Multiple molecular targets in breast cancer therapy by betulinic acid

Antitumor activity and transcriptome sequencing (RNA-seq) analyses of hepatocellular carcinoma cells in response to exposure triterpene-nucleoside conjugates

Fifteen betulonic/betulinic acid conjugated with nucleoside derivatives were synthesized to enhance antitumor potency and water solubility. Among these, the methylated betulonic acid-azidothymidine compound (8c) exhibited a broad-spectrum of antitumor activity against three tested tumor cell lines, including SMMC-7721 (IC50 = 5.02 μM), KYSE-150 (IC50 = 5.68 μM), and SW620 (IC50 = 4.61 μM) and along with lower toxicity (TC50 > 100 μM) estimated by zebrafish embryos assay. Compared to betulinic acid (<0.05 μg/mL), compound 8c showed approximately 40-fold higher water solubility (1.98 μg/mL). In SMMC-7721 cells, compound 8c induced autophagy and apoptosis as its concentration increased. Transcriptomic sequencing analysis was used to understand the potential impacts of the underlying mechanism of 8c on SMMC-7721 cells. Transcriptomic studies indicated that compound 8c could activate autophagy by inhibiting the PI3K/AKT pathway in SMMC-7721 cells. Furthermore, in the xenograft mice study, compound 8c significantly slowed down the tumor growth, as potent as paclitaxel treated group. In conclusion, methylated betulonic acid-azidothymidine compound (8c) not only increases water solubility, but also enhances the potency against hepatocellular carcinoma cells by inducing autophagy and apoptosis, and suppressing the PI3K/Akt/mTOR signaling pathway.

The Emerging Role of Natural Products in Cancer Treatment

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

Tuning of the Anti-Breast Cancer Activity of Betulinic Acid via Its Conversion to Ionic Liquids

Betulinic acid (BA) is a natural pentacyclic triterpene with diverse biological activities. However, its low water solubility limits its pharmaceutical application. The conversion of pharmaceutically active molecules into ionic liquids (ILs) is a promising strategy to improve their physicochemical properties, stability, and/or potency. Here, we report the synthesis and characterization of 15 novel ILs containing a cation ethyl ester of a polar, non-polar, or charged amino acid [AAOEt] and an anion BA. Except for [ValOEt][BA], we observed preserved or up to 2-fold enhanced cytotoxicity toward hormone-dependent breast cancer cells MCF-7. The estimated IC50 (72 h) values within the series varied between 4.8 and 25.7 µM. We found that the most cytotoxic IL, [LysOEt][BA]2, reduced clonogenic efficiency to 20% compared to that of BA. In addition, we evaluated the effect of a 72 h treatment with BA or [LysOEt][BA]2, the most cytotoxic compound, on the thermodynamic behavior of MCF-7 cells. Based on our data, we suggest that the charged amino acid lysine included in the novel ILs provokes cytotoxicity by a mechanism involving alteration in membrane lipid organization, which could be accompanied by modulation of the visco-elastic properties of the cytoplasm.

Value of micro-flow imaging and high-definition micro-flow imaging in differentiating malignant and benign breast lesions

AIM

To evaluate the value of non-contrast micro-flow imaging (MFI) and high-definition micro-flow imaging (HD-MFI) in differentiating malignant and benign breast lesions.

MATERIALS AND METHODS

One hundred and thirty-three patients with 138 breast lesions (80 benign and 58 malignant lesions) were examined using colour Doppler flow imaging (CDFI), MFI, and HD-MFI before biopsy, with blood flow signals graded into four types (grade 0, 1, 2, and 3) and penetrating vessels evaluated. The micro-vascular patterns of MFI and HD-MFI were evaluated and classified into five patterns: avascular, line-like, tree-like, root hair-like, and crab claw-like pattern. The diagnostic efficiency of micro-vascular patterns was analysed. Moreover, ultrasound Breast Imaging Reporting and Data System (BI-RADS) 4A lesions were also re-assessed according to the micro-vascular patterns of MFI or HD-MFI.

