A team from the US, Finland and Hong Kong have found that curcumin, found in the Indian spice turmeric, prevents activation of a genetic factor leading to liver inflammation and necrosis.
Yesterday we reported on a study showing how curcumin can prevent the blood cancer multiple myeloma, by de-activating the nuclear factor kappa-B (NF-kappaB) which seems to be linked to production of cancerous cells.
NF-kB is also involved in a number of tissues that are sensitive to alcohol, and as scientists have already shown that curcumin can suppress tumour blood vessel growth and the activation of NF-KB, this raised the possibility that the substance might be useful in preventing alcoholic liver disease(ALD).
In a study on rats, the team found that curcumin prevented ALD, at least in part, by inhibiting lipid peroxidation, activation of NF-KB, and expression of pro-inflammatory mediators. Their findings appear in the February 2003 edition of the American Journal of Physiology - Gastrointestinal and Liver Physiology.
Four groups of rats were treated with the compound for four weeks. One group received fish oil plus ethanol (FE); a second group received fish oil plus dextrose (FD). The third and fourth groups received FE or FD supplemented with curcumin.
The researchers found that rats fed the FE diet for four weeks had fatty liver, necrosis, and inflammation but treatment with curcumin prevented both alcohol-induced necrosis and inflammation. The degree of fatty liver also decreased in curcumin-treated rats. And there was no evidence of liver injury in these groups.
The FE diet led to increased NF-KB binding activity compared with the FD diet. Interestingly, curcumin prevented the activation of NF-KB in rats fed the FE diet consistent with its ability to inhibit lipid peroxidation and liver injury.
Also, various NF-KB responsive genes have been found to be overexpressed in experimental ALD. The researchers found markedly elevated levels of these pro-inflammatory mediators in the livers of rats fed FE compared to the FD diet. Remarkably, treatment with curcumin resulted in a normalisation of levels of each of the these proinflammatory mediators.
Although curcumin is known to inhibit the activation of NF-KB and suppress inflammation, this is the first time it has been shown to prevent alcoholic liver disease, according to researchers.
However they added that it is no yet certain whether curcumin can also be used to treat established ALD. But because the compound can be given safely to humans - taken orally, as in milk or food - the results of this study have potentially important therapeutic implications for individuals at risk for ALD.
Leader of the study Dr Nanji is now focusing on whether such a compound will be useful in diseases such as non-alcoholic steatohepatitis. Steatohepatitis can lead to liver cirrhosis and liver cancer.