Target molecules in 3T3-L1 adipocytes differentiation are regulated by maslinic acid, a natural triterpene from Olea europaea

A Nutrigenetic Strategy for Reducing Blood Lipids and Low-Grade Inflammation in Adults with Obesity and Overweight

The pathogenesis of obesity and dyslipidemia involves genetic factors, such as polymorphisms related to lipid metabolism alterations predisposing their development. This study aimed to evaluate the effect of a nutrigenetic intervention on the blood lipid levels, body composition, and inflammation markers of adults with obesity and overweight. Eleven genetic variants associated with dyslipidemias in Mexicans were selected, and specific nutrigenetic recommendations for these polymorphisms were found. One hundred and one adults were recruited and assigned to follow either a standard or nutrigenetic diet for eight weeks. Anthropometric, biochemical, body composition, and inflammation markers were evaluated through standardized methods. Weighted genetic risk scores (wGRSs) were computed using the study polymorphisms. After intervention, both diets significantly decreased the anthropometric parameters and body composition (p < 0.05). Only the nutrigenetic diet group showed significant reductions in VLDL-c (p = 0.001), triglycerides (p = 0.002), TG:HDL (p = 0.002), IL-6 (p = 0.002), and TNF-α (p = 0.04). wGRSs had a high impact on the ΔTGs and ΔVLDL-c of both groups (standard diet: ΔTGs: Adj R2 = 0.69, p = 0.03; ΔVLDL-c: Adj R2 = 0.71, p = 0.02; nutrigenetic diet: ΔTGs: Adj R2 = 0.49, p = 0.03 and ΔVLDL-c: R2 = 0.29, p = 0.04). This nutrigenetic intervention improved lipid abnormalities in patients with excessive body weight. Hence, nutrigenetic strategies could be coadjuvant tools and enhance the standard dietary treatment for cardiometabolic diseases.

Analysis of the Mechanism of Maslinic Acid on Papillary Thyroid Carcinoma Based on RNA-Seq Technology

Objective

This study analyzed gene sequence changes in the thyroid papillary carcinoma (PTC) cell line TPC-1 treated with the natural compound maslinic acid (MA) through RNA-sequencing (RNA-seq) and identified the necessary genes to provide a basis for the study of the molecular mechanism of action of MA in PTC treatment.

Methods

RNA-seq technology was used to detect genetic differences between the normal cell group (Nthy-ori 3-1) and the TPC-1 cell group (N vs T). Then, gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Venn diagram analysis of shared genes, and protein–protein interaction (PPI) network analysis were used to analyze the therapeutic effect of the MA on TPC-1 cells. Real-time quantitative PCR (qRT-PCR) was used to verify six key genes.

Results

GO and KEGG analyses showed that four crucial signaling pathways are related to TPC development: cytoplasmic molecule (cell adhesion molecules), neuroactive ligand–receptor interaction, tumor transcriptional disorder, and cytokine–cytokine interaction. The Venn diagram revealed 434 genes were shared between the MA vs T-group and 387 genes were shared between the MATH vs T and N vs T groups. PPI and ClueGO showed that NLRP3, SERPINE1, CD74, EDN1, HMOX1, and CXCL1 genes were significantly associated with PTC, while CXCL1, HMOX1, and other factors were mainly involved in the cytokine–cytokine interaction. The qRT-PCR results showed that the expression of NLRP3, EDN1, HMOX1, and CXCL1 genes was significantly upregulated in the TPC-1 group but significantly downregulated after MA treatment (p < 0.01). SERPINE1 and CD74 genes were not expressed in TPC-1 cells, whereas they were significantly upregulated after MA treatment (p < 0.01).

Conclusions

This present study proves for the first time that MA can treat PTC, and the preliminary identification of key genes and rich signal transduction pathways provides potential biomarkers. It also provides potential biomarkers for the treatment of PTC with the natural compound MA and preliminarily discusses the therapeutic mechanism of action of MA against PTC, which is helpful for the further diagnosis and treatment of PTC patients.