RESULTS

The capability of detecting blood flow and penetrating vessels from high to low was HD-MFI, MFI, and CDFI, respectively (p<0.05). Rich blood flow signals, penetrating vessels, and root hair-like or crab claw-like pattern were more likely in malignant breast lesions, while few blood flow signals, tree-like pattern were mostly in benign lesions (p<0.05). The diagnostic efficiency of HD-MFI and MFI were higher than CDFI (p>0.05). MFI could reduce unnecessary biopsy of 52 US BI-RADS 4A lesions but with two malignancies missed, while 56 ultrasound BI-RADS 4A lesions could be downgraded by HD-MFI with none malignancies missed.

CONCLUSIONS

MFI and HD-MFI can detect more blood flow in breast lesions than CDFI, and could help distinguish benign and malignant breast lesions. HD-MFI could reduce the unnecessary biopsy of US BI-RADS 4A lesions without missed malignancy.

Progress in Antimelanoma Research of Natural Triterpenoids and Their Derivatives: Mechanisms of Action, Bioavailability Enhancement and Structure Modifications

Melanoma is one of the most dangerous forms of skin cancer, characterized by early metastasis and rapid development. In search for effective treatment options, much attention is given to triterpenoids of plant origin, which are considered promising drug candidates due to their well described anticancer properties and relatively low toxicity. This paper comprehensively summarizes the antimelanoma potential of natural triterpenoids, that are also used as scaffolds for the development of more effective derivatives. These include betulin, betulinic acid, ursolic acid, maslinic acid, oleanolic acid, celastrol and lupeol. Some lesser-known triterpenoids that deserve attention in this context are 22β-hydroxytingenone, cucurbitacins, geoditin A and ganoderic acids. Recently described mechanisms of action are presented, together with the results of preclinical in vitro and in vivo studies, as well as the use of drug delivery systems and pharmaceutical technologies to improve the bioavailability of triterpenoids. This paper also reviews the most promising structural modifications, based on structure-activity observations. In conclusion, triterpenoids of plant origin and some of their semi-synthetic derivatives exert significant cytotoxic, antiproliferative and chemopreventive effects that can be beneficial for melanoma treatment. Recent data indicate that their poor solubility in water, and thus low bioavailability, can be overcome by complexing with cyclodextrins, or the use of nanoparticles and ethosomes, thus making these compounds promising antimelanoma drug candidates for further development.

Betulinic acid in the treatment of breast cancer: Application and mechanism progress

Betulinic acid (BA) is a pentacyclic triterpene compound, which can be obtained by separation, chemical synthesis and biotransformation. BA has excellent biological activities, especially its role in the treatment of breast cancer deserves attention. Its mechanisms mainly include inducing mitochondrial oxidative stress, regulating specific protein (Sp) transcription factors, inhibiting breast cancer metastasis, inhibiting glucose metabolism and NF-κB pathway. In addition, BA can also increase the sensitivity of breast cancer cells to other chemotherapy drugs such as paclitaxel and reduce its toxic side effects. This article reviews the application and possible mechanism of BA in the treatment of breast cancer.

Substances of Natural Origin in Medicine: Plants vs. Cancer

Continuous monitoring of the population's health is the main method of learning about disease prevalence. National and international data draw attention to the persistently high rates of cancer incidence. This necessitates the intensification of efforts aimed at developing new, more effective chemotherapeutic and chemopreventive drugs. Plants represent an invaluable source of natural substances with versatile medicinal properties. Multidirectional activities exhibited by natural substances and their ability to modulate key signaling pathways, mainly related to cancer cell death, make these substances an important research direction. This review summarizes the information regarding plant-derived chemotherapeutic drugs, including their mechanisms of action, with a special focus on selected anti-cancer drugs (paclitaxel, irinotecan) approved in clinical practice. It also presents promising plant-based drug candidates currently being tested in clinical and preclinical trials (betulinic acid, resveratrol, and roburic acid).

