RETRACTED: Combination of carvacrol and rosiglitazone ameliorates high fat diet induced changes in lipids and inflammatory markers in C57BL/6J mice

Terpenes in the management of chronic kidney disease

Chronic kidney disease (CKD) is a chronic and progressive systemic condition that characterizes irreversible alterations in the kidneys' function and structure over an extended period, spanning months to years. CKD is the one of the major causes of mortality worldwide. However, very limited treatment options are available in the market for management of the CKD. Diabetes and hypertension are the key risk factors for the progression of CKD. It is majorly characterised by glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Plants are considered safe and effective in treating various chronic conditions. A diverse group of phytoconstituents, including polyphenols, flavonoids, alkaloids, tannins, saponins, and terpenes, have found significant benefits in managing chronic ailments. Terpenes constitute a diverse group of plant compounds with various therapeutic benefits. Evidence-based pharmacological studies underscore the crucial role played by terpenes in preventing and managing CKD. These substances demonstrate the capacity to hinder detrimental pathways, such as oxidative stress, inflammation and fibrosis, thereby demonstrating benefit in renal dysfunction. This review offers a comprehensive overview of the roles and positive attributes of commonly occurring terpenes in managing the causes and risk factors of CKD and the associated conditions.

Use of Monoterpenes as Potential Therapeutics in Diabetes Mellitus: A Prospective Review

Monoterpenes are secondary metabolites of plants belonging to the terpenoid class of natural products. They are the most abundant components of essential oils that are generally considered to have various pharmacological properties. These compounds are reported to have antidiabetic effects in recent years. Due to nature's complex biosynthetic machinery, they also exhibit a reasonable degree of structural complexity/diversity for further analysis in structure-activity studies. Therefore, monoterpenes as antidiabetic agents have been investigated by recent in vitro and in vivo studies extensively reported in the scientific literature and claimed by patent documents. The purpose of this survey is to provide a comprehensive and prospective review concerning the potential applications of monoterpenes in the treatment of diabetes. The data for this research were collected through the specialized databases PubMed, Scopus, Web of Science, and ScienceDirect between the years 2014 and 2022, as well as the patent databases EPO, WIPO, and USPTO. The research used 76 articles published in the leading journals in the field. The main effect observed was the antidiabetic activity of monoterpenes. This review showed that monoterpenes can be considered promising agents for prevention and/or treatment of diabetes as well as have a marked pharmaceutical potential for the development of bioproducts for therapeutics applications.

Therapeutic application of carvacrol: A comprehensive review

Carvacrol is a major natural constituent and is significantly present as an essential oil in aromatic plants and is well known for its numerous biological activities. Therapeutic properties of carvacrol have been demonstrated as anti-oxidant, anticancer, diabetes prevention, cardioprotective, anti-obesity, hepatoprotective and reproductive role, antiaging, antimicrobial, and immunomodulatory properties. The carvacrol biosynthesis has been mediated through mevalonate pathway. Carvacrol has the anticancer ability against malignant cells via decreasing the expressions of matrix metalloprotease 2 and 9, inducing apoptosis, enhancing the expression of pro-apoptotic proteins, disrupting mitochondrial membrane, suppressing extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase signal transduction, and also decreasing the phosphoinositide 3-kinase/protein kinase B. It also decreased the concentrations of alanine aminotransferase, alkaline phosphatase and aspartate aminotransferase, and gamma-glutamyl transpeptidase as well as also restored liver function, insulin level, and plasma glucose level. Carvacrol also has been found to exert antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Coagulase-negative staphylococcus, Salmonella spp., Enterococcus sp. Shigella, and Escherichia coli. The current review article summarizes the health-promoting perspectives of carvacrol through various pathways.

