Blackcurrant extract shows anti-asthma potential

Extracts from blackcurrants may reduce inflammation in the lungs and potentially offer benefits to the increasing number of asthmatics, says a new study from New Zealand.

Researchers from Plant & Food Research report that the compound epigallocatechin, a known antioxidant and a major component of proanthocyanidins found in blackcurrants, could reduce inflammation in lung tissue.

The study is reportedly the first to show a beneficial effect of the metabolites of blackcurrant proanthocyanidins for suppressing the secretion of inflammatory molecules, state the authors in the journal Molecular Nutrition and Food Research.

“Understanding which (and how) plant-derived phytochemicals, such as fruit-derived proanthocyanidin and anthocyanin compounds, modulate these cellular events may ultimately lead to the development of functional foods that reduce the risk of allergy-induced asthma and/or allergic conditions in general,” they wrote.

According to the European Federation of Allergy and Airway Diseases Patients Association (EFA), over 30m Europeans suffer from asthma, costing Europe €17.7bn every year. The cost due to lost productivity is estimated to be around €9.8bn.

Study details

Led by Dr Roger Hurst, the New Zealand-based researchers examined the effects of the anthocyanidin-rich blackcurrant extract on cells from lung tissue.

The researchers focussed on a compound called eotaxin-3 or CCL26, which is expressed in the lungs after stimulation of the cells by cytokine interleukin-4 (IL-4). According to their findings, epigallocatechin (EGC) worked in conjunction with other natural immune responses to suppress CCl26 expression, and therefore inflammation. Furthermore, these actions were distinct from the inflammation-reducing activity of anthocycanins, said the researchers.

The bioavailability of plant-derived phytochemicals, although not the focus of this particular study, is an important consideration in the design of a functional food,” wrote Dr Hurst and his co-workers.

“In particular, blackcurrant- derived proanthocyanidins mainly (480 per cent) consist of high molecular weight polymers, however, recent findings show that these large proanthocyanidins can be broken down by chemical, enzymatic and/or resident microflora in various regions of the digestive tract to release small oligomers and monomers that are easily absorbed, such as EGC and epicatechin.

“Therefore, it is feasible that blackcurrant metabolites, such as EGC, may be able to modulate eotaxin expression in lung tissue,” they added.

Plant & Food Research’s Dr Roger Hellens, Genomics Science Group Leader, will be presenting at the upcoming NutraIngredients Antioxidants 2010 Conference in Brussels on the subject of super Vegetables. For more information and to register, please click here.

Source: Molecular Nutrition and Food Research

Published online ahead of print, doi: 10.1002/mnfr.200900297

“Blackcurrant proanthocyanidins augment IFN-gamma-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells”

Authors: S.M. Hurst, T.K. McGhie, J.M. Cooney, D.J. Jensen, E.M. Gould, K.A. Lyall, R.D. Hurst