Multifunctional Roles of Betulinic Acid in Cancer Chemoprevention: Spotlight on JAK/STAT, VEGF, EGF/EGFR, TRAIL/TRAIL-R, AKT/mTOR and Non-Coding RNAs in the Inhibition of Carcinogenesis and Metastasis

The pursual of novel anticancer molecules from natural sources has gained worthwhile appreciation, and a significant fraction of conceptual knowledge has revolutionized our understanding about heterogeneous nature of cancer. Betulinic acid has fascinated interdisciplinary researchers due to its tremendous pharmacological properties. Ground-breaking discoveries have unraveled previously unprecedented empirical proof-of-concept about momentous chemopreventive role of betulinic acid against carcinogenesis and metastasis. Deregulation of cell signaling pathways has been reported to play a linchpin role in cancer progression and colonization of metastatically competent cancer cells to the distant organs for the development of secondary tumors. Importantly, betulinic acid has demonstrated unique properties to mechanistically modulate oncogenic transduction cascades. In this mini-review, we have attempted to provide a sophisticated compendium of regulatory role of betulinic acid in cancer chemoprevention. We have partitioned this multi-component review into different sections in which we summarized landmark research-works which highlighted betulinic acid mediated regulation of JAK/STAT, VEGF, EGF/EGFR, TRAIL/TRAIL-R, AKT/mTOR and ubiquitination pathways in the inhibition of cancer. In parallel, betulinic acid mediated regulation of signaling cascades and non-coding RNAs will be critically analyzed in cell culture and animal model studies. Better comprehension of the pharmaceutical features of betulinic acid and mapping of the existing knowledge gaps will be valuable in the translatability of preclinical studies into rationally designed clinical trials.

Role of Medicinal plant-derived Nutraceuticals as a potential target for the treatment of breast cancer

Breast cancer (BC) is one of the most challenging cancers to treat, accounting for many cancer-related deaths. Over some years, chemotherapy, hormone treatment, radiation, and surgeries have been used to treat cancer. Unfortunately, these treatment options are unsuccessful due to crucial adverse reactions and multidrug tolerance/resistance. Although it is clear that substances in the nutraceuticals category have a lot of anti-cancer activity, using a supplementary therapy strategy, in this case, could be very beneficial. Nutraceuticals are therapeutic agents, which are nutrients that have drug-like characteristics and can be used to treat diseases. Plant nutraceuticals categorized into polyphenols, terpenoids, vitamins, alkaloids, and flavonoids are part of health food products, that have great potential for combating BC. Nutraceuticals can reduce BC's severity, limit malignant cell growth, and modify cancer-related mechanisms. Nutraceuticals acting by attenuating Hedgehog, Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Notch, and Wnt/β-catenin signaling are the main pathways in controlling the self-renewal of breast cancer stem cells (BCSCs). This article reviews some important nutraceuticals and their modes of action, which can be very powerful versus BC. PRACTICAL APPLICATIONS: Nutraceuticals' importance to the control and diagnosis of breast cancer is undeniable and cannot be overlooked. Natural dietary compounds have a wide range of uses and have been used in traditional medicine. In addition, these natural chemicals can enhance the effectiveness of other traditional medicines. They may also be used as a treatment process independently because of their capacity to affect several cancer pathways. This study highlights a variety of natural chemicals, and their mechanisms of action, routes, synergistic effects, and future potentials are all examined.

Betulinic acid: A natural promising anticancer drug, current situation, and future perspectives

Natural products serve as the single most productive source for the discovery of drugs and pharmaceutical leads. Among the various chemicals derived from microbes, plants, and animals, phytochemicals have emerged as potential candidates for the development of anticancer drugs due to their structural diversities, complexities, and pleiotropic effects. Herein, we discuss betulinic acid (BA), a ubiquitously distributed lupane structured pentacyclic triterpenoid, scrutinized as a promising natural agent for the prevention, suppression, and management of various human malignancies. Ease of availability, common occurrences, cell-specific cytotoxicity, and astonishing selectivity are the important factors that contribute to the development of BA as an anticancer agent. The current review delineates the mechanistic framework of BA-mediated cancer suppression through the modulation of multiple signaling pathways and also summarizes the key outcomes of BA in preclinical investigations.

