Amifostine protects from the peripheral sensory neuropathy induced by oxaliplatin in mice

Sensory neuropathy is a dose-limiting side effect of oxaliplatin-based cancer treatment. This study investigated the antinociceptive effect of amifostine and its potential neuroprotective mechanisms on the oxaliplatin-related peripheral sensory neuropathy in mice. Oxaliplatin (1 mg/kg) was injected intravenously in Swiss albino male mice twice a week (total of nine injections), while amifostine (1, 5, 25, 50, and 100 mg/kg) was administered subcutaneously 30 min before oxaliplatin. Mechanical and thermal nociceptive tests were performed once a week for 49 days. Additionally, c-Fos, nitrotyrosine, and activating transcription factor 3 (ATF3) immunoexpressions were assessed in the dorsal root ganglia. In all doses, amifostine prevented the development of mechanical hyperalgesia and thermal allodynia induced by oxaliplatin (P<0.05). Amifostine at the dose of 25 mg/kg provided the best protection (P<0.05). Moreover, amifostine protected against neuronal hyperactivation, nitrosative stress, and neuronal damage in the dorsal root ganglia, detected by the reduced expression of c-Fos, nitrotyrosine, and ATF3 (P<0.05 vs the oxaliplatin-treated group). In conclusion, amifostine reduced the nociception induced by oxaliplatin in mice, suggesting the possible use of amifostine for the management of oxaliplatin-induced peripheral sensory neuropathy.

Amifostine reduces inflammation and protects against 5-fluorouracil-induced oral mucositis and hyposalivation

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) tissue levels, and positive immunostaining for TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.

Effect of Amifostine to prevent radiotherapy-induced acute and late toxicity in head and neck cancer patients who had normal or mild impaired salivary gland function.

BACKGROUND: Amifostine has a potential role for salivary gland protection in head and neck cancer patients who had radiotherapy. MATERIAL AND METHOD: Sixty-seven head and neck cancer patients were randomized to receive radiotherapy or radiotherapy plus Amifostine. The efficacy of the treatment was determined by a questionnaire evaluating dryness of mouth and the oral comfort, the RTOG/EORTC acute/late radiation morbidity scoring criteria, collection of the whole saliva and the 99mTc-pertecnetate scintigraphy of the salivary glands. RESULTS: Amifostine significantly reduced the mean questionnaire scores from 6.49 to 3.73, the incidence of grade > or = 2 mucositis from 75% to 36% and acute xerostomia from 82% to 39%. The salivary gland function returned to normal at a rate of 36.3% in the Amifostine group versus 9.1% in the control group. CONCLUSION: Amifostine is effective in reducing the incidence and severity of acute mucositis, acute and late xerostomia in head and neck cancer patients.

Otoproteção da amifostina aos efeitos ototóxicos da cisplatina: estudo em cobaias albinas por emissões otoacústicas produtos de distorção e microscopia eletrônica de varredura

A Cisplatina é uma potente droga antineoplásica, largamente utilizada para o tratamento do câncer, tanto em adultos quanto em crianças. Dentre seus efeitos colaterais, a ototoxicidade se apresenta como um dos mais importantes e leva à perda auditiva irreversível, bilateral, para as altas freqüências (4KHz -8KHz). Estudos têm tentado identificar drogas que, associadas à cisplatina, possam atuar como otoprotetores. Sabe-se que o mecanismo da ototoxicidade pela cisplatina está relacionado a alterações nos mecanismos antioxidantes das células ciliadas, principalmente as células ciliadas externas da cóclea. A amifostina tem conhecida ação antioxidante, com conhecido efeito otoprotetor aos efeitos lesivos da radioterapia. OBJETIVO: Nossa proposta foi avaliar através de emissões otoacústicas, por produtos de distorção (EOAPD) e por microscopia eletrônica de varredura (MEV), a existência de possível efeito otoprotetor da amifostina no tratamento com cisplatina. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: O estudo foi realizado em cobaias albinas, que foram divididas em três grupos: Grupo 1: 6 animais -12 orelhas - cisplatina 8,0 mg/Kg/dia (via intraperitoneal) por três dias; Grupo 2: 6 animais - 12 orelhas - amifostina 100 mg/Kg/ dia (via intraperitoneal) e 90 minutos após, cisplatina 8,0 mg/Kg/dia (via intraperitoneal) por três dias; Grupo 3: 03 animais - 06 orelhas - amifostina 100 mg/Kg/dia (via intraperitoneal) por três dias. RESULTADO: Encontramos EOAPD presentes e células ciliadas externas presentes, sem lesão anatômica a MEV, nos grupos 2 e 3. Concluímos que a amifostina, por sua ação antioxidante, atua como otoprotetor a ototoxicidade pela cisplatina. No entanto, seu uso não é recomendável nos casos de tumores potencialmente curáveis, por não se saber exatamente a influência da cisplatina na eficácia da quimioterapia.

Pancitoproteção seletiva: revolução na terapia oncológica / Selective pancytoprotective: revolution on cancer therapy

Amifostina é um agente pancitoprotetor seletivo que protege os teci- dos normais, mas não os tumorais, contra os danos citotóxicos induzidos pela quimioterapia e irradiação ionizante. Trata-se de pró- droga que requer defosforilação pela fosfatase alcalina da membrana celular dos tecidos para formação de seu principal metobólito, o WR- 1065, o qual é imediatamente captado pelos tecidos normais, com resultante citoproteção. A droga é geralmente bem tolerada, exibindo efeitos colaterais moderados e transitórios. É o pancitoprotetor seletivo que reúne o maior banco de dados pré-clínicos.

Amifostine is a selective pancytoprotective agent that protects normal, but not maligmant tissues, from the cytotoxic damage induced by chemotherapy and irradiation therapy. It is a pro- drug that requires dephosphorilation at the tissue site by mem- brane-bound alkaline phosphatase in order to produce its main Amifostine is a selective pancytoprotective agent that protects normal, but not maligmant tissues, from the cytotoxic damage active metabolite, WR-I065, which is immediately taken up by the normal tissues, resulring in cytoprotection. The drug is usually well tolerated, with moderate and transient side-effects. To date, amifostine is the selective pancytoprotective agent with the largest preclinical databases.

Current role of chemotherapy protectors in cancer treatment

The administration of full doses of chemotherapy according to an established schedule improves the response rate and duration of response in cancer patients. However, frequently there are delays in therapy due to dose-limiting side effects and chemotherapy could affect permanently normal tissues. This has led to the development of chemotherapy protectors and of rescue agents in the past years. We will discuss some of these new agents and their use in cancer treatment. Some of these agents include amifostine (Ethyol), dexrazoxane (Zinecard), mesna (Mesnex), leucovorin, G-CSF, GM CSF, recombinant erythropoietin and thrombopoietin. Oncologists must learn the adequate use of different strategies in reducing chemotherapy toxicity in order to improve both the quality and quantity of life of cancer patients