A Critical Review on Role of Available Synthetic Drugs and Phytochemicals in Insulin Resistance Treatment by Targeting PTP1B

Insulin resistance (IR) is a condition of impaired response of cells towards insulin. It is marked by excessive blood glucose, dysregulated insulin signalling, altered pathways, damaged pancreatic β-cells, metabolic disorders, etc. Chronic hyperglycemic conditions leads to type 2 diabetes mellitus (T2DM) which causes excess generation of highly reactive free radicals, causing oxidative stress, further leading to development and progression of complications like vascular dysfunction, damaged cellular proteins, and DNA. One of the causes for IR is dysregulation of protein tyrosine phosphatase 1B (PTP1B). Advancements in drug therapeutics have helped people manage IR by regulating PTP1B, however have been reported to cause side effects. Therefore, there is a growing interest on usage of phytochemical constituents having IR therapeutic properties and aiding to minimize these complications. Medicinal plants have not been utilized to their full potential as a therapeutic drug due to lack of knowledge of their active and effective chemical constituents, mode of action, regulation of IR parameters, and dosage of administration. This review highlights phytochemical constituents present in medicinal plants or spices, their potential effectiveness on proteins (PTP1B) regulating IR, and reported possible mechanism of action studied on in vitro models. The study gives current knowledge and future recommendations on the above aspects and is expected to be beneficial in developing herbal drug using these phytochemical constituents, either alone or in combination, for medication of IR and diabetes.

Involvement of the PI3K/AKT Intracellular Signaling Pathway in the AntiCancer Activity of Hydroxytyrosol, a Polyphenol from Olea europaea, in Hematological Cells and Implication of HSP60 Levels in Its Anti-Inflammatory Activity

Hydroxytyrosol (HT), the main representative of polyphenols of olive oil, has been described as one of the most powerful natural antioxidants, also showing anti-inflammatory, antimicrobial, cardioprotective and anticancer activity in different type of cancers, but has been little studied in hematological neoplasms. The objective of this work was to evaluate the anticancer potential of HT in acute human leukemia T cells (Jurkat and HL60) and the anti-inflammatory potential in murine macrophages (Raw264.7). For this, cytotoxicity tests were performed for HT, showing IC₅₀ values, at 24 h, for Jurkat, HL60 and Raw264.7 cells, of 27.3 µg·mL⁻¹, 109.8 µg·mL⁻¹ and 45.7 µg·mL⁻¹, respectively. At the same time, HT caused cell arrest in G₀/G₁ phase in both Jurkat and HL60 cells by increasing G₀/G₁ phase and significantly decreasing S phase. Apoptosis and cell cycle assays revealed an antiproliferative effect of HT, decreasing the percentage of dividing cells and increasing apoptosis. Furthermore, HT inhibited the PI3K signaling pathway and, consequently, the MAPK pathway was activated. Inflammation tests revealed that HT acts as an anti-inflammatory agent, reducing NO levels in Raw264.7 cells previously stimulated by lipopolysaccharide (LPS). These processes were confirmed by the changes in the expression of the main markers of inflammation and cancer. In conclusion, HT has an anticancer and anti-inflammatory effect in the cell lines studied, which were Raw264.7, Jurkat, and HL60, and could be used as a natural drug in the treatment of liquid cancers, leukemias, myelomas and lymphomas.