The Role of Essential Oils and Their Main Compounds in the Management of Cardiovascular Disease Risk Factors

Cardiovascular diseases (CVDs) are a global health burden that greatly impact patient quality of life and account for a huge number of deaths worldwide. Despite current therapies, several side effects have been reported that compromise patient adherence; thus, affecting therapeutic benefits. In this context, plant metabolites, namely volatile extracts and compounds, have emerged as promising therapeutic agents. Indeed, these compounds, in addition to having beneficial bioactivities, are generally more amenable and present less side effects, allowing better patient tolerance. The present review is an updated compilation of the studies carried out in the last 20 years on the beneficial potential of essential oils, and their compounds, against major risk factors of CVDs. Overall, these metabolites show beneficial potential through a direct effect on these risk factors, namely hypertension, dyslipidemia and diabetes, or by acting on related targets, or exerting general cellular protection. In general, monoterpenic compounds are the most studied regarding hypotensive and anti-dyslipidemic/antidiabetic properties, whereas phenylpropanoids are very effective at avoiding platelet aggregation. Despite the number of studies performed, clinical trials are sparse and several aspects related to essential oil’s features, namely volatility and chemical variability, need to be considered in order to guarantee their efficacy in a clinical setting.

Investigating the effects of carvacrol in rats using oxygen-induced retinopathy model

Purpose:

Investigating the effects of intraperitoneal carvacrol administration in rats using the oxygen-induced retinopathy (OIR) model.

Methods:

A total of 28 newborn Sprague Dawley rats were used and the OIR model was created using the 50/10% oxygen model. The study composed of four groups in total. While the OIR model was not used in Group I (control group), it was created for Groups II, III, and IV. About 0.01 mL carvacrol, bevacizumab, or 0.9% NaCl was administered intraperitoneal (IP) to the rats in all groups on postnatal day (PND) 14 as follows: Group I and Group II were administered 0.9% NaCl, Group III was administered bevacizumab, and Group IV was administered carvacrol. On PND 18, rats were sacrificed and their right eyes were enucleated.

Results:

Histopathological and immunohistochemical studies showed that the number of vascular endothelial cells (VECs), vascular endothelial growth factor (VEGF), and tumor necrosis factor-α (TNF-α) decreased similarly in Group III and Group IV compared with Group II. VECs values for Group I, Group II, Group III, and Group IV were measured as 0 ± 0, 26.45 ± 4.57, 7.75 ± 1.98, and 5.78 ± 1.72, respectively, and it differed significantly between groups (P < 0.001). Likewise, VEGF levels were observed as 0.06 ± 0.01, 3.31 ± 0.53, 2.47 ± 0.44, and 2.49 ± 0.52, respectively, and it differed significantly between groups (P < 0.001). TNF-α levels were recorded as 0.06 ± 0.01, 3.58 ± 0.38, 2.46 ± 0.49, and 2.29 ± 0.25, respectively, and it differed significantly between groups (P < 0.001). VECs, VEGF, and TNF-α were similar between Group III and IV (range of P values were 0.486–0.998).

Conclusion:

The study demonstrated that carvacrol significantly reduced retinal pathological angiogenesis, NV, VEC nuclei count, VEGF, and TNF-α levels. Moreover, the observed effects were comparable to those of bevacizumab.

Anti-atherosclerotic Effects of Spice-Derived Phytochemicals

Cardiovascular diseases are the leading cause of death in the world. Atherosclerosis is characterized by oxidized lipid deposition and inflammation in the arterial wall and represents a significant problem in public health and medicine. Some dietary spices have been widely used in many countries; however, the mechanism of their action as it relates to the prevention and treatment of atherosclerosis is still poorly understood. In this review, we focus on the properties of various spice-derived active ingredients used in the prevention and treatment of atherosclerosis, as well as associated atherosclerotic risk factors. We provide a summary of the mechanisms of action, epidemiological analyses, and studies of various components of spice used in the clinic, animal models, and cell lines related to atherosclerosis. Most notably, we focused on mechanisms of action by which these spice-derived compounds elicit their lipid-lowering, anti-inflammatory, antioxidant, and immunomodulatory properties, as well as their involvement in selected biochemical and signal transduction pathways. It is suggested that future research should aim to design well-controlled clinical trials and more thoroughly investigate the role of spices and their active components in the prevention/treatment of atherosclerosis. Based on this literature review, it appears that spices and their active components are well tolerated and have few adverse side effects and, therefore, provide a promising adjunctive treatment strategy for patients with atherosclerosis.

