Red yeast rice extract reduces interleukin-1 beta secretion from peripheral blood mononuclear cells when treated with cholesterol crystals

P. V. Kavanagh¹, P. T. Walsh²,M. Lucitt¹. ¹Pharmacology and Therapeutics, Trinity College Dublin, Dublin, Ireland, ²Clinical Medicine, Trinity College Dublin, Dublin, Ireland

Introduction: Red yeast rice (RYR) nutraceutical contains monacolin K, a natural occurring statin (1). Here we compare lovastatin and simvastatin effects on interleukin-1 beta (IL-1β) levels to that of extracts from a RYR product sold in health food stores in Ireland.

Method: Standard curves using 0.375-24 μg/mL of lovastatin pre and post hydrolysis with NaOH were constructed using liquid chromatography-mass spectrometry (LC-MS) operated with selected ion monitoring (SIM) and a mass-to-charge ratio (m/z) of 427 to detect the lactone and m/z of 445 to detect the hydroxyl acid forms of lovastatin. RYR, 0.22μm filtered ethanol extractions pre and post hydrolysis were analysed by LC-MS for lactone (inactive) and hydroxyl acid (active) forms and quantified from the standard curves generated above. Human peripheral blood mononuclear cells (PBMCs) treated in vitro with lovastatin (100μM), simvastatin (100μM) or RYR extracts (9μg/ml, 18μg/ml) and stimulated with lipopolysaccharide (LPS) (100ng/ml) for 3hrs, followed by cholesterol crystals (CC) (1mg/ml) stimulation overnight. IL-Iβ levels in the supernatants form PBMCs were measured by ELISA. Data shown as mean ± sem, N=3. Statistical analysis carried out using unpaired students t-test with significance taken at P<0.05.

Results: Extracts from 9g of RYR (3 capsules) analysed by LCMS detected 1.86-2.43mg /capsule of the lactone. Extract levels of monacolin K lactone form to monacolin K hydroxyl acid form, pre and post hydrolysis was determined, (15:1 ) pre and (1:2 ) post hydrolysis. PBMCs treated with lovastatin or simvastatin reduced secreted levels of IL-1β when stimulated with LPS and CC, (0.99 ± 0.05ng/ml) lovastatin, (1.75 ± 0.14ng/ml) simvastatin vs. ( 2.6 ± 0.47ng/ml) LPS and CC treatment alone. Similarly, in vitro treatment of PBMCs with RYR extracts also resulted in reduced IL-1β secretion when stimulated with LPS and CC (2.6 ± 0.47ng/ml) vs. (1.15 ± 0.09ng/ml) RYR 18μg/ml and (1.49 ± 0.28ng/ml) RYR 9μg/ml. Values presented are mean ± sem, n=3.

Conclusions: As part of our preliminary investigations, we have demonstrated extraction of lactone and hydroxyl acid forms of monacolin K from a RYR commercial available product. LPS and CC induced IL-1β release by PBMCs are reduced when treated with prescription statins, and levels of IL-1β released are reduced to comparable levels when treated with RYR extracts. These data identify a previously unappreciated anti-inflammatory effect of RYR supplements that may have potential benefit in atherosclerosis disease.

References:

1. Zhao SP et al. (2004). Circulation 110: 915-920.