美国科学日报: 维生素C注射可减缓小鼠肿瘤的生长(英中对照)

大壮

维生素C注射可减缓小鼠肿瘤的生长
http://www.sciencedaily.com/releases/2008/08/080804190645.htm

    美国科学日报（2008年8月5日）--美国国立卫生研究院（NIH）的研究人员在2008年8月5日发表的美国科学院论文集中报告说：注射大剂量的维生素C（又名抗坏血酸）可以使脑癌、卵巢癌和胰腺癌小鼠模型中的肿瘤重量和生长率降低大约百分之五十。.
研究人员认为抗坏血酸的抗癌效果是由于在肿瘤周围的胞外液中形成了过氧化氢，而正常细胞不受影响。
    如果口服的话，自然的生理调节机制会精确调节身体所吸收的抗坏血酸浓度。 该研究的主要发起人、美国国立卫生研究院下属的美国国立糖尿病及消化和肾脏疾病研究所分子和临床营养处的负责人Mark Levine博士说，“如果你每天吃的食品中含有200毫克以上的维生素C，例如2个橙子和一个花椰菜，但你的身体会防止血液中的抗坏血酸浓度超出一定的范围”。
    为了绕过身体这种正常的控制机制，美国国立卫生研究院的科学家把抗坏血酸通过注射注入受到脑瘤、卵巢瘤和胰腺瘤侵害的小鼠的静脉或腹腔中。从而使体内获得大剂量的抗坏血酸，每天高达4克/公斤体重。Levine说，“通过注射大剂量的维生素C，我们希望能产生类似药物的效果，可能有助于癌症的治疗”。
    维生素C起着非常重要的健康作用，长期缺乏维生素C会引起坏血病，并且最终导致死亡。一些称为酶的、具有至关重要的生物化学功能的蛋白质需要维生素来维持其正常的功能。维生素C还可以作为抗氧化剂，保护细胞免于自由基的破坏作用。然而，美国国立卫生研究院的研究人员通过大剂量维生素C注射测试, 认为维生素C可能具有氧化强化剂而不是抗氧化剂的作用。
氧化强化剂可以产生自由基并且形成过氧化氢，科学家们猜测过氧化氢可以杀死肿瘤细胞。在对43个癌细胞系和5个正常细胞系的实验中，研究人员发现高浓度的维生素C对所测试的75%的癌细胞系具有抗癌效果，而对正常细胞却没有影响。在论文中，研究人员还表明可以使人体内达到这种高浓度的维生素C。
    接着，研究人员用患有快速扩散的卵巢瘤、胰腺瘤和成胶质细胞瘤（脑）的免疫缺乏小鼠试验了抗坏血酸注射疗法。维生素C注射疗法使肿瘤增长率和肿瘤重量降低了41%到53%。在成胶质细胞瘤对照组中，30%小鼠的癌变扩散到了其它器官，而经过维生素C治疗过的小鼠中没有发现癌变扩散的迹象。 研究人员得出结论，“这些临床前的数据为进一步研究抗坏血酸在人类癌症治疗的药理学上提供了第一个可靠的依据”。
    大约30年前，对维生素C癌症治疗潜力的研究曾引起极大的兴趣，同时一系列病例表明病人可能受益。然而，在1979年和1985年，另外一些研究人员报告说，两次的双盲、安慰剂对照临床试验表明癌症病人口服大剂量维生素C不受益。
    美国国立卫生研究院的研究人员通过观察到的几种现象促使他们重新研究了抗坏血酸是否可以成为一种癌症治疗方法。  Levine说, “过去12年进行的临床和药代动力学研究表明，口服维生素C在血浆和组织中的浓度受到严格控制。虽然受益病例中的维生素C采用口服和静脉给药，但在证明其无效的试验中，抗坏血酸只采用口服给药。当时没有意识到，只有通过抗坏血酸注射才能达到产生抗肿瘤效果所需的浓度”。她指出抗坏血酸做为一种癌症治疗方法的新临床试验还处于计划阶段。
    在2000年，根据Levine早期关于饮食中维生素C的调节和吸收的研究数据, 修订了药物的推荐膳食容许量研究所针对维生素的建议。Levine领导的、目前的研究团队由NIH（美国国立卫生研究院）下属的NIDDK（美国国家糖尿病、消化和肾脏病研究所）和NCI（美国国家癌症研究所）以及堪萨斯州立大学的科学家组成。他说，“美国国立卫生研究院独特的转化环境允许研究人员追寻高风险、高回报的创意想法, 因此, 我们才得以从事这一研究工作”。
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Vitamin C Injections Slow Tumor Growth In Mice
http://www.sciencedaily.com/releases/2008/08/080804190645.htm