Dietary phytochemicals/nutrients as promising protector of breast cancer development: a comprehensive analysis

Genetic change, particularly epigenetic alteration, is one of the imperative factors for sporadic breast cancer development in the worldwide population of women. The DNA methylation process is essential and natural for human cellular renewal and tissue homeostasis, but its dysregulation contributes to many pathological changes, including breast tumorigenesis. Chemopreventive agents mainly protect the abnormal DNA methylation either by hindering the division of pre-malignant cells or looming the DNA damage, which leads to malignancy. The present review article is about understanding the potential role of dietary phytochemicals in breast cancer prevention. Accordingly, a literature search of the published article until August 2021 has been performed. Further, we have investigated the binding affinity of different phytochemicals isolated from diverse dietary sources against the various oncogenic proteins related to breast cancer initiation to understand the common target(s) in breast cancer prevention mechanisms. Various small phytochemicals, especially dietary phytochemicals including sulforaphane, mahanine, resveratrol, linolenic acid, diallyl sulfide, benzyl/phenethyl isothiocyanate, etc. are being investigated as the chemopreventive agent to manage breast cancer development, and some of them have shown promising outcomes in the cited research. In this present review, we discuss the recent advancement in acceptance of such types of potential dietary phytochemicals as a chemopreventive agent against breast cancer development and their inner lining mechanism. The critical clinical trials and cohort studies have also been considered to understand the progress in contemporary perspectives.

Biodegradable and Bioactive Carriers Based on Poly(betulin disuccinate-co-sebacic Acid) for Rifampicin Delivery

This paper describes the preparation and characterization of polymer-drug systems based on polymeric microspheres obtained from poly(betulin disuccinate-co-sebacic acid). The active compound that was coupled to the betulin-based carriers was rifampicin (RIF), an ansamycin drug used in the treatment of tuberculosis. Poly(betulin disuccinate-co-sebacic acid) microspheres were prepared using a solvent evaporation technique from copolymers obtained by polycondensation of betulin disuccinate (DBB) and sebacic acid (SEB). The content of sebacic acid in the copolymers was 20, 40, 60 and 80 wt%, respectively. Small and large rifampicin-loaded microspheres were obtained for each of the copolymers. The initial amount of drug was 10, 30 or 50 wt%, based on the weight of the polymer. Particles obtained in this study were round in shape with diameter in the range of 2-21 μm and of orange to red colour originating from rifampicin. The RIF encapsulation efficacy varied from 7% to 33%. Drug loading varied from 2% to 13% and increased at a higher RIF ratio. The highest degree of drug loading was observed for large particles, in which the initial amount of drug (at the particle preparation stage) was 50 wt%. Microspheres prepared from betulin-based polyanhydrides may have significant applications in drug delivery systems. The concentration of loaded drug was enough to obtain bactericidal effects against reference S. Aureus ATCC 25923 bacteria.

Therapeutic Potential of Certain Terpenoids as Anticancer Agents: A Scoping Review

Cancer is a life-threatening disease and is considered to be among the leading causes of death worldwide. Chemoresistance, severe toxicity, relapse and metastasis are the major obstacles in cancer therapy. Therefore, introducing new therapeutic agents for cancer remains a priority to increase the range of effective treatments. Terpenoids, a large group of secondary metabolites, are derived from plant sources and are composed of several isoprene units. The high diversity of terpenoids has drawn attention to their potential anticancer and pharmacological activities. Some terpenoids exhibit an anticancer effect by triggering various stages of cancer progression, for example, suppressing the early stage of tumorigenesis via induction of cell cycle arrest, inhibiting cancer cell differentiation and activating apoptosis. At the late stage of cancer development, certain terpenoids are able to inhibit angiogenesis and metastasis via modulation of different intracellular signaling pathways. Significant progress in the identification of the mechanism of action and signaling pathways through which terpenoids exert their anticancer effects has been highlighted. Hence, in this review, the anticancer activities of twenty-five terpenoids are discussed in detail. In addition, this review provides insights on the current clinical trials and future directions towards the development of certain terpenoids as potential anticancer agents.

