Synthesis and screening of ursolic acid-benzylidine derivatives as potential anti-cancer agents

Application of Chalcone in the Structural Modification of Natural Products: An Overview

Natural products frequently display a range of biological activities, yet many exhibit only moderate efficacy during initial evaluations. Often, these natural substances necessitate structural alterations to yield promising lead compounds. Chalcones, characterized by their β-unsaturated carbonyl aromatic ketone structure, are prevalent in plant life and serve as fundamental scaffolds for the biosynthetic precursors of flavonoids and isoflavones. Due to their straightforward synthesis and extensive spectrum of biological effects, chalcones have found extensive application in medicinal chemistry. Chalcone analogs have demonstrated significant potential for drug discovery and development, as structural modifications can both amplify pharmacological efficacy and effectively mitigate toxic side effects. This paper endeavors to delve into the applications of chalcones in the structural modification of natural products, providing a theoretical foundation for future endeavors in derivatization and drug development. The full paper is organized into categories based on the biological activities of the derivatives, including anti-dyslipidemic, antibacterial, antimalarial, anti-inflammatory, anticancer, anti-Alzheimer, and α-glucosidase inhibitory activities.

Synthesis and potential anti-inflammatory response of indole and amide derivatives of ursolic acid in LPS-induced RAW 264.7 cells and systemic inflammation mice model: Insights into iNOS, COX2 and NF-κB

Ursolic acid (3-hydroxy-urs-12-ene-28-oic acid, UA) is a pentacyclic triterpene present in numerous plants, fruits and herbs and exhibits various pharmacological effects. However, UA has limited clinical applicability since it is classified as BCS class IV molecule, characterized by low solubility, low oral bioavailability and low permeability. In the present study, UA was isolated from the biomass marc of Lavandula angustifolia and was structurally modified by an induction of indole ring at the C-3 position and amide group at the C-17 position with the aim to enhance its pharmacological potential. This modification resulted in the synthesis of a series of compounds which were investigated for their anti-inflammatory potential both in-vitro and in animal models in comparison to UA. In RAW 264.7 cells, UA and its derivatives were non-cytotoxic up to 10 µM. The derivative UA-1 exhibited a significantly lower IC50 (2.2 ± 0.4 µM) for NO inhibition compared to UA (17.5 ± 2.0 µM). Molecular docking showed strong interactions of UA-1 with TNF-α and NF-κB. UA-1 significantly reduced LPS-induced pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) in RAW 264.7 macrophages with the inhibition levels of 74.2 ± 2.1 % for TNF-α, 55.9 ± 3.7 % for IL-6 and 59.7 ± 4.2 % for IL-1β at 5.0 µM, respectively and reactive oxygen species while upregulating anti-inflammatory cytokine, IL-10. It also downregulated iNOS, COX-2, p-NF-κB p65, and p-IκBα at both mRNA and protein levels. In LPS-induced systemic inflammation mice model, UA-1 significantly lowered NO, TNF-α, IL-6, IL-1β and serum biochemical parameters, reduced tissue damage, and exhibited improved aqueous solubility and moderate lipophilicity. Overall, UA-1 demonstrated superior anti-inflammatory potential, improved solubility, and better therapeutic potential compared to UA.

In vitro and in vivo evaluation of novel ursolic acid derivatives as potential antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA)

The misuse and abuse of antibiotics have led to the increase of drug resistance and the emergence of multi-drug resistant bacteria. Therefore, it is an urgent need to develop novel antimicrobial agents to address this problem. Natural products (NPs) could provide an effective strategy for the discovery of drug due to their wide range of source and biological activities. Ursolic acid (UA) is a naturally occurring compound known for its wide range of biological properties. In this study, a series of UA derivatives were rationally designed and synthesized by incorporating antibacterial potential fragments of benzenesulfonamide and indole, with the aim of obtaining novel UA derivatives for the treatment of bacterial infections. Based on the preliminary screening, UA derivatives 27 (yield of 26 %), containing 4-chlorobenzenesulfonamide and 6-carboxyindole pharmacophores, as well as 34 (yield of 42 %), containing 4-carboxybenzenesulfonamide and unsubstituted indole pharmacophores, were identified as promising antibacterial agents against Staphylococcus aureus, especially for methicillin-resistant Staphylococcus aureus (MRSA), possessing MICs of 1 μM. Furthermore, both of them also displayed low hemolytic activity, non-resistance, and low-toxicity to mammalian cells. In addition, further mechanistic studies revealed that 27 and 34 were able to inhibit and eliminate MRSA biofilm formation, affecting the permeability of bacterial cell membrane, leading to increase intracellular reactive oxygen species (ROS) and ultimately inducing bacterial death. Notably, 27 and 34 also showed promising in vivo efficacy against MRSA in a mouse wound model. These results suggested that 27 and 34 should have promising applications against MRSA infection.

An Update on Pentacyclic Triterpenoids Ursolic and Oleanolic Acids and Related Derivatives as Anticancer Candidates

Cancer is a global health problem, with the incidence rate estimated to reach 40% of the population by 2030. Although there are currently several therapeutic methods, none of them guarantee complete healing. Plant-derived natural products show high therapeutic potential in the management of various types of cancer, with some of them already being used in current practice. Among different classes of phytocompounds, pentacyclic triterpenoids have been in the spotlight of research on this topic. Ursolic acid (UA) and its structural isomer, oleanolic acid (OA), represent compounds intensively studied and tested in vitro and in vivo for their anticancer and chemopreventive properties. Since natural compounds can rarely be used in practice as such due to their characteristic physico-chemical properties, to tackle this problem, their derivatization has been attempted, obtaining compounds with improved solubility, absorption, stability, effectiveness, and reduced toxicity. This review presents various UA and OA derivatives that have been synthesized and evaluated in recent studies for their anticancer potential. It can be observed that the most frequent structural transformations were carried out at the C-3, C-28, or both positions simultaneously. It has been demonstrated that conjugation with heterocycles or cinnamic acid, derivatization as hydrazide, or transforming OH groups into esters or amides increases anticancer efficacy.

