UP12, a novel ursolic acid derivative with potential for targeting multiple signaling pathways in hepatocellular carcinoma

Exploiting the Integrated Valorization of Eucalyptus globulus Leaves: Chemical Composition and Biological Potential of the Lipophilic Fraction before and after Hydrodistillation

E. globulus leaves have been mainly exploited for essential oil recovery or for energy generation in industrial pulp mills, neglecting the abundance of valuable families of extractives, namely, triterpenic acids, that might open new ways for the integrated valorization of this biomass. Therefore, this study highlights the lipophilic characterization of E. globulus leaves before and after hydrodistillation, aiming at the integrated valorization of both essential oils and triterpenic acids. The lipophilic composition of E. globulus leaves after hydrodistillation is reported for the first time. Extracts were obtained by dichloromethane Soxhlet extraction and analyzed by gas chromatography-mass spectrometry. In addition, their cytotoxicity on different cell lines representative of the innate immune system, skin, liver, and intestine were evaluated. Triterpenic acids, such as betulonic, oleanolic, betulinic and ursolic acids, were found to be the main components of these lipophilic extracts, ranging from 30.63–37.14 g kg−1 of dry weight (dw), and representing 87.7–89.0% w/w of the total content of the identified compounds. In particular, ursolic acid was the major constituent of all extracts, representing 46.8–50.7% w/w of the total content of the identified compounds. Other constituents, such as fatty acids, long-chain aliphatic alcohols and β-sitosterol were also found in smaller amounts in the studied extracts. This study also demonstrates that the hydrodistillation process does not affect the recovery of compounds of greatest interest, namely, triterpenic acids. Therefore, the results establish that this biomass residue can be considered as a promising source of value-added bioactive compounds, opening new strategies for upgrading pulp industry residues within an integrated biorefinery context.

Ursolic acid: a pentacyclic triterpenoid that exhibits anticancer therapeutic potential by modulating multiple oncogenic targets

The world is currently facing a global challenge against neoplastic diseases. Chemotherapy, hormonal therapy, surgery, and radiation therapy are some approaches used to treat cancer. However, these treatments are frequently causing side effects in patients, such as multidrug resistance, fever, weakness, and allergy, among others side effects. As a result, current research has focused on phytochemical compounds isolated from plants to treat deadly cancers. Plants are excellent resources of bioactive molecules, and many natural molecules have exceptional anticancer properties. They produce diverse anticancer derivatives such as alkaloids, terpenoids, flavonoids, pigments, and tannins, which have powerful anticancer activities against various cancer cell lines and animal models. Because of their safety, eco-friendly, and cost-effective nature, research communities have recently focused on various phytochemical bioactive molecules. Ursolic acid (UA) and its derivative compounds have anti-inflammatory, anticancer, apoptosis induction, anti-carcinogenic, and anti-breast cancer proliferation properties. Ursolic acid (UA) can improve the clinical management of human cancer because it inhibits cancer cell viability and proliferation, preventing tumour angiogenesis and metastatic activity. Therefore, the present article focuses on numerous bioactivities of Ursolic acid (UA), which can inhibit cancer cell production, mechanism of action, and modulation of anticancer properties via regulating various cellular processes.

Ursolic Acid Analogs as Potential Therapeutics for Cancer

Ursolic acid (UA) is a pentacyclic triterpene isolated from a large variety of vegetables, fruits and many traditional medicinal plants. It is a structural isomer of Oleanolic Acid. The medicinal application of UA has been explored extensively over the last two decades. The diverse pharmacological properties of UA include anti-inflammatory, antimicrobial, antiviral, antioxidant, anti-proliferative, etc. Especially, UA holds a promising position, potentially, as a cancer preventive and therapeutic agent due to its relatively non-toxic properties against normal cells but its antioxidant and antiproliferative activities against cancer cells. Cell culture studies have shown interference of UA with multiple pharmacological and molecular targets that play a critical role in many cells signaling pathways. Although UA is considered a privileged natural product, its clinical applications are limited due to its low absorption through the gastro-intestinal track and rapid elimination. The low bioavailability of UA limits its use as a therapeutic drug. To overcome these drawbacks and utilize the importance of the scaffold, many researchers have been engaged in designing and developing synthetic analogs of UA via structural modifications. This present review summarizes the synthetic UA analogs and their cytotoxic antiproliferative properties reported in the last two decades.

Linoleic Acid-Glucosamine Hybrid for Endogenous Iron-Activated Ferroptosis Therapy in High-Grade Serous Ovarian Cancer

As the most common subtype in ovarian malignancies, high-grade serous ovarian cancer (HGSOC) made less therapeutic progress in past decades due to the lack of effective drug-able targets. Herein, an effective linoleic acid (LA) and glucosamine (GlcN) hybrid (LA-GlcN) was synthesized for the treatment of HGSOC. The GlcN was introduced to recognize the glucose transporter 1 (GLUT 1) overexpressed in tumor cells to enhance the uptake of LA-GlcN, and the unsaturated LA was employed to trigger ferroptosis by iron-dependent lipid peroxidation. Since the iron content of HGSOC was ∼5 and 2 times, respectively, higher than that of the normal ovarian cells and low-grade serous ovarian cancer cells, these excess irons make them a good target to enhance the ferroptosis of LA-GlcN. The in vitro study demonstrated that LA-GlcN could selectively kill HGSOC cells without affecting normal cells; the in vivo study revealed that LA-GlcN at the dose of 50 mg kg^-1 achieved a comparable tumor inhibition as doxorubicin hydrochloride (4 mg kg^-1) while the overall survival of mice was extended largely due to the low toxicity, and when the dose was increased to 100 mg kg^-1, the therapeutic outcomes could be improved further. This dietary hybrid which targets the excess endogenous iron to activate ferroptosis represents a promising drug for HGSOC treatment.

Novel Synthesized N-Ethyl-Piperazinyl-Amides of C2-Substituted Oleanonic and Ursonic Acids Exhibit Cytotoxic Effects through Apoptotic Cell Death Regulation

A series of novel hybrid chalcone N-ethyl-piperazinyl amide derivatives of oleanonic and ursonic acids were synthesized, and their cytotoxic potential was evaluated in vitro against the NCI-60 cancer cell line panel. Compounds 4 and 6 exhibited the highest overall anticancer activity, with GI₅₀ values in some cases reaching nanomolar values. Thus, the two compounds were further assessed in detail in order to identify a possible apoptosis- and antiangiogenic-based mechanism of action induced by the assessed compounds. DAPI staining revealed that both compounds induced nuclei condensation and overall cell morphological changes consistent with apoptotic cell death. rtPCR analysis showed that up-regulation of pro-apoptotic Bak gene combined with the down-regulation of the pro-survival Bcl-XL and Bcl-2 genes caused altered ratios between the pro-apoptotic and anti-apoptotic proteins’ levels, leading to overall induced apoptosis. Molecular docking analysis revealed that both compounds exhibited high scores for Bcl-XL inhibition, suggesting that compounds may induce apoptotic cell death through targeted anti-apoptotic protein inhibition, as well. Ex vivo determinations showed that both compounds did not significantly alter the angiogenesis process on the tested cell lines.