A Network Pharmacology Analysis of the Systems-Perspective Anticancer Mechanisms of the Herbal Drug FDY2004 for Breast Cancer

Breast cancer is a malignant tumor with high incidence, prevalence, and mortality rates in women. In recent years, herbal drugs have been assessed as anticancer therapy against breast cancer, owing to their promising therapeutic effects and reduced toxicity. However, their pharmacological mechanisms have not been fully explored at the systemic level. Here, we conducted a network pharmacology analysis of the systems-perspective molecular mechanisms of FDY2004, an anticancer herbal formula that consists of Moutan Radicis Cortex, Persicae Semen , and Rhei Radix et Rhizoma, against breast cancer. We determined that FDY2004 may contain 28 active compounds that exert pharmacological effects by targeting 113 breast cancer-related human genes/proteins. Based on the gene ontology terms, the FDY2004 targets were involved in modulating biological processes such as cell growth, cell proliferation, and apoptosis. Pathway enrichment analysis identified various breast cancer-associated pathways that may mediate the anticancer activity of FDY2004, including the PI3K-Akt, MAPK, TNF, HIF-1, focal adhesion, estrogen, ErbB, NF-kappa B, p53, and VEGF signaling pathways. Thus, our analysis offers novel insights into the anticancer properties of herbal drugs for breast cancer treatment from a systemic perspective.

Mito-Bomb: Targeting Mitochondria for Cancer Therapy

Cancer has been one of the most common life-threatening diseases for a long time. Traditional cancer therapies such as surgery, chemotherapy (CT), and radiotherapy (RT) have limited effects due to drug resistance, unsatisfactory treatment efficiency, and side effects. In recent years, photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT) have been utilized for cancer treatment owing to their high selectivity, minor resistance, and minimal toxicity. Accumulating evidence has demonstrated that selective delivery of drugs to specific subcellular organelles can significantly enhance the efficiency of cancer therapy. Mitochondria-targeting therapeutic strategies are promising for cancer therapy, which is attributed to the essential role of mitochondria in the regulation of cancer cell apoptosis, metabolism, and more vulnerable to hyperthermia and oxidative damage. Herein, the rational design, functionalization, and applications of diverse mitochondria-targeting units, involving organic phosphine/sulfur salts, quaternary ammonium (QA) salts, peptides, transition-metal complexes, guanidinium or bisguanidinium, as well as mitochondria-targeting cancer therapies including PDT, PTT, CDT, and others are summarized. This review aims to furnish researchers with deep insights and hints in the design and applications of novel mitochondria-targeting agents for cancer therapy.

Betulinic acid abates N-nitrosodimethylamine-induced changes in lipid metabolism, oxidative stress, and inflammation in the liver and kidney of Wistar rats

N-nitrosamines have been linked with cancer in humans due to their presence in drinking water and diets. This study evaluated the role of betulinic acid (BA) in abating oxidative stress, inflammation, and hyperlipidemia in rats treated with N-nitrosodimethylamine (NDMA). Twenty-four male rats were assigned into four equal groups. Group I served as the control, Group II received BA (25 mg/kg), Group III received NDMA (5 mg/kg) and, Group IV received BA (25 mg/kg) and NDMA (5 mg/kg). Results showed that the administration of NDMA significantly (p < 0.05) elevated malondialdehyde in the liver and kidney relative to controls. Activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, and the level of glutathione were significantly (p < 0.05) decreased by NDMA, while treatment with BA elevated the activities of these enzymes in the liver and kidney. The BA lowered serum interleukin-6 and tumor necrosis factor-alpha levels against the NDMA effect. Furthermore, NDMA increased hepatic and renal triglyceride while phospholipids levels were decreased. NDMA significantly modulated the activities of drug-metabolizing enzymes (aniline hydroxylase, aminopyrine-N-demethylase, and uridyldiphosphoglucuronyltransferase), while BA was able to restore these enzymes to values close to controls. Histology revealed the presence of infiltration and fibroplasia in the liver, while cortical degeneration was noticed in the kidney in NDMA-administered rats. These lesions were reduced in the NDMA rats treated with BA. The findings suggest that BA improves NDMA-induced damage in the liver and kidney of rats through reactions that can be linked with antioxidant, anti-inflammatory, and lipid-lowering pathways.