Effect of long-term treatment of Carvacrol on glucose metabolism in Streptozotocin-induced diabetic mice

BACKGROUND

Carvacrol is a food additive with various bioactivities, including reducing the blood glucose level as well as improvement of heart function, in diabetic mice. We explored the antihyperglycemic effect of carvacrol and its effect on the key hepatic enzymes accounting for glucose metabolism.

METHODS

A streptozotocin (STZ)-induced diabetes-mellitus model in mice was used. Mice were divided randomly into a control group, diabetic group, low dose carvacrol-treated diabetic group (10 mg/kg body weight [BW]), and high dose carvacrol-treated diabetic group (20 mg/kg BW). Carvacrol was injected intraperitoneally (i.p.) in each carvacrol-treated group daily for 4 weeks and 6 weeks, respectively. The level of random plasma glucose, fasting plasma glucose, and plasma insulin was determined at 4 weeks and 6 weeks after carvacrol administration. The plasma level of total cholesterol (TC), triglycerides (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and the activity of hepatic key enzymes related to glucose metabolism were determined.

RESULTS

Carvacrol treatment decreased the levels of random plasma glucose and fasting plasma glucose, significantly in a dose-dependent manner. A significant improvement in glucose tolerance and a significant decrease in the plasma level of TG were observed in carvacrol-treated diabetic mice at a dose of 20 mg/kg BW compared with that in vehicle-treated diabetic mice. There was no significant difference in the plasma level of TC and insulin between vehicle-treated diabetic mice and carvacrol-treated diabetic mice. Carvacrol treatment at a dose of 20 mg/kg BW significantly reduced the plasma level of LDH but not AST, ALT, or ALP, compared with that in the vehicle-treated diabetic group. The activity of hexokinase (HK), 6-phosphofructokinase (PFK), and citrate synthetase (CS) was increased by carvacrol treatment in diabetic mice.

CONCLUSIONS

Carvacrol exerted an anti-hyperglycemic effect in STZ-induced diabetic mice. This was achieved through regulating glucose metabolism by increasing the activity of the hepatic enzymes HK, PFK, and CS.

Antidiabetic Potential of Monoterpenes: A Case of Small Molecules Punching above Their Weight

Monoterpenes belong to the terpenoids class of natural products and are bio-synthesized through the mevalonic acid pathway. Their small molecular weight coupled with high non-polar nature make them the most abundant components of essential oils which are often considered to have some general antioxidant and antimicrobial effects at fairly high concentrations. These compounds are however reported to have antidiabetic effects in recent years. Thanks to the ingenious biosynthetic machinery of nature, they also display a fair degree of structural complexity/diversity for further consideration in structure-activity studies. In the present communication, the merit of monoterpenes as antidiabetic agents is scrutinized by assessing recent in vitro and in vivo studies reported in the scientific literature. Both the aglycones and glycosides of these compounds of rather small structural size appear to display antidiabetic along with antiobesity and lipid lowering effects. The diversity of these effects vis-à-vis their structures and mechanisms of actions are discussed. Some key pharmacological targets include the insulin signaling pathways and/or the associated PI3K-AKT (protein kinase B), peroxisome proliferator activated receptor-γ (PPARγ), glucose transporter-4 (GLUT4) and adenosine monophosphate-activated protein kinase (AMPK) pathways; proinflammatory cytokines and the NF-κB pathway; glycogenolysis and gluconeogenesis in the liver; glucagon-like-1 receptor (GLP-1R); among others.