Chitosan modified poly (lactic acid) nanoparticles increased the ursolic acid oral bioavailability

Ursolic acid (UA) is a naturally occurring triterpene that has been investigated for its antitumor activity. However, its lipophilic character hinders its oral bioavailability, and therapeutic application. To overcome these limitations, chitosan (CS) modified poly (lactic acid) (PLA) nanoparticles containing UA were developed, characterized, and had their oral bioavailability assessed. The nanoparticles were prepared by emulsion-solvent evaporation technique and presented a mean diameter of 330 nm, zeta potential of +28 mV, spherical shape and 90% encapsulation efficiency. The analysis of XRD and DSC demonstrated that the nanoencapsulation process induced to UA amorphization. The in vitro release assay demonstrated that 53% of UA was released by diffusion after 144 h, following a second-order release kinetics. In simulated gastrointestinal fluids and mucin interaction tests, CS played an important role in stability and mucoadhesiveness improvement of PLA nanoparticles, respectively. In the presence of erythrocytes, nanoparticles proved their hemocompatibility. In tumor cells, nanoparticles presented lower cytotoxicity than free UA, due to slow UA release. After a single oral dose in rats, CS modified PLA nanoparticles increased the UA absorption, reduced its clearance and elimination, resulting in increased bioavailability. The results show the potential application of these nanoparticles for UA oral delivery for cancer therapy.

Biostable Double-Strand Circular Aptamers Conjugated Onto Dendrimers for Specific Capture and Inhibition of Circulating Leukemia Cells

Background/Objective

Circulating tumor cells (CTCs) are known as the root of cancer metastasis. Capture and inhibition of CTCs may prevent metastasis. Due to the rarity of CTCs in vivo, the current technology about CTCs capture is still challenging. The aim of our study was to conjugate the enhanced biostable double-strand (ds) circular aptamer (dApR) with dendrimers for capturing and restraining CTCs in vitro and in vivo.

Methods

CEM-targeting aptamer (Ap) was looped by ligation after phosphorylation to form circular ds aptamer dApR, which was then conjugated to dendrimers by biotin-streptavidin affinity reaction and named as G-dApR. The physicochemical properties of G-dApR were characterized by using PAGE gel electrophoresis, UV, DLS, AFM, fluorophotometer and laser confocal microscope. Biostability of G-dApR was also analyzed by gel electrophoresis. Confocal microscopy and flow cytometry were then performed to determine the binding specificity of G-dApR to CEM cells and the captured CTCs in mice and in human blood. Apoptosis of the captured cells was finally evaluated by using MTT assay, DAPI staining, AO/EB staining, cell cycle analysis and Annexin V-FITC/PI staining.

Results

Physicochemical characterization demonstrated the entity of dApR and G-dApR, and the nano-size of G-dApR (about 180 nm in aqueous phase). G-dApR exhibited the excellent biostability that confers their resistance to nuclease-mediated biodegradation in serum for at least 6 days. In our established CTCs model, we found that G-dApR could specifically and sensitively capture CTCs not non-target cells even in the presence of millions of interfering cells (10⁸), in mice and in human blood. Finally, the activity of captured CTCs was significantly down-regulated by G-dApR, resulting in apoptosis.

Conclusion

We created the enhanced biostable dApR-coated dendrimers (G-dApR) that could specifically capture and restrain CTCs in vitro and in vivo for preventing CTC-mediated cancer metastasis.

Ursolic acid inhibits the invasiveness of A498 cells via NLRP3 inflammasome activation

Renal cell cancer is a common malignant tumor of the urinary system. Ursolic acid (UA) serves an important antitumor role in certain types of cancer, such as lung cancer, breast cancer and hepatocellular carcinoma; however, to the best of our knowledge, the effect of UA on renal cancer has not yet been investigated. In the present study, A498 cells were treated with different concentrations of UA for 12, 24 and 48 h, and then MCC950, an inhibitor of the NLR family pyrin domain-containing 3 (NLRP3) receptor, was added to block NLRP3 signaling. The proliferation of A498 cells was analyzed using an MTS assay and invasiveness was analyzed using a Transwell assay. The expression levels of NLRP3, cleaved caspase-1, IL-1β and MMP-2 were detected using western blotting. The present results demonstrated that the invasiveness of A498 cells was significantly decreased following UA treatment (P<0.05), while expression levels of NLRP3, cleaved caspase-1 and IL-1β were significantly increased, and MMP-2 expression was decreased following UA stimulation (P<0.05). This was reversed by MCC950 treatment (P<0.05), with the exception of NLRP3. In conclusion, the present results indicated that UA exposure decreased the proliferation and invasiveness of A498 cells. Additionally, UA exposure significantly decreased MMP-2 production and induced the activation of NLRP3 inflammasome, which was reversed by MCC950 treatment, indicating that NLRP3 activation may be involved in UA inhibition of A498 cell invasiveness.

Self-assembled amphiphile-based nanoparticles for the inhibition of hepatocellular carcinoma metastasis via ICAM-1 mediated cell adhesion

Nanosized drug delivery systems have emerged to improve the therapeutic performance of anticancer drugs. Here, an amphiphile-based nanoparticle consisting of amphiphilic prodrug N-[3b-acetoxy-urs-12-en-28-oyl]-amino-2-methylpiperazine was developed (UP12 NPs) with uniform sizes (~100 nm), which possessed the advantages of small molecules and nanomedicine. The positively charged UP12 NPs significantly enhanced the cellular drug uptake on HepG2 cells than negatively charged UA NPs. Meanwhile, UP12 and these therapeutic amphiphile-based nanoparticles could induce cell apoptosis more efficiently than that of UA and UA NPs. Moreover, molecular docking demonstrated that the UP12 and intercellular adhesion molecule 1 (ICAM-1) could dock well. UP12 and UP12 NPs significantly decreased the mRNA expression of ICAM-1 and inhibited the migration and adhesion of liver cancer cells (HepG2 cells), which indicated that UP12 might be one of the potential ICAM-1 inhibitors. In vivo, UP12 NPs enhanced tumor accumulation, inhibited tumor lung metastasis and showed good biocompatibility. Overall, UP12 or UP12 NPs could be developed as prospective drugs for cancer metastasis therapy via ICAM-1 mediated cell adhesion. STATEMENT OF SIGNIFICANCE: In this study, we fabricated the therapeutic amphiphile-based nanoparticles by assembly of ursolic acid piperazine derivative N-[3b-acetoxy-urs-12-en-28-oyl]-amino-2-methylpiperazine (name as UP12 NPs) with low cytotoxicity. UP12 NPs exhibited spherical morphology and uniform sizes. Particularly, these therapeutic amphiphile-based nanoparticles significantly enhanced tumor accumulation and inhibited tumor lung metastases via intercellular adhesion molecule 1 (ICAM-1) mediated cell adhesion.

