Vitamin C may reduce adverse effects of cancer treatment

Cancer patients who are treated with the chemotherapy drug doxorubicin may experience side effects that have long-lasting consequences. Among these, damage to the heart muscle and wasting away of skeletal muscle can affect a survivor’s physical stamina and quality of life. It is, however, a potent anti-cancer drug and is currently on the World Health Organization’s List of Essential Medicines. It is used to treat breast cancer, bladder cancer, Kaposi’s sarcoma, lymphoma, and types of leukemia. The fact that it can cause serious side effects is of great concern to patients and doctors alike.

The results of a recent study to test the effect of vitamin C supplementation in rats treated with doxorubicin will be presented at the annual meeting of the American Physiological Society. This meeting will be held under the auspices of the annual Experimental Biology (EB) 2022 meeting, where scientists gather to share the newest research findings in anatomy, biochemistry, molecular biology, investigative pathology, pharmacology and physiology. 

“Our results suggest vitamin C as a potential adjunct therapy to assist in the management of peripheral muscle disorders after treatment with doxorubicin, thereby improving functional capacity and quality of life and reducing mortality,” said study first author Antonio Viana do Nascimento Filho, a master’s student in medicine at the University Nove de Julho (UNINOVE) in Brazil. Nascimento Filho will present the findings at the American Physiological Society annual meeting.

Previous research, conducted in conjunction with scientists from the University of Manitoba in Canada, found that vitamin C supplementation improved markers of heart health and survival in rats given doxorubicin. The heart pathology resulting from treatment with doxorubicin appears to involve inflammation and oxidative stress, and vitamin C acts as an anti-oxidant that can reduce these processes. This led the authors to investigate whether vitamin C could also help to prevent the drug’s negative effects on skeletal muscle.

The researchers worked with four groups of rats, each with eight to 10 individuals. One group received both vitamin C and doxorubicin, while another received neither. A third group received only doxorubicin and a fourth received only vitamin C. The researchers then measured and compared skeletal muscle mass and markers of oxidative stress in all the rats. 

The results showed that rats that received vitamin C along with doxorubicin had reduced oxidative stress and better muscle mass compared with those that were given doxorubicin but not vitamin C.

“It is exciting that the vitamin C prophylactic and concurrent treatment, given for just one week before and maintained for another two weeks after the use of doxorubicin, was sufficient to attenuate the side effects of this drug on skeletal muscle, contributing to a hugely positive impact on the health of the studied animals,” said Nascimento Filho. “Our work demonstrated that vitamin C treatment can mitigate the loss in muscle mass and improve many markers of free radical imbalance in rats subjected to doxorubicin administration.”

Future research would need to include randomized clinical trials in order to confirm whether vitamin C is also helpful for human patients receiving treatment with doxorubicin. In addition, appropriate dosages of vitamin C would need to be established for humans. Previous studies have suggested vitamin C could interfere with the effects of chemotherapy drugs, so patients are not advised to take these supplements during cancer treatments unless directed to do so by their doctor.

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By Alison Bosman, Earth.com Staff Writer