Laboratory studies 

Laboratory studies using blackcurrants

Hundreds of laboratory studies using cells and animals, have been completed showing beneficial effects with blackcurrants and are too numerous to summarise them all. A smaller number of significant laboratory studies have been chosen to include here:

inhibits influenza virus infection

Blackcurrants have been shown in laboratory studies  to have properties that restrict the infection rate of viruses such as the common cold and flu viruses, for example influenza type A and B.

1. This study showed that treatment of cultured cells with blackcurrant extract in the laboratory protected them from infection by influenza virus.

Fractionation of blackcurrant extract has found that polyphenols are responsible for the observed antiviral activity. The compounds act by inhibiting haemagglutinin function. Haemagglutinin is the molecule on the surface of viral particles that binds the virus to cells it is infecting.

2. Studies in mice found that consumption of blackcurrant extract reduced virus accumulation and as a result mortality was greatly improved.

3.This study investigated the inhibitory effect of extracts of blackcurrant  on four different strains of influenza virus, by the inhibition of virus adhesion to the surface of the cells.The study showed that the extract of blackcurrant could disinfect all of four influenza strains that were examined. The efficiency of the blackcurrant extract was better than the blueberry extract, used as a control.

The extracts of blackcurrant showed definite potential for use as a disinfectant and antiseptic agent to prevent influenza virus infection.

decreases airway inflammation

1. During allergen induced asthma, a cascade of responses leads to increased levels of eosinophils that result in airway inflammation and tissue damage. A 2010 New Zealand laboratory study showed that blackcurrant extract, and a purified component, epigallocatechin, significantly suppressed two of the responses in the cascade:
- eotaxin-3 (CCL26) and
- phosphorylation of STAT-6.
This study shows that it is feasible that components of blackcurrants may be taken up by the digestive tract into the bloodstream, and reduce eosinophil levels and airway inflammation.

2. Following on from  the 2010 laboratory study on extracts of blackcurrants on  allergen-induced asthma, a 2013 laboratory study has been completed.
A range of different New Zealand blackcurrant varieties were analysed  and it was found that, in in vitro studies, many reduced a key inflammatory step associated with allergy-induced asthma. Analysis of the composition of these fruits suggests that the ratio of two specific compounds, known as anthocyanins, is an important factor in this inflammation control.
This finding supports the potential use of blackcurrants in managing lung inflammation in allergic disease.

3. Following on from the 2013 study, a 2017 study was completed, which focused on CCL11, a signalling protein involved in the inflammation process in the airways during allergic asthma. The findings showed that mice fed blackcurrant had a significant reduction in CCL11 levels when compared to mice not fed blackcurrant, highlighting that New Zealand blackcurrant extract can alleviate inflammation of allergic asthma in mice and that blackcurrant may have potential benefits for lung health.

The study also tested extracts from 10 different blackcurrant varieties and highlighted that the ratio of specific anthocyanins in the fruit is important in alleviating lung inflammation. 

PROMOTES GUT HEALTH by ENHANCING probiotic bacteria

These studies examined the potential of blackcurrants to promote gut health, which is an important part of a healthly immune system. Gut pathogens (disease causing organisms) can upset the balance of gut bacteria with detrimental effects to health, while the addition of probiotic (beneficial) bacteria has been reported to inhibit the adhesion of pathogens to the gut cells, to restore favourable microbial balance.

1. In this animal study rats were fed blackcurrant powder three times weekly for a month. This treatment was very effective at promoting the growth of lactobacilli and bifidobacteria, which are probiotic (beneficial) bacteria in the caecum (start of the large intestine) of these rats. As a result of this study a human clinical trial was then completed, which is reported on our gut health page. To read about this study, click here.

2.This study on gut cells, all the blackcurrant juices tested inhibited the growth of the pathogenic bacteria Salmonella and inhibited the ability of the Salmonella to bind to the gut cells.  Correspondingly, all the juices enhanced the growth of the beneficial bacteria, Lactobacillus rhamnosus.

chemopreventive effects in cell systems

A.) A recent paper reviewed the studies of the effects of blackcurrants on tumour cells.