The miRNA-149-5p/MyD88 axis is responsible for ursolic acid-mediated attenuation of the stemness and chemoresistance of non-small cell lung cancer cells

Although the inhibitory roles of ursolic acid (UA) have been established in various tumors, its effects on the stemness of non-small cell lung cancer (NSCLC) cells are still unclear. Here, we constructed NSCLC cells with paclitaxel resistance (A549-PR) and showed that A549-PR exhibited a remarkably stronger stemness than the parental A549 cells, which is evident by the increase of spheroid formation capacity, stemness marker expression, and ALDH1 activity. Additionally, UA significantly reduced the stemness and paclitaxel resistance of A549-PR cells. Mechanistic investigations revealed that UA inhibited the miR-149-5p/MyD88 signaling, which is responsible for UA-mediated effects on the stemness of A549-PR cells. Notably, miR-149-5p/MyD88 axis promoted the stemness of A549 cells, while inhibition of this axis attenuated the stemness of A549-PR cells. Therefore, these results suggest that UA could attenuate the stemness and chemoresistance of NSCLC cells through targeting miR-149-5p/MyD88 axis.

Co-delivery of Bmi1 small interfering RNA with ursolic acid by folate receptor-targeted cationic liposomes enhances anti-tumor activity of ursolic acid in vitro and in vivo

Overexpression of Bmi1 gene is an important feature of cancer stem cell in various human tumors. Therefore, Bmi1 gene can be a potential target for small interfering RNA (siRNA) mediated cancer therapy. Ursolic acid (UA) as a natural product plays a pivotal role in anti-tumor field, although its performance is limited by low bioavailability and poor hydrophilicity. A folate receptor-targeted cationic liposome system was designed for the purpose of investigating the relationship between Bmil siRNA and UA. The folate receptor-targeted cationic liposomes co-delivering UA and Bmi1 siRNA (FA-UA/siRNA-L) were fabricated by electrostatic interaction between folate UA liposome (FA-UA-L) and Bmi1 siRNA. Tumor growth is inhibited by FA-UA/siRNA-L in vitro and in vivo and this inhibition is contributed by a synergistic anti-tumor effect of UA and Bmi1 siRNA. The western blot measurement of apoptosis-protein and cancer stem cell (CSC) marked-protein demonstrated that UA led to activation-induced tumor cell death and Bmi1 siRNA resulted in inhibition of cancer stem cells. Overall, these results indicate that Bmi1 as a regulating gene for cancer stem cell is an effective target for cancer treatment using siRNA and co-delivery of UA and Bmi1 siRNA using folate-targeted liposomes is a promising strategy for improved anti-tumor effect.

Polymeric micelles loading with ursolic acid enhancing anti-tumor effect on hepatocellular carcinoma

Ursolic acid (UA) is widely found in many dietary plants, which has been proved to be effective in cancer therapy. But unfortunately its hydrophobic property limits its clinical application. Polymer micelles (PMs) are constructed from amphiphilic block copolymers that tend to self-assemble and form the unique core-shell structure consisting of a hydrophilic corona outside and a hydrophobic inner core. PMs could entrap the hydrophobic substance into its hydrophobic inner core for solubilizing these poorly water-soluble drugs and it is widely applied as a novel nano-sized drug delivery system. This study aimed to develop the drug delivery system of UA-loaded polymer micelles (UA-PMs) to overcome the disadvantages of UA in clinical application thus enhancing antitumor effect on hepatocellular carcinoma. UA-PMs was prepared and characterized for the physicochemical properties. It was investigated the cell-growth inhibition effect of UA-PMs against the human hepatocellular carcinoma cell line HepG2 and human normal liver cell line L-02. UA-PMs was evaluated about the in vivo toxicity and the antitumor activity. We took a diblock copolymer of methoxy poly (ethylene glycol)-poly(L-lactic acid) (mPEG-PLA) as carrier material to prepare UA-PMs by the thin-film dispersion method. MTT assay and wound-healing assay were investigated to assess the inhibition effect of UA-PMs against HepG2 cells on cell-growth and cell-migration. Further, we chose KM mice for the acute toxicity experiment and assessed the antitumor effect of UA-PMs on the H22 tumor xenograft. UA-PMs could markedly inhibit the proliferation and migration of HepG2 cells. In vivo study showed that UA-PMs could significantly inhibit the growth of H22 xenograft and prolong the survival time of tumor-bearing mice. It demonstrated that UA-PMs possess great potential in liver cancer therapy and may enlarge the application of UA in clinical therapy.

Mitochondria and Nuclei Dual-Targeted Hollow Carbon Nanospheres for Cancer Chemophotodynamic Synergistic Therapy

Dual-targeted nanoparticles are gaining increasing importance as a more effective anticancer strategy by attacking double key sites of tumor cells, especially in chemophotodynamic therapy. To retain the nuclei inhibition effect and enhance doxorubicin (DOX)-induced apoptosis by mitochondrial pathways simultaneously, we synthesized the novel nanocarrier (HKH) based on hollow carbon nitride nanosphere (HCNS) modified with hyaluronic acid (HA) and the mitochondrial localizing peptide D[KLAKLAK]2 (KLA). DOX-loaded HKH nanoparticles (HKHDs) showed satisfactory drug-loading efficiency, excellent solubility, and very low hemolytic effect. HA/CD44 binding and electrostatic attraction between positively charged KLA and A549 cells facilitated HKHD uptake via the endocytosis mechanism. Acidic microenvironment, hyaluronidase, and KLA targeting together facilitate doxorubicin toward the mitochondria and nuclei, resulting in apoptosis, DNA intercalation, cell-cycle arrest at the S phase, and light-induced reactive oxygen species production. Intravascular HKHD inhibited tumor growth in A549-implanted mice with good safety. The present study, for the first time, systemically reveals biostability, targetability, chemophotodynamics, and safety of the functionalized novel HKHD.

Anticancer effect of ursolic acid via mitochondria-dependent pathways

Ursolic acid is a plant-derived pentacyclic triterpenoid found in various medicinal herbs and fruits. It has generated clinical interest due to its anti-inflammatory, antioxidative, antiapoptotic and anticarcinogenic effects. An increasing amount of evidence supports the anticancer effect of ursolic acid in various cancer cells. One of the hallmarks of malignant transformation is metabolic reprogramming that sustains macromolecule synthesis, bioenergetic demand and tumor cell survival. Mitochondria are important regulators of tumorigenes is as well as a major site of the metabolic reactions that facilitate this reprogramming and adaption to cellular and environmental changes. The current review explored the close association between the anticancer effect of ursolic acid and the activation of mitochondrial-dependent signaling pathways.

Cis-3-O-p-hydroxycinnamoyl Ursolic Acid Induced ROS-Dependent p53-Mediated Mitochondrial Apoptosis in Oral Cancer Cells

Cis-3-O-p-hydroxycinnamoyl ursolic acid (HCUA), a triterpenoid compound, was purified from Elaeagnus oldhamii Maxim. This traditional medicinal plant has been used for treating rheumatoid arthritis and lung disorders as well as for its anti-inflammation and anticancer activities. This study aimed to investigate the anti-proliferative and apoptotic-inducing activities of HCUA in oral cancer cells. HCUA exhibited anti-proliferative activity in oral cancer cell lines (Ca9-22 and SAS cells), but not in normal oral fibroblasts. The inhibitory concentration of HCUA that resulted in 50% viability was 24.0 µM and 17.8 µM for Ca9-22 and SAS cells, respectively. Moreover, HCUA increased the number of cells in the sub-G1 arrest phase and apoptosis in a concentration-dependent manner in both oral cancer cell lines, but not in normal oral fibroblasts. Importantly, HCUA induced p53-mediated transcriptional regulation of pro-apoptotic proteins (Bax, Bak, Bim, Noxa, and PUMA), which are associated with mitochondrial apoptosis in oral cancer cells via the loss of mitochondrial membrane potential. HCUA triggered the production of intracellular reactive oxygen species (ROS) that was ascertained to be involved in HCUA-induced apoptosis by the ROS inhibitors YCG063 and N-acetyl-L-cysteine. As a result, HCUA had potential antitumor activity to oral cancer cells through eliciting ROS-dependent and p53-mediated mitochondrial apoptosis. Overall, HCUA could be applicable for the development of anticancer agents against human oral cancer.

