Oleanolic Acid Treatment Research Articles

Anticancer effects of oleanolic acid on human melanoma cells

Owing to the ineffectiveness of the currently used therapies against melanoma, there has been a shift in focus toward alternative therapies involving the use of natural compounds. This study assessed the anticancer effects of oleanolic acid (OA) and its ability to induce apoptosis in A375SM and A375P melanoma cells in vivo. Compared to the control group, viability of A375P and A375SM cells decreased following OA treatment. In OA-treated A375SM and A375P cells, 4′,6-diamidino-2-phenylindole staining showed an increase in the apoptotic body, and flow cytometry revealed increased number of apoptotic cells compared to that in the control group. OA-treated A375SM cells exhibited an increased expression of the apoptotic proteins, cleaved poly (ADP-ribose) polymerase (PARP) and B-cell lymphoma (Bcl)-2-associated X protein (Bax) as well as decreased expression of the antiapoptotic protein Bcl-2 compared to that in the control group. In OA-treated A375P cells, expression patterns of cleaved PARP and Bcl-2 were similar to those in OA-treated A375SM cells; however, no difference was reported in the expression of Bax compared to that in the control group. Additionally, OA-treated melanoma cells showed decreased expression of phospho-nuclear factor-κB (p–NF–κB), phospho-inhibitor of nuclear factor-κBα (p-IκBα), and phospho-IκB kinase αβ than that in the control group. Moreover, immunohistochemistry showed a comparatively decreased level of p–NF–κB in the OA-treated group than that in the control group. Xenograft analysis confirmed the in vivo anticancer effects of OA against A375SM cells. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay revealed an increased number of TUNEL-positive cells in the OA-treated group compared to that in the control group. In conclusion, the study results suggest that OA induces apoptosis of A375SM and A375P cells in vitro and apoptosis of A375SM cells in vivo. Furthermore, the in vitro and in vivo anticancer effects were mediated by the NF-κB pathway.

Oleanolic acid reshapes the gut microbiota and alters immune-related gene expression of intestinal epithelial cells.

Oleanolic acid (OA) is a pentacyclic triterpenoid compound that is present at high levels in olive oil and has several promising pharmacological effects, such as liver protection and anti-inflammatory, antioxidant, and anticancer effects. The purpose of the present study was to assess whether OA treatment affects gut health compared to a control condition, including gut microbiota and intestinal epithelial immunity. Illumina MiSeq sequencing (16S rRNA gene) was used to investigate the effect of OA on the microbial community of the intestinal tract, while Illumina HiSeq (RNA-seq) technology was used to investigate the regulatory effect of OA on gene expression in intestinal epithelial cells, which allowed for a comprehensive analysis of the effects of OA on intestinal health. The results showed that the consumption of OA initially controlled weight gain in mice and altered the composition of the gut microbiota. At the phylum level, OA significantly increased the relative abundances of cecum Firmicutes but decreased the abundance of Actinobacteria, and at the genus level it increased the relative abundance of potentially beneficial bacteria such as Oscillibacter and Ruminiclostridium 9. Oleanolic acid treatment also altered the expression of 12 genes involved in the Kyoto Encyclopedia of Genes and Genomes（KEGG）pathways of complement and coagulation cascades, hematopoietic cell lineage, and leukocyte transendothelial migration in intestinal epithelial cells to improve gut immunity. Intake of OA can contribute beneficial effects by optimizing gut microbiota and altering the immune function of intestinal epithelial cells, potentially to improve intestinal health status. © 2021 Society of Chemical Industry.

Effects of oleanolic acid on inflammation and metabolism in diabetic rats

ABSTRACT Diabetes mellitus (DM) is a chronic metabolic disease that threatens the health of the world population. We investigated the effects of oleanolic acid (OA) administration on inflammation status and metabolic profile in streptozotocin (STZ) induced diabetic rats. Four experimental groups were established: healthy rats not administered OA, healthy rats administered OA, diabetic rats not administered OA, diabetic rats administered OA. OA, 5 mg/kg, was administered by oral gavage for 21 days. Serum samples collected at the end of the experiment and analyzed for toll–like receptor–9, interleukin-18, nuclear factor kappa B, malondialdehyde MDA, glucose, total cholesterol, triglycerides, high–density lipoprotein, low-density lipoprotein, calcium, phosphorus, magnesium and potassium. Pancreas tissue was examined for pathology. Induction of DM caused increased serum concentrations of inflammation and oxidative damage markers. DM also caused hyperglycemia-hyperlipidemia and decreased serum concentration of minerals. The islets of Langerhans were degenerated and necrotic. Administration of OA reversed the adverse effects of DM. OA treatment can ameliorate inflammation and oxidative damage due to DM by normalizing hyperglycemia and decreasing TLR-9, IL-18, NF-κB and MDA levels.

