Red Yeast Rice (RYR) fermented from Monascus is a traditional fermented product with both dietary and medicinal uses and is widely used for lipid regulation. Clinically, it is utilized to lower blood lipid levels and manage hyperlipidemia. Contemporary research indicates that RYR is abundant in secondary metabolites, such as monacolin K, Monascus pigments, and γ-aminobutyric acid, which contribute to its lipid-lowering, blood sugar-reducing, anti-inflammatory, neuroprotective, and antihypertensive properties. These metabolites may play a significant role in the prevention and treatment of Alzheimer's disease (AD) through mechanisms that include cholesterol-dependent pathways, anti-neuroinflammation, antioxidant activity, neuroprotection, modulation of intestinal flora, inhibition of high-risk factors for AD, and suppression of AD-related β-amyloid peptide deposition and tau protein hyperphosphorylation. Consequently, RYR demonstrates potential for a multi-component synergistic approach to preventing and treating AD. However, current research on the use of RYR for AD prevention and treatment remains limited. This review focuses on the primary functional substances in RYR, elucidates the anti-AD effects and mechanisms of each metabolite, analyzes the advantages of its multi-component and multi-target properties, and provides a foundation for the further development of RYR.

Statins are widely regarded as the gold standard first-line treatment for hyperlipidemia, as they inhibit HMG-CoA reductase in the liver. This effectively reduces LDL cholesterol levels and reduces cardiovascular risks, such as heart attack and stroke. Simvastatin is a well-established, effective, and cost-efficient statin for lowering LDL cholesterol and reducing cardiovascular risk. However, it causes myopathy, rhabdomyolysis, myalgia, constipation, kidney failure, headache, abdominal pain, diarrhoea, nausea, and increased blood sugar levels with its use and higher doses of 80 mg/day. To address this, a liposomal simvastatin formulation with particle sizes of 150-250 nm was developed for intravenous administration. This formulation can potentially accumulate in the liver via passive targeting via the RES, thereby enhancing hepatic uptake and improving safety. The liposome was formulated using the thin-film hydration method and optimised using a central composite design. The optimized formulation's vesicle size was 204.66 ± 2.84 nm, with a PDI of 0.27 and a zeta potential of -58.11 mV, indicating uniform distribution and high stability. In-vitro drug release demonstrated controlled release of up to 92.46% over 60 h. The cellular toxicity assay showed that the optimized liposome was 10 times safer than pure simvastatin. In-vivo, the liposomal formulation significantly reduced lipid levels after administration of a 5 mg/kg dose in Triton X-100-induced hyperlipidemic rats, outperforming marketed formulations and standard drugs. Simvastatin-liposomes are safe, stable, and a more potent alternative to traditional oral simvastatin, offering improved liver targeting and a reduced toxicity profile.

Epigallocatechin gallate (EGCG) imparts distinctive health benefits and flavor to tea, and its accumulation is modulated by plant growth regulators (PGRs). However, the regulatory mechanisms of Paclobutrazol (PAC) and Lovastatin (LS) underlying EGCG biosynthesis remain uncharacterized. We integrated quantitative analysis, transcriptomics, and metabolomics to investigate the regulatory effects of exogenous PAC and LS on EGCG accumulation in tea plants and systematically elucidate the underlying molecular mechanism governing EGCG biosynthesis. The results demonstrated that exogenous PAC and LS treatments significantly elevated the accumulation of EGCG, as well as endogenous auxin and jasmonic acid (JA) contents. The variation trend of these key metabolites was highly consistent with the accumulation patterns of upstream flavonoid components, including eriodictyol, delphinidin, and epigallocatechin. Transcriptomic profiling further verified the critical involvement of auxin and JA signal transduction pathways in PGR-induced EGCG differential accumulation, and we screened a total of 14 auxin-related and 8 JA-related core signal regulatory factors. Furthermore, integrated bioinformatic analyses and antisense oligonucleotide (AsODN) functional validation experiments revealed that the core hormone signaling genes CsARF2 and CsMYC2 regulate the expression of CsSCPL16 through the transcription factor CsMYB80, and ultimately promote the conversion of epigallocatechin to EGCG and promote the accumulation of EGCG in tea plants. Collectively, the PGRs boost EGCG biosynthesis by mediating endogenous auxin and JA signal transduction. These results support the development of targeted agronomic practices to improve tea quality and lay a theoretical basis for expanding the industrial exploitation of tea bioactive constituents.

