Curcumin is the hydrophobic polyphenol evolved from the plant source Curcuma longa constituting broader aspects of biological and pharmacological activities. The commercial curcumin consists of approximately 77% diferuloylmethane, 17% demethoxycurcumin, and 6% bisdemethoxycurcumin. The crude extract curcuminoid makes up upto 1-6% of turmeric by weight with distribution of 60%-70% curcumin; 20%-27% demethoxycurcumin; and 10%-15% bis-demethoxycurcumin 1. Curcumin has shown potential effects towards treatment of several cancers such as gastrointestinal diseases, metabolic diseases, dermatologic conditions, cardiovascular diseases, neurodegenerative diseases, autoimmune conditions, and psychiatric disorders.
Some of the evidence reveals the therapeutic efficacy of curcumin. Not only in cancer treatment, but curcumin has shown beneficial effects on other diseases as well. Although there are several positive outcomes on the use of curcumin, still doctors report a major criticism of curcumin regarding its poor bioavailability. The researchers have revealed its negative outcome after the clinical trials as a result of its instability, reactivity, and non bioavailable nature. Hence, the features of poor availability of curcumin is confirmed; while many studies representing very low, or even undetectable, concentrations in blood and extra-intestinal tissue. Its poor absorption, rapid metabolism, chemical instability, and rapid systemic elimination have resulted in poor availability of curcumin. Most people excrete the oral curcumin in the faeces (≤90%). Hence, doctors undertake several methods for increasing the bioavailability of curcumin.
Oral Curcumin Bioavailability
The origin, food processing, and macronutrients affect the bioavailability of polyphenols in the dietary sources. The dietary lipids affect the solubility and absorption of curcumin. Doctors recommend to consume turmeric as cuisine linking it with lecithin-rich ingredients; such as eggs or vegetable oils for increasing the dietary intake of curcuminoids 2. Also the powdered curcuminoids when mixed in buttermilk before yoghourt manufacturing resulted in 15 times increase in the bio accessibility of curcuminoids when compared with neat curcuminoids. Hence, estimated of the form of curcuminoids with enhanced bio accessibility are low. Digestive steps of curcumin contribute towards lower bioavailability of polyphenols affecting solubility, degradation in the intestinal environment, and the permeation rate in the small intestine.
Overcoming bioavailability issues of curcumin
Doctors have adopted different methods in order to increase the bioavailability of curcumin. The use of adjuvants including piperine, formulating liposomal curcumin, curcumin nanoparticles, curcumin phospholipid complexes, and the use of structural analogs of curcumin including turmeric oil have been effective in increasing the bioavailability of curcumin. These methods have shown successful integration with increased blood concentrations. But still, therapeutic potencies and pharmacodynamic response of other bioavailable forms of curcumin have not been depicted due to lack of human trials on the same.
Association of bioavailability of curcumin with human health
Doctors determine the oral bioavailability of curcumin to be low. Doctors have implanted various strategies for increasing the uptake and availability of curcumin while determining its biological activities. One of the most important strategies is the inhibition of curcumin metabolism with adjuvants which interfere with metabolizing enzymes. The other phytochemicals are also capable of altering the curcuminoid metabolism and further its bioavailability. The administration of curcumin as a delivery system in the form of nanoparticles, and liposomes which is designed for enhancing the solubility and stability in the gastrointestinal tract. The combination of curcumin with other compounds have increased the solubility, extended the residence in plasma, and improved the pharmacokinetic profile and the cellular uptake. These strategies of increasing the bioavailability of curcumin helps in enhancing the health-beneficial potential of curcuminoids and thus stimulate their use as ingredients in dietary supplements and functional foods.
This way, curcumin has gained more attention towards its use providing multiple health benefits. It possesses anti-oxidant and anti-inflammatory properties which helps in treatment of several cancers along with other treatment of several other diseases. One can achieve these advantages of curcumin by combining it with agents such as piperine that eventually increases its bioavailability. Curcumin helps in the management of oxidative and inflammatory conditions, metabolic syndrome, arthritis, anxiety, and hyperlipidemia. It is effective in the management of exercise-induced inflammation and muscle soreness, thus enhancing recovery and subsequent performance in active individuals. Low dose of curcumin intake tends to provide health benefits for the individuals who do not have a diagnosis of other any health condition.
- 1.Nelson KM, Dahlin JL, Bisson J, Graham J, Pauli GF, Walters MA. The Essential Medicinal Chemistry of Curcumin. J Med Chem. Published online January 11, 2017:1620-1637. doi:10.1021/acs.jmedchem.6b00975
- 2.Esatbeyoglu T, Huebbe P, Ernst IMA, Chin D, Wagner AE, Rimbach G. Curcumin-From Molecule to Biological Function. Angew Chem Int Ed. Published online May 4, 2012:5308-5332. doi:10.1002/anie.201107724