Drug Evaluation Based on a Multi-Channel Cell Chip with a Horizontal Co-Culture.

We developed a multi-channel cell chip containing a three-dimensional (3D) scaffold for horizontal co-culture and drug toxicity screening in multi-organ culture (human glioblastoma, cervical cancer, normal liver cells, and normal lung cells). The polydimethylsiloxane (PDMS) multi-channel cell chip (PMCCC) was based on fused deposition modeling (FDM) technology. The architecture of the PMCCC was an open-type cell chip and did not require a pump or syringe. We investigated cell proliferation and cytotoxicity by conducting 3-(4,5-dimethylthiazol-2-yl)-2,5-dphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays and analysis of oleanolic acid (OA)-treated multi-channel cell chips. The results of the MTT and LDH assays showed that OA treatment in the multi-channel cell chip of four cell lines enhanced chemoresistance of cells compared with that in the 2D culture. Furthermore, we demonstrated the feasibility of the application of our multi-channel cell chip in various analysis methods through Annexin V-fluorescein isothiocyanate/propidium iodide staining, which is not used for conventional cell chips. Taken together, the results demonstrated that the PMCCC may be used as a new 3D platform because it enables simultaneous drug screening in multiple cells by single point injection and allows analysis of various biological processes.

Oleanolic Acid Modulates 25-Hydroxyvitamin D3 1-alpha-hydroxylase in Osteoblasts and Human Mesenchymal Stem Cells

Objectives: 25-Hydroxyvitamin D3 1-alpha-hydroxylase (CYP27B1) catalyzes the hydroxylation of 25-hydroxyvitamin D3 (25(OH)D3) to 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3), the bioactive form of vitamin D3. Our previous studies suggested that oleanolic acid (OA), a pentacyclic triterpenoid presents in many food and herbs, can improve circulating 1,25(OH)2D3 in ovariectomized (OVX) mice and increase CYP27B1 expression in human renal proximal tubular cells (HKC-8). However, the role of OA in regulating CYP27B1 in bone is far from clear. The present study is designed to study the effects of OA on CYP27B1 expressions and 1,25(OH)2D3 production in bone cells. Methods: The mRNA and protein expressions of CYP27B1, as well as bone metabolism markers were determined in osteoblast-like UMR-106 cells in response to treatments of parathyroid hormone (PTH) (10–7 M) or OA (10–9 - 10–5 M) for 24 hours. By using excessive 25(OH)D3 (10–6 M) as substrate, cellular production of 1,25(OH)2D3 was measured to determine CYP27B1 activity. To mimic the physiological condition, human mesenchymal stem cells (hMSCs) were pre-treated with 25(OH)D3 (10–7 M) for 12 hours, followed by OA treatment (10–9 - 10–6 M) for another 24 hours, the osteogenic effects of OA on alkaline phosphatase (ALP) activity and CYP27B1 expression were evaluated. Results: PTH (10–7 M, p<0.001) and OA (10–9 M, p<0.05) significantly upregulated mRNA and protein expressions of CYP27B1 in UMR-106 cells. 4-hour treatments of PTH (10–7 M) and OA (10–9 M) also stimulated the 1,25(OH)2D3 production by 46.02 % (p<0.001) and 17.60 % (p<0.01), respectively. Moreover, the mRNA expressions of ALP and osteocalcin (OCN) involved in osteoblast differentiation, were upregulated in response to PTH and OA in UMR-106 cells (p<0.05). The protein expression of CYP27B1 was upregulated by treatment with OA in hMSCs supplemented with 25(OH)D3 (10–8 M, p<0.05 vs. supplement alone). Furthermore, OA (10–8 M) potentiated the effects of 25(OH)D3 on osteogenesis in hMSCs by enhancing ALP activity by 47.77 % (p<0.01). Conclusions: Our results indicated that the bone anabolic effects of OA are associated with its actions to improve local bioactivation of vitamin D3 in osteoblasts and hMSCs, suggesting the involvement of paracrine or autocrine activities of 1,25(OH)2D3 in mediating the actions of OA in bone. Funding Sources: This work is supported by research studentship of Wen-Xuan Yu, The Hong Kong Polytechnic University.