Ursolic Acid in Cancer Treatment and Metastatic Chemoprevention: From Synthesized Derivatives to Nanoformulations in Preclinical Studies

BACKGROUND

Cancer metastasis has emerged as a major public health threat that causes majority of cancer fatalities. Traditional chemotherapeutics have been effective in the past but suffer from low therapeutic efficiency and harmful side-effects. Recently, it has been reported ursolic acid (UA), one of the naturally abundant pentacyclic triterpenes, possesses a wide range of biological activities including anti-inflammatory, anti-atherosclerotic, and anti-cancer properties. More importantly, UA has the features of low toxicity, liver protection and the potential of anti-cancer metastasis.

OBJECTIVE

This article aimed at reviewing the great potential of UA used as a candidate drug in the field of cancer therapy relating to suppression of tumor initiation, progression and metastasis.

METHODS

Selective searches were conducted in Pubmed, Google Scholar and Web of Science using the keywords and subheadings from database inception to December 2017. Systemic reviews are summarized here.

RESULTS

UA has exhibited chemopreventive and therapeutic effects of cancer mainly through inducing apoptosis, inhibiting cell proliferation, preventing tumor angiogenesis and metastatic. UA nanoformulations could enhance the solubility and bioavailability of UA as well as exhibit better inhibitory effect on tumor growth and metastasis.

CONCLUSION

The information presented in this article can provide useful references for further studies on making UA a promising anti-cancer drug, especially as a prophylactic metastatic agent for clinical applications.

Ursolic and Oleanolic Acids as Potential Anticancer Agents Acting in the Gastrointestinal Tract

Background:

Cancer is one of the main causes of death worldwide. Contemporary therapies, including chemo- and radiotherapy, are burdened with severe side effects. Thus, there exists an urgent need to develop therapies that would be less devastating to the patient’s body. Such novel approaches can be based on the anti-tumorigenic activity of particular compounds or may involve sensitizing cells to chemotherapy and radiotherapy or reducing the side-effects of regular treatment.

Objective:

Natural-derived compounds are becoming more and more popular in cancer research. Examples of such substances are Ursolic Acid (UA) and Oleanolic Acid (OA), plant-derived pentacyclic triterpenoids which possess numerous beneficial properties, including anti-tumorigenic activity.

Results:

In recent years, ursolic and oleanolic acids have been demonstrated to exert a range of anticancer effects on various types of tumors. These compounds inhibit the viability and proliferation of cancer cells, prevent their migration and metastasis and induce their apoptosis. Both in vitro and in vivo studies indicate that UA and OA are promising anti-cancer agents that can prevent carcinogenesis at each step. Furthermore, cancers at all stages are susceptible to the activity of these compounds. </P><P> Neoplasms that are formed in the gastrointestinal tract, i.e. gastric, colorectal, pancreatic, and liver cancers, are among the most common and most lethal malignancies. Their localization in the digestive system, however, facilitates the action of orally-administered (potential) anti-cancer agents, making chemopreventive drugs more accessible.

Isolation of 4,4'-bond secalonic acid D from the marine-derived fungus Penicillium oxalicum with inhibitory property against hepatocellular carcinoma

4,4'-bond secalonic acid D (4,4'-SAD) is a known compound isolated from the marine-derived fungus Penicillium oxalicum. No study about the antitumor effect of this compound has been reported, except for a few focusing on its bactericidal properties. Herein, we performed an in vitro biology test and found that 4,4'-SAD stimulated the apoptosis of tumor cells in the human hepatocellular carcinoma cell lines PLC/PRF/5 and HuH-7 by activating caspase-3, caspase-8, caspase-9, PARP, p53, and cyclin B1, as well as by regulating the Bax/Bcl-2 ratio. In vivo studies showed that 4,4'-SAD had antitumor efficacy in H22 cell xenograft model. Immunohistochemical analysis revealed that 4,4'-SAD could regulate Bax expression, which is a biomarker of tumor growth. In summary, 4,4'-SAD significantly inhibited tumor growth both in vivo and in vitro.

Rigid dinuclear ruthenium-arene complexes showing strong DNA interactions

Six novel dinuclear Ru(II)-arene complexes [Ru₂(η⁶-p-cymene)₂(1,3-bib)₂Cl₂]×₂·Solvent (X = Cl^- (1), I^- (2), NO₃^- (3), BF₄^- (4), PF₆^- (5), CF₃SO₃^- (6); 1,3-bib = 1,3-di(1H-imidazol-1-yl) benzene) were synthesized and fully characterized by FT-IR, ¹H NMR, ESI-MS, Elemental Analysis (EA) and Powder X-ray Diffraction (PXRD). Single crystal X-ray diffractions studies showed that 3 and 4 have rigid bowl-like structures, where one counter-anion (NO₃^- for 3 and BF₄^- for 4) was trapped inside the cavity to balance the charge, respectively. Even complexes 1-6 showed only moderate or little anti-proliferative activity toward cancer cells, strong interactions with DNA molecules through intercalation, however, were confirmed by UV-Vis, CD and fluorescence spectroscopy. Apoptosis and cell cycle arrest studies for complex 2 with cancer A549 cells indicated concentration-dependent late apoptosis and the G1/G0 phase arrest. Interactions with the tripeptide glutathione (γ-L-Glu-L-Cys-Gly, GSH) might explain the relatively low antiproliferative potency of these complexes. This class of rigid dinuclear cations hold potential as DNA-targeting anticancer agents if their uptake and delivery could be under controlled.

Homopiperazine-rhodamine B adducts of triterpenoic acids are strong mitocans

Parent pentacyclic triterpenoic acids such as ursolic-, oleanolic, glycyrrhetinic, betulinic and boswellic acid were converted into their acetylated piperazinyl amides that were coupled with rhodamine B. SRB assays to evaluate their cytotoxicity showed all of these triterpene-homopiperazinyl-rhodamine adducts 16-20 being highly cytotoxic for a panel of human tumor cell lines even in nanomolar concentrations while being significantly less cytotoxic for non-malignant cells. Interestingly enough, these compounds were even more cytotoxic than previously prepared piperazinyl analogs, thus making the homopiperazinyl spacer a very interesting scaffold for the development of biologically active compounds. Extra staining experiments showed that the cytostatic effect of compounds 18 and 20 onto A2780 cancer cells is due to their ability to act as a mitocan.

