The connection between a high intake of dietary plants and a reduced risk of degenerative diseases is supported by a large amount of epidemiological evidence. Emerging evidence from nutritional genomics suggest that plants exert their protective effect through affecting cellular signalling and gene expression. Aberrant NF-κB activation has been linked to various diseases, and several phytochemicals possess NF-κB modulating properties that could have potential in prevention of disease.
In this thesis, the modulation of NF-κB activation by phytochemical-rich plant extracts was studied by the use of transgenic reporter mice.The aims of this project were to perform in vivo experiments with an extract combined of five efficient in vitro NF-κB inhibitors. Secondly, the thesis involved separate studies on the in vivo NF-κB modulating potential of three of the five dietary plants found in the combination extract.
The treatment of transgenic reporter mice with combination extract significantly inhibited lipopolysaccharide (LPS)-induced NF-B activity. The area under curve (AUC) was 35 % lower in the extract group compared to the control group (0-6 h). We found organ specific inhibition of NF-κB, particularly in the organs of phytochemical metabolisation, as well as in the male reproductive organs.
The in vivo experiments with thyme, clove and walnut extracts revealed a significant difference of 104% higher overall NF-κB activation at 6 h in the walnut group compared to the control group. We also found organ specific NF-κB modulation by the single food extracts, particularly in the liver, spleen and the male reproductive organs.
We have found that food extracts can modulate LPS-induced NF-κB activation, on an overall basis, and in an organ-specific manner. Based on this thesis, further work to elucidate the mechanisms of action of the NF-κB modulating food extracts is a possible future area of priority.