Oleanolic acid inhibits cervical cancer Hela cell proliferation through modulation of the ACSL4 ferroptosis signaling pathway

Cervical cancer remains the leading cause of cancerous death among women worldwide. Oleanolic acid (OA) is a substance that occurs naturally in the leaves, fruits, and rhizomes of plants and has anti-cancer activity. In this study, tumor-bearing mice were used as the animal model and Hela cells were used as cellular model. In vivo experiments have showed that OA significantly reduced the size and mass of cervical cancer tumors in mice. In vitro experiments have showed that OA significantly reduced the viability and proliferative capacity of Hela cells. In both in vivo and in vitro assays, OA increased the oxidative stress levels and Fe2+ content, and increased the expression of ferroptosis-related proteins. We found that ACSL4 was highly expressed in both xenograft models and cervical carcinoma cells with OA treatment. Further use of siRNA to interfere with ACSL4 expression in cervical cancer cells revealed that the inhibitory effect of OA on cell viability and proliferative capacity was counteracted, while a decrease in ROS levels and GPX4 was detected, suggesting that OA activated ferroptosis in Hela cells by promoting ACSL4 expression, thereby reducing the survival rate of Hela cells. Therefore, promotion of ACSL4-dependent ferroptosis by OA may be a potential approach for the treatment of cervical cancer.

Oleanolic acid exerts neuroprotective effects in subarachnoid hemorrhage rats through SIRT1-mediated HMGB1 deacetylation

Anti-inflammatory therapy for early brain injury after subarachnoid hemorrhage is a promising treatment for improving the prognosis. HMGB1 is the initiator of early inflammation after subarachnoid hemorrhage. Oleanolic acid is a natural pentacyclic triterpenoid compound with strong anti-inflammatory activity. It can relieve early brain injury in subarachnoid hemorrhage rats, but its mechanism is not very clear. Here, we study the potential mechanism of Oleanolic acid in the treatment of subarachnoid hemorrhage. First, we demonstrated that oleanolic acid alleviated early brain injury after subarachnoid hemorrhage, including improvement of grading score, neurological score, brain edema and permeability of brain blood barrier. Then we found that oleanolic acid could inhibit the transfer of HMGB1 from nucleus to cytoplasm and reduce the level of serum HMGB1. Furthermore, we found that oleanolic acid decreased the acetylation level of HMGB1 by increasing SIRT1 expression rather than by inhibiting JAK/STAT3 pathway. SIRT1 inhibitor sirtinol eliminated all beneficial effects of oleanolic acid on subarachnoid hemorrhage, which indicated that oleanolic acid inhibited the acetylation of HMGB1 by up regulating SIRT1. In addition, oleanolic acid treatment also reduced the levels of TLR4 and apoptosis related factors and reduced neuronal apoptosis after subarachnoid hemorrhage. In summary, our findings suggest that oleanolic acid may activate SIRT1 by acting as an activator of SIRT1, thereby reducing the acetylation of HMGB1, thus playing an anti-inflammatory role to alleviate early brain injury after subarachnoid hemorrhage.

Oleanolic acid ameliorates intestinal alterations associated with EAE

BackgroundMultiple sclerosis (MS) is a chronic demyelinating autoimmune disease affecting the CNS. Recent studies have indicated that intestinal alterations play key pathogenic roles in the development of autoimmune diseases, including MS. The triterpene oleanolic acid (OA), due to its anti-inflammatory properties, has shown to beneficially influence the severity of the experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS. We herein investigate EAE-associated gut intestinal dysfunction and the effect of OA treatment.MethodsMice with MOG35–55-induced EAE were treated with OA or vehicle from immunization day and were daily analyzed for clinical deficit. We performed molecular and histological analysis in serum and intestinal tissues to measure oxidative and inflammatory responses. We used Caco-2 and HT29-MTX-E12 cells to elucidate OA in vitro effects.ResultsWe found that OA protected from EAE-induced changes in intestinal permeability and preserved the mucin-containing goblet cells along the intestinal tract.Serum levels of the markers for intestinal barrier damage iFABP and monocyte activation sCD14 were consistently and significantly reduced in OA-treated EAE mice. Beneficial OA effects also included a decrease of pro-inflammatory mediators both in serum and colonic tissue of treated-EAE mice. Moreover, the levels of some immunoregulatory cytokines, the neurotrophic factor GDNF, and the gastrointestinal hormone motilin were preserved in OA-treated EAE mice. Regarding oxidative stress, OA treatment prevented lipid peroxidation and superoxide anion accumulation in intestinal tissue, while inducing the expression of the ROS scavenger Sestrin-3. Furthermore, short-chain fatty acids (SCFA) quantification in the cecal content showed that OA reduced the high iso-valeric acid concentrations detected in EAE-mice. Lastly, using in vitro cell models which mimic the intestinal epithelium, we verified that OA protected against intestinal barrier dysfunction induced by injurious agents produced in both EAE and MS.ConclusionThese findings reveal that OA ameliorates the gut dysfunction found in EAE mice. OA normalizes the levels of gut mucosal dysfunction markers, as well as the pro- and anti-inflammatory immune bias during EAE, thus reinforcing the idea that OA is a beneficial compound for treating EAE and suggesting that OA may be an interesting candidate to be explored for the treatment of human MS.