Molecular Mechanisms Underlying the Effects of Olive Oil Triterpenic Acids in Obesity and Related Diseases

Dietary components exert protective effects against obesity and related metabolic and cardiovascular disturbances by interfering with the molecular pathways leading to these pathologies. Dietary biomolecules are currently promising strategies to help in the management of obesity and metabolic syndrome, which are still unmet medical issues. Olive oil, a key component of the Mediterranean diet, provides an exceptional lipid matrix highly rich in bioactive molecules. Among them, the pentacyclic triterpenic acids (i.e., oleanolic acid) have gained clinical relevance in the last decade due to their wide range of biological actions, particularly in terms of vascular function, obesity and insulin resistance. Considering the promising effects of these triterpenic compounds as nutraceuticals and components of functional foods against obesity and associated complications, the aim of our review is to decipher and discuss the main molecular mechanisms underlying these effects driven by olive oil triterpenes, in particular by oleanolic acid. Special attention is paid to their signaling and targets related to glucose and insulin homeostasis, lipid metabolism, adiposity and cardiovascular dysfunction in obesity. Our study is aimed at providing a better understanding of the impact of dietary components of olive oil in the long-term management of obesity and metabolic syndrome in humans.

Effects of Erythrodiol on the Antioxidant Response and Proteome of HepG2 Cells

Erythrodiol (EO) is a pentacyclic triterpenic alcohol found in olive tree leaves and olive oil, and it has important effects on the health properties and quality of olive oil. In this study, we characterized the cytotoxic effects of EO on human hepatocarcinoma (HepG2) cells by studying changes in cell viability, reactive oxygen species (ROS) production, antioxidant defense systems, and the proteome. The results reveal that EO markedly decreased HepG2 cell viability without changing ROS levels. The concentrations of glutathione and NADPH were significantly reduced, with selective changes in the activity of several antioxidant enzymes: glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase. Proteomic data reveal that EO led to the complete elimination or decreased abundance of 41 and 3 proteins, respectively, and the abundance of 29 proteins increased. The results of functional enrichment analysis show that important metabolic processes and the nuclear transport of mature mRNA were impaired, whereas AMP biosynthesis and cell cycle G2/M phase transition were induced. The transcription factors and miRNAs involved in this response were also identified. These potent antiproliferative effects make EO a good candidate for the further analysis of its hepatic antitumor effects in in vivo studies.

Maslinic acid activates mTORC1 and human TGR5 and induces skeletal muscle hypertrophy

Maslinic acid, a naturally occurring pentacyclic triterpene in more than 30 plants (including olives), reportedly increases human muscle mass and muscle strength; however, the underlying molecular mechanism remains unknown. C57BL/6J mice were fed a standard diet or supplemented with 0.27% maslinic acid for 4 weeks, and their skeletal muscle mass was measured. Mice that consumed maslinic acid displayed significant increases in gastrocnemius and soleus muscle mass. Cultured mouse-C2C12 skeletal muscle cells were treated with mammalian target of rapamycin complex 1 (mTORC1) or protein kinase b (Akt) inhibitor, and protein synthesis was quantified. Maslinic acid accelerated protein synthesis via mTORC1 activation independent of Akt. Furthermore, maslinic acid activated human Takeda G protein-coupled receptor 5 (TGR5) more strongly than mouse TGR5, augmenting the expression of several genes related to muscular hypertrophy. Maslinic acid activated mTORC1 and human TGR5, implying its contribution to human muscular hypertrophy through these effects.

Inhibitory effect of chloroform extracts from Citrus aurantium L. var. amara Engl. on fat accumulation

BACKGROUND

Excess lipid accumulation can accelerate the development of various metabolic diseases. Blossoms of Citrus aurantium L. var. amara Engl. (CAVA) have been reported to possess inhibitory capacities on lipid deposition. However, the constituents responsible for the observed bioactivity and the underlying mechanisms are still not clearly understood.

PURPOSE

To screen constituents from blossoms of CAVA with inhibitory effects on lipid accumulation and to explore the action mechanism.

METHODS

The chloroform (CHL) extracts are prepared from blossoms of CAVA by fractional extraction and are characterized using LC-MS assay. 3T3-L1 preadipocytes are induced with differentiation medium (DMI) and treated with CHL extracts. High fat diet (HFD)-induced obese mice are further established and administrated with CHL extracts for 12 weeks. Hematoxylin and eosin (HE) staining, Oil Red O staining, ELISA, RT-qPCR, western blot and 16S rRNA gene sequence methods are employed.