In vivo inhibition of circulating tumor cells by two apoptosis-promoting circular aptamers with enhanced specificity

Circulating tumor cells (CTCs) are known as the root cause of cancer metastasis that accounts for 90% of cancer death. Owing to the rarity of blood CTCs and their microenvironmental complexity, the existing biotechnology could not precisely capture and apoptosize CTCs in vivo for cancer metastasis prevention. Here, we designed two double strand circular aptamers aimed to simultaneously target MUC1 and HER2 surface biomarkers on mesenchymal cancer cells. The circular aptamers are composed of a capture arm for binding and seizing CTCs and a circular body for resisting degradation by exonucleases. We conjugated the two circular aptamers onto dendrimer PAMAM G4.5 (dcAp1-G-dcAp2), and the conjugate entity showed both significantly-enhanced biostability in serum for days compared with their linear counterparts and capture specificity in RBC (1:10⁸) compared with their single circular aptamers. dcAp1-G-dcAp2 apoptosized the targeted cells and inhibited their bioenergetic activities significantly by lowing △Ψm, ATP and lactate productions while increasing ROS production. dcAp1-G-dcAp2 captured CTCs in mice in vivo and in patient blood. This study lays the foundation for developing multiple biostable circular aptamers and conjugating them together to precisely capture and apoptosize mesenchymal CTCs in vivo.

Carrier-free nanodrug by co-assembly of chemotherapeutic agent and photosensitizer for cancer imaging and chemo-photo combination therapy

Nanosized drug delivery systems (NDDS) with photothermal therapy (PTT) and photodynamic therapy (PDT) have been extensively exploited to improve the therapeutic performance and bio-safety of chemotherapeutic drugs in cancer. In this work, a carrier-free nanodrug was developed by co-assembly of the anti-cancer agent ursolic acid (UA), an asialoglycoprotein receptor (ASGPR), which can recognize the target molecule lactobionic acid (LA), and the near-infrared (NIR) probe dye indocyanine green (ICG) to form UA-LA-ICG NPs by a simple and green self-assembly approach. The UA-LA-ICG NPs had suitable stability, showed controlled release profile of UA drugs, and exhibited preferable temperature response (∼59.4 °C) under laser irradiation (808 nm, 1 W/cm2). Compared with free ICG, the UA-LA-ICG NPs significantly enhanced the intracellular ICG uptake. Upon irradiation of the NIR laser, co-assembled nanodrugs demonstrated great performance as a reactive oxygen species (ROS) producer and exhibited more anti-proliferative activities on ASGPR-overexpressing HepG2 cells than ASGPR low-expressing HeLa cells. Meanwhile, in vivo NIR fluorescence imaging exhibited that the co-assembled nanodrugs were specifically targeted to the tumor by the active targeting property of LA, and its circulation time was much longer than that of free ICG. In addition, UA-LA-ICG NPs + NIR irradiation treatment displayed enhanced inhibitory effect on tumor growth in H22 tumor-bearing mice. Overall, the co-assembly of chemotherapeutic agent and photosensitizer by the self-assembly approach might open an alternative avenue and give inspiration to fabricate new carrier-free nanodrugs for cancer imaging and chemo-photo combination therapy.

STATEMENT OF SIGNIFICANCE

The present study for the first time reported carrier-free nanoparticles (NPs) by co-assembly of a natural product ursolic acid (UA), an asialoglycoprotein receptor (ASGPR)-recognized sugar molecule lactobionic acid (LA), and the near-infrared dye indocyanine green (ICG) through a simple and green approach. The preparation process of nanodrugs is simple, rapid, effective, and labor-saving. The co-assembled nanodrugs were capable of stabilizing the ICG molecules and specifically targeting to the tumor, which could increase the tumor accumulation in cancer imaging and also enhance the efficacy of chemo-phototherapy.

A self-assembly nanodrug delivery system based on amphiphilic low generations of PAMAM dendrimers-ursolic acid conjugate modified by lactobionic acid for HCC targeting therapy

Ursolic acid (UA), a natural triterpene acid, is a promising anti-cancer drug due to its inhibitory effect on tumor growth and metastasis. However, clinical translation of UA is limited by its poor water solubility and low bioavailability. To overcome these problems, herein an amphiphilic self-assembly nanodrug composed of UA, lactobionic acid (LA) and low-polyamidoamine (low-PAMAM) dendrimers is developed. This near-spherical nanodrug with a uniform size (~180 nm) demonstrated to have an enhanced cytotoxicity against liver cancer SMMC7721 cells, and could attenuate the migration and adhesion of SMMC7721 cells at non-toxic concentrations by suppressing metastasis-related protein MMP-9 expression. Furthermore, in vivo study indicates that the nanodrug exhibited prolonged circulation time in blood as well as increased AUC, MRT and Cmax, and could effectively inhibit the tumor growth in H22 mice model. Overall, the UA-based nanodrug delivery system reported in the present work represents a novel strategy for targeted tumor therapy.

Iso-pencillixanthone A from a marine-derived fungus reverses multidrug resistance in cervical cancer cells through down-regulating P-gp and re-activating apoptosis

The occurrence of multidrug resistance (MDR) is highly associated with the overexpression of ATP-binding cassette (ABC) transporters, among which, P-glycoprotein (P-gp) plays one of the most important roles. Iso-pencillixanthone A (iso-PXA) is a compound isolated from the marine-derived fungus Penicillium oxalicum. No studies on the anti-tumor effect of this compound have been reported, except for a few focusing on its bactericidal properties. In this study, we found iso-PXA could stimulate P-gp ATPase activity and attenuate P-gp expression to increase the intracellular drug concentration in the cervical vincristine (VCR)-resistant cell line HeLa/VCR. Then, it increased ROS generation, depolarized MMP, promoted the release of cytochrome c from mitochondria, and further activated caspase-9, caspase-3 and PARP to induce cell apoptosis effectively through the intrinsic pathway. Caspase-8 medicated cleavage of Bid into the truncated form tBid partially initiated the mitochondrial apoptotic events. The elevation of the Bax/Bcl-2 ratio, the accumulation of FBW7 and the degradation of Mcl-1 accelerated the iso-PXA induced apoptotic process. The HeLa/VCR cell xenograft model again confirmed that iso-PXA had much better efficacy than vincristine in vivo. Taken together, these findings demonstrated that iso-PXA elicited remarkable anti-tumor and anti-MDR activity through inhibiting P-gp expression and function and re-activating the intrinsic apoptosis pathway in vitro and in vivo, suggesting it as a potential chemotherapeutic lead compound in the treatment of cervical MDR cancers.

Our study reveals the anti-tumor and anti-MDR effect and mechanism of iso-PXA for the first time.

Recent developments on the extraction and application of ursolic acid. A review

Ursolic acid (UA) is a pentacyclic triterpenoid widely found in herbs, leaves, flowers and fruits; update information on the major natural sources or agro-industrial wastes is presented. Traditional (maceration, Soxhlet and heat reflux) and modern (microwave-, ultrasound-, accelerated solvent- and supercritical fluid) extraction and purification technologies of UA, as well as some patented process, are summarized. The great interest in this bioactive compound is related to the beneficial effects in human health due to antioxidant, antimicrobial, anti-inflammatory, hepatoprotective, immunomodulatory, anti-tumor, chemopreventive, cardioprotective, antihyperlipidemic and hypoglycemic activities, and others. UA may augment the resistance of the skin barrier to irritants, prevent dry skin and could be suitable to develop antiaging products. The development of nanocrystals and nanoparticle-based drugs could reduce the side effects of high doses of UA in organisms, and increase its limited solubility and poor bioavailability of UA which limit the potential of this bioactive and the further applications. Commercial patented applications in relation to cosmetical and pharmaceutical uses of UA and its derivatives are surveyed.