Oleanolic acid protection against experimental autoimmune myocarditis modulates the microbiota and the intestinal barrier integrity

Abstract Background Autoimmune myocarditis is a cause of dilated cardiomyopathy and heart failure. Recent studies have indicated that leaky gut may allow environmental factors to enter the body and trigger the initiation/development of autoimmune disease. Moreover, there is a growing literature supporting that, beside myocardial fibrosis, a leaky intestinal barrier and gut dysbiosis are pathogenic factors linked to heart failure. The natural triterpene oleanolic acid (OA) has been shown to beneficially influence the severity of the experimental autoimmune myocarditis (EAM), a preclinical model of human myocarditis, via anti-oxidant and immunomodulatory mechanisms. Herein, we investigate gastrointestinal (GI) disturbances and the gut microbiota composition associated with EAM as potential therapeutic target of OA. Methods and results BALB/c mice were α-myosin-inmunized to induce EAM and treated with OA (25 mg/kg/day, i.p). On day 21, heart fibrosis and parameters related to gut damage such as oxidative stress (O2- ions, lipid peroxidation), gut permeability (D-lactate; I-FABP), inflammation and mucins were determined in serum and/or colon. Fecal microbial profiles were identified by 16S rRNA gene sequencing analysis. Firstly, histological analysis of hearts showed presence of fibrosis (Sirius Red stain) in EAM mice, whereas these effects were not detectable in myocardium from healthy or OA-treated EAM mice. In addition, OA preserved the mucin-containing goblet cells along the colon (Alcian Blue/PAS stain). Consistently, serum levels of the epithelial gut damage markers, including D-lactate and iFABP were significantly reduced in OA treated-EAM mice. The beneficial OA effects also included a decrease in the pro-inflammatory mediators sPLA2-IIA and IL-1β and a protection from the oxidative stress response (DHE stain and TBARS) in serum and colonic tissue of EAM-mice. Furthermore, gut microbiota composition showed a lower bacterial diversity and different relative abundance of certain bacterial taxa in EAM-mice compared to control mice. The families of Muribaculaceae, Lachnospiraceae, and Ruminococcaceae were significantly affected in EAM mice, and only Muribaculaceae recovered levels similar to the healthy-control group, after treatment with OA. Conclusion Our data show that in addition to the heart, the intestinal barrier and gut microbiota are altered in myocarditis, and that OA treatment could ameliorate this profile. Our data contribute to the idea that gut dysbiosis and GI dysfunction influences myocarditis pathogenesis, and provides new findings regarding the beneficial activity of OA in EAM, suggesting that it may be an interesting candidate to be explored for the treatment of human patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): MINECO, ISCIII, CIBERCV-ISCIII

Oleanolic Acid Suppressed DMBA-Induced Liver Carcinogenesis through Induction of Mitochondrial-Mediated Apoptosis and Autophagy