Statins, anti-hyperlipidemic drugs, are associated with skeletal muscle myopathy. New strategies to preserve muscle strength in statin-induced myopathy (SIM) are needed. This study assessed the effect of quercetin on simvastatin-induced myopathy in adult male rats, focusing on the modulation of autophagy-apoptosis crosstalk. Forty adult albino male rats were randomly divided into four groups. The control group (C) received distilled water, the quercetin group (Q) received quercetin (50 mg/kg/day, orally), the simvastatin (S) group received simvastatin (80 mg/kg/day, orally), and the quercetin + simvastatin (Q + S) group received both quercetin (50 mg/kg/day) and simvastatin (80 mg/kg/day, orally), all for 30 days. Gastrocnemius muscle contractility, muscle weight/tibial length ratio, histopathological examination, serum creatine kinase (CK) levels, oxidative stress markers, lipid profile, autophagy-related gene expression (LC3 and LAMP2), and apoptosis markers (BAX and caspase-3) were evaluated. Simvastatin induced muscle atrophy and significantly elevated serum CK levels. These changes were associated with increased oxidative stress, altered expression of autophagy-related genes (increased LC3 and decreased LAMP2), and increased expression of the apoptotic markers BAX and Caspase-3. Quercetin ameliorated these alterations by improving muscle contractility, reducing CK levels and oxidative stress, attenuating apoptosis, and modulating autophagy-related gene expression. Quercetin alleviated simvastatin-induced myopathy through its antioxidant and antiapoptotic effects and was associated with modulation of autophagy-related gene expression. These findings suggest that quercetin may represent a promising adjuvant strategy for mitigating statin-associated myopathy. Further studies evaluating autophagic flux at the protein level are warranted to clarify the underlying mechanisms.

Simvastatin is a commonly prescribed medication and a sensitive CYP3A4 substrate requiring dosage modification with CYP3A4 precipitants. Unlike other CYP3A4 substrates, grapefruit juice (GFJ) causes the largest increase in simvastatin exposure of any CYP3A4 inhibitor, leading to misunderstanding of simvastatin fraction escaping CYP3A4 metabolism in the gut (Fg, CYP3A4) and fraction metabolized by CYP3A4 in the liver (fm,CYP3A4). Simvastatin is a prodrug that is converted to the active simvastatin acid, though the mechanisms responsible for in vivo simvastatin acid formation are not well-understood. GFJ also decreases the simvastatin acid:simvastatin exposure ratio, suggesting inhibition of simvastatin acid formation. In the current work, we used a static approach to define simvastatin CYP3A4 parameters, using clinical data with index substrate midazolam; estimated simvastatin Fg,CYP3A4 and fm,CYP3A4 were ~ 0.4 and ~ 0.9, respectively. In vitro data assessing the stability of simvastatin and simvastatin acid demonstrated rapid conversion in gastric fluid that was highly pH-dependent. A simvastatin PBPK model was constructed incorporating these CYP3A4 parameters and simvastatin acid formation in stomach, intestine and plasma. The model reproduced the nonlinear pharmacokinetics of simvastatin and CYP3A4 precipitant effects, thus qualifying the model for prediction of CYP3A4-mediated interactions on both simvastatin and simvastatin acid. Simvastatin overall Fg was estimated as ~ 0.2, lower than the Fg,CYP3A4 due to additional intestinal esterase-mediated formation of simvastatin acid. The simvastatin-GFJ effect was explained by inhibition of this intestinal simvastatin acid formation, along with CYP3A4 inhibition. The unique effect of food on the simvastatin acid:simvastatin exposure ratio could also be replicated using this PBPK model.

