Oleanolic Research Articles

On the Perspective of Solid-State Fermented Olive Leaves for High-Added Value Applications

PurposeThe effect of solid-state fermentation (SSF), employing different microbial strains (single or co-cultured), to the chemical composition of olive leaves (OL) and the possible perspectives of the derived material for high added-value applications was explored.MethodsEmphasis was given on bioactives (oleuropein, OLE, hydroxytyrosol, HT, elenolic acid (EA) related compounds, maslinic (MA) and oleanolic (OA) acids). In parallel, the levels of other chemical components with nutritional/antinutritional interest for feed application and certain minerals were also measured.ResultsA gradual decrease in OLE and an EA derivative till their complete loss was found. HT progressively increased and then consumed reaching low levels. MA and OA were unaffected. A. niger resulted in the highest formation of HT (1 mg/g dw), and the lowest loss of OL antioxidant potential (13.8% at 72 h). Varying levels of protein production were observed potentially improving their nutritional value.ConclusionThe study demonstrated that fermented OL significantly altered phenolic compounds, particularly OLE and HT, and maintained triterpenic acids such as MA and OA. Despite reductions in certain phenolics, fermented OL showed improved nutritional profiles, particularly in protein content and antioxidant potential, suggesting their potential for added-value applications in various industrial sectors, including animal feed. To our knowledge this is the first time that the co-cultures selected in the present study were employed for OL SSF and that under all conditions examined the triterpentic acids MA and OA were the dominant bioactives despite some improvements in HT formationGraphical

Polymorphism of Butyl Ester of Oleanolic Acid—The Dominance of Dispersive Interactions over Electrostatic

Oleanolic (OA) and glycyrrhetinic acids (GE), as well as their derivatives, show a variety of pharmacological properties. Their crystal structures provide valuable information related to the assembly modes of these biologically active compounds. In the known-to-date crystals of OA esters, their 11-oxo derivatives, and GE ester crystals, triterpenes associate, forming different types of ribbons and layers whose construction is based mainly on van der Waals forces and weak C-H···O interactions. New crystal structures of 11-oxo OA methyl ester and the polymorph of OA butyl ester reveal an alternative aggregation mode. Supramolecular architectures consist of helical chains which are stabilized by hydrogen bonds of O-H···O type. It was found that two polymorphic forms of butyl OA ester (layered and helical) are related monotropically. In a structure of metastable form, O-H···O hydrogen bonds occur, while the thermodynamically preferred phase is governed mainly by van der Waals interactions. The intermolecular interaction energies calculated using CrystalExplorer, PIXEL, and Psi4 programs showed that even in motifs formed through O-H···O hydrogen bonds, the dispersive forces have a significant impact.

<i>Rhodococcus rhodochrous</i> IEGM 1360, an Efficient Biocatalyst of C3 Oxidative Transformation of Oleanane Triterpenoids

Abstract—The optimal conditions for C3 oxidative biotransformation of 1.0 g/L pentacyclic triterpenoids oleanolic (OA) and glycyrrhetic (GA) acids were determined using the resting cells of Rhodococcus rhodochrous IEGM 1360 from the Regional Specialised Collection of Alkanotrophic Microorganisms. Suspensions of the resting cells with OD600 2.6 in pH 8.0 buffer and OD600 2.2 in pH 6.0 buffer showed the highest catalytic activity against OA and GA, which ensured the formation of 61 and 100% of their 3-oxo derivatives, respectively. Using phase contrast, atomic force, and confocal laser scanning microscopy, an adaptive response of rhodococci to the effects of OA and GA was revealed. In silico, the apoptotic and antioxidant activities of 3-oxo-OA and 3-oxo-GA, respectively, have been assumed. In vitro, a pronounced antibacterial activity of 3-oxo-OA against Micrococcus luteus, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis was shown. The absence of toxic effects of the triterpenoids and their 3-oxo derivatives on aquatic and plant objects was demonstrated in silico and in vitro, respectively.