Phytochemicals appeared as a rich source of efficient and safe agents against many diseases like cancer. Various herbal sources are rich in oleanolic acid (OA). The scope of this study was to assess the biochemical and molecular mechanisms implicated in the ameliorative potency of OA against DMBA-induced liver carcinogenesis. Forty-eight male albino mice were assigned randomly to five groups (eight mice each) as follows: control healthy group, olive oil group, OA group, DMBA group, and DMBA with OA. Apoptosis, autophagy, inflammation, proliferation, and angiogenesis were investigated in the tissue samples. Histopathological examination was carried out as well as liver enzymes activity and other hepatic antioxidant and inflammatory biomarkers. The treatment with OA effectively suppressed the DMBA-initiated liver carcinogenesis via modulation of antioxidant status, induction of apoptosis and autophagy through modulating the expression of Caspase-3, Bcl-2 and Beclin-1, inhibiting angiogenesis (VEGF), proliferation (PCNA), and improved liver function and histological picture with a reduction in AFP level. Additionally, OA applies its antitumor effects by inhibition of proinflammatory transcription factor NF-κB and inflammatory markers (TNF-α and Cox-2) associated with DMBA administration. The present study shows that OA treatment efficiently suppressed the DMBA-initiated liver carcinogenesis through induction of mitochondrial-mediated apoptosis and autophagy and modulating inflammation.

Application of Oleanolic Acid and Its Analogues in Combating Pathogenic Bacteria In Vitro/Vivo by a Two-Pronged Strategy of β-Lactamases and Hemolysins.

The rapid spread of β-lactamase-producing bacteria in clinical practice has increasingly deteriorated the performance of β-lactam antibiotics against such resistant strains. Thus, novel agents or strategies for the war against β-lactamase-producing bacteria, especially hypervirulent resistant bacteria (such as toxin-secreting Staphylococcus aureus) carrying complex β-lactamases, are urgently needed. In this study, we found that the natural compound oleanolic acid (OA) and its analogues (especially corosolic acid (CA)) significantly inhibited the activity of important β-lactamases (NDM-1, KPC-2, and VIM-1) in Enterobacteriaceae and β-lactamases (β-lactamase N1) in S. aureus. The results showed significant synergy with β-lactams against β-lactamase-positive bacteria (fractional inhibitory concentration (FIC) index <0.5). Additionally, OA treatment significantly inhibited the activity of hemolysin from various bacteria. In the mouse infection models, the combined therapy with OA and β-lactams exhibited a significant synergistic effect in the treatment of β-lactamase-producing bacteria, as evidenced by the survival rate of S. aureus- or Escherichia coli-infected mice, which increased from 25.0 to 75.0% or from 44.4 to 61.1% (CA increased to 77.8%), respectively, compared to treatment with individual β-lactams. Although OA treatment alone led to systemic protection against S. aureus-infected mice by directly targeting α-hemolysin (Hla), a relatively better therapeutic effect was observed for the combined therapy. To the best of our knowledge, this study is the first to find effective inhibitors against resistant bacterial infections with a two-pronged strategy by simultaneously targeting resistance enzymes and toxins, which may provide a promising therapeutic strategy for drug-resistant bacterial infections.

Bioactive assessment of the antioxidative and antidiabetic activities of oleanane triterpenoid isolates of sprouted quinoa yoghurt beverages and their anti-angiogenic effects on HUVECS line

• 1 H NMR structural elucidation confirmed the isolated compounds as oleanolic acids. • Optimal antioxidative activities were observed at 24 h germination time. • OA extracts of QYB inhibited α-glucosidase and DPP-IV in a dose-dependent manner. • Germination optimized the cytotoxic effects of OA extracts of QYB. • The anti-angiogenic disruption of tubes formation was most prominent in OA of QY124. Oleanolic acid (OA), a pentacyclic triterpene was isolated from sprouted quinoa yoghurt beverage (QYB). The influence of sprouting on the antioxidative, antidiabetic and anti-angiogenic activities of the OA extracts were assessed. The results showed that all samples exhibited significant (p < 0.05) DPPH, ABTS, and FRAP antioxidant capacities. At IC 50 of 7.41%, 6.83%, and 10.46%, α-glucosidase activities of QY100, QY124, and QY172 were comparable to the control. For DPP-IV assay, QY124 (IC 50 = 12.89%) recorded the highest activity. Additionally, the viability of HUVEC s significantly (p > 0.05) reduced after OA treatment at ranges of 52.39–65.81%, 31.47–80.46%, and 22.84–43.22% in QY100, QY124 and QY172 respectively. Significant (p > 0.05) reductions in tube lengths and branches were also observed. Germination influenced the production of bioactive OA in QYB and therefore had dietary potentials of being effective against several cardiovascular-related diseases.

Oleanolic Acid Attenuates Renal Fibrosis through TGF-β/Smad Pathway in a Rat Model of Unilateral Ureteral Obstruction.

