Cancer is the condition in which DNA damage leads to abnormal and uncontrolled cell division with a damaged genetic material. It has a major impact on society all over the world. According to the American Cancer Society, 595,690 Americans in the United States die due to cancer in 2016. [1] The dietary indiscretion and cigarette smoking are two great contributory factors in cancer progression. There are several types of cancers, such as bladder cancer, breast cancer, cervical cancer, colorectal cancer, endometrial cancer, esophageal cancer, laryngeal cancer, leukemia, lung cancer, lymphoma, ovarian cancer, prostate cancer, skin cancer, stomach cancer, testicular cancer. Several conventional therapies that are used currently to treat cancer include chemotherapy, radiation therapy, and surgery, which may not be applicable to treat many types of cancers like lungs, pancreas, liver, bones and in an advanced stage of breast and colon cancer. But this advancement of medical cannot provide a complete protection against cancer; even the available treatment has several challenges, like chemotherapeutic and radiation-related serious adverse effects, drug resistances etc. Turmeric can help to reduce these has along with providing wide cancer-preventive action. Different study result describes that curcumin, the active ingredients of turmeric is effective to provide the inhibitory effects on almost every type of tumor and carcinogenic cells, including reproductive cancers, digestive cancer, lymphatic cancer, urinary cancer, pulmonary cancer, cancer in the nervous system, skeletal systems, and the skin. It also boosts the immune system. [2]
Mechanism of Action of Curcumin as Anti-cancer
Curcumin has the ability to restrain instigation, advancement, and metastasis of multiple tumors. These anti-cancer effects are primarily intervening due to its down-regulating effect on various growth factors, transcription factors, protein kinases, inflammatory cytokines and other oncogenic molecules. It also abrogates cancer cells proliferation by arresting them at different cell cycle specific phases and/or by initiating their apoptosis. [2]
Figure: Potential Anti-cancer function of Curcumin2
Recent clinical trials have been conducted with curcumin to reveal the anticancer properties, including tolerability, safety, and efficacy studies, which reported that curcumin has been well tolerated in the human body at higher doses i.e. almost 12 g/day. Curcumin has a small half-life and poor water solubility which causes lower bioavailability in systemic circulation and tissues. But Phase II clinical trial has proved that the smaller amount of curcumin in the biological system is able to provide great impact on NF-κB, COX-2, and phosphoSTAT-3 in peripheral blood mononuclear cells. Curcumin is potentially initiating apoptosis, inactivation of NF-κB. The bioavailability of Curcumin is increased by combining it with Piperine from black pepper. [3]
Research evidences
- Curcumin present in turmeric, when combined with other chemotherapeutic agents provides an improved approach against breast cancer, colorectal cancer, leukemia and lymphoma, lung cancer, oral cancer and cervical cancer. (4)
- According to a trial conducted at the University of Rochester, the curcumin reduces radiation-induced dermatitis in breast cancer patients and thus decreases adverse effects of cancer therapy. (5)
- Cancer stem cells provide deleterious effect against chemotherapeutic agents and cause drug resistance. But recent study result showed curcumin targets breast cancer stem cells and an addition of curcumin supplementation or turmeric with other chemotherapeutic agents may prevent drug resistance. (4)
- Curcumin potentially acts against malignant brain tumor prognosis. (6)
Turmeric as cancer adjuvant therapy
Turmeric is a source of curcumin and this active ingredient of turmeric is not only effective as an anticancer agent in single therapy, but research study evidence showed that a reduced dose of the chemotherapeutic agent with curcumin as an adjuvant therapy able to provide same treatment efficacy. This means the addition of curcumin in combination with other chemotherapeutic agents can reduce the risk of higher dose-related severe adverse effect. A cancer patient can easily tolerate a lower dose of the chemotherapeutic agent. A research study showed that combination of curcumin and cisplatin therapy is markedly decreased cancer growth in a lower dose of cisplatin than the alone therapy. In this case, Curcumin inhibits NF-κB activity. Moreover, the curcumin also provides a synergistic effect with radiation therapy; because this herbal product arrests the cell cycle and suppresses the growth. [7]
Dose of curcumin isolated from turmeric
Highly absorbable curcumin formulation can be provided at 400 milligrams daily with food which can able to give preventive action, whereas for adjuvant cancer therapy the dose may increase up to 800-1,200 milligrams daily with food. [8]
References
- https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2016.html
- https://www.ncbi.nlm.nih.gov/pubmed/25665066
- https://www.ncbi.nlm.nih.gov/pubmed/19806380
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5386596/
- https://clinicaltrials.gov/ct2/show/NCT01042938
- https://www.hindawi.com/journals/omcl/2016/9324085/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3055228/
- http://onlinelibrary.wiley.com/doi/10.1002/pros.1074/abstract
