Abstract
The increasing use of red yeast rice (RYR) as a natural supplement to manage blood cholesterol levels is driven by its active compound, monacolin K (MK), which is chemically identical to the statin drug lovastatin (LOV). Despite its growing popularity, concerns persists regarding the safety and efficacy of RYR compared to pure statins. This study aimed to evaluate the phytochemical composition, pharmacological effects, and safety profile of various RYR samples in comparison with LOV. RYR samples with different MK content were analyzed using HPLC‐DAD to quantify monacolins and other bioactive compounds. The inhibitory activity on HMG‐CoA reductase was assessed through an enzymatic assay, while pharmacokinetic properties were predicted using in vitro simulated digestion and
in silico
models. In vitro cytotoxicity was evaluated in intestinal, hepatic, renal, and skeletal muscle cell models. Additionally, the transcriptional levels of muscle damage‐related target genes were evaluated by qRT‐PCR in skeletal muscle cells treated with a selection of RYR samples. Significant variability in the phytochemical composition of RYR samples was observed, particularly in the content of secondary monacolins, triterpenes, and polyphenols. The RYR phytocomplex exhibited superior inhibition of HMG‐CoA reductase activity compared to isolated LOV, suggesting synergistic effects between secondary monacolins and other compounds. Molecular insights revealed that RYR samples had a lower impact on muscle cells than LOV, as reflected also by cell viability. These findings suggest that RYR could serve as a safe alternative to purified statins. However, further research is needed to fully elucidate the mechanisms behind the synergistic activity of the phytocomplex and to firmly establish the clinical efficacy of this natural product.