Renal fibrosis is a common final pathological process in the progression of kidney disease. Oleanolic acid is a bioactive pentacyclic triterpenoid and is widely found in medicinal herbs around the world. In this study, we explored the effect of oleanolic acid on renal fibrosis and the underlying molecular mechanisms by using a rat model of unilateral ureteral obstruction (UUO). Male Sprague-Dawley rats were orally administered with oleanolic acid (6 mg/kg/d) or vehicle (olive oil) for 21 days after the UUO surgery. Upon termination, urine and blood were collected for renal function analysis, and kidneys were harvested for pathological analysis by using hematoxylin-eosin and Masson trichrome staining. Changes of extracellular matrix mRNA expressions and TGF-β/Smad signaling in the kidneys were also determined. As a result, oleanolic acid significantly reduced the kidney index, the level of serum creatinine and blood urea nitrogen, and the urinary level of microalbumin, α1-microglobulin, and N-acetyl-β-glucosaminidase. Masson trichrome staining showed significantly less collagen deposition in the UUO rats with oleanolic acid treatment. Diminished mRNA expressions of collagen I, collagen III, fibronectin, and α-SMA in the kidney tissues were observed after the treatment. Oleanolic acid led to decreased protein expressions of TGF-β, TGF-β receptor I, and TGF-β receptor II, as well as the phosphorylation of Smad2. Our current study suggested that oleanolic acid could be a complementary and alternative therapy for renal fibrosis potentially by targeting the TGF-β/Smad pathway.

Oleanolic acid inhibits cell proliferation migration and invasion and induces SW579 thyroid cancer cell line apoptosis by targeting forkhead transcription factor A.

Oleanolic acid (OA) is a naturally occurring triterpenoid that possesses antitumor activity against several tumor cell lines. However, the potential mechanism underlying OA-induced thyroid carcinoma cell death is poorly understood. We investigated the biological functions of OA by performing migration, invasion, colony formation, and apoptosis assays on SW579 cells. Forkhead box A1 (FOXA1) expression was used to predict poor prognosis in patients with thyroid carcinoma among the TCGA samples from the UALCAN and gene expression profiling interactive analysis databases. Western blot was used to detect protein expression level. Results revealed that OA inhibited the migration, colony formation, and invasion of thyroid carcinoma cells in a dose-dependent manner. Further investigation verified that OA treatment induced significant apoptosis of thyroid carcinoma cells. Moreover, high FOXA1 expression predicted the poor prognosis of patients with thyroid cancer. The proliferation, migration, and invasion of thyroid carcinoma cells were significantly decreased when FOXA1 was silenced. OA significantly increased Akt phosphorylation and reduced FOXA1 expression in SW579 cells, but only PI3K/Akt inhibitor LY294002 attenuated OA-induced FOXA1 downregulation. Furthermore, Akt overexpression suppressed the FOXA1 expression in SW579 cells. In addition, molecular docking assay revealed that OA possessed high affinity toward FOXA1 with a low binding energy. OA may be a potential chemotherapeutic agent against thyroid carcinoma cells.

Short-Term Neonatal Oral Administration of Oleanolic Acid Protects against Fructose-Induced Oxidative Stress in the Skeletal Muscles of Suckling Rats.

Nutritional manipulations in the neonatal period are associated with the development of negative or positive health outcomes later in life. Excessive fructose consumption has been attributed to the increase in the global prevalence of metabolic syndrome (MetS) and the development of oxidative stress. Oleanolic acid (OA) has anti-diabetic and anti-obesity effects. We investigated the protective potential of orally administering OA in the neonatal period, to prevent fructose-induced oxidative stress, adverse health outcomes and maturation of the gastrointestinal tract (GIT) in suckling rats. Seven-day old Sprague-Dawley rats (N = 30) were gavaged daily with 10 mL/kg of: distilled water (DW), oleanolic acid (OA; 60 mg/kg), high fructose solution (HF; 20% w/v), or OAHF for 7 days. On day 14, tissue samples were collected to determine clinical health profiles, hepatic lipid content, and activity of anti-oxidant enzymes. Furthermore, biomarkers of oxidative stress and anti-oxidant capacity in the skeletal muscles were assessed. The gastrointestinal tract (GIT) morphometry was measured. Rats in all groups grew over the 7-day treatment period. There were no significant differences in the terminal body masses, GIT morphometry, surrogate markers of general health, liver lipid content across all treatment groups (p < 0.05). Neonatal fructose administration decreased the activity of catalase, depleted GSH and increased lipid peroxidation. However, the level of GSH and catalase activity were improved by neonatal OA treatment. Short-term oral OA administration during the critical developmental period protects against fructose-induced oxidative stress without adverse effects on health outcomes associated with MetS or precocious development of the GIT in suckling male and female rats.