Methyl jasmonate enhances ursolic, oleanolic and rosmarinic acid production and sucrose induced biomass accumulation, in hairy roots of Lepechinia caulescens

BackgroundUrsolic (UA), oleanolic (OA) and rosmarinic (RA) acids are bioactive metabolites found in Lepechinia caulescens that have generated interest for their health benefits, which include antimicrobial, antioxidant, antimutagenic, gastroprotective, antidiabetic, antihypertensive and anti-inflammatory properties, among others. To date, very few attempts have been made to evaluate the potential for simultaneous production of these bioactive compounds, using a biotechnological approach. Hairy root cultures offer a biotechnology approach that can be used to study the factors affecting the biosynthesis and the production of UA, OA and RA. In the current study, we established hairy root cultures of L. caulescens and evaluated the effect of sucrose on biomass accumulation, and the effect of different concentrations and times of exposure of methyl jasmonate (MeJA), on the accumulation of UA, OA and RA.MethodsLeaves from plants of L. caulescens were inoculated with Agrobacterium rhizogenes strain ATCC 15834. PCR of rolB gene confirmed the transgenic nature of hairy roots. Hairy roots were subcultured in semisolid MSB5 medium, supplemented with 15, 30, 45 or 60 g/L sucrose and after 4 weeks, dry weight was determined. The accumulation of UA, OA and RA of wild plants and hairy roots were determined by HPLC. Finally, the hairy roots were treated with 0, 100, 200 and 300 µM of MeJA and the content of bioactive compounds was analyzed, after 24, 48 and 72 h.ResultsHigh frequency transformation (75%) was achieved, using leaf explants from axenic seedlings, infected with A. rhizogenes. The hairy roots showed an enhanced linear biomass accumulation, in response to the increase in sucrose concentration. The hairy root cultures in MSB5 medium, supplemented with 45 g/L sucrose, were capable to synthesizing UA (0.29 ± 0.00 mg/g DW), OA (0.57 ± 0.00 mg/g DW) and RA (41.66 ± 0.31 mg/g DW), about two, seven and three times more, respectively, than in roots from wild plants. Elicitation time and concentration of MeJA resulted in significant enhancement in the production of UA, OA and RA, with treatments elicited for 24 h, with a concentration of 300 µM of MeJA, exhibiting greatest accumulation.ConclusionThis is the first report on development of hairy root cultures of L. caulescens. Future studies should aim towards further improving triterpenes and polyphenolic compound production in hairy roots of L. caulescens, for use in the pharmaceutical and biotechnological industry.

Same analytical method for both (bio)assay and zone isolation to identify/quantify bioactive compounds by quantitative nuclear magnetic resonance spectroscopy

Differing sensitivity is the main obstacle for a direct combination of HPTLC with NMR spectroscopy. A sufficient amount of the isolated compound zone must be provided by HPTLC for subsequent offline NMR detection (HPTLC//NMR). To fill the gap, a straightforward procedure was developed using the same analytical HPTLC system for both bioprofiling and isolation of bioactive zones from multicomponent mixtures. The HPTLC-effect-directed analysis (EDA) revealed several bioactive compounds in five botanical extracts, i.e. Salvia officinalis, Thymus vulgaris and Origanum vulgare, all Lamiaceae, and peels of red and green apples (Jonagored and Granny Smith, respectively), both Rosaceae. A tricky case study was designed to show how to deal with potentially coeluting bioactive structural isomers, e.g., ursolic (UA), oleanolic (OA) and betulinic acids (all C30H48O3), which are most difficult to identify and assign. A multipotent bioactive HPTLC zone showed the same hRF value and mass signal in HPTLCHRMS, though containing the coeluting structural isomers UA and OA. After zone isolation from the HPTLC plate, first the 1H NMR spectrum allowed to distinguish distinct allylic H-18 protons, i.e. 2.20ppm for UA and 2.85ppm for OA, and at the same time, to quantify the two isomers by using the PUlse Length-based CONcentration methodology (HPTLC//1H qNMR-PULCON). In case of a partial overlap of the diagnostic signal with that of the matrix, results were corroborated with those obtained by using the 1H deconvoluted or 2D 1H-13C Heteronuclear Single Quantum Coherence spectra. The comparison of the quantitative results showed a good correlation (R2=0.9718) between the two orthogonal methods HPTLC-Vis and HPTLC//1H qNMR-PULCON. A sufficient zone isolation from the HPTLC plate (mean isolation rate of 82%) for both UA and OA (0.27 - 4.67mM) was achieved for HPTLC//qNMR, comparing the isolated bioactive compound zone with the respective zone in the botanical extract via HPTLC-Vis densitometry. The HPTLC-EDA-Vis//1H qNMR-PULCON procedure for bioprofiling and quantification/identification/confirmation of bioactive compounds in botanical extracts is considered as straightforward, eco-friendly (only 16mL solvent required), simple (NMR calibration used over weeks) and reliable new alternative to the status quo of bioactivity-guided fractionation.

