Turmeric spices up drug development

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The dye contained in turmeric roots is not easily absorbed by the body. Source: Ulrich Prokop

06.01.2011  - 

Turmeric (Curcuma longa) has been cultivated in India as a spice and medicine for thousands of years. More recently, the scientific community has been taking a closer look at the essential components of the turmeric spice. While many scientists to date have focused on the effects of the dye contained within, known as curcumin, a German project group is hoping to clarify an entirely different question. Under the leadership of Jan Frank of the University of Hohenheim, a method is being researched that could raise the bioavailability of the substance. The Federal Ministry of Education and Research (BMBF) is supporting the project over the next three years with around 1.5 million euros.

In the traditional Indian ayurvedic system of medicine, the turmeric spice is considered to have a healing effect. The yellow powder is thought to be effective against rheumatism, inflammations and skin diseases, as well as infections of the upper respiratory tract. Modern biological research is also well aware of this supposed wonder treatment:  In PubMed, the largest medical literature database, there are over 3,700 articles that deal with the turmeric dye. Most of these are concerned with its antioxidant effect, which could one day find application in cancer therapy. In the meantime, clinical trials are underway to examine the effect of the spice on Alzheimer's. Moreover, other research results indicate that it can lower cholesterol and help prevent inflammation.

How can we get valuable plant substances into the body?

The team of researchers headed by Jan Frank of the University of Hohenheim is attempting to shed light on a fundamental problem of the versatile substance. “The question is: How can we bring valuable plant substances into the body, and ensure that they stay there long enough to have a positive impact on health?” says the biologist Frank, summarising the issues that are occupying him and his colleagues. Turmeric is just one representative of a whole class of plant proteins, the so-called secondary plant compounds. In contrast to nutrients and minerals, for example the vitamins, the body only absorbs these secondary plant compounds to a limited extent before they are quickly expelled. Turmeric is known for its low bioavailability. “In humans, even after taking twelve grams of curcumin in capsule form, no measurable quantities of the substance can be detected in the blood,” says Frank.

The BMBF is funding the project over three years until July 2013. Up to 1.5 million euros is available for the research network as part of the Biomedical Nutrition Research funding line. Together with partners from the universities of Kiel and Jena, and the University Hospital of Frankfurt, Frank wants to investigate how turmeric can be better absorbed by the body.

Camouflage or deception

“The organism recognises them as foreign substances, and tries to get rid of them immediately,” says project coordinator Frank. “This is why we are investigating strategies to outwit the body and encourage it to either absorb larger quantities of the secondary substances or delay their expulsion from the body.” Thereby, he is considering two fundamentally different mechanisms: camouflage and distraction.

 “With the camouflage approach, we package the turmeric,” says the Hohenheim-based researcher. Thereby, the turmeric is enclosed in so-called micelles. These are microscopic hollow spheres that consist of both water-and fat-soluble substances. Micelles also occur naturally in the gut. “They serve as transport vehicles for fat-soluble nutrients. We are able to use artificial product micelles for this purpose.” Darmstadt-based AQUANOVA AG, one of the project's industrial partners, specialises in the production of product micelles. The other packaging method is to use micronisates, which are porous carrier substances. The Kulmbach-based company Raps GmbH & Co. KG, a specialist manufacturer of this product class, produces the microsinates used in the project.

The other parts of the plant might be pretty on the eye, but it’s the roots that give this plant its reputation.Source: John Hill / wikimedia.org

However, it will take some time until turmeric but can be used for the production of high value foodstuffs. “We still have a lot of work ahead of us before we can think of marketing these types of functional foods,” thinks project manager Frank. “We need to test whether the bioavailability of nutraceuticals differs between young and old people, and between men and women.” Nevertheless, potential marketers are standing at the ready: The jams manufacturer Schwartauer Werke GmbH & Co. KG and the beverage manufacturer Hassia Mineralquellen GmbH & Co. KG from Bad Vilbel in Hesse have expressed interest in the project, as well as Kampffmeyer Food Innovation GmbH in Hamburg.