Hoslundia opposita vahl; a potential source of bioactive compounds with antioxidant and antibiofilm activity for wound healing

BACKGROUND

Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination. Antioxidants work synergistically with antibacterial agents against biofilms. Hence recent research has suggested plants as candidates in the development of new alternatives in biofilm treatments and as antioxidants due to the presence of phytocompounds which are responsible for their bioactivities. Hoslundia opposita Vahl is one of the plants used by traditional healers to treat wounds and other infections, this makes it a potential candidate for drug discovery hence, in this study, we investigate the antibiofilm and antioxidant activity of methanolic extract of hoslundia opposita Vahl from Uganda. We also identify phytochemicals responsible for its bioactivity.

METHOD

the plant was extracted by maceration using methanol, and the extract was investigated for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. The antibiofilm activity using microtiter plate assay (MTP) assay where the Minimum biofilm inhibitory concentration required to inhibit 50% or 90% of the biofilm (MBIC50 and MBIC90) and Minimum biofilm eradication concentration required to remove 50% or 90% of the biofilm (MBEC50 and MBEC90) were measured. It was further analysed for its phytochemical composition using quantitative screening, as well as Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography mass-spectrometry (LC-MS).

RESULTS

H. Opposita Vahl extract showed good antioxidant activity with of 249.6 mg/mL. It inhibited the growth of P. aeruginosa and S. aureus biofilms with MBIC50 of 28.37 mg/mL and 10 mg/mL, respectively. It showed the ability to eradicate P. aeruginosa and S. aureus biofilms with MBEC50 of 23.85 and 39.01 mg/mL respectively. Phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, and phenols. GC-MS analysis revealed 122 compounds in the extract of which, 23 have evidence of antioxidant or antibiofilm activity in literature. The most abundant compounds were; 1,4- Citric acid, Tetracontane-1,40-diol (43.43.3%, 1, Olean-12-en-28-oic acid, 3-hydroxy-, methyl ester, (3.beta) (15.36%) 9-Octadecenamide (12.50%), Squalene (11.85%) Palmitic Acid 4TMS (11.28%), and alpha Amyrin (11.27%). The LC-MS identified 115 and 57 compounds in multiple reaction mode (MRM) and scan modes respectively.

CONCLUSION

H. opposita Vahl showed antibiofilm and antioxidant activity due to bioactive compounds identified, hence the study justifies its use for wound healing. It can be utilised in further development of new drugs as antibiofilm and antioxidants.

Neuroprotective effect of ketamine and sevoflurane against TNF-α induced cognitive impairment

In the present study, neuroprotective effect of sevoflurane in combination with ketamine was investigated on TNF-α induced necroptosis of neurons and cognitive impairment in the rat model. The results demonstrated that exposure to TNF-α/z-VAD led to a significant decrease in viability of HT-22 neuronal cells. However, incubation of HT-22 cells with ketamine plus sevoflurane inhibited decrease in viability induced by TNF-α/z-VAD exposure. The increase in production of ROS by TNF-α/z-VAD exposure in HT-22 cells was effectively suppressed on pre-treatment with ketamine plus sevoflurane. Moreover, suppression of TNF-α/z-VAD induced ROS production in HT-22 cells by ketamine plus sevoflurane pretreatment was higher in comparison to ketamine or sevoflurane treatment alone. Treatment of HT-22 cells with ketamine plus sevoflurane suppressed TNF-α/z-VAD induced increase in RIP1 and p-MLKL protein expression. Ketamine plus sevoflurane treatment effectively reversed decrease in movement speed as well as total distance traveled in TNF-α injected rats. The number of neurons in rat hippocampus injected with TNF-α showed a significant decrease more specifically in carbonic anhydrase-3 region. However, no significant change in the density of neurons was observed in the hippocampus of rats pretreated with ketamine plus sevoflurane by TNF-α injection. The increase in expression of p-MLKL and p-RIP3 by TNF-α injection was effectively reversed in rats on treatment with ketamine plus sevoflurane. In silico studies revealed that ketamine interacts with p-MLKL protein in different confirmations with the binding affinities ranging from -9.7 to -8.4 kcal/mol. It was found that ketamine binds to p-MLKL protein by interacting with alanine (ALA A:295), proline (PRO A:306), glutamine (GLN A: 307) and isoleucine (ILE A:293) amino acid residues. In summary, ketamine plus sevoflurane combination alleviates TNF-α/z-VAD induced decrease in viability of HT-22 cells in vitro and rat hippocampus neurons in vivo. Moreover, ketamine plus sevoflurane combination prevented TNF-α injection induced cognitive impairment in rats. Therefore, sevoflurane plus ketamine combination can be developed as a potential therapeutic regimen for treatment of isoflurone induced cognitive impairment.

Tretinoin (2,4-difluoro-phenyl) triazole activates proapoptotic protein expression and targets NRP2 protein to inhibit esophageal carcinoma cell growth

The present study investigated the effect of tretinoin (2,4-difluoro-phenyl) triazole (TDFPT) on the growth and proliferation of Kyse-270 and EC9706 esophageal carcinoma cells and explored the underlying mechanism. The results demonstrated that TDFPT treatment of Kyse-270 and EC9706 cells led to a dose-dependent reduction in cell proliferation. Colony formation was significantly (p < .05) reduced in Kyse-270 and EC9706 cells on treatment with various concentrations of TDFPT. In TDFPT-treated Kyse-270 and EC9706 cells, the expression of Bcl-2 protein showed a remarkable decrease, whereas the level of Bax protein was found to be higher compared with the control cells. Cell invasion showed a prominent decrease in Kyse-270 and EC9706 cells on treatment with TDFPT. Treatment with TDFPT led to a prominent suppression in the expression of MMP-9 and NRP2 in Kyse-270 and EC9706 cells. In silico studies using the AutoDock Vina and discovery studio software revealed that various confirmations of TDFPT bind to NRP2 protein with the affinity ranging from -8.6 to -6.1 kcal/mol. It was found that the TDFPT interacts with NRP2 protein by binding to alanine (ALA A:295), proline (PRO A:306), glutamine (GLN A:307), and isoleucine (ILE A:293) amino acid residues. In summary, TDFPT exposure suppresses esophageal carcinoma cell proliferation, inhibits colony formation ability, and activates apoptotic pathway. Thus, TDFPT acts as an effective antiproliferative agent for esophageal carcinoma cells and needs to be investigated further as chemotherapeutic molecule.