Long-Term Impact of Neonatal Intake of Oleanolic Acid on the Expression of AMP-Activated Protein Kinase, Adiponectin and Inflammatory Cytokines in Rats Fed with a High Fructose Diet.

AMP-activated protein kinase (AMPK) is known to regulate both glucose and lipid metabolism, which play vital roles in the development of metabolic syndrome. One way of regulating AMPK is through hormonal activation using adiponectin. Patients diagnosed with type-2 diabetes (T2D) and obesity exhibit low adiponectin concentration levels in their blood. Moreover, studies have also shown that inflammatory processes play a significant role in the etiology of these metabolic diseases. In this study, the long-term effects of neonatal intake of oleanolic acid (OA) on the AMPK gene, genes associated with glucose transport and lipid metabolism, adiponectin levels, and inflammatory biomarkers in rats fed with a high fructose diet were investigated. Seven day old pups were randomly divided into five groups and treated as follows; 0.5% dimethylsulphoxide v/v in distilled water vehicle control (CON), oleanolic acid (OA, 60 mg/kg), high fructose diet (HF, 20% w/v), high fructose diet combined with oleanolic acid (HF+OA), and high fructose diet combined with metformin (HF+MET, 500 mg/kg). The treatments were administered once daily until day 14. The rats were then weaned at day 21 and fed standard rat chow and had ad libitum access to plain drinking water until day 112. The quantitative polymerase chain reaction (qPCR) was used to analyze the gene expressions of AMPK, Glut-4, Cpt-1, AdipoR1, AdipoR2, TNF-α, and IL-6 in the skeletal muscles. Bio-Plex Pro magnetic bead-based assay was used to measure plasma levels of inflammatory markers (TNF-α, IL-6, VEGF, and MCP-1) while ELISA kits were used to measure adiponectin concentration in blood plasma. The results obtained in this study showed that neonatal supplementation with OA significantly increased AMPK gene expression approximately ~4-fold in OA fed rats compared to those that were fed with HF alone. In addition, glut-4 gene expression was also significantly higher in the OA treatment group compared to all the other experimental groups except the CON group whereas Cpt-1 gene was more expressed when OA was administered alone. Together, these results indicated that OA can play a role in glucose and lipid metabolism gene regulation. Furthermore, the results showed that the OA group had ~1.5-fold increase in adiponectin concentration when comparedto the HF group. Moreover, HF increased levels of inflammatory cytokines, which was attenuated by neonatal administration of OA. Plasma concentration and gene expression in the skeletal muscle for TNF-α and IL-6 were significantly increased in rats that were treated with HF alone when compared to all the other groups. On the contrary, the high levels of TNF-α and IL-6 were reduced when OA was administered. These findings suggest that intake of oleanolic acid during the neonatal stage of development could be a potential strategic intervention for the long-term prevention of metabolic diseases such as T2D and obesity.

High-throughput metabolomics investigates anti-osteoporosis activity of oleanolic acid via regulating metabolic networks using ultra-performance liquid chromatography coupled with mass spectrometry

BackgroundOsteoporosis has brought about heavy socio-economic burden in the morbidity and medical expenses associated with osteoporosis treatment and various restrictions on behavior of their social roles. Oleanolic acid (OA) is an anti-osteoporosis natural product, but molecular mechanisms of therapeutic effect are not still well known. PurposeIn this study, we explore anti-osteoporosis activity of oleanolic acid and predict the underlying mechanisms by metabolomics strategy. MethodsSD rats were intraperitoneal injection with prednison for once to establish osteoporosis model. Using metabolomics strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight/ mass spectrometry (UPLC-TOF/MS), serum samples of 24 rats were analyzed to seek differential metabolites and pathway associated with OA treatment of osteoporosis. In addition, the effect of OA on osteoporosis rats was also evaluated by clinical biochemistry indicators and bone density analysis. ResultsClinical biochemistry indicators and bone density of lumbar and femur were reversed by OA treatment. A total of 25 potential biomarkers were identified in the rats model of glucocorticoid-induced osteoporosis, and oleanolic acid have a regulatory effect on 17 of them that related to some vital metabolic pathway such as linoleic acid metabolism, valine, leucine and isoleucine biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis as well as cysteine and methionine metabolism. The ingenuity pathway analysis (IPA) platform is applied to further understanding the relationship between metabolic changes and therapeutic effect of OA, which the disordered state carbohydrate metabolism, molecular transport and lipid metabolism in glucocorticoid-induced osteoporosis rats are mainly ameliorated by oleanolic acid. ConclusionMetabolomics provides a novel method to investigate the anti-osteoporosis effects of OA and probe into the potential mechanisms, and will contributes to the development of new drugs.