Pharmacokinetics of maslinic and oleanolic acids from olive oil – Effects on endothelial function in healthy adults. A randomized, controlled, dose–response study

To date, pharmacokinetics of maslinic (MA) and oleanolic (OA) acids, at normal dietary intakes in humans, have not been evaluated, and data concerning their bioactive effects are scarce. We assessed MA and OA pharmacokinetics after ingestion of olive oils (OOs) with high and low triterpenic acid contents, and specifically the effect of triterpenes on endothelial function. We performed a double-blind, dose–response, randomized, cross-over nutritional intervention in healthy adults, and observed that MA and OA increased in biological fluids in a dose-dependent manner. MA bioavailability was greater than that of OA, and consumption of pentacyclic triterpenes was associated with improved endothelial function. To the best of our knowledge, this is the first time MA pharmacokinetics, and effects on endothelial function in vivo, have been reported in humans.

Lipophilic extracts from leaves, inflorescences and fruits of Prunus padus L. as potential sources of corosolic, ursolic and oleanolic acids with anti-inflammatory activity

Chloroform extracts from leaves, inflorescences and fruits of Prunus padus were analysed for anti-inflammatory activity and accumulation of corosolic (CA), ursolic (UA) and oleanolic (OA) acids. The analytes were identified and quantified by GC-MS and UHPLC-PDA. Their total levels depend on plant material type and harvesting time, and varied from 0.25 mg/g DW in fruits, through 0.76–1.09 mg/g DW in flowers, to 1.41–4.54 mg/g DW in leaves. Significant variation in the leaf analytes contents was observed during vegetation with the peak amounts in autumn, which indicated the optimal harvesting season. The plant extracts inhibited pro-inflammatory enzymes (lipoxygenase and hyaluronidase) in a concentration-dependent manner, and their activity parameters correlated with the levels and activity of pure triterpene acids, especially CA and UA. The results of the comparison with the positive controls (heparin, indomethacin, dexamethasone) might partly support the application of P. padus in anti-inflammatory therapies, reported by traditional medicine.

In Vitro Cytotoxicity of Oleanolic/Ursolic Acids-Loaded in PLGA Nanoparticles in Different Cell Lines.

Oleanolic (OA) and ursolic (UA) acids are recognized triterpenoids with anti-cancer properties, showing cell-specific activity that can be enhanced when loaded into polymeric nanoparticles. The cytotoxic activity of OA and UA was assessed by Alamar Blue assay in three different cell lines, i.e., HepG2 (Human hepatoma cell line), Caco-2 (Human epithelial colorectal adenocarcinoma cell line) and Y-79 (Human retinoblastoma cell line). The natural and synthetic mixtures of these compounds were tested as free and loaded in polymeric nanoparticles in a concentration range from 2 to 32 µmol/L. The highest tested concentrations of the free triterpene mixtures produced statistically significant cell viability reduction in HepG2 and Caco-2 cells, compared to the control (untreated cells). When loaded in the developed PLGA nanoparticles, no differences were recorded for the tested concentrations in the same cell lines. However, in the Y-79 cell line, a decrease on cell viability was observed when testing the lowest concentration of both free triterpene mixtures, and after their loading into PLGA nanoparticles.