Therapeutic potential of Pseudomonas aeruginosa-mannose sensitive hemagglutinin (PA-MSHA) in cancer treatment

Pseudomonas aeruginosa is a Gram-negative bacteria and it has been demonstrated that immunization with the outer membrane proteins of the microbe produces most of the relevant human antibodies. The peritrichous P. aeruginosa strain with MSHA fimbriae (PA-MSHA strain) has been found to be effective in the inhibition of growth and proliferation of different types of cancer cells. Furthermore, it has been revealed that PA-MSHA exhibits cytotoxicity because of the presence of MSHA and therefore it possesses anti-carcinogenic ability against different types of human cancer cell lines including, gastric, breast, hepatocarcinoma and nasopharyngeal cells. Studies have revealed that PA-MSHA exhibits therapeutic potential against cancer growth by induction of apoptosis, arrest of cell cycle, activating NF-κB/TLR5 pathway, etc. In China, PA-MSHA injections have been approved for the treatment of malignant tumor patients from very long back. The present review article demonstrates the therapeutic potential of PA-MSHA against various types of human cancers and explains the underlying mechanism.

Evaluation of Antituberculosis Activity and in Silico Properties of Oxymethylene-cyclo-1,3-diones

Tuberculosis is a leading infectious disease that has infected one-third of the world's population and is more prevalent among people belonging to developing countries such as India and China. In the present study, a series of substituted oxymethylene-cyclo-1,3-diones was synthesized and screened for anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv (M. tuberculosis). The compounds were synthesized by condensation of 1,3-cyclicdione, substituted phenols/ alcohols and triethyl orthoformate. The synthesized compounds were screened for anti-tuberculosis activity against M.tuberculosis H37Rv using Middlebrook 7H9 broth assay. Results demonstrated that among the synthesized library of molecules, two compounds 2-(2-hydroxyphenoxymethylene)-5,5-dimethylcyclohexane-1,3-dione and 5,5-dimethyl-2-(2-trifluoromethylphenoxymethylene)cyclohexane-1,3-dione were found to be most active against M. tuberculosis (MICs of 1.25 μg/mL-1 ). The MICs of 2-(2,4-difluoro-phenoxymethylene)-5,5-dimethylcyclohexane-1,3-dione and 2-(2-bromophenoxymethylene)-5,5-dimethylcyclohexane-1,3-dione were found to be 5 and 10 μg mL-1 , respectively. Data from the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that all the four most active compounds did not exhibit cytotoxicity against human cell lines. Molecular docking studies revealed that the most active compound targets mycobacterial InhA enzyme. In summary, the present study demonstrates the methodology for the synthesis of oxymethylene-cyclo-1,3-diones and identified two potential anti-tuberculosis compounds.

Synthesis, Biological Activity, ADME and Molecular Docking Studies of Novel Ursolic Acid Derivatives as Potent Anticancer Agents

A series of new ursolic acid (UA) derivatives substituted with various amino acids (AAs) or dipeptides (DP) at the C-3 position of the steroid skeleton was designed and synthesized. The compounds were obtained by the esterification of UA with the corresponding AAs. The cytotoxic activity of the synthesized conjugates was determined using the hormone-dependent breast cancer cell line MCF-7 and the triple-negative breast cancer cell line MDA. Three derivatives (l-seryloxy-, l-prolyloxy- and l-alanyl-l-isoleucyloxy-) showed micromolar IC₅₀ values and reduced the concentrations of matrix metalloproteinases 2 and 9. Further studies revealed that for two compounds (l-seryloxy- and l-alanyl-l-isoleucyloxy-), a possible mechanism of their antiproliferative action is the activation of caspase-7 and the proapoptotic Bax protein in the apoptotic pathway. The third compound (l-prolyloxy- derivative) showed a different mechanism of action as it induced autophagy as measured by an increase in the concentrations of three autophagy markers: LC3A, LC3B, and beclin-1. This derivative also showed statistically significant inhibition of the proinflammatory cytokines TNF-α and IL-6. Finally, for all synthesized compounds, we computationally predicted their ADME properties as well as performed molecular docking to the estrogen receptor to assess their potential for further development as anticancer agents.

The Drp1-Mediated Mitochondrial Fission Protein Interactome as an Emerging Core Player in Mitochondrial Dynamics and Cardiovascular Disease Therapy

Mitochondria, the membrane-bound cell organelles that supply most of the energy needed for cell function, are highly regulated, dynamic organelles bearing the ability to alter both form and functionality rapidly to maintain normal physiological events and challenge stress to the cell. This amazingly vibrant movement and distribution of mitochondria within cells is controlled by the highly coordinated interplay between mitochondrial dynamic processes and fission and fusion events, as well as mitochondrial quality-control processes, mainly mitochondrial autophagy (also known as mitophagy). Fusion connects and unites neighboring depolarized mitochondria to derive a healthy and distinct mitochondrion. In contrast, fission segregates damaged mitochondria from intact and healthy counterparts and is followed by selective clearance of the damaged mitochondria via mitochondrial specific autophagy, i.e., mitophagy. Hence, the mitochondrial processes encompass all coordinated events of fusion, fission, mitophagy, and biogenesis for sustaining mitochondrial homeostasis. Accumulated evidence strongly suggests that mitochondrial impairment has already emerged as a core player in the pathogenesis, progression, and development of various human diseases, including cardiovascular ailments, the leading causes of death globally, which take an estimated 17.9 million lives each year. The crucial factor governing the fission process is the recruitment of dynamin-related protein 1 (Drp1), a GTPase that regulates mitochondrial fission, from the cytosol to the outer mitochondrial membrane in a guanosine triphosphate (GTP)-dependent manner, where it is oligomerized and self-assembles into spiral structures. In this review, we first aim to describe the structural elements, functionality, and regulatory mechanisms of the key mitochondrial fission protein, Drp1, and other mitochondrial fission adaptor proteins, including mitochondrial fission 1 (Fis1), mitochondrial fission factor (Mff), mitochondrial dynamics 49 (Mid49), and mitochondrial dynamics 51 (Mid51). The core area of the review focuses on the recent advances in understanding the role of the Drp1-mediated mitochondrial fission adaptor protein interactome to unravel the missing links of mitochondrial fission events. Lastly, we discuss the promising mitochondria-targeted therapeutic approaches that involve fission, as well as current evidence on Drp1-mediated fission protein interactions and their critical roles in the pathogeneses of cardiovascular diseases (CVDs).