Betulinic acid in the treatment of tumour diseases: Application and research progress

Betulinic acid (BA) is a pentacyclic triterpene compound that can be obtained by separation, chemical synthesis and biotransformation from birch. BA has antitumour activity, and its mechanisms of action mainly include the induction of mitochondrial oxidative stress; the regulation of specificity protein transcription factors, and the inhibition of signal transducer and activator of transcription 3 and nuclear factor-κB signalling pathways. In addition, BA can increase the sensitivity of cancer cells to other chemotherapy drugs. Recent studies have shown that BA plays an anticancer role in several kinds of tumour diseases. In this article, the anticancer mechanism of BA and its application in the treatment of tumour diseases are reviewed.

Combination Treatment With Inhibitors of ERK and Autophagy Enhances Antitumor Activity of Betulinic Acid in Non-small-Cell Lung Cancer In Vivo and In Vitro

Aberrant activation of the Ras-ERK signaling pathway drives many important cancer phenotypes, and several inhibitors targeting such pathways are under investigation and/or approved by the FDA as single- or multi-agent therapy for patients with melanoma and non-small-cell lung cancer (NSCLC). Here, we show that betulinic acid (BA), a natural pentacyclic triterpenoid, inhibits cell proliferation, and induces apoptosis and protective autophagy in NSCLC cells. Thus, the cancer cell killing activity of BA is enhanced by autophagy inhibition. Mitogen-activated protein kinases, and especially ERK that facilitates cancer cell survival, are also activated by BA treatment. As such, in the presence of ERK inhibitors (ERKi), lung cancer cells are much more sensitive to BA. However, the dual treatment of BA and ERKi results in increased protective autophagy and AKT phosphorylation. Accordingly, inhibition of AKT has a highly synergistic anticancer effect with co-treatment of BA and ERKi. Notably, autophagy inhibition by hydroxychloroquine (HCQ) increases the response of lung cancer cells to BA in combination with ERKi. In vivo, the three-drug combination (BA, ERKi, and HCQ), resulted in superior therapeutic efficacy than single or dual treatments in the xenograft mouse model. Thus, our study provides a combined therapy strategy that is a highly effective treatment for patients with NSCLC.

Acankoreagenin and acankoreosides, a family of lupane triterpenoids with anti-inflammatory properties: an overview

Acankoreagenin (ACK, also known as acankoreanogenin and HLEDA) and impressic acid are two lupane-type triterpenes that can be isolated from various Acanthopanax and Schefflera species. They efficiently block activation of the NF-κB signaling pathway and the release of proinflammatory cytokines and/or the action of inflammation mediators (HMGB1, iNOS, and NO). These effects are the basis for the antiviral and anticancer activities reported with these pentacyclic compounds or their various glycoside derivatives. More than 15 acankoreosides (Ack-A to -O, and -R) and a few other mono- and bidesmosidic saponins (acantrifoside A and acangraciliside S) derive from the ACK aglycone. Compounds like Ack-A and -B are remarkable anti-inflammatory agents, inhibiting cytokine release from activated macrophages. Despite their effectiveness, ACK and impressic acid are far much less known and studied than the structurally related compounds betulinic acid and 23-hydroxybetulinic acid (anemosapogenin). The structural differences (notably the R/S stereoisomerism of the 3-hydroxyl group) and functional similarities of these compounds are discussed. The complete series of acankoreosides is presented for the first time. These natural products deserve further attention as anti-inflammatory agents, and ACK is recommended as a template for the design of new anticancer and antiviral drugs.

Deciphering the antitumoral potential of the bioactive metabolites from medicinal mushroom Inonotus obliquus

ETHNOPHARMACOLOGICAL RELEVANCE

The crude extracts of the medicinal mushroom Inonotus obliquus have been used as an effective traditional medicine to treat malicious tumors, gastritis, gastric ulcers, and other inflammatory conditions in Russia and most Baltic countries.

AIM OF THIS REVIEW

Deciphering the antitumoral potential of the bioactive metabolites from I. obliquus and addressing its possibility to be used as effective agents for tumor treatment, restoration of compromised immunity and protection of gastrointestinal damage caused by chemotherapy.

MATERIALS AND METHODS

We analysed the current achievements and dilemma in tumor chemo- or immunotherapy. In this context, we searched the published literatures on I. obliquus covering from 1990 to 2020, and summarized the activities of antitumor, antioxidation, and immunomodulation by the polysaccharides, triterpenoids, small phenolic compounds, and hispidin polyphenols. By comparing the merits and shortcomings of current and traditional methodology for tumor treatment, we further addressed feasibility for the use of I. obliquus as an effective natural drug for tumor treatment and prevention.