In vitro 
pharmacological effects were shown for whole fruit extract on the following cancer cell types:
- HT29 colon cancer
- MCF-7 breast cancer cells
- HeLa cervical cancer cells
- Prostate cancer
- HepG2 human liver cancer

Mechanisms for the effects were dose dependent and included:
- inhibition of cancer cell growth
- decreased proliferation of cancer cells
- reduced cell viability

There are two in vivo studies of pharmacological effects of dietary blackcurrant fruit extract in transplanted tumor models in animals:
- Solid tumour growth was reduced in Ehrlich carcinoma bearing mice.
- There was an inhibition incidence, multiplicity, size and volume of nodules in cells giving rise to liver cancer in rats as well as suppression of abnormal cellular proliferation.
Note: There are no clinical trials on the dietary effect of blackcurrant extracts on tumour cells.

LOWERS METABOLIC RISKS ASSOCIATED WITH OBESITY

This study fed overweight mice a high fat diet along with six different types of berries which had differing anthocyanin types.  The results showed that delphinidin-based and malvidin-based anthocyanins, the major anthocyanin type in blackcurrants and blueberries respectively, were more effective than other anthocyanin types in improving key metabolic risk factors associated with obesity caused by consumption of energy dense foods and a sedentary lifestyle. The dose of anthocyanins given to the mice was equivalent to a readily achievable daily dose in humans. 

Scientific Literature

1.Knox, M.Y., Suzutani, T., Yoshida, I., Azuma, M. Anti-influenza virus activity of crude extract of RibesnigrumL. PHYTOTHERAPY RESEARCH 2003, 17: 120-122.
2.Noguchi, A., Takeda, T., Watanabe, T., Yasui, H. Inhibitory effect of Cassis extract against influenza virus infection. JOURNAL OF THE FACULTY OF AGRICULTURE, SHINSHU UNIVERSITY 2008, 44 No. 1.2.
3.Kazufumi Ikuta, Katsumi Mizuta and Tatsuo SuzutaniAnti-Influenza virus activity of two extracts of the blackcurrant (Ribes Nigrum L.) from New Zealand and Poland. FUKUSHIMA JOURNAL OF MEDICAL SCIENCE 2013, Vol. 59, No.1: 35-38.
4.Hurst, S.M., McGhie, T.K., Cooney, J., Jensen, D., Gould, E.M., Lyall, K.A., Hurst, R.D. Blackcurrant proanthocyanidins augment IFN-γ-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells. MOLECULAR NUTRITION & FOOD RESEARCH 2010, 54: S159-S170.
5. Tafadzwa Nyanhanda, Elaine Gould. Tony McGhie. Oddette Shaw, Jacquie Harper, Roger Hurst. Blackcurrrant cultivar polyphenolic extracts suppress CCL26 secretion from alveolar epithelial cells. FOOD AND FUNCTION, 2014, 5, 671-677.
6. Abdul-Lateef Molan, Zhuojian Liu, Marlena Kruger, The ability of blackcurrant extracts to positively modulate key markers of gastrointestinal function in rats WORLD J MICROBIOL BIOTECHNOL (2010) 26:1735–1743.
7. Parkar, S., Redgate, E.,McGhie, T., Hurst, R. In vitro studies of modulation of pathogenic and probiotic bacterial proliferation and adhesion to intestinal cells by blackcurrant juices.  Journal of Functional Foods, 8C, 2014, 35-44.
8. Ashwin Gopalan,Sharon C. Reuben, Shamima Ahmed, Altaf S. Darvesh, Judit Hohmann,  Anupam Bishayee The health benefits of blackcurrants. FOOD & FUNCTION 2012, 3, 795-809.
9. Bishayee, A., Mbimba, T., Thoppil, R., Haznagy-Radnai, E., Sipos, P., Darvesh, A., Folkesson, H., Hohmann, J. Anthocyanin-rich blackcurrant (Ribes nigrum L.) extract affords chemoprevention against diethylnitrosamine-induced hepatocellular carcinogenesis in rats. Journal of Nutritional Biochemistry (2011) 22:1035 – 1046.
10. Overall, J. et al, Metabolic Effects of Berries with Structurally Diverse Anthocyanins. International Journal of Molecular Science, 2017, 18(2), 422.