RESULTS

14 compounds are identified in CHL extracts and trigonelline hydrochloride, nobiletin and 7-demethylsuberosin are most abundant. CHL extracts treatment significantly inhibit differentiation of 3T3-L1 cells by regulating expression of preadipocyte factor-1 (Pref-1), fatty acid synthase (FAS) and CCAAT/enhancer binding protein α (C/EBPα). CHL extracts intervention also significantly attenuate features of obesity and improved plasma biochemical profiles in HFD-fed mice. HFD-triggered hepatic steatosis and epididymal adipose tissues (EATs) hypertrophy are also reversed by CHL extracts administration through enhancing antioxidant responses and modulating lipogenesis and energy expenditure-related genes and proteins. 16S rRNA gene sequence data further show that CHL extracts enhance the diversity of gut microbiota. CHL extracts at lower concentrations reduce the ratio of Firmicutes to Bacteroidetes and the abundance of Erysipelotrichaceae. CHL extracts at higher doses markedly increase the abundance of Lachnospiraceae.

CONCLUSION

These findings suggest that CHL extracts probably suppress lipid accumulation through inhibiting differentiation of 3T3-L1 cells and attenuating metabolic syndromes in HFD-fed mice.

Indole- and Pyrazole-Glycyrrhetinic Acid Derivatives as PTP1B Inhibitors: Synthesis, In Vitro and In Silico Studies

Regulating insulin and leptin levels using a protein tyrosine phosphatase 1B (PTP1B) inhibitor is an attractive strategy to treat diabetes and obesity. Glycyrrhetinic acid (GA), a triterpenoid, may weakly inhibit this enzyme. Nonetheless, semisynthetic derivatives of GA have not been developed as PTP1B inhibitors to date. Herein we describe the synthesis and evaluation of two series of indole- and N-phenylpyrazole-GA derivatives (4a-f and 5a-f). We measured their inhibitory activity and enzyme kinetics against PTP1B using p-nitrophenylphosphate (pNPP) assay. GA derivatives bearing substituted indoles or N-phenylpyrazoles fused to their A-ring showed a 50% inhibitory concentration for PTP1B in a range from 2.5 to 10.1 µM. The trifluoromethyl derivative of indole-GA (4f) exhibited non-competitive inhibition of PTP1B as well as higher potency (IC₅₀ = 2.5 µM) than that of positive controls ursolic acid (IC₅₀ = 5.6 µM), claramine (IC₅₀ = 13.7 µM) and suramin (IC₅₀ = 4.1 µM). Finally, docking and molecular dynamics simulations provided the theoretical basis for the favorable activity of the designed compounds.

Ziziphus jujuba Mill. leaf extract restrains adipogenesis by targeting PI3K/AKT signaling pathway

The escalation in the global prevalence of obesity has focused attention on finding novel approaches for its management. Ziziphus jujuba Mill. (ZJL) leaf extract is reported as a traditional remedy for diverse pathological conditions, including obesity. The present study investigated whether ZJL affects adipogenic differentiation in human adipocytes. Additionally, following metabolite profiling of the extract, apigenin (APG), betulinic acid (BA) and maslinic acid (MA) were selected for biological activity evaluation. The possible interactions between APG, BA, MA and target proteins with a central role in adipogenesis were assessed through molecular docking. The potential mechanisms of ZJL, APG, BA and MA were identified using transcriptional analysis through real-time quantitative PCR and protein abundance evaluation by Western blotting. The obtained results revealed a concentration-dependent reduction of accumulated lipids after ZJL, BA and MA application. The key adipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT-enhancer-binding protein alpha (C/EBPα) were strongly decreased at a protein level by all treatments. Moreover, the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was found to be involved in the anti-adipogenic effect of ZJL, APG and BA. Collectively, our findings indicate that ZJL and its pure compounds hampered adipocyte differentiation through PI3K/AKT inhibition. Among the selected compounds, BA exhibits the most promising anti-adipogenic activity. Furthermore, being a complex mixture of phytochemicals, the ZJL extract could be utilized as source of yet unknown bioactive leads with potential implementation in obesity management.