Oleanolic acid improves diet-induced obesity by modulating fat preference and inflammation in mice

Obesity, triggered by high-fat diet (HFD), is associated to altered gustatory perception of dietary lipids. Oleanolic acid (OLA), a triterpene, has been reported to exert anti-obesity effects in animal models. Hence, we investigated the role of OLA in the modulation of oro-sensory perception of lipids in control and HFD-induced obese mice. As expected, OLA-treated obese mice exhibited a decrease in body, liver, and visceral adipose tissue weights. OLA treatment improved glucose tolerance, insulin level, plasma lipopolysaccharide (LPS), and hepatic cholesterol and triglyceride concentrations. OLA-treated obese mice exhibited higher fat preference compared to untreated obese mice, probably due to the increase in mRNA encoding CD36, a fat taste receptor, in mouse taste bud cells (mTBC). This phenomenon was associated with fatty-acid induced increases in free intracellular calcium concentrations, [Ca2+]i, induced in mTBC from OLA-treated obese mice. OLA also influenced the expression of mRNA encoding pro-inflammatory cytokines (IL-1β and IL-6) and some lipogenic genes (PPARα, SREBP1, FAS, ChREBP, and G6Pase) in liver and adipose tissue. These findings reveal that OLA improves gustatory perception of lipids and exerts protective effects in obesity.

Lipid-lowering effects of oleanolic acid in hyperlipidemic patients

Oleanolic acid (OA) is a pentacyclic triterpenoid compound extracted from olea europaeal, a traditional Chinese medicine herb. OA has been used in the clinic as a hepatoprotective medicine in China since 1970s. In our previous study, we observed that OA could ameliorate hyperlipidemia in animal models. In the present study, we conducted a small-scale clinical trial to evaluate the hypolipidemia effect of OA in hyperlipidemic patients. Hyperlipidemic patients were administrated with OA for four weeks (4 tablets once, three times a day). The blood samples of the patients were collected before and after OA treatment. The biological parameters were measured. Furthermore, three patients' blood samples were studied with DNA microarray. After OA administration, the TC, TG, and HDLC levels in serum decreased significantly. DNA microarray analysis results showed that the expressions of 21 mRNAs were significantly changed after OA treatment. Bioinformatics analysis showed 17 mRNAs were up-regulated and 4 mRNAs were down-regulated significantly after OA treatment. Five mRNAs (CACNA1B, FCN, STEAP3, AMPH, and NR6A1) were selected to validate the expression levels by qRT-PCR. Therefore, OA administration differentially regulated the expression of genes involved in lipid metabolism. The data showed a clinical evidence that OA could improve hyperlipidemia and also unveiled a new insight into the molecular mechanisms underlying the pharmacological effect of OA on hyperlipidemia.

Oleanolic acid induces osteosarcoma cell apoptosis by inhibition of Notch signaling.

Oleanolic acid (OA), a naturally occurring triterpenoid, exhibits potential antitumor activity in several tumor cell lines. Although the inhibition effects of OA on proliferation and survival in human cancers have been confirmed, the potential mechanism underlying OA-induced osteosarcoma cell death has not yet been fully elucidated. Our results in this study showed that OA inhibits proliferation and viability of osteosarcoma cells in a dose-dependent manner. Flow cytometry assays revealed that apoptosis in osteosarcoma cells was significantly induced by OA treatment, while this induction was blocked by Jagged1-mediated activation of Notch signaling. Western blot analysis and a mitochondrial membrane potential assay demonstrated that OA functions through the mitochondrial apoptosis pathway. More importantly, our data revealed that OA treatment interrupted the balance between pro-apoptotic factors and anti-apoptotic factors in osteosarcoma cells by inhibition of the Notch signaling pathway. These data suggest that OA induces osteosarcoma cell apoptosis by targeting mitochondria in a Notch signaling-dependent manner. Thus, OA may be a promising drug for adjuvant chemotherapy in osteosarcoma.