Curcumin is a biologically active component of turmeric (Curcuma longa). This spice has been part of traditional Indian and Chinese medicine for thousands of years. Curcumin is the most important biologically active phytochemical compound of Turmeric. Curcumin is one of 3 curcuminoids of turmeric. The other two curcuminoids are bisdemethoxycurcumin and demethoxycurcumin. Curcuminoids comprise about 2-9% of turmeric.
The available findings show that doses of at least 3.6 to 4 g per day are essential in order for curcumin to accumulate to detectable levels in the blood. Doses of turmeric less than 3.6 g per day do not appear to significantly alter blood levels of curcumin. Clinical trials indicate that the systemic bioavailability of orally administered curcumin is relatively low. Some capsules of curcumin contain piperine, a compound found in pepper which aids absorption of curcumin into the blood stream. Nanoparticle or liposomal formulations can also increase absorption.
Cancer Prevention Properties and Research Findings
Curcumin (diferuloylmethane) has been shown to exhibit antioxidant, anti-inflammatory and anticancer activities. Curcumin may help prevent and treat cancer by different mechanisms. Evidence from test tube and animal studies suggests that turmeric may help prevent or treat several types of cancers, including breast, prostate colon and skin cancer. Curcumin has been shown in recent years to be a strong immunomodulatory agent that can modulate the activation of T cells, B cells, macrophages, neutrophils, natural killer cells, and dendritic cells. Pre-clinical trials in a variety of cancer cell lines including prostate,cervical, breast, hepatic, colon, gastric, pancreatic, and leukemia have consistently shown that curcumin possesses anti-cancer effects in vitro and in pre-clinical animal models.
Curcumin, is a strong antioxidant. In laboratory experiments, curcumin does prove effective as an antioxidant that provides protection against cell-damaging free radicals. Reactive oxygen species (ROS) attach to amino acids in DNA and cause cell injury or death. Animal-based research showed curcumin provides antioxidant activity by protecting against damage caused by reactive oxygen species. Curcumin also appears to reduce the risk of lung cancer associated with smoking. Experimental studies on curcumin and nicotine, cancer-causing chemical, showed that curcumin reduced the effects of nicotine as a carcinogen by 50 %.
Curcumin is an compound capable of inhibiting the activity of inflammatory enzymes. Inflammation plays a role in the development of cancer and curcumin is useful for cancer prevention and cure. New findings that curcumin exhibits powerful antioxidant and anti-inflammatory activities and modulates the expression of transcription factors, cell cycle proteins, and signal transducing kinases has prompted the mechanism-based researches on the potential of curcumin to primarily prevent and treat cancer.
Various research findings indicates that curcumin might help protect against cancer and stop its progression. In lab and animal models, curcumin has been shown to induce cell death (apoptosis), in cancer cells. Curcumin also inhibits several pathways involved in cell growth. Findings from some studies done by scientists at “Oregon State University” demonstrate that curcumin inhibits cancer cell proliferation by inducing cell cycle arrest and apoptosis.
Results from an animal-based study reported in the Nov 2009 edition of Carcinogenesis found that turmeric (curcumin) might inhibit lung cancer progression. Scientists at the China Medical University discovered curcumin’s mechanisms of action in regards to lung cancer. The researchers, concluded that curcumin is effective in stopping the spread of cancer cells through apoptosis, or cell death. A study using human saliva at UCLA’s Jonsson Comprehensive Cancer Center, reported in the Sep, 2011, edition of “Clinical Cancer Research“, found that curcumin seems to suppress a cell signaling pathway that drives head and neck cancer growth. In this pilot study, 21 head and neck cancer patients were given 1000 mg of curcumin, and an independent lab confirmed the findings on blind samples. Scientists at the “University of Michigan Comprehensive Cancer Center” found that a compound derived from curcumin, FLLL32, may help tumor cells overcome resistance to cancer therapies. This data may allow for lower and less toxic doses of cisplatin.
Curcumin, has shown biological activity in pancreatic cancer patients and there are ongoing research to test its effect as an addition to cancer therapy. In a Phase II clinical trial with curcumin, reported in “Clinical Cancer Research” in 2008, patients with advanced pancreatic cancer who took curcumin demonstrated some signs of improvement during therapy. Curcumin, temporarily stopped advanced pancreatic cancer growth in 2 patients and substantially reduced the size of a tumor in another patient, according to a small study reported July in the journal “Clinical Cancer Research”.
Scientists find curcumin may be beneficial in the prevention of prostate and breast cancers, which both are associated to inflammation and in reducing their metastatic risk. A study reported in the October 2005, edition of Clinical Cancer Research found that curcumin prevents the progression of breast cancer cells. Triple negative breast cancer is a type of cancer that defies conventional treatment. A study from “Zheijian Provincial People’s Hospital” showed that curcumin is capable of inducing apoptosis within triple negative breast cancer cells. The nuclear receptor activators are important in other forms of cancer, including breast cancer. Scientists at the “Jefferson’s Kimmel Cancer Center” found that curcumin may aid in the slowing of tumor growth in castration-resistant prostate cancer individuals who are receiving ADT (androgen deprivation therapy). The curcumin suppressed 2 known nuclear receptor activators that work against ADT (androgen deprivation therapy).
Curcumin might prevent recurrence of colon cancer, according to a study reported in the Apr 2011 edition of the journal Pharmaceutical Research. Curcumin suppresses colon cancer when combined with other polyphenols such as resveratrol. In researches with curcumin and resveratrol these 2 compound seem to stop tumour cell growth and induce cancer cell death in neuroblastomas by activating the p53 gene pathway (Anticancer Research 2004 March). Scientists from the “Barbara Ann Karmanos Cancer Institute” presented evidences showing that adding resveratrol or curcumin to standard chemotherapy could be effective in preventing the growth of chemo-resistant colon cancer cells. Karmanos Cancer Institute scientists investigated whether the addition of resveratrol and curcumin to chemotherapy would decrease the survival of colon cancer cells. Researches confirmed that both are effective and inhibit the growth of new colon cancer cells, with curcumin appearing to be superior. Colon polyps are a risk factor for developing colon cancer. Patients with a genetic form of potentially cancerous polyps in the colon were given quercetin and curcumin, over a time period of six months. During this time the average number of polyps dropped by over 60 %, with the average polyp size decreasing by over 50 %.