Natural Compounds as Metabolic Modulators of the Tumor Microenvironment

The tumor microenvironment (TME) is a heterogenous assemblage of malignant and non-malignant cells, including infiltrating immune cells and other stromal cells, together with extracellular matrix and a variety of soluble factors. This complex and dynamic milieu strongly affects tumor differentiation, progression, immune evasion, and response to therapy, thus being an important therapeutic target. The phenotypic and functional features of the various cell types present in the TME are largely dependent on their ability to adopt different metabolic programs. Hence, modulating the metabolism of the cells in the TME, and their metabolic crosstalk, has emerged as a promising strategy in the context of anticancer therapies. Natural compounds offer an attractive tool in this respect as their multiple biological activities can potentially be harnessed to ‘(re)-educate’ TME cells towards antitumoral roles. The present review discusses how natural compounds shape the metabolism of stromal cells in the TME and how this may impact tumor development and progression.

Natural products and analogs as preventive agents for metabolic syndrome via peroxisome proliferator-activated receptors: An overview

Natural products and synthetic analogs have drawn much attention as potential therapeutical drugs to treat metabolic syndrome. We reviewed the underlying mechanisms of 32 natural products and analogs with potential pharmacological effects in vitro, and especially in rodent models and/or patients, that usually act on the PPAR pathway, along with other molecular targets. Recent outstanding total syntheses or semisyntheses of these lead compounds are stated. In general, they can activate the transcriptional activity of PPARα, PPARγ, PPARα/γ, PPARβ/δ, PPARα/δ, PPARγ/δ and panPPAR as weak, partial agonists or selective PPARγ modulators (SPPARγM), which may be useful for managing obesity, type 2 diabetes (T2D), dyslipidemia and non-fatty liver disease (NAFLD). Terpenoids is the largest group of compounds that act as potential modulators on PPARs and are comprised from small lipophilic cannabinoids to lipophilic pentacyclic triterpenes and polar saponins. Shikimates-phenylpropanoids include polar heterocyclic flavonoids and phenolic compounds containing at least one C3-C6 unit and usually a double bond on the propyl chain. Quercetin (19), resveratrol (24) and curcumin (27), stand out from this group for exhibiting beneficial effects on patients. Alkaloids, the minor group of potential modulators on PPARs, include berberine (30), which has been widely explored in preclinical and clinical studies for its potential beneficial effects on T2D and dyslipidemia. However, large-scale clinical trials may be warranted for the promising compounds.

Antiproliferative and Pro-Apoptotic Effect of Uvaol in Human Hepatocarcinoma HepG2 Cells by Affecting G0/G1 Cell Cycle Arrest, ROS Production and AKT/PI3K Signaling Pathway

Natural products have a significant role in the development of new drugs, being relevant the pentacyclic triterpenes extracted from Olea europaea L. Anticancer effect of uvaol, a natural triterpene, has been scarcely studied. The aim of this study was to understand the anticancer mechanism of uvaol in the HepG2 cell line. Cytotoxicity results showed a selectivity effect of uvaol with higher influence in HepG2 than WRL68 cells used as control. Our results show that uvaol has a clear and selective anticancer activity in HepG2 cells supported by a significant anti-migratory capacity and a significant increase in the expression of HSP-60. Furthermore, the administration of this triterpene induces cell arrest in the G₀/G₁ phase, as well as an increase in the rate of cell apoptosis. These results are supported by a decrease in the expression of the anti-apoptotic protein Bcl2, an increase in the expression of the pro-apoptotic protein Bax, together with a down-regulation of the AKT/PI3K signaling pathway. A reduction in reactive oxygen species (ROS) levels in HepG2 cells was also observed. Altogether, results showed anti-proliferative and pro-apoptotic effect of uvaol on hepatocellular carcinoma, constituting an interesting challenge in the development of new treatments against this type of cancer.

