Beneficial Effects of Carvacrol on In Vitro Models of Metabolically-Associated Liver Steatosis and Endothelial Dysfunction: A Role for Fatty Acids in Interfering with Carvacrol Binding to Serum Albumin

Formation of PEG-PLGA Microspheres for Controlled Release of Simvastatin and Carvacrol: Enhanced Lipid-Lowering Efficacy and Improved Patient Compliance in Hyperlipidemia Therapy

Polymer-based drug-controlled release systems offer greater efficacy and potency than conventional therapies. However, prominent drug side effects, lower circulation, and low drug loading capabilities limit their application range. In this work, the combination of Simvastatin (SIV) and Carvacrol (CAV) into PEG-PLGA microspheres (SIV-CAV-PP-MS) was achieved via an emulsification-solvent evaporation technique, resulting in microspheres characterized by high encapsulation efficiency and reduced particle size. In vitro studies demonstrated that the cumulative drug release increased with higher SIV and CAV levels in the release medium, reaching 88.91% and 89.35% at 25 days. Pharmacokinetic analysis revealed that the concentrations of SIV and CAV reached their maximum levels at approximately seven days in the SIV-CAV-PP-MS group, which indicates that using PEG-PLGA as a carrier significantly delays drug release. In vivo, evaluation demonstrated that the SIV-CAV-PP-MS high-dose group and positive drug control group showed reductions in low-density lipoprotein cholesterol levels by 0.39-fold and 0.36-fold compared to the Hyperlipidemia model group, and the addition of CAV significantly enhanced the lipid-lowering effects of SIV. Histological examinations indicated that the SIV-CAV-PP-MS medium-dose group displayed histological features more closely resembling those of normal mice compared to the Simvastatin control group, with a well-organized hepatocyte structure, a significant reduction in lipids, and improved liver health. The prepared polymeric microsphere utilizing SIV and SAV will be a promising dosage form for hyperlipidemia disease patients, with superior lipid-lowering efficacy and improved patient compliance.

Unraveling the metabolic activities of bioactive compounds on cellular models of hepatosteatosis and adipogenesis through docking analysis with PPARs

Obesity is associated with fatty liver disease. Available therapies show modest efficacy, and nutraceuticals with good effectiveness and safety are largely investigated. We focused on five natural compounds, three plant phenolic compounds (carvacrol, rosmarinic acid, silybin), and two thyroid hormones (T2: 3,5-diiodo-l-thyronine; T3: 3,5,3'-triiodo-L-thyronine) as comparison, to assess their beneficial effects on two cellular models of hepatosteatosis and adipogenesis. All compounds ameliorated the lipid accumulation and oxidative stress in both models, but with different potencies. The peroxisome proliferator-activated receptors (PPARs) are pivotal controllers of adipogenesis and lipid metabolism. For the main isoforms, PPARγ and PPARa, we assessed their possible binding to the compounds by molecular docking calculations, and their expression pattern by real-time PCR. All compounds bind both PPARs with different affinity, while not all compounds affect their expression. The results may clarify the distinctive molecular mechanisms underlying the action of the five compounds in the different cell models with possible applications to treat obesity.

Protective effects of carvacrol on lipid profiles, oxidative stress, hypertension, and cardiac dysfunction - A comprehensive review

Cardiovascular diseases (CVDs) are a class of illnesses that affect the heart or blood vessels, leading to the most common causes of death worldwide. In 2017, CVD caused approximately 17.8 million deaths that were increased approximately to 20.5 million deaths in 2021, globally. Also, nearly 80% of worldwide CVD deaths occur in some countries. Some herbs and their constituents due to their several pharmacological activities have been used for medicinal purposes. Carvacrol is a phenolic mono-terpenoid found in the oils of aromatic herbs with several biological properties. The possible therapeutic effects of carvacrol on lipid profiles, oxidative stress, hypertension, and cardiac dysfunction were summarized in the current study. The data from this review article were obtained by searching the terms including; "Carvacrol", "Hypertension", Hypotensive, "Cardiac dysfunction", "Ischemia", "Lipid profile", and Oxidative stress in several web databases such as Web of Sciences, PubMed Central, and Google Scholar, until November 2023. The results of the reviewed studies revealed that carvacrol inhibits acetylcholinesterase (AchE) activity and alters lipid profiles, reducing heart rate as well as systolic and diastolic blood pressure (BP). Carvacrol also decreased the proinflammatory cytokine (IL-1β), while increasing secretion of anti-inflammatory cytokine (IL-10). Moreover, carvacrol improved oxidative stress and mitigated the number of apoptotic cells. The pharmacological effects of carvacrol on CVD might be through its antioxidative, anti-inflammatory, and antiapoptotic effects. The mentioned therapeutic effects of carvacrol on lipid profile, hypertension, and cardiac dysfunction indicate the possible remedy effect of carvacrol for the treatment of CVD.