A novel synthetic ursolic acid derivative inhibits growth and induces apoptosis in breast cancer cell lines

The present study investigated the anticancer functions of ursolic acid (UA) and its novel derivatives, with a nitrogen-containing heterocyclic scaffold and the privileged fragment at the C-28 position on apoptosis induction, cell proliferation and cell cycle in human BC lines. UA was chemically modified in the present study to increase its antitumor activity and bioavailability. A novel UA derivative, FZU3010, was synthesized using a nitrogen-containing heterocyclic scaffold and a privileged fragment at the C-28 position. Sulforhodimine B assays were used to measure the effect of UA and different concentrations of FZU3010 on the viability of breast cancer (BC) SUM149PT and HCC1937 cells. FZU3010 significantly repressed the proliferation of the two cancer cell lines in a dose-dependent manner, with a half-maximal inhibitory concentration of 4-6 µM, and exhibited decreased cytotoxicity compared with vehicle-treated cell lines. The effect of FZU3010 on cell cycle distribution and cellular apoptosis was also investigated. The results of this investigation indicated that FZU3010 significantly increased the number of SUM149PT and breast cancer HCC1937 cells in the G₀/G₁ phase in a dose-dependent manner. Additionally, at a concentration of 5 µM, the capability of FZU3010 to induce BC apoptosis was significantly higher than the capability of UA. Thus, the results of the current study indicated that FZU3010 induced apoptosis in BC cells, together with induction of cell cycle arrest at the S and G₀/G₁ phase. FZU3010 may therefore be considered as a potential therapeutic agent for the treatment of BC.

A carrier-free dual-drug nanodelivery system functionalized with aptamer specific targeting HER2-overexpressing cancer cells

Exploration of a green carrier to avoid potential systemic toxicity and the unclear metabolic mechanism of traditional nanocarriers is of high importance for cancer therapy. Hence, we developed a carrier-free nanosystem for co-delivery of dual anti-cancer drugs ursolic acid (UA) and doxorubicin (DOX) using a "green" and simple method. The co-assembled nanodrug was further modified with a HER2 aptamer by electrostatic interactions. The co-assembled dual nanodrug presented a spherical morphology with a uniform size (∼108.9 nm) and in a pH-triggered drug release manner. It made UA sensitize DOX to display synergistic anticancer effects at a low dose of DOX. Further, the aptamer surface decoration improved the intracellular drug retention of UA and DOX to as much as 2-fold in HER2 overexpressing cancer cells. In addition, the in vivo results further proved that the co-assembled nanodrug could significantly inhibit the tumor growth with a little side effects. In a word, this novel carrier-free dual-drug nanodelivery system could be a potential drug candidate for HER2 overexpressing cancer therapy, and UA could be used as a "green" nanocarrier for delivery of hydrophobic drugs and fluorescent dyes in cancer treatment and diagnosis.

Simultaneous inhibition of growth and metastasis of hepatocellular carcinoma by co-delivery of ursolic acid and sorafenib using lactobionic acid modified and pH-sensitive chitosan-conjugated mesoporous silica nanocomplex

Co-delivery multiple drugs using nanocarriers has been recognized as a promising strategy for cancer treatment to enhance therapeutic efficacy. In this study, a pH sensitive mesoporous silica nanoparticles (MSN) based controlled release nanoparticles for co-delivery of sorafenib (SO), a multi-tyrosine kinase inhibitor, and ursolic acid (UA), a sensitive agent for SO, was developed, which was decorated with pH sensitive chitosan (CS) and lactobionic acid (LA) targeting to asialoglycoprotein receptor (ASGPR) over-expressing hepatocellar carcinoma cells (denoted as USMNs-CL). The nanocomplex enhanced bioavailability of hydrophobic drugs, efficient tumor cell targeting and exhibited pH-responsive function and sustained release profile. USMNs-CL showed synergistic cytotoxicity and could attenuate the adhesion, migration of ASGPR over-expressing liver cancer SMMC-7721 cells at non-toxic concentrations. Moreover, the complex nanoparticles significantly increased the cellular apoptosis and down-regulated the expression of EGFR and VEGFR2 proteins related with cell proliferation and tumor angiogenesis. In vivo, compared with UA or SO alone, the nanocomplex significantly reduced the tumor burden in hepatocellular carcinoma (HCC) H22 tumor-bearing mice model and inhibited the lung metastasis in the H22 lung metastasis models. Overall, co-delivery of UA and SO by MSN-CS-LA nanocarriers could provide a promising strategy for HCC combinational therapy, especially for the HCC metastasis chemoprevention.

Dual-Targeting Multifuntional Mesoporous Silica Nanocarrier for Codelivery of siRNA and Ursolic Acid to Folate Receptor Overexpressing Cancer Cells

A targeting drug delivery system (TDDS) can selectively deliver antitumor drugs to cancerous parts to improve its anticancer efficacy. Hence, a targeted drug delivery system (UA/siVEGF@MSN-FA) coloading ursolic acid (UA) and vascular endothelial growth factor (VEGF) targeted siRNA (siVEGF) based on mesoporous silica (MSN) nanocarrier modified by a folic acid (FA) molecule was designed and synthesized. The MSN-FA nanoparticles were investigated for shape, diameter, and zeta potential and and by infrared (IR) spectroscopy. FR-overexpressing HeLa cells and FR-negative HepG2 cell lines were used to evaluate the in vitro cellular uptake and the cytotoxicity of MSN-FA nanoparticles. The morphology of HeLa cells transfected with siVEGF@MSN-FA was observed using fluorescence microscopy. Our findings demonstrated that UA@MSN-FA nanoparticles were near-spherical, and the particle size was about 209 ± 9.21 nm. The MSN-FA nanocarrier not only could enhance the in vitro transfection efficiency and the stability of siVEGF but also could further improve the targeted anticancer efficacy of UA and siVEGF via the active targeting property of FA. Overall, the MSN-FA drug delivery system could serve as an excellent material in biomedical applications.

A smart pH-responsive nano-carrier as a drug delivery system for the targeted delivery of ursolic acid: suppresses cancer growth and metastasis by modulating P53/MMP-9/PTEN/CD44 mediated multiple signaling pathways

Ursolic acid (UA) has been recently used as a promising anti-tumor and cancer metastatic chemo-preventive agent due to its low toxicity and liver-protecting property. However, the low bioavailability and nonspecific tumor targeting restrict its further clinical application. To address the problem, a silica-based mesoporous nanosphere (MSN) controlled-release drug delivery system (denoted UA@M-CS-FA) was designed and successfully synthesized, and was functionalized with folic acid (FA) and pH-sensitive chitosan (CS) for the targeted delivery of UA to folate receptor (FR) positive tumor cells. UA@M-CS-FA were spherical with mean diameter below 150 nm, and showed about -20 mV potential. Meanwhile, UA@M-CS-FA exhibited a pH-sensitive release manner and high cellular uptake in FR over-expressing HeLa cancer cells. Also, in vitro cellular assays suggested that UA@M-CS-FA inhibited cancer cell growth, invasion and migration. Mechanistically, UA@M-CS-FA induced cancer cell apoptosis and inhibited migration via cell cycle arrest in the G0/G1 stage, regulating the PARP/Bcl-2/MMP-9/CD44/PTEN/P53. Importantly, in vivo experiments further confirmed that UA@M-CS-FA significantly suppressed the tumor progression and lung metastasis in tumor-bearing nude mice. Immunohistochemical analysis revealed that UA@M-CS-FA treatment regulated CD44, a biomarker of cancer metastasis. Overall, our data demonstrated that a CS and FA modified MSN controlled-release drug delivery system could help broaden the usage of UA and reflect the great application potential of the UA as an anticancer or cancer metastatic chemopreventive agent.