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.

Evidence of the Beneficial Effects of Ursolic Acid against Lung Cancer

Lung cancer is the leading cause of cancer-related deaths globally. Despite current treatment approaches that include surgery, chemotherapy, radiation and immunotherapies, lung cancer accounted for 1.79 million deaths worldwide in 2020, emphasizing the urgent need to find novel agents and approaches for more effective treatment. Traditionally, chemicals derived from plants, such as paclitaxel and docetaxel, have been used in cancer treatment, and in recent years, research has focused on finding other plant-derived chemicals that can be used in the fight against lung cancer. Ursolic acid is a polyphenol found in high concentrations in cranberries and other fruits and has been demonstrated to have anti-inflammatory, antioxidant and anticancer properties. In this review, we summarize recent research examining the effects of ursolic acid and its derivatives on lung cancer. Data from in vitro cell culture and in vivo animal studies show potent anticancer effects of ursolic acid and indicate the need for clinical studies.

Synthesis and Biological Evaluation of Novel Fusidic Acid Derivatives as Two-in-One Agent with Potent Antibacterial and Anti-Inflammatory Activity

Fusidic acid (FA), a narrow-spectrum antibiotics, is highly sensitive to various Gram-positive cocci associated with skin infections. It has outstanding antibacterial effects against certain Gram-positive bacteria whilst no cross-resistance with other antibiotics. Two series of FA derivatives were synthesized and their antibacterial activities were tested. A new aromatic side-chain analog, FA-15 exhibited good antibacterial activity with MIC values in the range of 0.781–1.563 µM against three strains of Staphylococcus spp. Furthermore, through the assessment by the kinetic assay, similar characteristics of bacteriostasis by FA and its aromatic derivatives were observed. In addition, anti-inflammatory activities of FA and its aromatic derivatives were evaluated by using a 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse ear edema model. The results also indicated that FA and its aromatic derivatives effectively reduced TPA-induced ear edema in a dose-dependent manner. Following, multiform computerized simulation, including homology modeling, molecular docking, molecular dynamic simulation and QSAR was conducted to clarify the mechanism and regularity of activities. Overall, the present work gave vital clues about structural modifications and has profound significance in deeply scouting for bioactive potentials of FA and its derivatives.

Pentacyclic triterpenoids from spikes of Prunella vulgaris L. with thyroid tumour cell cytostatic bioactivities

Five new triterpenoids, including four ursane types (1-4) and one oleanane type (5), together with 15 known ursane types pentacyclic triterpenoids (6-20) were isolated from the fruit spikes of Prunella vulgaris L., a traditional Chinese herbal medicine. Their structures were elucidated based on IR, HR-ESI-MS, and NMR spectroscopic data. The SW579 cell line was used to evaluate anti-thyroid cancer activities of (1-20). The results indicated that (7-9), (16), and (19) exhibited apparent inhibitory activity with IC₅₀ values of 25.73-71.41 μM (cisplatin as positive control, IC₅₀ 14.49 ± 0.97 μM). Network pharmacology and molecular docking were also used for the prediction of the synergistic actions and the underlying mechanisms. Accordingly, four potential targets have been characterized.

Design, synthesis, anticancer activity and mechanism studies of novel 2-amino-4-aryl-pyrimidine derivatives of ursolic acid

A series of novel 2-amino-4-aryl-pyrimidine derivatives of ursolic acid were designed, synthesized, and evaluated for their anticancer activities against four cancer cell lines (MCF-7, HeLa, HepG2, and A549) and a human hepatocyte cell line (LO2) via MTT assay.

The Almond (Prunus dulcis): Chemical Properties, Utilization, and Valorization of Coproducts

Almonds (Prunus dulcis) are one of the most consumed tree-nuts worldwide, with commercial production in arid environments such as California, Spain, and Australia. The high consumption of almonds is partly due to their versatile usage in products such as gluten-free flour and dairy alternatives as well as them being a source of protein in vegetarian diets. They contain high concentrations of health-promoting compounds such as Vitamin E and have demonstrated benefits for reducing the risk of cardiovascular disease and improving vascular health. In addition, almonds are the least allergenic tree nut and contain minute quantities of cyanogenic glycosides. Production has increased significantly in the past two decades with 3.12 billion pounds of kernel meat produced in California alone in 2020 (USDA 2021), leading to a new emphasis on the valorization of the coproducts (e.g., hulls, shells, skins, and blanch water). This article presents a review of the chemical composition of almond kernels (e.g., macro and micronutrients, phenolic compounds, cyanogenic glycosides, and allergens) and the current research exploring the valorization of almond coproducts. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Hollongdione arylidene derivatives induce antiproliferative activity against melanoma and breast cancer through pro-apoptotic and antiangiogenic mechanisms

The use of natural compounds as starting point for semisynthetic derivatives has already been proven as a valuable source of active anticancer agents. Hollongdione (4,4,8,14-tetramethyl-18-norpregnan-3,20-dion), obtained by few steps from dammarane type triterpenoid dipterocarpol, was chemically modified at C2 and C21 carbon atoms by the Claisen-Schmidt aldol condensation to give a series of arylidene derivatives. The anticancer activity of the obtained compounds was assessed on NCI-60 cancer cell panel, revealing strong antiproliferative effects against a large variety of cancer cells. 2,21-Bis-[3-pyridinyl]-methylidenohollongdione 9 emerged as the most active derivative as indicated by its GI₅₀ values in the micromolar range which, combined with its high selectivity index values, indicated its suitability for deeper biological investigation. The mechanisms involved in compound 9 antiproliferative activity, were investigated through in vitro (DAPI staining) and ex vivo (CAM assay) tests, which exhibited its apoptotic and antiangiogenic activities. In addition, compound 9 showed an overall inhibition of mitochondrial respiration. rtPCR analysis identified the more intimate activity at pro-survival/pro-apoptotic gene level. Collectively, the hollongdione derivative stand as a promising therapeutic option against melanoma and breast cancer provided that future in vivo analysis will certify its clinical efficacy.