Concentrates of triterpenic acids obtained from crude olive pomace oils: characterization and evaluation of their potential antioxidant activity.

Pentacyclic triterpenic acids (TA) are phytochemicals of increasing nutritional interest owing to their bioactive properties, such as anti-inflammatory, antitumoral, antihyperglycemic and hepatoprotective. Crude olive pomace oils constitute a non-exploited significant source of these compounds. In the present study, concentrates of TA were extracted and characterized from crude olive pomace oils that were obtained by centrifugation and subsequent solvent extraction, respectively. Specifically, the concentrates were obtained from the byproduct generated in the filtration of the oils. The solids were subjected to Soxhlet extractions with hexane to remove the residual oil and then with ethanol for the TA extraction. Concentrates containing 850-980 g kg-1 TA were isolated from the oils obtained by centrifugation, whereas those isolated from oils obtained by hexane extraction presented levels of TA that ranged from 510 to 900 g kg-1 . Oleanolic (OA) and maslinic (MA) acids were the TA found in the concentrates. The relative contents of OA and MA were, respectively, 30:70 (w/w) and 77:23 (w/w). All concentrates also presented phenolic compounds at levels of g kg-1 and displayed slight antioxidant properties. Concentrates of TA, containing MA and OA, can be readily obtained from a byproduct generated by filtration of crude olive pomace oils. Concentrates isolated from oils obtained by centrifugation were rich in MA, whereas those from oils extracted with hexane were rich in OA. The concentrates showed slight antioxidant properties that can be mainly attributed to the presence of phenolic compounds and not to TA. © 2018 Society of Chemical Industry.

Selective in vitro anti-melanoma activity of ursolic and oleanolic acids

Products of natural origin have become important agents in the treatment of cancer, and the active principles of natural sources could be used in combination with chemotherapeutic agents to increase their effects and to minimize their toxicity. Oleanolic (OA) and ursolic (UA) acids are intensely studied for their promising anticancer potential. The aim of this study was focused on the in vitro toxicological effects induced by UA and OA human mesenchymal stem cells and on melanoma, one of the most frequent cancers whose incidence is increasing every year. The two compounds were tested for their cytotoxic, cell cycle arrest and pro-apoptotic effects on melanoma cells (A375 and B164A5) and mesenchymal stem cells. UA exerted a cytotoxic effect in a dose-dependent manner on melanoma cells, while OA’s activity has been shown to be low or moderate. Both compounds produced alterations of the cell cycle, arresting cells in the G0/G1 phase. Furthermore, UA induced significant apoptosis through the bcl-2 genes family pathway, with the decrease of the bcl-2 gene expression. The two compounds exerted selective effects on melanoma cells with no effects on human mesenchymal stem cells. The presented results reveal the anticancer potential of UA on melanoma cells, with no detectable toxicity on the mesenchymal stem cells.

Liquid chromatography tandem mass spectrometric determination of triterpenes in human fluids: Evaluation of markers of dietary intake of olive oil and metabolic disposition of oleanolic acid and maslinic acid in humans

