Vitamin C High-dose makes cancer treatment more effective

Islamabad-A new clinical trial tests the effect of high-dose vitamin C in combination with standard treatment on health outcomes for patients with cancer.

The new research was led by scientists at the University of Iowa in Iowa City.

Each infusion raised the patients’ blood levels of vitamin C to 20,000 micromoles (µM). The average level of vitamin C in adults is approximately 70 µM.

Overall, the treatment was tolerated well. The team noted very few minor side effects, such as dry mouth or rare and brief episodes of high blood pressure.

This safety test was the first phase of a series of clinical trials that will investigate whether high-dose vitamin C can effectively increase the lifespan and quality of life for patients that are being treated with chemotherapy and radiation therapy.

For now, the data from the phase I trial show that patients with glioblastoma survived for 4 to 6 months longer than the average survival time noticed in patients who undergo conventional treatment alone. Specifically, patients who also received high doses of ascorbic acid survived for 18 to 22 months compared with 14 to 16 months, which is the typical survival rate for glioblastoma.

The mechanism that might explain the potential efficacy of vitamin C in treating lung and brain cancer relates to the cancer cells’ metabolism.

As a consequence of the faulty metabolism that occurs inside the cancer cells’ mitochondria, these cells produce abnormally high levels of so-called redox active iron molecules.

These molecules react with vitamin C and form hydrogen peroxide and hydrogen peroxide-derived free radicals.

Scientists think that these free radicals drive cancer cell death by damaging the cells’ DNA. The free radicals are also thought to weaken the cancer cells and make them more vulnerable to radiation therapy and chemotherapy.

Garry Buettner, study co-author said that “This paper reveals a metabolic frailty in cancer cells that is based on their own production of oxidizing agents that allows us to utilize existing redox active compounds, like vitamin C, to sensitize cancer cells to radiation [therapy] and chemotherapy.”

Co-senior author Douglas Spitz also comments on the significance of the findings showed that “This is a significant example of how knowing details of potential mechanisms and the basic science of redox active compounds in cancer versus normal cells can be leveraged clinically in cancer therapy,” he explains. “Here, we verified convincingly that increased redox active metal ions in cancer cells were responsible for this differential sensitivity of cancer versus normal cells to very high doses of vitamin C.”

Meanwhile, the study led by Kathryn A Cunningham, a professor of pharmacology and director of the Centre for Addiction Research in the University of Texas Medical Branch at Galveston. Opioids are substances that attach to Opioid receptors in parts of the brain that control pain and emotion. Examples include heroin, morphine, and certain prescription pain relievers such as Oxycodone, codeine, and Fentanyl.

While treatments for Opioid use disorder exist, they are not ideal because they are often associated with high relapse rates and too many people stopping treatments early, note the authors of the new study.

One of the problems with many of the current treatments is that while they reduce the feeling of euphoria that results from taking Opioids such as Oxycodone, they do not address “cue reactivity” – the powerful effect that a familiar drug-taking environment can exert on anticipation of the drug experience.

Cue reactivity is often the reason that people on Opioid misuse treatment relapse when they encounter the people, places, situations, and equipment that they associate with their Opioid use. It results from the repeated pairing of these stimuli with the experience of the drug use.

In their new research, which takes the form of a preclinical study, the team shows that the prescription weight-loss drug Lorcaserin reduced not only the use but also the craving for Oxycodone.

So, for the new study, the researchers allowed rats to give themselves Oxycodone when they were exposed to a particular pattern of lights and sounds – thus creating a specific drug-taking environment.

After a period during which the rats got used to self-administering Oxycodone in the drug-taking environment, the team withdrew the Oxycodone. They exposed the rats to their familiar drug-taking environment and gave some of them Lorcaserin and the rest a placebo.

They then allowed the rats to self-administer Oxycodone again.

To confirm that this effect was due to Lorcaserin, the researchers gave a group of rats Lorcaserin plus a drug that blocks its effect by denying access to serotonin 2C receptors.

These rats then ‘tried very hard’ to self-administer the Oxycodone.

The researchers say that the study shows that Lorcaserin appears not only to reduce Oxycodone self-administration, but also cue reactivity associated with relapse.