Metapristone (RU486 metabolite) suppresses NSCLC by targeting EGFR-mediated PI3K/AKT pathway

Therapies targeting epidermal growth factor receptor (EGFR) can effectively treat with non-small cell lung cancer (NSCLC), but NSCLC’s drug resistance makes it intractable. Herein, we showed that RU486 metabolite metapristone inhibited the proliferation of various NSCLC cell lines with either wild (A549, H1299, H520) or mutated EGFR (H1975, HCC827). The suppression was resulted from inhibition by metapristone of EGFR signaling pathways through down-regulating the EGFR, PTEN, as well as AKT and ERK proteins. In addition, metapristone inhibited anti-apoptotic marker Bcl-2, and activated pro-apoptotic key signaling proteins caspase-3, and poly (ADP-ribose) polymerase. Metapristone induced A549 and H1975 cell cycle via arrest at the G0-G1 stage. What’s more, metapristone inhibited the growth of NSCLC xenografts in BALB/c nude mice through decreasing the expression of tumor growth biomarkers PCNA and EGFR. Taken together, the present study demonstrated that metapristone suppressed NSCLC proliferation by promoting apoptosis via decrease the cellular EGFR-mediated PI3K/AKT pathways. The results suggest metapristone a new treatment for EGFR-overexpressed NSCLC.

Ursolic Acid and Chronic Disease: An Overview of UA's Effects On Prevention and Treatment of Obesity and Cancer

Chronic diseases pose a worldwide problem and are only continuing to increase in incidence. Two major factors contributing to the increased incidence in chronic disease are a lack of physical activity and poor diet. As the link between diet and lifestyle and the increased incidence of chronic disease has been well established in the literature, novel preventive, and therapeutic methods should be aimed at naturally derived compounds such as ursolic acid (UA), the focus of this chapter. As chronic diseases, obesity and cancer share the common thread of inflammation and dysregulation of many related pathways, the focus here will be on these two chronic diseases. Significant evidence in the literature supports an important role for natural compounds such as UA in the prevention and treatment of chronic diseases like obesity and cancer, and here we have highlighted many of the ways UA has been shown to be a beneficial and versatile phytochemical.

Ursolic acid-mediated changes in glycolytic pathway promote cytotoxic autophagy and apoptosis in phenotypically different breast cancer cells

Plant-derived pentacyclic triterpenotids with multiple biological activities are considered as promising candidates for cancer therapy and prevention. However, their mechanisms of action are not fully understood. In the present study, we have analyzed the effects of low dose treatment (5-20 µM) of ursolic acid (UA) and betulinic acid (BA) on breast cancer cells of different receptor status, namely MCF-7 (ER+, PR+/-, HER2-), MDA-MB-231 (ER-, PR-, HER2-) and SK-BR-3 (ER-, PR-, HER2+). UA-mediated response was more potent than BA-mediated response. Triterpenotids (5-10 µM) caused G0/G1 cell cycle arrest, an increase in p21 levels and SA-beta-galactosidase staining that was accompanied by oxidative stress and DNA damage. UA (20 µM) also diminished AKT signaling that affected glycolysis as judged by decreased levels of HK2, PKM2, ATP and lactate. UA-induced energy stress activated AMPK that resulted in cytotoxic autophagy and apoptosis. UA-mediated elevation in nitric oxide levels and ATM activation may also account for AMPK activation-mediated cytotoxic response. Moreover, UA-promoted apoptosis was associated with decreased pERK1/2 signals and the depolarization of mitochondrial membrane potential. Taken together, we have shown for the first time that UA at low micromolar range may promote its anticancer action by targeting glycolysis in phenotypically distinct breast cancer cells.

pH-Sensitive mesoporous silica nanoparticles anticancer prodrugs for sustained release of ursolic acid and the enhanced anti-cancer efficacy for hepatocellular carcinoma cancer

Ursolic acid (UA) as a nature product exhibits good anti-cancer activity, low toxicity, and good liver protection features. However, the low-solubility and poor bioavailability restrict its further clinical application. To overcome this problem, a pH-sensitive prodrug delivery system (UA@MSN-UA) that incorporated acid-sensitive linkage between drug and silica-based mesoporous nanosphere (MSN) was successfully designed and synthesized. The physicochemical properties of the UA@MSN-UA nanoparticles were investigated for shape, particle size, zeta potential, nitrogen adsorption-desorption and infrared (IR) spectroscopy. The nanoparticles were further evaluated for in vitro cytotoxicity, including proliferation inhibition, cell cycle distribution and apoptotic effects against human hepatocellular carcinoma HepG2 cells. The TEM image showed that the size of synthesized MSN nanoparticle was a near-spherical shape with ~100nm diameter. In vitro cytotoxicity testing demonstrated that UA@MSN-UA nanoparticles prodrug exhibited higher proliferation inhibition, cell cycle arrest at the G2/M phase and significantly caused the early and late apoptosis in HepG2 cells, which would be contributed to high loading capacity, high cellular uptake and sustained release of UA. Overall, the UA-modified MSN prodrug delivery system can be a promising drug carrier for improving the bioavailability of UA, and further enhance its anti-cancer efficacy.

Anti-hepatocellular carcinoma activity and mechanism of chemopreventive compounds: ursolic acid derivatives

CONTEXT

Hepatocellular carcinoma (HCC) is a common cancer around the world, with high mortality rate. Currently, there is no effective drug for the therapy of HCC. Ursolic acid (UA) is a natural product which exists in various medicinal herbs and fruits, exhibiting multiple biological effects such as its outstanding anticancer and hepatoprotective activity, which has drawn many pharmacists' attention.

OBJECTIVE

This paper summarizes the current status of the hepatoprotective activity of UA analogues and explains the related mechanism, providing a clear direction for the development of novel anti-HCC drugs.

METHODS

All of the data resources were derived from PubMed. By comparing the IC50 values and analyzing the structure-activity relationships, we listed compounds with good pharmacological activity from the relevant literature, and summarized their anti-HCC mechanism.

RESULTS

From the database, 58 new UA derivatives possessing wonderful anticancer and hepatoprotective effects were listed, and the relevant anti-HCC mechanism were discussed.

CONCLUSION

UA's anti-HCC effect is the result of combined action of many mechanisms. These 58 new UA derivatives, particularly compounds 45 and 53, can be used as potential drugs for the treatment of liver cancer.