Olive oil is rich in several minor components like maslinic (MA) and oleanolic (OA) acids which have cardioprotective, antitumor, and anti-inflammatory properties. In order to assess the health benefits in humans provided by the olive oil triterpenes (MA and OA), suitable analytical methods able to quantify the low concentrations expected in human fluids are required. In this study, the LC-MS/MS quantification of both OA and MA in plasma and urine has been evaluated. The plasmatic method is based on the direct determination of the analytes. The urinary detection requires more sensitivity which was reached by derivatization with 2-picolylamine. Additionally, the urinary species present after MA and OA ingestion were evaluated by the direct detection of several phase II metabolites previously synthesized. Our results showed that OA is metabolized as both sulfate and glucuronide conjugates whereas MA is mainly excreted as glucuronide. Based on this information, the method for the urinary detection of MA and OA involved an enzymatic hydrolysis. Both plasmatic and urinary methods were validated with suitable precision and accuracy at all tested levels. Required sensitivity was achieved in both matrices. Up to our knowledge, this is the first method able to quantify the low concentration levels of triterpenes present in urine. Samples from two healthy volunteers who received virgin olive oils with different triterpenes content were analyzed. Some preliminary clues on the metabolic disposition of OA and MA after olive oil intake are provided.

Complexation between oleanolic and maslinic acids with native and modified cyclodextrins

Oleanolic (OA) and maslinic (MA) acids are two natural triterpenoids with a wide range of beneficial effects for human health. However, their low solubility and permeability make their application in the food, or pharmaceutical, industry difficult. The complexation of OA and MA with α- β-, γ-, HP-α-, HP-β- and HP-γ-CDs, under different pH and temperature conditions, has been studied. Neither α- nor HP-α-CDs formed inclusion complexes, while β-, HP-β- and HP-γ-CDs provided AL type and γ-CDs BS phase solubility diagrams. Complexation was shown to be more stable in the case of MA but complexation efficiency was greater for OA. Increasing the pH and temperature of the complexation media tended to improve the complexation process with triterpenic acids.

The impact of oleanolic and ursolic acid on corneal epithelial cells in vitro

INTRODUCTION. Oleanolic (OA) and ursolic (UA) acids belong to the triterpene group widely present in plants. These compounds are recognised to have anti-inflammatory properties and thus are considered to be used in therapies as well as in cosmetic, natural health, or diet products. AIM. The scientific hypothesis of our study was to show that OA and UA influence corneal epithelial cells cultured in vitro . METHODS. Toxicity tests, based on MTT and Neutral Red (NR) uptake, measurement of nitric oxide (NOx) level, as well as analysis of metalloproteinases (MMP-2 and MMP-9) amount and activity were performed. RESULTS . UA expressed significantly higher toxicity on cells than OA. At the lowest concentration applied (5 μM), UA limited cellular metabolism and viability on average by 22% as compared to untreated control, while 25 μM resulted in values lower than 10%. On the other hand, OA at the highest (100 μM) concentration limited cellular metabolism and viability by about 20%. NOx level significantly increased when OA and UA were applied at concentrations of 25 and 100 μM, respectively. OA and UA had a stronger impact on the level of MMP-2 than MMP-9. OA and UA reduced MMP-2 and MMP-9 in the whole range of concentrations. Tested triterpenoids had no significant impact on MMP activity. CONCLUSIONS. OA and UA have a different impact on human corneal epithelial cells. UA is toxic for corneal epithelial cells, while OA exhibits milder activity, which may be useful for further analysis in ocular pharmacology.

Evaluation of seasonal changes of triterpenic acid contents in Viscum album from different host trees

Context: Viscum album L. (Loranthaceae) is a semi-parasitic plant used in pharmacy and medicine mostly for its hypotensive and anticancer activity. The effects may be related to the presence of triterpenic acids, such as betulinic (BA) and oleanolic (OA) acids. Objectives: In our investigations the content of triterpenic acids in V. album from different host trees depending on the season of harvest was determined. Material and methods: V. album herb was dried and extracted with ethyl acetate using ultrasound energy. The reversed phase HPLC-PDA method was used for the analysis of triterpenic acids. The structure of the target components was confirmed by mass spectrometry with an electrospray ionization source. Results: Diversity in the content of both compounds was noted; however, OA was the dominant triterpenic acid and the amount thereof was ∼10 times higher than that of BA. The analysis of changes in the amount of triterpenic acids during the spring-winter period revealed the highest content of OA in summer (from 6.84 to 13.65 mg/g). In turn, in the other seasons of harvest, the content was in the range of 4.41–9.83, 6.41–9.56 and 5.59–12.16 mg/g for spring, autumn and winter, respectively. In most cases, a similar tendency was observed for BA. Discussion and conclusion: In most cases, the highest amount of the investigated compounds was found in summer; thus, this period seems to be optimal for acquisition of plant material rich in triterpenic acids.

