PHENOLIC RICH EXTRACTS OBTAINED FROM SMALL RED BEANS IN PREVENTING MACROPHAGE MEDIATED CHRONIC INFLAMMATION

Small red beans, commonly called Mexican beans, are a part of the legume family, the genus Phaseolus vulgaris, i.e., dry edible beans or the common bean. In addition to being a rich source of nutrients, small red beans also contain phenolic compounds, such as flavonoids, tannins, phenolic acids, and anthocyanins that have shown a plethora of health benefits against such conditions as obesity, diabetes, heart disease and cancer. In particular, the phenolic compounds common to the red beans have been reported to protect against chronic inflammation that if left unchecked can lead to various other chronic degenerative diseases. These benefits may be attributed to the phenolic compounds acting in combination as either synergists or additives. Optimal parameters are therefore needed to characterize the type and amount of these diverse phenolic compounds in any food system or matrix, and then to correlate the results to the condition of interest, which in this study is inflammation. However, such studies are non-existent for small red beans despite the presence of chemically diverse phenols at relatively high levels, (depending on the extraction parameters). Therefore, the objective of this research was to apply response surface methods (RSM) to obtain phenolic rich extracts from two lines of small red beans (NE36 and NE40). The study was completed using three factor face centered cube design (FCCD) to investigate the effect of three independent variables, solid:solvent ratio, solvent polarity and mix time on response of total phenols (TP), total flavonoids (TF) and anti-oxidative capacity (AC). The most effective factors that resulted in overall maximum TP yields were acetone: solvent (water) composition of 50%, a solid:solvent ratio of 10% and a mix time of 60 min. For optimal TF extractions, an acetone:water composition of 75%, solid:solvent ratio of 10% and mix time of 180 min were required. Maximum AC values were achieved with an ethanol:water composition of 75%, solid:solvent ratio of 10% and a mix time of 180 min. In most cases, a second order polynomial model was developed to optimize the extractions with the exception of TP for ethanol extractions and TF for acetone extractions for NE36. Preliminary data obtained in our lab indicated that higher order models (cubic) better explained the complex interactions. The extractions that produced the highest yields of TP, TF and AC were then tested for the ability to remediate inflammation using lipopolysaccharide (LPS) activated RAW 264.7 macrophages. As nitric oxide is an indicator of inflammation, this test was applied to extract treated cells to determine their ability to remediate inflammation. Only the extracts with high TF show significant anti-inflammatory activities using this vitro model, with the NE36 line showing the most efficacious results. In summary, this study has shown that that optimum phenolic yields (TP and TF) and potent AC and anti-inflammatory extracts are dependent upon the extraction methods and solvents used, and also vary with different lines of red beans. This research is therefore significant as it has shown the potential of small red beans as a health impacting food system, with an emphasis on remediating inflammation. Advisor: Vicki Schlege