Therapeutic Potential of Ursolic Acid in Cancer and Diabetic Neuropathy Diseases

Ursolic acid (UA) is a pentacyclic triterpenoid frequently found in medicinal herbs and plants, having numerous pharmacological effects. UA and its analogs treat multiple diseases, including cancer, diabetic neuropathy, and inflammatory diseases. UA inhibits cancer proliferation, metastasis, angiogenesis, and induced cell death, scavenging free radicals and triggering numerous anti- and pro-apoptotic proteins. The biochemistry of UA has been examined broadly based on the literature, with alterations frequently having been prepared on positions C-3 (hydroxyl), C12-C13 (double bonds), and C-28 (carboxylic acid), leading to several UA derivatives with increased potency, bioavailability and water solubility. UA could be used as a protective agent to counter neural dysfunction via anti-oxidant and anti-inflammatory effects. It is a potential therapeutic drug implicated in the treatment of cancer and diabetic complications diseases provide novel machinery to the anti-inflammatory properties of UA. The pharmacological efficiency of UA is exhibited by the therapeutic theory of one-drug → several targets → one/multiple diseases. Hence, UA shows promising therapeutic potential for cancer and diabetic neuropathy diseases. This review aims to discuss mechanistic insights into promising beneficial effects of UA. We further explained the pharmacological aspects, clinical trials, and potential limitations of UA for the management of cancer and diabetic neuropathy diseases.

3-Pyridinylidene Derivatives of Chemically Modified Lupane and Ursane Triterpenes as Promising Anticancer Agents by Targeting Apoptosis

Cancer persists as a global challenge due to the extent to which conventional anticancer therapies pose high risks counterbalanced with their therapeutic benefit. Naturally occurring substances stand as an important safer alternative source for anticancer drug development. In the current study, a series of modified lupane and ursane derivatives was subjected to in vitro screening on the NCI-60 cancer cell line panel. Compounds 6 and 7 have been identified as highly active with GI₅₀ values ranging from 0.03 µM to 5.9 µM (compound 6) and 0.18–1.53 µM (compound 7). Thus, these two compounds were further assessed in detail in order to identify a possible antiproliferative mechanism of action. DAPI (4′,6-diamidino-2-phenylindole) staining revealed that both compounds induced nuclei condensation and overall cell morphological changes consistent with apoptotic cell death. rtPCR analysis showed that both compounds induced upregulation of proapoptotic Bak and Bad genes while downregulating Bcl-XL and Bcl-2 antiapoptotic genes. Molecular docking analysis revealed that both compounds exhibited high scores for Bcl-XL inhibition, while compound 7 showed higher in silico Bcl-XL inhibition potential as compared to the native inhibitor ATB-737, suggesting that compounds may induce apoptotic cell death through targeted antiapoptotic protein inhibition, as well.

Synthesis and antitumor potential of new arylidene ursolic acid derivatives via caspase-8 activation

Continuing our studies on NO-donating ursolic acid-benzylidene derivatives as potential antitumor agents, we designed and synthesized a series of new arylidene derivatives containing NO-donating ursolic acid and aromatic heterocyclic units. Compounds 5c and 6c showed a significant broad-spectrum antitumor activity. Compound 5c exhibited nearly three- to nine-fold higher cytotoxicity as compared with the parent drug in A549, MCF-7, HepG-2, HT-29, and HeLa cells, and it was also found to be the most potent apoptosis inducer of MCF-7 cells. More importantly, compound 5c arrested the MCF-7 cell cycle in the G1 phase, which was associated with caspase activation and a decrease of the Bcl-2/Bax ratio. Meanwhile, compound 5c caused changes in morphological features, dissipation of the mitochondrial membrane potential, and accumulation of reactive oxygen species. A docking study revealed that the nitroxyethyl moiety of compound 5c may form hydrogen bonds with caspase-8 amino acid residues (SER256 and HIS255). Together, these data suggest that NO-donating ursolic acid-arylidene derivatives are potent apoptosis inducers in tumor cells.

Phytochemical composition, antisnake venom and antibacterial activities of ethanolic extract of Aegiphila integrifolia (Jacq) Moldenke leaves

Snakebites are considered a major neglected tropical disease, resulting in around 100,000 deaths per year. The recommended treatment by the WHO is serotherapy, which has limited effectiveness against the toxins involved in local tissue damage. In some countries, patients use plants from folk medicines as antivenoms. Aegiphila species are common plants from the Brazilian Amazon and are used to treat snakebites. In this study, leaves from Aegiphila integrifolia (Jacq) Moldenke were collected from Roraima state, Brazil and its ethanolic extract was evaluated through in vitro and in vivo experiments to verify their antiophidic activity against Bothrops atrox crude venom. The isolated compounds from A. integrifolia were analyzed and the chemical structures were elucidated on the basis of infrared, ultraviolet, mass, ¹H and ¹³C NMR spectrometry data. Among the described compounds, lupeol (7), betulinic acid (1), β-sitosterol (6), stigmasterol (5), mannitol (4), and the flavonoids, pectolinarigenin (2) and hispidulin (3), were identified. The ethanolic extract and flavonoids (2 and 3) partially inhibited the proteolytic, phospholipase A2 and hyaluronidase activities of B. atrox venom, and the skin hemorrhage induced by this venom in mice. Antimicrobial activity against different bacteria was evaluated and the extract partially inhibited bacterial growth. Thus, taken together, A. integrifolia ethanolic extract has promising use as an antiophidic and antimicrobial.

A Carrier-Free Folate Receptor-Targeted Ursolic Acid/Methotrexate Nanodelivery System for Synergetic Anticancer Therapy

PURPOSE

To avoid undefined metabolic mechanisms and to eliminate potential side effects of traditional nanocarriers, new green carriers are urgently needed in cancer treatment. Carrier-free nanoparticles (NPs) based on ursolic acid (UA) have attracted significant attention, but the UA NPs targeting the folate receptor have never been explored. We designed a novel self-assembled UA-Methotrexate (MTX) NPs targeting the folate-receptor and its synergetic anticancer activity was studied in vitro and in vivo.