Oleanolic, Ursolic, and Betulinic Acids as Food Supplements or Pharmaceutical Agents for Type 2 Diabetes: Promise or Illusion?

Oleanolic (OA), ursolic (UA), and betulinic (BA) acids are three triterpenic acids (TAs) with potential effects for treatment of type 2 diabetes (T2DM). Mechanistic studies showed that these TAs act as hypoglycemic and antiobesity agents mainly through (i) reducing the absorption of glucose; (ii) decreasing endogenous glucose production; (iii) increasing insulin sensitivity; (iv) improving lipid homeostasis; and (v) promoting body weight regulation. Besides these promising beneficial effects, it is believed that OA, UA, and BA protect against diabetes-related comorbidities due to their antiatherogenic, anti-inflammatory, and antioxidant properties. We also highlight the protective effect of OA, UA, and BA against oxidative damage, which may be very relevant for the treatment and/or prevention of T2DM. In the present review, we provide an integrative description of the antidiabetic properties of OA, UA, and BA, evaluating the potential use of these TAs as food supplements or pharmaceutical agents to prevent and/or treat T2DM.

"Fungal elicitors combined with a sucrose feed significantly enhance triterpene production of a Salvia fruticosa cell suspension".

Oleanolic (OA) and ursolic acid (UA) are plant secondary metabolites with diverse pharmacological properties. To reach reasonable productivities with plant cell suspension cultures, elicitation is a widely used strategy. Within the presented work, the effects of different elicitors on growth and production of OA and UA in a Salvia fruticosa cell suspension culture were examined. Beside commonly used elicitors like jasmonic acid (JA) and yeast extract, the influence of medium filtrates of the endophytic fungi Aspergillus niger and Trichoderma virens was investigated. The best eliciting effects were achieved with JA and fungal medium filtrates. Both increased the triterpene content by approximately 70%. Since JA showed significant growth inhibition, the volumetric triterpene yield did not increase. But, adding fungal filtrates increased the volumetric triterpene yield by approximately 70% to 32.6mgOAl(-1) and 65.9mgUAl(-1) for T. virens compared to the control with 19.4mgOAl(-1) and 33.3mgUAl(-1). An elicitation strategy combining fungal medium filtrate of T. virens with sucrose feeding significantly enhanced cell dry weight concentration to 22.2gl(-1) as well as triterpene content by approximately 140%. In total, this led to an approximately 500% increase of volumetric triterpene yield referring to the control with final values of 112.9mgOAl(-1) and 210.4mgUAl(-1). Despite the doubled cultivation duration, productivities of 6.7mgOA l(-1)day(-1) and 12.4mgUAl(-1)day(-1) were reached. These results demonstrate methods by which increased productivities of triterpenes can be achieved to attain yields competing with intact plants.

Antibacterial activity of constituents from Salvia buchananii Hedge (Lamiaceae)

The dichloromethane extract obtained from the aerial parts of Salvia buchananii Hedge was investigated for its antimicrobial properties following a bioassay-oriented fractionation approach. The extract displayed a clear inhibitory activity against several Gram-positive multidrug-resistant clinical strains including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Enterococcus faecium and Enterococcus faecalis. No activity was observed on Gram-negative strains and on Candida species. Phytochemical investigation of this extract led to the isolation of three new clerodane diterpenes (5, 6 and 8) and eight known clerodane diterpenes (1-4, 7, 9-11) as well as ursolic (UA) and oleanolic (OA) acids. Their structures were established by extensive 1D, 2D NMR and HR-MS spectroscopic methods. The mixture UA/OA manifested a broad and powerful activity on several Gram-positive species, while diterpenes 3, 6, 8 and 9 showed moderate inhibitory activity on the Enterococcus species.