A novel co-drug of aspirin and ursolic acid interrupts adhesion, invasion and migration of cancer cells to vascular endothelium via regulating EMT and EGFR-mediated signaling pathways: multiple targets for cancer metastasis prevention and treatment

Metastasis currently remains the predominant cause of breast carcinoma treatment failure. The effective targeting of metastasis-related-pathways in cancer holds promise for a new generation of therapeutics. In this study, we developed an novel Asp-UA conjugate, which was composed of classical "old drug" aspirin and low toxicity natural product ursolic acid for targeting breast cancer metastasis. Our results showed that Asp-UA could attenuate the adhesion, migration and invasion of breast cancer MCF-7 and MDA-MB-231 cells in a more safe and effective manner in vitro. Molecular and cellular study demonstrated that Asp-UA significantly down-regulated the expression of cell adhesion and invasion molecules including integrin α6β1, CD44 ,MMP-2, MMP-9, COX-2, EGFR and ERK proteins, and up-regulated the epithelial markers "E-cadherin" and "β-catenin", and PTEN proteins. Furthermore, Asp-UA (80 mg/kg) reduced lung metastasis in a 4T1 murine breast cancer metastasis model more efficiently, which was associated with a decrease in the expression of CD44. More importantly, we did not detect side effects with Asp-UA in mice such as weight loss and main viscera tissues toxicity. Overall, our research suggested that co-drug Asp-UA possessed potential metastasis chemoprevention abilities via influencing EMT and EGFR-mediated pathways and could be a more promising drug candidate for the prevention and/or treatment of breast cancer metastasis.

Aspirin, lysine, mifepristone and doxycycline combined can effectively and safely prevent and treat cancer metastasis: prevent seeds from gemmating on soil

Recent scientific advances have increased our understanding of the cancer metastatic complexities and provided further impetus for new combination therapies to prevent cancer metastasis. Here, we demonstrated that a combination (HAMPT) of aspirin, lysine, mifepristone and doxycycline can effectively and safely prevent cancer metastasis. The pharmaceutically-formulated HAMPT inhibited adhesion of cancer cells to either endothelial cells or extracellular matrix via down-regulating cell adhesion molecules ICAM-1 and α₄-integrin. HAMPT inhibited the cloak effect by activated platelets on cancer cells, thereby interfering adhesion and invasion of cancer cells to the underlying stroma. At the effective concentration, HAMPT induced cancer cells into dormancy with minor inhibition on cell viability. Four-day pretreatment followed by 30-day oral administration of HAMPT (33.5-134 mg/kg) to the mice inoculated with cancer cells produced significant inhibition on cancer metastasis dose-dependently without marked side effects. Fifty-day rat toxicity study with HAMPT at doses (335-1340 mg/kg) 20-fold higher than its therapeutic dose produced no significant toxicity. Interestingly, the acute toxic death could not be reached at the maximum administrable dose (5 g/kg). This proof-of-concept study provides the first conceptual evidence that cancer metastasis can be controlled by using affordable old drugs to restrain circulating tumor cells from gemmating on the metastatic soil without the need for cytotoxicity.

Oxidative removal of phenol by HRP-immobilized beads and its environmental toxicology assessment

Horseradish peroxidase shows potential biological and environmental applications on the removal of phenolic compounds. In the present study, the HRP-immobilized beads were synthesized to detect the efficiency of the removal of phenol at optimum pH and H2O2 concentration. Comparative in vitro cytotoxicity of phenol/treated solutions were evaluated in HeLa, HepG2 and mcf-7 cells by using MTT method along with flow cytometry study for cell viability and cell cycle distributions. The results showed that the toxicity of phenol solutions were greatly reduced after treated by HRP-immobilized beads, and phenol could lead to deactivate of cells in the S phase and preventing them from going into the G2/M checkpoint. In addition, molecular docking study showed that phenol was a valid inhibitor for the cyclin E in the cell cycle and cell metabolism. Thereby, we established a suitable strategy with promising application for efficient harmless removal of phenol, which significantly decreased the cytotoxic impacts of phenol.

Ursolic acid (UA): A metabolite with promising therapeutic potential

Plants are known to produce a variety of bioactive metabolites which are being used to cure various life threatening and chronic diseases. The molecular mechanism of action of such bioactive molecules, may open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle dreadful diseases such as cancer and cardiovascular and neurodegenerative disorders. Ursolic acid (UA) is one among the categories of such plant-based therapeutic metabolites having multiple intracellular and extracellular targets that play role in apoptosis, metastasis, angiogenesis and inflammatory processes. Moreover, the synthetic derivatives of UA have also been seen to be involved in a range of pharmacological applications, which are associated with prevention of diseases. Evidences suggest that UA could be used as a potential candidate to develop a comprehensive competent strategy towards the treatment and prevention of health disorders. The review article herein describes the possible therapeutic effects of UA along with putative mechanism of action.

Synthesis and Biological Evaluation of Novel Ursolic acid Derivatives as Potential Anticancer Prodrugs

Ursolic acid (UA) is a natural product which has been shown to possess a wide range of pharmacological activities, in particular those with anticancer activity. In this study, 13 novel ursolic acid derivatives were designed and synthesized in an attempt to further improve compound potency. The structures of the newly synthesized compounds were confirmed using mass spectrometry, infrared spectroscopy, and (1) H NMR. The ability of the UA derivatives to inhibit cell growth was assayed against both various tumor cell lines and a non-pathogenic cell line, HELF. Analysis of theoretical toxicity risks for all derivatives was performed using OSIRIS and indicated that the majority of compounds would present moderate to low risks. Pharmacological results indicated that the majority of the derivatives were more potent growth inhibitors than UA. In particular, 5b demonstrated IC50 values ranging from 4.09 ± 0.27 to 7.78 ± 0.43 μm against 12 different tumor cell lines. Flow cytometry analysis indicated that 5b induced G0/G1 arrest in three of these cell lines. These results were validated by structural docking studies, which confirmed that UA could bind to cyclins D1 (Cyc D1) and cyclin-dependent kinases (CDK6), the key regulators of G0/G1 transition in cell cycle, while the piperazine moiety of 5b could bind with glucokinase (GK), glucose transporter 1 (GLUT1), and ATPase, which are the main proteins involved in cancer cell metabolism. Acridine orange/ethidium bromide staining confirmed that 5b was capable of inducing apoptosis and decreasing cell viability in a dose-dependent manner.

Synthesis and Evaluation of Novel Triterpene Analogues of Ursolic Acid as Potential Antidiabetic Agent

Ursolic acid (UA) is a naturally bioactive compound that possesses potential anti-diabetic activity. The relatively safe and effective molecule intrigued us to further explore and to improve its anti-diabetic activity. In the present study, a series of novel UA analogues was synthesized and their structures were characterized. Their bioactivities against the α-glucosidase from baker's yeast were determined in vitro. The results suggested that most of the analogues exhibited significant inhibitory activity, especially analogues 8b and 9b with the IC50 values of 1.27 ± 0.27 μM (8b) and 1.28 ± 0.27 μM (9b), which were lower than the other analogues and the positive control. The molecular docking and 2D-QSAR studies were carried out to prove that the C-3 hydroxyl could interact with the hydrophobic region of the active pocket and form hydrogen bonds to increase the binding affinity of ligand and the homology modelling protein. Thus, these results will be helpful for understanding the relationship between binding mode and bioactivity and for designing better inhibitors from UA analogues.