Statins, inhibitors of 3-hydroxy-3-methylglutaryl CoA reductase, are widely prescribed lipid-lowering agents. Nevertheless, their use is occasionally associated with muscle toxicity, including rhabdomyolysis. Exercise reportedly exacerbates statin-induced muscle injury; however, the underlying mechanisms remain poorly understood. Here, we investigated the role of protein kinase C (PKC) signaling in the development of statin-induced cytotoxicity using a rhabdomyosarcoma-derived cell line (RD cells), with particular emphasis placed on the regulation of monocarboxylate transporter 4 (MCT4), a lactate transporter implicated in intracellular acidification and cytotoxic responses. Treatment with simvastatin, atorvastatin, and fluvastatin reduced RD cell viability in a concentration-dependent manner. Co-treatment with bisindolylmaleimide I (BIM), an inhibitor of PKCα, β, γ, δ, and ε, attenuated statin-induced cytotoxicity and tended to suppress simvastatin-induced MCT4 upregulation. Furthermore, co-treatment with Gö6976, a selective inhibitor of PKCα and β, did not mitigate the simvastatin-induced reduction in cell viability. Small interfering RNA-mediated knockdown of PKCδ significantly rescued simvastatin-induced cytotoxicity. Tamoxifen, a clinically available drug with PKC inhibitory activity, including against the δ isoform, attenuated simvastatin-induced cell injury, paralleling the effects of BIM. Collectively, our findings demonstrate that PKCδ contributes to statin-induced cytotoxicity in rhabdomyosarcoma cells, at least in part by regulating MCT4 expression.

Drug Combinations offer increased therapeutic efficacy and reduced toxicity compared with single agents. Understanding a drug combination's mechanisms of action (MoA) can provide important insights into therapeutic efficacy. The MoA of many FDA-approved drugs, however, often remains unclear. To decipher the underlying molecular mechanisms of drugs used alone and in combination, we investigated the combination of a statin (atorvastatin or simvastatin) plus ezetimibe using drug-treated RNA-seq transcriptome data from the human hepatocyte-like SOAT2-only-HepG2 cells and from liver biopsies of non-obese normolipidemic patients with uncomplicated cholesterol gallstone disease in the Stockholm Study. We proposed a novel Boolean logical modeling framework to simulate the MoA of a drug combination using fourteen two-variable Boolean models. Thereafter, a pattern matching approach was applied to associate drug-induced differentially expressed genes with the idealized differential expression templates derived from Boolean models. We found 1560 and 565 genes differentially expressed in at least one treatment condition in SOAT2-only-HepG2 cells and liver biopsies, respectively. Our analysis revealed both expected and novel combinatorial modes of the statins and ezetimibe. We mapped the downstream genes of each combinatorial mode to the human protein-protein interactome and obtained underlying pathways, which are important for understanding the therapeutic effects of the drug combinations. Functional enrichment and disease-association analyses of the downstream genes also provide critical insights into the additional therapeutic actions of the drugs. Our study demonstrates that drug-induced transcriptomes, integrated with the human interactome, are informative in deciphering the MoA of drug combinations using Boolean logical modeling.

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by lipotoxic hepatocellular injury, inflammation, and fibrosis, with excess hepatic cholesterol contributing to disease pathogenesis. While the SCAP-INSIG-SREBP2 pathway classically regulates cholesterol biosynthetic gene expression via sterol sensing at the endoplasmic reticulum, the epigenetic mechanisms coupling cellular sterol status to gene expression remain unclear. Here, we investigated the role of sirtuin 6 (SIRT6), a nuclear histone deacetylase, in sterol-induced feedback regulation of cholesterol biosynthetic genes in hepatocytes. In HepG2 and AML12 cells, 25-hydroxycholesterol (25-HC) reduced the expression of SREBP2 and downstream cholesterol biosynthetic genes, including HMGCR and HMGCS1. This repression was associated with SIRT6 activation, as evidenced by reduced acetylation of histone H3 lysine 9 and lysine 56. Pharmacological SIRT6 inhibition reversed the repression of cholesterol biosynthetic genes, whereas SIRT6 activators phenocopied the inhibitory effects of 25-HC on the SREBP2 pathway. Conversely, sterol depletion via lovastatin inhibited SIRT6 activity, leading to the compensatory upregulation of cholesterol biosynthetic genes. Notably, SIRT6 overexpression or pharmacological activation reversed lovastatin-induced upregulation of SREBP2 and its target genes. These findings establish SIRT6 as a sterol-responsive nuclear regulator that converts intracellular cholesterol status into epigenetic repression of the cholesterol biosynthetic program. This SIRT6-dependent pathway complements endoplasmic reticulum-based sterol sensing and provides a mechanistic insight into hepatic cholesterol dysregulation in MASH.