ScienceDaily (Aug. 5, 2008) — High-dose injections of vitamin C, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian, and pancreatic cancers, researchers from the National Institutes of Health (NIH) report in the August 5, 2008, issue of the Proceedings of the National Academy of Sciences.
The researchers traced ascorbate's anti-cancer effect to the formation of hydrogen peroxide in the extracellular fluid surrounding the tumors. Normal cells were unaffected.
Natural physiologic controls precisely regulate the amount of ascorbate absorbed by the body when it is taken orally. "When you eat foods containing more than 200 milligrams of vitamin C a day--for example, 2 oranges and a serving of broccoli--your body prevents blood levels of ascorbate from exceeding a narrow range," says Mark Levine, M.D., the study's lead author and chief of the Molecular and Clinical Nutrition Section of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the NIH.
To bypass these normal controls, NIH scientists injected ascorbate into the veins or abdominal cavities of rodents with aggressive brain, ovarian, and pancreatic tumors. By doing so, they were able to deliver high doses of ascorbate, up to 4 grams per kilogram of body weight daily. "At these high injected doses, we hoped to see drug-like activity that might be useful in cancer treatment," said Levine.
Vitamin C plays a critical role in health, and a prolonged deficiency leads to scurvy and eventually to death. Some proteins known as enzymes, which have vital biochemical functions, require the vitamin to work properly. Vitamin C may also act as an antioxidant, protecting cells from the damaging effects of free radicals. The NIH researchers, however, tested the idea that ascorbate, when injected at high doses, may have prooxidant instead of antioxidant activity.
Prooxidants would generate free radicals and the formation of hydrogen peroxide, which, the scientists hypothesized, might kill tumor cells. In their laboratory experiments on 43 cancer and 5 normal cell lines, the researchers discovered that high concentrations of ascorbate had anticancer effects in 75 percent of cancer cell lines tested, while sparing normal cells. In their paper, the researchers also showed that these high ascorbate concentrations could be achieved in people.
The team then tested ascorbate injections in immune-deficient mice with rapidly spreading ovarian, pancreatic, and glioblastoma (brain) tumors. The ascorbate injections reduced tumor growth and weight by 41 to 53 percent. In 30 percent of glioblastoma controls, the cancer had spread to other organs, but the ascorbate-treated animals had no signs of disseminated cancer. "These pre-clinical data provide the first firm basis for advancing pharmacologic ascorbate in cancer treatment in humans," the researchers conclude.
Interest in vitamin C as a potential cancer therapy peaked about 30 years ago when case series data showed a possible benefit. In 1979 and 1985, however, other researchers reported no benefit for cancer patients taking high oral doses of vitamin C in two double-blind, placebo-controlled clinical trials.
Several observations led the NIH researchers to revisit ascorbate as a cancer therapy. "Clinical and pharmacokinetic studies conducted in the past 12 years showed that oral ascorbate levels in plasma and tissue are tightly controlled. In the case series, ascorbate was given orally and intravenously, but in the trials ascorbate was just given orally. It was not realized at the time that only injected ascorbate might deliver the concentrations needed to see an anti-tumor effect," said Levine, who noted that new clinical trials of ascorbate as a cancer treatment are in the planning stages.
Data from Levine's earlier studies of the regulation and absorption of dietary vitamin C were used in the revision of the Institute of Medicine's Recommended Dietary Allowance for the vitamin in 2000. In the current study, Levine led a team of scientists from the NIDDK and the National Cancer Institute (NCI), both components of the NIH, as well as the University of Kansas. "NIH's unique translational environment, where researchers can pursue intellectual high-risk, out-of-the-box thinking with high potential payoff, enabled us to pursue this work," he said.

风雨中走来

我在网上也看过类似的文章,说外国有人每次注射20克维生素C,每星期注射两次,二,三年肿瘤消失, 我当时也咨询了一下医生,医生说没听说过,也不会给病人输10克以上的维生素液,一般输2克,
      不知有哪位病人用注射大量维生素C来治疗过没有?也不知道效果怎么样?真有那么神,还买什么特罗凯呀!
       可能这都只是病理上的推究,就好象有人说患癌只要把酸性体质改为碱性体质,癌不攻自破,这些都谈何容易.

大壮

个人觉得输入大剂量的Vc同服用易瑞沙或特罗凯不一定矛盾。我们都知道即使靶向药物起效，但最终的耐药性或早或晚是无法避免的，因此都在寻找一种能够同靶向药物一同使用的、能够减缓耐药性的方法。而大剂量Vc静脉滴注可能就是一个不错的选项。首先它是水溶性的，在血液内可短期保持保持治疗的高浓度，并随血液到达身体各部，随后会随尿液排出，不会积蓄起来产生付作用；其次它相对比较安全，只针对问题细胞，而不会伤害正常细胞； 再次，它的价格便宜，病人可以负担得起（这一条因为使医院无法获得暴利而宁可使用杀人的放疗方法，而不推广这种方法）。
  日常生活中的经验告诉我，口腔内发生溃疡时，含一片Vc，并且使之尽量靠近患处，会很快复原。这不是高浓度Vc的作用又是什么呢? 但口服Vc无法使之在血液中达到希望的治疗浓度, 因此只能采用静脉滴注了。
  至少，我觉得Vc能有助于缓解服用易瑞沙而发生的皮肤炎症。
  最近正准备在家里给老爷子采用高浓度Vc静脉滴注的治疗方案，当然易瑞沙会继续服用。
另外考虑到国内学术界的造假现象，我更加相信国外严肃期刊的文章。