Thermal degradation, kinetic analysis, and apoptosis induction in human melanoma for oleanolic and ursolic acids

This study deals with the comparative analysis of thermal degradation (including kinetic study) in dynamic air atmosphere, for two similar-structured triterpenoid acids—ursolic (URS) and oleanolic (OLE) acids. As kinetic methods, two integral methods (Kissinger–Akahira–Sunose and Flynn–Wall–Ozawa) and one differential method (Friedman) were used. The “in-depth” kinetic analysis was completed by applying the nonparametric kinetics (NPK) method, which confirmed the multiprocess degradation suggested by isoconversional methods (the observed variation in Ea vs. conversion degree). The NPK method revealed that ursolic acid is degraded solely by two parallel chemical processes, while in the case of oleanolic acid, the processes are accompanied by physical ones. The physicochemical investigation was completed with a bioactivity evaluation regarding the apoptotic process caused by the two compounds in A2058 human melanoma cell line. It was found that the similar-structured triterpenoids possess different biological effects, OLE being antiapoptotic, while URS being strong apoptotic.

Macrophage Activation by Ursolic and Oleanolic Acids during Mycobacterial Infection.

Oleanolic (OA) and ursolic acids (UA) are triterpenes that are abundant in vegetables, fruits and medicinal plants. They have been described as active moieties in medicinal plants used for the treatment of tuberculosis. In this study, we analyzed the effects of these triterpenes on macrophages infected in vitro with Mycobacterium tuberculosis (MTB). We evaluated production of nitric oxide (NO), reactive oxygen species (ROS), and cytokines (TNF-α and TGF-β) as well as expression of cell membrane receptors (TGR5 and CD36) in MTB-infected macrophages following treatment with OA and UA. Triterpenes caused reduced MTB growth in macrophages, stimulated production of NO and ROS in the early phase, stimulated TNF-α, suppressed TGF-β and caused over-expression of CD36and TGR5 receptors. Thus, our data suggest immunomodulatory properties of OA and UA on MTB infected macrophages. In conclusion, antimycobacterial effects induced by these triterpenes may be attributable to the conversion of macrophages from stage M2 (alternatively activated) to M1 (classically activated).

Parallel damage in mitochondrial and lysosomal compartments promotes efficient cell death with autophagy: The case of the pentacyclic triterpenoids.

The role of autophagy in cell death is still controversial and a lot of debate has concerned the transition from its pro-survival to its pro-death roles. The similar structure of the triterpenoids Betulinic (BA) and Oleanolic (OA) acids allowed us to prove that this transition involves parallel damage in mitochondria and lysosome. After treating immortalized human skin keratinocytes (HaCaT) with either BA or OA, we evaluated cell viability, proliferation and mechanism of cell death, function and morphology of mitochondria and lysosomes, and the status of the autophagy flux. We also quantified the interactions of BA and OA with membrane mimics, both in-vitro and in-silico. Essentially, OA caused mitochondrial damage that relied on autophagy to rescue cellular homeostasis, which failed upon lysosomal inhibition by Chloroquine or Bafilomycin-A1. BA caused parallel damage on mitochondria and lysosome, turning autophagy into a destructive process. The higher cytotoxicity of BA correlated with its stronger efficiency in damaging membrane mimics. Based on these findings, we underlined the concept that autophagy will turn into a destructive outcome when there is parallel damage in mitochondrial and lysosomal membranes. We trust that this concept will help the development of new drugs against aggressive cancers.