Background/Objectives: Obesity and its metabolic comorbidities, including dyslipidemia and non-alcoholic fatty liver disease (NAFLD), are a growing global health burden, and current pharmacotherapies have limited efficacy and notable adverse effects. The gut microbiome has emerged as a key regulator of host metabolism, and its dysregulation is implicated in obesity. This study investigated the therapeutic potential of Piper sarmentosum Roxb. aqueous extract (PSRW) on metabolic dysfunction and gut microbiota composition in a high-fat diet (HFD)-induced obese rat model. Methods: HFD-induced obese male Wistar rats received PSRW, simvastatin, or their combination for 12 weeks. Serum lipids (TC, TG, HDL, LDL), liver enzymes (AST, ALT), and renal markers were measured, and gut microbiota were profiled by 16S rRNA (V4) sequencing with PICRUSt2/KEGG functional prediction. The phenolic composition of the same extract was characterized by HPLC in a companion study. Results: PSRW did not cause weight loss but significantly lowered serum TC, AST, and ALT, with efficacy comparable to simvastatin and significantly lower TG than control, though not significantly different from HFD. Co-administration of PSRW and simvastatin produced a greater reduction in TC and liver enzymes than either agent alone. HFD shifted microbial community structure and enriched pro-inflammatory phyla such as Desulfobacterota; PSRW partially reversed these changes, suppressing obesogenic Lachnospiraceae genera while enriching beneficial microbes including Dwaynesavagella, and functionally reprogrammed taxa such as Kineothrix and Muribaculum from detrimental to protective associations. HFD enriched microbial glycosphingolipid biosynthesis, whereas the PSRW simvastatin combination uniquely enhanced glycine, serine, and threonine metabolism. Conclusions:P. sarmentosum extract ameliorates HFD-induced dyslipidemia and hepatotoxicity, and these effects are accompanied by remodeling of the composition and predicted functional capacity of the gut microbiome. Its ability to act in combination with statins highlights its potential as a candidate complementary therapy for hyperlipidemia and NAFLD.

Red yeast rice (RYR) food supplements are widely used for cholesterol management due to their monacolin content, particularly monacolin K (MK), which shares the same chemical structure as lovastatin, a compound associated with several side effects. The European Food Safety Authority (EFSA) highlighted uncertainties regarding the compositional variability, characterization of bioactive constituents, and safety of RYR products, concluding that a safe level of monacolin intake could not be established. In this study, twenty-seven commercial semi-processed RYR ingredients for food supplements manufacturing were investigated through a combined chemical and biological approach to characterize their composition and evaluate potential safety concerns. Targeted LC-MS/MS analyses revealed substantial variability in MK, monacolin hydroxy acid (MKA), and dehydromonacolin K (DMK) levels among products. Exploratory qualitative untargeted metabolomics enabled the putative annotation of multiple secondary metabolites, including azaphilones and polyketides, highlighting differences in chemical profiles. Correlation analyses indicated that DMK content was associated with pigment distribution and cytotoxic responses in human hepatocellular carcinoma cells and primary human skeletal muscle cells, whereas MK and MKA showed no significant association with toxicity under the tested conditions. Exploratory proteomic profiling suggested distinct protein-abundance patterns between RYR- and simvastatin-treated cells, providing hypothesis-generating information on functional annotations associated with these patterns. These findings emphasize the importance of comprehensive chemical characterization and quality control strategies considering both monacolins and secondary metabolites to improve the safety assessment of RYR supplements.