METHODS

UA-MTX NPs were prepared using the solvent precipitation method. Characterization of the UA-MTX NPs preparation was performed using a size analyzer, transmission electron microscopy, and UV-vis spectrophotometry. The in vitro pH-responsive drug release capability of UA-MTX NPs was tested at different pH values. The UA-MTX NPs targeting of folates was determined by comparing the endocytosis rates of cell lines with low or overexpression of the folate receptor (A549 and MCF-7 cells). The cytotoxicity and cell apoptosis of UA-MTX NPs were also studied to determine the in vitro synergistic effects. Combination chemotherapy of UA-MTX NPs in vivo was evaluated using MCF-7 xenografted tumor models.

RESULTS

Compared with free UA or MTX, the water solubility of UA-MTX NPs improved significantly. Drug-release from the UA-MTX NPs was faster at pH 5.0 than pH 7.4, suggesting MTX-UA NPs could rapidly release MTX in the acidic conditions of the tumor microenvironment. Confocal laser scanning microscopy revealed the excellent folate receptor targeting of UA-MTX NPs in MCF-7 cells. Cytotoxicity and cell apoptosis results demonstrated greater antiproliferative capacity of UA-MTX NPs than that of free drug in folate receptor overexpressing MCF-7 cells. Anticancer effects in vivo suggested MTX-UA NPs exhibited good biological safety and could enhance antitumor efficacy due to the combination therapy.

CONCLUSION

Our findings indicate that the UA-MTX NPs targeting folate-receptors is an efficient strategy for combination chemotherapy.

Design and discovery of new 1,2,4-triazolo[4,3-c]quinazolines as potential DNA intercalators and topoisomerase II inhibitors

A new series of 1,2,4-triazolo[4,3-c]quinazoline derivatives was designed and synthesized as Topo II inhibitors and DNA intercalators. The cytotoxic effect of the new members was evaluated in vitro against a group of cancer cell lines including HCT-116, HepG-2, and MCF-7. Compounds 14c , 14d , 14e , 14e , 15b , 18b , 18c , and 19b exhibited the highest activities with IC50 values ranging from 5.22 to 24.24 µM. Furthermore, Topo II inhibitory activities and DNA intercalating affinities of the most promising candidates were evaluated as a possible mechanism for the antiproliferative effect. The results of the Topo II inhibition and DNA binding tests were coherent with that of in vitro cytotoxicity. Additionally, the most promising compound 18c was analyzed in HepG-2 cells for its apoptotic effect and cell cycle arrest. It was found that 18c can induce apoptosis and arrest the cell cycle at the G2-M phase. Finally, molecular docking studies were carried out for the designed compounds against the crystal structure of the DNA-Topo II complex as a potential target to explore their binding modes. On the basis of these studies, it was hypothesized that the DNA binding and/or Topo II inhibition would participate in the noted cytotoxicity of the synthesized compounds.

Ursolic Acid Regulates Cell Cycle and Proliferation in Colon Adenocarcinoma by Suppressing Cyclin B1

Aims: The biological functions of cyclin B1 (CCNB1) in colon adenocarcinoma (COAD) will be explored in this study. Furthermore, the therapeutic effects and potential molecular mechanisms of ursolic acid (UA) in COAD cells will also be investigated in vitro.

Methods: COAD data were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Differentially expressed genes (DEGs) were determined with differential analysis. The biological functions of CCNB1 were analyzed through the GeneCards, the Search Tool for the Retrieval of Interacting Genes (STRING), and the Database for Annotation, Visualization, and Integrated Discovery (DAVID) databases. Therapeutic effects of UA on COAD cell lines HCT-116 and SW-480 were analyzed by CCK-8 and high-content screening (HCS) imaging assay. Flow cytometry was utilized to detect cell cycle changes of SW-480 and HCT-116 cells. Levels of mRNA and expression proteins of HCT-116, SW-480, and normal colon epithelial cells NCM-460 were determined by qRT-PCR and western blot.

Results: CCNB1 was highly expressed and acted as an oncogene in COAD patients. CCNB1 and its interacting genes were significantly enriched in the cell cycle pathway. UA effectively inhibited the proliferation and injured COAD cells. In addition, UA arrested cell cycle of COAD cells in S phase. With regard to the molecular mechanisms of UA, we demonstrated that UA can significantly downregulate CCNB1 and its interacting genes and proteins, including CDK1, CDC20, CCND1, and CCNA2, which contributed to cell cycle blocking and COAD treatment.

Conclusion: Results from this study revealed that UA possesses therapeutic effects on COAD. The anti-COAD activities of UA are tightly related to suppression of CCNB1 and its interacting targets, which is crucial in abnormal cell cycle process.

Development of four ruthenium polypyridyl complexes as antitumor agents: Design, biological evaluation and mechanism investigation

Ruthenium complexes are expected to be new opportunities for the development of antitumor agents. Herein, four ruthenium polypyridyl complexes ([Ru(bpy)₂(CAPIP)](ClO₄)₂ (Ru(II)-1, bpy = 2,2'-bipyridine; CAPIP = (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phenanthroline), [Ru(phen)₂(CA-PIP)](ClO₄)₂ (Ru(II)-2, phen = 1,10-phenanthroline), [Ru(dmb)₂(CAPIP)](ClO₄)₂ (Ru(II)-3, dmb = 4,4'-dimethyl-2,2'-bipyridine), [Ru(dmb)₂(ETPIP)](ClO₄)₂ (Ru(II)-4, ETPIP = 2-(4-(thiophen-2-ylethynyl)phenyl)-1H-imidazo[4,5-f][1,10]phen-anthroline)) have been investigated as mitochondria-targeted antitumor metallodrugs. DNA binding studies indicated that target Ru(II) complexes interacts with CT DNA (calf thymus DNA) by an intercalative mode. Cytotoxicity assay results demonstrate that Ru(II) complexes show high cytotoxicity against A549 cells with low IC₅₀ value of 23.6 ± 2.3, 20.1 ± 1.9, 22.7 ± 1.8 and 18.4 ± 2.3 μM, respectively. Flow cytometry and morphological analysis revealed that these Ru(II) complexes can induce apoptosis in A549 cells. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were also investigated by ImageXpress Micro XLS system. The experimental results indicate that the reactive oxygen species in A549 cells increased significantly and mitochondrial membrane potential decreased obviously. In addition, colocalization studies shown these complexes could get to the cytoplasm through the cell membrane and accumulate in the mitochondria. Furthermore, Ru(II) complexes can effectively induces cell cycle arrest at the S phase in A549 cells. Finally, cell invasion assay and quantitative studies were also performed to investigate the mechanism of this process. All in together, this study suggested that these Ru(II) complexes could induce apoptosis in A549 cells through cell cycle arrest and ROS-mediated mitochondrial dysfunction pathway.