Nutritional and Physiological Properties of Thymbra spicata: In Vitro Study Using Fecal Fermentation and Intestinal Integrity Models

(Poly)phenolic-rich Mediterranean plants such as Thymbra spicata have been associated with several health-promoting effects. The nutritional value, as well as physiological interaction of T. spicata with the gastrointestinal tract, has not been investigated before. The nutritional composition of T. spicata leaves was here characterized by standard analytical methods. T. spicata leaves were subjected to ethanolic extraction, simulated gastrointestinal digestion, and anaerobic microbial gut fermentation. Phenols/flavonoid contents and radical scavenging activity were assessed by colorimetric methods. The volatile organic compounds (VOCs) were detected by gas chromatography coupled with mass spectrometry. The effect on intestinal integrity was evaluated using a Caco-2 monolayers mounted in a Ussing chamber. T. spicata contains a high amount of fiber (12.3%) and unsaturated fatty acids (76% of total fat). A positive change in VOCs including short-chain fatty acids was observed without significant change in viable microbe. T. spicata and carvacrol (main phenolic compound) enhanced ionic currents in a concentration-dependent manner without compromising the Caco-2 monolayer's integrity. These effects were partially lost upon simulated digestion and completely abolished after colonic fermentation in line with polyphenols and carvacrol content. Conclusion: T. spicata represents a promising nutrient for the modulation of gut microbiota and the gut barrier. Further studies must better define its mechanisms of action.

Hepatoprotective effect of Artemisia Argyi essential oil on bisphenol A-induced hepatotoxicity via inhibition of ferroptosis in mice

The environmental pollutant bisphenol A (BPA), used in the manufacture of plastic packaging materials for various diets, is widely distributed in the environment and causes severe hepatotoxicity by inducing oxidative stress. Artemisia argyi essential oil (AAEO), a volatile oil component isolated from Artemisia argyi H.Lév. & Vaniot, has pharmacological effects, especially for hepatoprotective actions. However, the potential effect of AAEO in BPA induced hepatotoxicity has not been characterized. First, we analyzed the chemical composition in AAEO by gas chromatography-mass spectrometry. Herein, we investigated the effect of AAEO on hepatic metabolic changes in mice exposed to BPA. Results showed that compared with the BPA group, AAEO could reduce the level of liver function enzymes in BPA mice serum, and ameliorate hepatic lesions and fibrosis. Additionally, 20 differential metabolites screened by metabolomics were mainly involved in the reprogramming of glutathione metabolism, purine metabolism, and polyunsaturated fatty acid synthesis. Moreover, AAEO could reduce hepatic ferroptosis induced by BPA, as demonstrated by reducing xanthine oxidase activity, up-regulating the activities of glutathione peroxidase 4 (GPX4), superoxide dismutase, and catalase and the expression of SLC7A11 to promote the glutathione synthetic, while inhibiting transferrin receptor 1 (TFR1) expression to reduce the accumulation of Fe2+ in cells. Therefore, our study identified AAEO as a hepatic protectant against BPA-induced hepatotoxicity by reversing the occurrence of ferroptosis.

Adipocyte-hepatocyte crosstalk in cellular models of obesity: Role of soluble factors

Hepatic steatosis is often a consequence of obesity. Adipose tissue is an important endocrine regulator of metabolic homeostasis in the body. In obesity, adipocytes become hypertrophic and develop an inflammatory phenotype, altering the panel of secreted adipokines. Moreover, excess fatty acids are, in part, released by adipocytes and delivered to the liver. These multiple pathways of adipose-liver crosstalk contribute to the development and progression of liver disease: TNFα induces hepatocyte dysfunction, excess of circulating fatty acids promotes hepatic steatosis and inflammation, whilst adipokines mediate and exacerbate liver injury. In this study, we investigated in vitro the effects and mechanisms of the crosstalk between adipocytes and hepatocytes, as a function of the different adipocyte status (mature vs hypertrophic) being mediated by soluble factors. We employed the conditioned medium method to test how mature and hypertrophic adipocytes distinctively affect the liver, leading to metabolic dysfunction. The media collected from adipocytes were characterized by high triglyceride content and led to lipid accumulation and fat-dependent dysfunction in hepatocytes. The present findings seem to suggest that, in addition to triglycerides, other soluble mediators, cytokines, are released by mature and hypertrophic adipocytes and influence the metabolic status of liver cells. Understanding the precise factors involved in the pathogenesis and pathophysiology of NAFLD in obesity will provide important insights into the mechanisms responsible for the metabolic complications of obesity, paving the way for new possible approaches.