Essential Oil of Pinus koraiensis Exerts Antiobesic and Hypolipidemic Activity via Inhibition of Peroxisome Proliferator-Activated Receptors Gamma Signaling

Essential Oils: Recent Advances on Their Dual Role as Food Preservatives and Nutraceuticals against the Metabolic Syndrome

Essential oils (EO) are compounds synthesized by plants as secondary products and are a complex mixture of volatile molecules. Studies have demonstrated their pharmacological activity in the prevention and treatment of metabolic syndrome (MetS). Moreover, they have been used as antimicrobial and antioxidant food additives. The first part of this review discusses the role of EO as nutraceuticals to prevent metabolic syndrome-related disorders (i.e., obesity, diabetes, and neurodegenerative diseases), showing results from in vitro and in vivo studies. Likewise, the second part describes the bioavailability and mechanisms of action of EO in preventing chronic diseases. The third part presents the application of EO as food additives, pointing out their antimicrobial and antioxidant activity in food formulations. Finally, the last part explains the stability and methods for encapsulating EO. In conclusion, EO dual role as nutraceuticals and food additives makes them excellent candidates to formulate dietary supplements and functional foods. However, further investigation is needed to understand EO interaction mechanisms with human metabolic pathways and to develop novel technological approaches to enhance EO stability in food systems to scale up these processes and, in this way, to overcome current health problems.

Investigation of Chemical Compounds and Evaluation of Toxicity, Antibacterial, and Anti-Inflammatory Activities of Three Selected Essential Oils and Their Mixtures with Moroccan Thyme Honey

Throughout history, honey has been used to treat various diseases. The present work examined and assessed the in vivo anti-inflammatory potential of Moroccan thyme honey and its association with essential oils from three selected plants: Origanum vulgare L.; Mentha spicata L.; Eucalyptus globulus L. The chemical composition of the essential oils was studied, and preliminary toxicity, in vitro anti-inflammatory, and antibacterial tests were conducted. Then the anti-inflammatory effect was determined by applying carrageenan and an experimental trauma-induced paw edema test in rats. The essential oils were rich in phytochemicals and showed significant antibacterial activity against four selected ATCC bacterial strains. The results revealed the significant anti-inflammatory potential of honey and mixtures with essential oils and indicated higher efficiency of mixtures compared to honey alone. It can be concluded that the mixtures of honey and essential oils have advantageous anti-inflammatory effects and may be used for treating different types of inflammation in humans after certain clinical trials.

A Comprehensive Review on Anti-obesity Potential of Medicinal Plants and their Bioactive Compounds

Background:

Obesity is a complex health and global epidemic issue. It is an increasing global health challenge covering significant social and economic costs. Abnormal accumulation of fat in the body may increase the health risks including diabetes, hypertension, osteoarthritis, sleep apnea, cardiovascular diseases, stroke and cancer. Synthetic drugs available on the market reported to have several side effects. Therefore, the management of obesity got to involve the traditional use of medicinal plants which helps to search the new therapeutic targets and supports the research and development of anti-obesity drugs.

Objective:

This review aim to update the data and provide a comprehensive report of currently available knowledge of medicinal plants and phyto-chemical constituents reported for their anti-obesity activity.

Methodology:

An electronic search of the periodical databases like Web of Science, Scopus, PubMed, Scielo, Niscair, ScienceDirect, Springerlink, Wiley, SciFinder and Google Scholar with information reported the period 1991-2019, was used to retrieve published data.

Results:

A comprehensive report of the present review manuscript is an attempt to list the medicinal plants with anti-obesity activity. The review focused on plant extracts, isolated chemical compounds with their mechanism of action and their preclinical experimental model, clinical studies for further scientific research.

Conclusion:

This review is the compilation of the medicinal plants and their constituents reported for the managements of obesity. The data will fascinate the researcher to initiate further research that may lead to the drug for the management of obesity and their associated secondary complications. Several herbal plants and their respective lead constituents were also screened by preclinical In-vitro and In-vivo, clinical trials and are effective in the treatment of obesity. Therefore, there is a need to develop and screen large number of plant extracts and this approach can surely be a driving force for the discovery of anti-obesity drugs from medicinal plants.

Cholesterol-lowering activity of natural mono- and sesquiterpenoid compounds in essential oils: A review and investigation of mechanisms using in silico protein-ligand docking

Mono- and sesquiterpenoids are the main chemical constituents of essential oils. Essential oils and their constituents have received increasing attention for lipid-lowering properties in both cell and animal models. Despite the chemical diversity of essential oil compounds, the effects of many of these compounds on cholesterol metabolism are highly similar. In this report, we review the literature regarding the effects of essential oils and their terpenoid constituents on cholesterol homeostasis, and explore likely mechanisms using protein-ligand docking. We identified 98 experimental and seven clinical studies on essential oils, isolated compounds, and blends; 100 of these described improvements either in blood cholesterol levels or in sterol metabolic pathways. Our review and docking analysis confirmed two likely mechanisms common to many essential oil compounds: (1) direct agonism of peroxisome-proliferator-activated receptors, and (2) direct interaction with sterol-sensing domains, motifs found in key sterol regulatory proteins including sterol regulatory element binding protein cleavage activating protein and HMG-CoA reductase. Notably, these direct interactions lead to decreased transcription and accelerated degradation of HMG-CoA reductase. Our work suggests that terpene derivatives in essential oils have cholesterol-lowering activity and could potentially work synergistically with statins, however, further high quality studies are needed to establish their clinical efficacy.