Pomace Olive Oil Concentrated in Triterpenic Acids Restores Vascular Function, Glucose Tolerance and Obesity Progression in Mice

Pomace olive oil, an olive oil sub-product, is a promising source of bioactive triterpenoids such as oleanolic acid and maslinic acid. Considering the vascular actions of pomace olive oil and the potential effects of the isolated oleanolic acid on metabolic complications of obesity, this study investigates for the first time the dietary intervention with a pomace olive oil with high concentrations of the triterpenic acids (POCTA), oleanolic and maslinic acid, during diet-induced obesity in mice. The results demonstrate that obese mice, when switched to a POCTA-diet for 10 weeks, show a substantial reduction of body weight, insulin resistance, adipose tissue inflammation, and particularly, improvement of vascular function despite high caloric intake. This study reveals the potential of a functional food based on pomace olive oil and its triterpenic fraction against obesity progression. Our data also contribute to understanding the health-promoting effects attributable to the Mediterranean diet.

Influence of olive oil and its components on mesenchymal stem cell biology

Extra virgin olive oil is characterized by its high content of unsaturated fatty acid residues in triglycerides, mainly oleic acid, and the presence of bioactive and antioxidant compounds. Its consumption is associated with lower risk of suffering chronic diseases and unwanted processes linked to aging, due to the antioxidant capacity and capability of its components to modulate cellular signaling pathways. Consumption of olive oil can alter the physiology of mesenchymal stem cells (MSCs). This may explain part of the healthy effects of olive oil consumption, such as prevention of unwanted aging processes. To date, there are no specific studies on the action of olive oil on MSCs, but effects of many components of such food on cell viability and differentiation have been evaluated. The objective of this article is to review existing literature on how different compounds of extra virgin olive oil, including residues of fatty acids, vitamins, squalene, triterpenes, pigments and phenols, affect MSC maintenance and differentiation, in order to provide a better understanding of the healthy effects of this food. Interestingly, most studies have shown a positive effect of these compounds on MSCs. The collective findings support the hypothesis that at least part of the beneficial effects of extra virgin olive oil consumption on health may be mediated by its effects on MSCs.

Effects of Gambisan in overweight adults and adults with obesity: A retrospective chart review

OBJECTIVE

A retrospective chart review was conducted to explore the effect of Gambisan, a granular extract of novel herbal medicine, for short-term (≤16 weeks) weight loss in adults who are overweight and those with obesity.

METHODS

Outpatients of Kyung Hee University Korean Medicine Hospital (Seoul, Korea) who took Gambisan and underwent bioelectric impedance analysis were selected (Jan 2011 to Dec 2015); their electronic medical records and clinical charts were retrospectively reviewed. The effectiveness of Gambisan was primarily evaluated by comparing body weight (BW) at baseline and endpoint, using paired t tests; the safety of Gambisan was evaluated on the basis of adverse events (AEs) experienced by patients.

RESULTS

Two hundred five patients were included in this study. The study population exhibited a significant reduction in BW (73.69 ± 14.49 kg to 69.01 ± 13.20 kg, P < .001) as well as percentage body fat (37.38 ± 5.38% to 34.50 ± 5.83%, P < .001). Moreover, 111 (54.1%) patients achieved modest weight loss (≥5%), while 35 (17.1%) achieved ≥10% weight loss. Furthermore, Gambisan induced significant reduction of BW in all subgroups (body mass index, sex, prescribed duration, and dosage). Among 139 patients with available data, 79 (56.8%) reported loss-of-appetite. In addition, 120 (mostly mild) AEs were reported in 69 (49.6%) patients, and the most frequent AEs were nausea, palpitation, and insomnia.

DISCUSSION

Despite limitations in interpreting the results of this retrospective medical record review, Gambisan induced statistically and clinically meaningful weight loss with a tolerable level of AEs. Based on the findings of this review, further well-designed clinical trials are warranted.

Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway

Maslinic acid is a pentacyclic triterpenoid that is distributed in the peel of olives. Previous studies found that maslinic acid inhibited inflammatory response and antioxidant effects. We investigated whether maslinic acid ameliorates nonalcoholic fatty liver disease in mice with high-fat-diet (HFD)-induced obesity and evaluated the regulation of lipogenesis in hepatocytes. Male C57BL/6 mice fed a normal diet or HFD (60% fat, w/w) were tested for 16 wk. After the fourth week, mice were injected intraperitoneally with maslinic acid for 12 wk. In another experiment, HepG2 cells were treated with oleic acid to induce lipid accumulation or maslinic acid to evaluate lipogenesis. Maslinic acid significantly reduced body weight compared with HFD-fed mice. Maslinic acid reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis. Furthermore, serum glucose, leptin, and free fatty acid concentrations significantly reduced, but the serum adiponectin concentration was higher, in the maslinic acid group than in the HFD group. In liver tissue, maslinic acid suppressed transcription factors involved in lipogenesis and increased adipose triglyceride lipase. In vitro, maslinic acid decreased lipogenesis by activating AMPK. These findings suggest that maslinic acid acts against hepatic steatosis by regulating enzyme activity involved in lipogenesis, lipolysis, and fatty acid oxidation in the liver.-Liou, C.-J., Dai, Y.-W., Wang, C.-L., Fang, L.-W., Huang, W.-C. Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway.

Hypoglycemic and hypolipidemic effects of triterpenoid-enriched Jamun (Eugenia jambolana Lam.) fruit extract in streptozotocin-induced type 1 diabetic mice

The edible berries of Eugenia jambolana Lam. (known as Jamun) are consumed in various parts of the world. Our previous studies revealed that a triterpenoid-enriched Jamun fruit extract (TJFE) showed beneficial effects on glucose homeostasis in non-diabetic mice. Herein, the anti-diabetic effects of TJFE (100 mg kg-1 by oral gavage for ten days) were evaluated in streptozotocin (STZ)-induced type 1 diabetic mice. TJFE significantly attenuated STZ-induced hyperglycemia and glucose intolerance, suppressed the abnormal elevation of hepatic gluconeogenesis, and improved dyslipidemia in the mice. Histopathology and mechanism-based studies revealed that TJFE preserved the architecture and function of pancreatic islets, attenuated insulin secretion deficiency, enhanced insulin/Akt signaling transduction, reduced lipogenic gene expression, and prevented the abnormal activation of Erk MAPK in the liver tissues of the STZ-induced diabetic mice. The current study adds to previously published data supporting the potential beneficial effects of this edible fruit on diabetes management.

Maslinic acid promotes autophagy by disrupting the interaction between Bcl2 and Beclin1 in rat pheochromocytoma PC12 cells

Maslinic acid (2α, 3β-dihydroxyolean-12-en-28-oic acid, MA) was isolated from natural plants and showed anti-cancer activity in rat Pheochromocytoma PC12 cells in our previous studies. We now discover that MA disrupts the interaction between Bcl2 and autophagy scaffold protein Beclin1 in the above cell line, leading to the up-regulation of autophagy. We investigated the effect of MA on the interaction between Bcl2 and Beclin1 by biochemical and biophysical methods in combination with autophagy characterization in the above cell line. Our results suggest that MA may serve as an autophagy activator by directly blocking the Bcl2-Beclin1 interaction to release free Beclin1 required for the recruitment of autophagy positive regulators, implying MA may exert its anti-cancer activity by regulating autophagy.

The oleanolic acid derivative, 3-O-succinyl-28-O-benzyl oleanolate, induces apoptosis in B16–F10 melanoma cells via the mitochondrial apoptotic pathway

Antiproliferative and proapoptotic effects of 3-O-succinyl-28-O-benzyl oleanolate on B16–F10 skin-melanoma cells.