Monascus-fermented rice has traditionally been used as a natural food colorant and food preservative of meat and fish for centuries. It has recently become a popular dietary supplement because of many of its bioactive constituents being discovered, including a series of active drug compounds, monacolins, indicated as the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors for reducing serum cholesterol level. The controversy of its safety has been provoked because a mycotoxin, citrinin, is also produced along with the Monascus secondary metabolites by certain strains or under certain cultivation conditions. This review introduces the basic production process and addresses on the compounds with bioactive functions. Current advances in avoiding the harmful ingredient citrinin are also discussed.

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to global public health. In an effort to develop novel anti-coronavirus therapeutics and achieve prophylactics, we used gene set enrichment analysis (GSEA) for drug screening and identified that Astragalus polysaccharide (PG2), a mixture of polysaccharides purified from Astragalus membranaceus, could effectively reverse COVID-19 signature genes. Further biological assays revealed that PG2 could prevent the fusion of BHK21-expressing wild-type (WT) viral spike (S) protein and Calu-3-expressing ACE2. Additionally, it specifically prevents the binding of recombinant viral S of WT, alpha, and beta strains to ACE2 receptor in our non-cell-based system. In addition, PG2 enhances let-7a, miR-146a, and miR-148b expression levels in the lung epithelial cells. These findings speculate that PG2 has the potential to reduce viral replication in lung and cytokine storm via these PG2-induced miRNAs. Furthermore, macrophage activation is one of the primary issues leading to the complicated condition of COVID-19 patients, and our results revealed that PG2 could regulate the activation of macrophages by promoting the polarization of THP-1-derived macrophages into an anti-inflammatory phenotype. In this study, PG2 stimulated M2 macrophage activation and increased the expression levels of anti-inflammatory cytokines IL-10 and IL-1RN. Additionally, PG2 was recently used to treat patients with severe COVID-19 symptoms by reducing the neutrophil-to-lymphocyte ratio (NLR). Therefore, our data suggest that PG2, a repurposed drug, possesses the potential to prevent WT SARS-CoV-2 S-mediated syncytia formation with the host cells; it also inhibits the binding of S proteins of WT, alpha, and beta strains to the recombinant ACE2 and halts severe COVID-19 development by regulating the polarization of macrophages to M2 cells.

N-Acetyl-D-galactosamine (GalNAc)-specific lectins are of great interest because they have been reported to detect tumor-associated antigens of malignant cells. We isolated a novel lectin from Carica papaya seeds, named C. papaya lectin (CPL). Purification of the lectin involved ammonium sulfate fractionation and DEAE anion exchange and repeated gel filtration chromatography. Inhibition of CPL causing hemagglutination on human erythrocytes showed that the lectin shows specificity to GalNAc and lactose. Surface plasmon resonance further revealed that the lectin possesses high specificity toward GalNAc with a dissociation constant of 5.5 × 10(-9) M. The lectin is composed of 38- and 40-kDa subunits with a molecular mass of ∼804 kDa estimated by size-exclusion high-performance liquid chromatography. Incubation of CPL with Jurkat T cells showed significant induction of IL-2 cytokine, which suggests that CPL has potent immunomodulatory effects on immune cells.

For easy obtaining the microorganisms with lipolytic specificity toward monoacylglycerols, we developed a simple and effective method to isolate the objective strains. This method employed a nile-blue agar-plate culture containing mono-and tri-acylglycerols for microorganism screening and selected the desired microorganisms by analysis of free fatty acid contents in lipid extracts obtained from culture broth. Using this strategy, we successfully isolated one mold strain with superior lipolytic ability for the hydrolysis of monoacylglycerols. The mold was identified and designated as Paecilomyces nostocoides NTU-FC-LP01. The lyophilized mycelia of the isolated mold used as a biocatalyst showed high specificity toward monoacylglycerols rather than di-and tri-acylglycerols. Furthermore, the lyophilized mycelia catalyzed the monoolein synthesis through the direct esterification of oleic acid and glycerol. It indicated that the lyophilized mycelia of the present P. nostocoides NTU-FC-LP01 could be used as a natural immobilized biocatalyst for the glycerol/oleic acid esterification to produce monoolein.

Monascus fermented products are conventional food colorant and seasoning in many Asian countries. In recent years, they were found to ameliorate several civilization diseases including hyperlipidemia, hypercholesterolemia, and hypertension. Therefore, Monascus related products are popular on the market and are vastly consumed as a dietary supplement. Monacolin K is one of its bioactive metabolites and has been approved as a clinical prescription named Lovastatin. Monascus can be a potential source of various bioactive compounds. In this chapter, we summarize these bio-functional metabolites and also review the process and factors controlling the production of Monascus related products.