Many cancer patients receive their classical therapies together with vitamin supplements. However, the effectiveness of these strategies is on debate. Here we aimed to evaluate how vitamin E supplementation affects the anticancer effects of interferon (IFN-α) using an early-model of liver cancer development (initiation-promotion, IP). Male Wistar rats subjected to this model were divided as follows: untreated (IP), IP treated with recombinant IFN-α-2b (6.5 × 10⁵ U/kg), IP treated with vitamin E (50 mg/kg), and IP treated with combination of vitamin E and IFN-α-2b. After treatments rats were fasted and euthanized and plasma and livers were collected. Combined administration of vitamin E and IFN-α-2b induced body weight drop, increased liver apoptosis and low levels of hepatic lipid levels. Interestingly, vitamin E and IFN-α-2b combination also induced an increase in altered hepatic foci number, but not in size. It seems that vitamin E acts on its antioxidant capability in order to block the oxidative stress induced by IFN-α-2b, blocking in turn its beneficial effects on preneoplastic livers, leading to harmful final effects. In conclusion, this study shows that vitamin E supplementation in IFN-α-2b-treated rats exerts unwanted effects; and highlights that in spite of being natural, nutritional supplements may not always exert beneficial outcomes when used as complementary therapy for the treatment of cancer.

许多癌症患者接受经典疗法和维生素补充剂。然而，这些策略的有效性仍存在争议。在这里，我们的目的是使用肝癌发展的早期模型（起始-促进，IP）来评估维生素 E 补充剂如何影响干扰素 (IFN-α) 的抗癌作用。接受该模型的雄性 Wistar 大鼠分为以下几类：未处理（IP）、用重组 IFN-α-2b（6.5 × 10 ⁵ U/kg）处理的 IP、用维生素 E（50 mg/kg）处理的 IP、以及 IP联合使用维生素 E 和 IFN-α-2b 进行治疗。治疗后，将大鼠禁食并安乐死，并收集血浆和肝脏。维生素 E 和 IFN-α-2b 联合给药可导致体重下降、肝细胞凋亡增加和肝脂质水平降低。有趣的是，维生素 E 和 IFN-α-2b 组合也诱导改变的肝病灶数量增加，但大小没有增加。维生素 E 似乎通过其抗氧化能力发挥作用，以阻止 IFN-α-2b 诱导的氧化应激，进而阻止其对肿瘤前肝脏的有益作用，从而导致有害的最终影响。总之，这项研究表明，在 IFN-α-2b 治疗的大鼠中补充维生素 E 会产生不良影响；并强调，尽管营养补充剂是天然的，但在用作癌症治疗的补充疗法时可能并不总是能产生有益的结果。