Purified <i>Monascus</i> Pigments: BiologicalActivities and Mechanisms of Action

<i>Monascus</i> pigments having yellow, orange, and red colors are widely studied for their potential beneficial properties. Many different biological activities have been reported regarding <i>Monascus</i> pigments and their derivatives, but the usual method is to test complex extracts from the mycelium of the fungus or from a fungus-fermented substrate. However, this review is mainly concerned with the biological activities of purified <i>Monascus</i> pigments. Both yellow (ankaflavin, monascin) and red (rubropunctamine, monascorubramine) <i>Monascus</i> pigments are proven antioxidants if used in concentrations of 10 μg/mL or higher. Antimicrobial activity against Gram-positive and Gram-negative bacteria and fungi has been observed with all <i>Monascus</i> pigments. However, the best antimicrobials are red <i>Monascus</i> pigments, and their amino acid derivatives (l-cysteine derivatives have MIC 4 μg/mL against <i>Enterococcus faecalis</i>). Yellow monaphilones and orange monaphilols seem to have the highest anti-inflammatory activity (IC₅₀ 1.7 μM of monaphilol D) and, together with red <i>Monascus</i> pigment derivatives, have mild antiobesity and antidiabetic activities. Further, monascin and ankaflavin in daily doses of 0.5 and 0.08 mg, respectively, lowered serum blood levels of low-density lipoprotein cholesterol complexes in rats on a high-fat diet. Orange <i>Monascus</i> pigments, rubropunctatin and monaphilols A and C, exhibit cytotoxic and antitumor activities (IC₅₀ 8–10 μM).