Preventive effect of ursolic acid derivative on particulate matter 2.5-induced chronic obstructive pulmonary disease involves suppression of lung inflammation

Respiratory diseases like chronic obstructive pulmonary disease (COPD) are associated with the presence of particulate matter 2.5 (PM2.5) in the air. In the present study, the effect of synthesized ursolic acid derivatives on mice model of PM2.5-induced COPD was investigated in vivo. The mice model of COPD was established by the administration of 25 μL of PM2.5 suspension through intranasal route daily for 1 week. The levels of oxidative stress markers and inflammatory cytokines like tumor necrosis factors-α and interleukin-6 in the mice bronchoalveolar fluids increased markedly on administration with PM2.5. However, treatment with ursolic acid derivative caused a significant suppression in PM2.5-induced increase in oxidative stress markers and inflammatory cytokines in dose-dependent manner. Hematoxylin and eosin staining showed excessive inflammatory cell infiltration in pulmonary tissues in mice with COPD. The inflammatory cell infiltration was inhibited on treatment of the mice with ursolic acid derivative. The ursolic acid derivative treatment increased level of superoxide dismutase in mice with COPD. The lung injury induced by PM2.5 in mice was also prevented on treatment with ursolic acid derivative. Thus, ursolic acid derivative inhibits pulmonary tissues damage in mice through suppression of inflammatory cytokine and oxidative enzymes. Therefore, ursolic acid derivative can be of therapeutic importance for treatment of PM2.5-induced COPD.

New ruthenium polypyridyl complexes functionalized with fluorine atom or furan: Synthesis, DNA-binding, cytotoxicity and antitumor mechanism studies

Two novel ruthenium(II) polypyridyl complexes, namely, [Ru(dmp)₂(CAPIP)](ClO₄)₂ (Ru(II)-1) and [Ru(dmp)₂(CFPIP)](ClO₄)₂ (Ru(II)-2), which respectively contain (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phen-anthroline (CAPIP) and (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline. (CFPIP), were first designed and characterized (dmp = 2,9-dimethyl-1,10-phenanthroline). DNA binding experiments indicated that Ru(II) complexes interact with CT DNA through intercalative mode. In addition, the complexes Ru(II)-1 and Ru(II)-2, showed remarkable cell cytotoxicity, giving the respective IC₅₀ values of 4.1 ± 1.4 μM and 6.1 ± 1.4 μM on the A549 cancer cells. These values indicated higher activity than CAPIP, CFPIP, cisplatin (8.2 ± 1.4 μM) and other corresponding Ru(II) polypyridyl complexes. Furthermore, the Ru(II) complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. Significantly, complexes Ru(II)-1 and Ru(II)-2 induced A549 cells apoptosis was mediated by increase of ROS levels and dysfunction of mitochondria, and resulted in cell cycle arrest and increased anti-migration activity on A549 cells. Overall, these results indicated that complexes Ru(II)-1 and Ru(II)-2 could be suitable candidates for further investigation as a chemotherapeutic agent in the treatment of tumors.

Synthesis and biological evaluation of ursolic acid derivatives bearing triazole moieties as potential anti-Toxoplasma gondii agents

Ursolic acid (UA), a plant-derived compound, has many properties beneficial to health. In the present study, we synthesised three series of novel UA derivatives and evaluated their anti-Toxoplasma gondii activity both in vitro and in vivo. Most derivatives exhibited an improved anti-T. gondii activity in vitro when compared with UA (parent compound), whereas compound 3d exhibited the most potent anti-T. gondii activity in vivo. Spiramycin served as the positive control. Additionally, determination of biochemical parameters, including the liver and spleen indexes, indicated compound 3d to effectively reduce hepatotoxicity and significantly enhance anti-oxidative effects, as compared with UA. Furthermore, our molecular docking study indicated compound 3d to possess a strong binding affinity for T. gondii calcium-dependent protein kinase 1 (TgCDPK1). Based on these findings, we conclude that compound 3d, a derivative of UA, could act as a potential inhibitor of TgCDPK1.

Ursolic acid suppresses the biological function of osteosarcoma cells

Osteosarcoma is a highly malignant tumour that occurs in adolescents. Upregulation or the constitutive activation of epidermal growth factor receptor (EGFR) is a hallmark of osteosarcoma. To investigate the effect of ursolic acid on the biological function of osteosarcoma, MTT assay was used to detect the effect of ursolic acid on the proliferation of HOS and MG63 cells, while flow cytometry was used to analyse the effect on the cell cycle and apoptosis. Transwell and Matrigel assays were used to detect the effect of ursolic acid on cell migration and invasion, respectively. Western blot analysis and reverse transcription-quantitative polymerase chain reaction were used to detect the effects of different concentrations of ursolic acid on EGFR signaling pathway-related proteins, cell cycle, apoptosis and cell migration-related proteins. After overexpression or silencing of EGFR, the effects of ursolic acid on EGFR pathway and cell biological function were subsequently detected, using the same methods. The present study identified that ursolic acid had inhibitory effects on the growth and metastatic ability of osteosarcoma cells by suppressing EGFR.