Evaluation of the Effects of Pinus koraiensis Needle Extracts on Serum Lipid and Oxidative Stress in Adults with Borderline Dyslipidemia: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial

Background. Dyslipidemia has been well-known as a common metabolic disorder contributing to cardiovascular disease. The aim of this study was to evaluate the effect of the Pinus koraiensis needle extracts (PKE) on the blood cholesterol and oxidative stress. Method. We conducted a 12-week randomized, double-blinded controlled trial to examine the effect of PKE on blood lipid profiles in adults with borderline dyslipidemia. Thirty-three eligible persons were recruited and randomly assigned into PKE (n = 20) and placebo groups (n = 13). Serum lipids including total cholesterol, low-density lipoprotein- (LDL-) cholesterol, high-density lipoprotein- (HDL-) cholesterol, very low-density lipoprotein- (VLDL-) cholesterol, and triglyceride were measured before and after trial. Serum insulin, glucose, and antioxidant indicators were also analyzed before and after trial and anthropometry and blood pressure were measured every 4 weeks. Results. After 12 weeks, PKE statically significant decreases in systolic blood pressure (p < 0.05) and waist circumference (p < 0.05) were observed. Also, VLDL-cholesterol significantly decreased (from 24.4 ± 10.0 mg/dL at baseline to 18.4 ± 4.1 mg/dL after 12 weeks) (p < 0.05) and superoxide dismutase (SOD) increased (6.12 ± 0.41 U/mL to 9.06 ± 0.62 U/mL) (p < 0.01) in PKE group. However, after adjustment with WC, VLDL-cholesterol was not significant between groups (p = 0.095) and while SOD remained significant between groups (p = 0.013). Conclusion. The results show that PKE was effective in improving the superoxide dismutase in the individuals with borderline dyslipidemia.

Ethanol extract of Pinus koraiensis leaves containing lambertianic acid exerts anti-obesity and hypolipidemic effects by activating adenosine monophosphate-activated protein kinase (AMPK)

Background

In this study, we investigated the anti-obesity and anti-hyperlipidemic mechanisms of lambertianic acid (LA) isolated from Pinus koraiensis leaves and the ethanol extract of Pinus koraiensis leaves (EPK), both in vitro and in vivo.

Methods

Differentiated 3T3L-1 cells were treated with EPK (25 or 50 μg/mL) or LA (200 μM) and analyzed by western blotting or RT-PCR. In vitro, lipid accumulation of adipocytes was observed using Oil-Red-O staining and triglyceride analysis. The contribution of AMPK to anti-obesity activity was assessed by siRNA-mediated AMPK knockdown. After AMPK silencing, expression of AMPK was observed by western blotting. To confirm the in vitro activity, an animal study was conducted by administering a normal diet, HFD, and EPK for 6 weeks. Obesity-related physiological parameters and protein levels were measured.

Results

LA induced the expression of p-AMPK and inhibited PPARγ, C/EBP α, adiponectin, FAS, SREBP-1, and HMGCR expression. EPK containing LA significantly decreased lipid accumulation and triglyceride levels in the differentiated 3 T3-L1 cells. EPK treatment suppressed the expression of adipogenic transcription factors, FABP, GPDH, and cholesterol-synthesis-related factors in the differentiated 3 T3-L1 cells. EPK increased the expression of p-AMPK. The effects of EPK were reversed on inhibiting AMPK by using AMPK siRNA and compound C. In vivo analysis showed that body weight gain, serum triglyceride, total cholesterol, LDL cholesterol and AI value in the EPK treatment group were lower than those in the HFD control group. EPK induced the expression of p-AMPK and inhibited PPARγ in liver and adipose tissue.

Conclusions

Overall, the results suggest that EPK containing LA exerts significant anti-obesity and cholesterol-lowering effects by activating AMPK.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1031-2) contains supplementary material, which is available to authorized users.

Essential oil of Pinus koraiensis inhibits cell proliferation and migration via inhibition of p21-activated kinase 1 pathway in HCT116 colorectal cancer cells

BACKGROUND

The essential oil of Pinus koraiensis (EOPK) is biologically active compound obtained from the leaves of P. koraiensis. The goal of this study was to investigate the anti-cancer mechanism of EOPK in HCT116 colorectal cancer cells.

METHODS

HCT116 cell proliferation was assessed by conducting crystal violet and BrdU assays. To assess the effects of EOPK on cell migration, we performed a wound-healing assay. Further, the contribution of PAK1 to EOPK-induced AKT and extracellular signal-regulated kinase (ERK) suppression was assessed by siRNA-mediated PAK1 knockdown. Changes to the expression and phosphorylation of PAK1 and its effectors were determined by western blotting, and changes to the actin cytoskeleton were determined by performing an immunofluorescence assay.

RESULTS

EOPK significantly decreased HCT116 cell proliferation and migration, and induced G1 arrest without affecting normal cells. Additionally, EOPK suppressed the expression of PAK1, and decreased ERK and AKT phosphorylation in HCT116 cells. Finally, EOPK suppressed β-catenin, cyclin D1, and CDK4/6 expression.

CONCLUSIONS

Our studies indicate that EOPK significantly reduced proliferation and migration of colorectal cancer cells. Furthermore, EOPK suppressed PAK1 expression in a dose-dependent manner, and this suppression of PAK1 led to inhibition of ERK, AKT, and β-catenin activities. Our findings suggest that EOPK exerts its anticancer activity via the inhibition of PAK1 expression, suggesting it may be a potent chemotherapeutic agent for colorectal cancer.