolism at normal tissue site by membrane-bound alkaline phosphatase. Toxicity of this drug is moderate with hypotension, nausea and vomiting, and hypocalcemia being observed. We report a phase II study using amifostine as a protective drug against high-dose cyclophosphamide (HDCY) (7 g/m2), used to mobilize peripheral blood progenitor cells (PBPC) and to reduce tumor burden. We enrolled 29 patients, 22 (75.9 percent) affected by aggressive and 7 (24.1 percent) by indolent non-Hodgkin's lymphoma (NHL), who were submitted to 58 infusions of amifostine and compared them with a historical group (33 patients) affected by aggressive NHL and treated with VACOP-B followed by HDCY. The most important results in favor of amifostine were the reduction of intensity of cardiac, pulmonary and hepatic toxicity, and a significant reduction of frequency and severity of mucositis (P = 0.04). None of the 29 patients died in the protected group, while in the historical group 2/33 patients died because of cardiac or pulmonary toxicity and 2 patients stopped therapy due to toxicity. Amifostine did not prevent the aplastic phase following HDCY. PBPC collection and hematological recovery were adequate in both groups. The number of CFU-GM (colony-forming units-granulocyte/macrophage) colonies and mononuclear cells in the apheresis products was significantly higher in the amifostine group (P = 0.02 and 0.01, respectively). Side effects were mild and easily controlled. We conclude that amifostine protection should be useful in HDCY to protect normal tissues, with acceptable side effects.