Synthesis and Antitumor Evaluation in Vitro of NO-Donating Ursolic Acid-Benzylidene Derivatives

Antitumor activity of triterpenoid and its derivatives has attracted great attention recently. Our previous efforts led to the discovery of a series of NO-donor betulin derivatives with potent antitumor activity. Herein, we prepared eight compounds derived from ursolic acid (UA). All the compounds were evaluated for their in vitro cytotoxicity against four human cancer cell lines (HepG-2, MCF-7, HT-29 and A549). Among the compounds tested, compound 4a was found to be most active against HT-29 (IC50 =4.28 μm). Further biological assays demonstrated that compound 4a could induce cell cycle arrest at G1 phase and apoptosis in a dose-dependent manner. In addition, compound 4a was found to upregulate pro-apoptotic Bax, p53 and downregulate anti-apoptotic Bcl-2. All these results suggested that compound 4a is a potential candidate drug for the therapy of colon cancer.

The Supramolecular Organogel Formed by Self-Assembly of Ursolic Acid Appended with Aromatic Rings

Ursolic acid (UA) as a natural ursane-triterpenoid has rich pharmacological activities. We have found that it possesses aggregation properties and could self-assemble into organogels. Based on the aggregation property of ursolic acid in suitable solvents, its derivative appended with aromatic rings by amide groups was synthesized. The property of self-assembly into organogel was studied in this paper. The results revealed that this derivative could form supramolecular gel in halogenated benzene and also gelate chloroform in the presence of toluene or p-xylene. By Fourier-transform infrared spectra (FT-IR) and variable temperature proton nuclear magnetic resonance (¹H NMR), it was proved that intermolecular hydrogen bonding and π⁻π stacking interaction were the primary driving forces for the aggregation to form organogel.

Dione-thiophene conjugate inhibits proliferation and metastasis of nasopharyngeal carcinoma cells through calcium binding protein-P down-regulation

In the present study a series of dione-thiophenol conjugates was prepared and evaluated against nasopharyngeal carcinoma (NPC) cells. MTT assay showed that compound 4a reduced proliferation of C666-1 and CNE-1 cells to 26 and 24%, respectively at 10 μmol/l concentration. Flow cytometry revealed that increasing the concentration of compound 4a from 2 to 10 μmol/l increased the proportion of early apoptotic C666-1 cells from 2.76 to 69.43%. A significant (P < 0.001) decrease in the expression of S100P was caused by compound 4a. In compound 4a treated C666-1 cells the expression of RAGE, EGFR, CD44, MMP2 and MMP9 was markedly decreased. In summary, compound 4a inhibits nasopharyngeal cancer cell proliferation and induces apoptosis through down-regulation of S100P. Moreover, compound 4a also decreases MMP-2, MMP-9, EGFR, CD44 and RAGE expression in nasopharyngeal cancer cells. Thus, compound 4a can be investigated further as a drug candidate for the treatment of nasopharyngeal cancer.

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.

Design and Synthesis of Novel Dehydroepiandrosterone Analogues as Potent Antiproliferative Agents

The aim of the present study was to determine the cytotoxic effects of a series of novel dehydroepiandrosterone derivatives containing triazole at the C₁₆ position on human cancer cells. The cancer cells used in the present study were A549, Hela, HepG-2, BEL7402, MCF-7, and HCT116. Several of the synthesised compounds exhibited potent antiproliferative effects. The most promising compound was (E)-3-hydroxy-16-((1-(4-iodophenyl)-1H-1,2,3-triazole-4-yl)methylene)-10,13-dimet-hyl-1,3,4,7,8,9,10,11,12,13,15,16-dodecahydro-2H-cyclopenta[a]phenanthren-17(14)-one (compound 2n), which showed considerably high antiproliferative activity in the HepG-2 cell line, with an IC₅₀ value of 9.10 µM, and considerably high activity against the MCF-7 cell line, with an IC₅₀ value of 9.18 µM. Flow cytometry assays demonstrated that compound 2n exerted antiproliferative effects by arresting cells in the G2 phase of the cell cycle and inducing apoptosis.

Ellagic acid, sulforaphane, and ursolic acid in the prevention and therapy of breast cancer: current evidence and future perspectives

Globally, breast cancer is the most common cancer and the second leading cause of cancer-related death among women. Surgery, chemotherapy, hormonal therapy, and radiotherapy are currently available treatment options for breast cancer therapy. However, chemotherapy, hormonal therapy, and radiotherapy are often associated with side effects and multidrug resistance, recurrence, and lack of treatment in metastasis are the major problems in the treatment of breast cancer. Recently, dietary phytochemicals have emerged as advantageous agents for the prevention and therapy of cancer due to their safe nature. Ellagic acid (EA), sulforaphane (SF), and ursolic acid (UA), which are found in widely consumed fruits and vegetables, have been shown to inhibit breast cancer cell proliferation and to induce apoptosis. This review encompasses the role of EA, SF, and UA in the fight against breast cancer. Both in vitro and in vivo effects of these agents are presented.

Ursolic Acid Attenuates Atherosclerosis in ApoE-/- Mice: Role of LOX-1 Mediated by ROS/NF-κB Pathway

Atherosclerosis, a chronic inflammatory disease, is a major contributor to cardiovascular diseases. Ursolic acid (UA) is a phytonutrient with widely biological effects including anti-oxidative, anti-inflammatory, and so on. At present, the effect of UA on atherosclerosis and the mechanism of action are still obscure. This study focused on investigating the effects of UA on atherosclerosis both in vivo and in vitro. We first selected LOX-1 as our target, which was reckoned as a new promising receptor for treating atherosclerosis. The evaluation in vitro suggested that UA significantly decreased endothelial LOX-1 expression induced by LPS both in mRNA and protein levels. Pre-treatment of UA also inhibited TLR4/MyD88 signaling activated by LPS. Moreover, UA reduced ROS production and suppressed the activation of NF-κB stimulated by LPS. Particularly, the evaluation in vivo further verified the conclusion obtained in vitro. In ApoE−/− mice fed with an atherogenic diet, both UA (100 mg/kg/day) and simvastatin significantly attenuated atherosclerotic plaque formation and shrunk necrotic core areas. The enhanced expression of LOX-1 in atherosclerotic aorta was also dramatically decreased by administration of UA. Taken together, these results suggested that UA, with anti-atherosclerotic activity through inhibition of LOX-1 mediated by ROS/NF-κB signaling pathways, may become a valuable vascular protective candidate for the treatment of atherosclerosis.

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.