RESULTS

The diverse bioactive metabolites confer I. obliquus great potential to inhibit tumor growth and metastasis. Its antitumor activities are achieved either through suppressing multiple oncogenic signals including but not limited to the activation of NF-κB and FAK, and the expression of RhoA/MMP-9 via ERK1/2 and PI3K/Akt signaling pathway. The antitumor activities can also be achieved by inhibiting tyrosinase activity via PAK1-dependent signaling pathway or altering lysosomal membrane permeabilization through blocking tubulin polymerization and/or disturbing energy metabolism through LKB1/AMPK pathway. In addition, the metabolites from I. obliquus also harbour the potentials to reverse MDR either through selective inhibition on P-gp/ABCB1 or MRP1/ABCC1 proteins or the induction of G2/M checkpoint arrest in tumor cells of chemoresistant phenotypes mediated by Nox/ROS/NF-kB/STAT3 signaling pathway. In addition to the eminent effects in tumor inhibition, the metabolites in I. obliquus also exhibit immunomodulatory potential to restore the compromised immunity and protect against ulcerative damage of GI tract caused by chemotherapy.

CONCLUSIONS

I. obliquus possesses the potential to reduce incidence of tumorigenesis in healthy people. For those whose complete remission has been achieved by chemotherapy, administration of the fungus will inhibit the activation of upstream oncogenic signals and thereby prevent metastasis; for those who are in the process of chemotherapy administration of the fungus will not only chemosensitize the tumor cells and thereby increasing the chemotherapeutic effects, but also help to restore the compromised immunity and protect against ulcerative GI tract damage and other side-effects induced by chemotherapy.

Betulinic acid exhibits antiviral effects against dengue virus infection

Dengue virus (DENV) is an arthropod-borne virus that has developed into a prominent global health threat in recent decades. The main causative agent of dengue fever, the virus infects an estimated 390 million individuals across the globe each year. Despite the sharply increasing social and economic burden on global society caused by the disease, there is still a glaring lack of effective therapeutics against DENV. In this study, betulinic acid, a naturally occurring pentacyclic triterpenoid was established as an inhibitor of DENV infection in vitro. Time-course studies revealed that betulinic acid inhibits a post-entry stage of the DENV replication cycle and subsequent analyses also showed that the compound is able to inhibit viral RNA synthesis and protein production. Betulinic acid also demonstrated antiviral efficacy against other serotypes of DENV, as well as against other mosquito-borne RNA viruses such as Zika virus and Chikungunya virus, which are commonly found co-circulating together with DENV. As such, betulinic acid may serve as a valuable starting point for the development of antivirals to combat potential DENV outbreaks, particularly in tropical and subtropical regions which make up a large majority of documented infections.

Triple Negative Breast Cancer and Breast Epithelial Cells Differentially Reprogram Glucose and Lipid Metabolism upon Treatment with Triterpenic Acids

Plant-derived pentacyclic triterpenic acids (TAs) have gained increasing attention due to their multiple biological activities. Betulinic acid (BA) and ursolic acid (UA) modulate diverse pathways in carcinogenesis, offering increased changes of success in refractory cancers, such as triple negative breast cancer (TNBC). The present work aimed to assess the metabolic effects of BA and UA in MDA-MB-231 breast cancer cells (TNBC model), as well as in MCF-10A non-cancer breast epithelial cells, with a view to unveiling the involvement of metabolic reprogramming in cellular responses to these TAs. Cell viability and cell cycle analyses were followed by assessment of changes in the cells exo- and endometabolome through 1H NMR analysis of cell culture medium supernatants, aqueous and organic cell extracts. In MDA-MB-231 cells, BA was suggested to induce a transient upregulation of glucose consumption and glycolytic conversion, tricarboxylic acid (TCA) cycle intensification, and hydrolysis of neutral lipids, while UA effects were much less pronounced. In MCF-10A cells, boosting of glucose metabolism by the two TAs was accompanied by diversion of glycolytic intermediates to the hexosamine biosynthetic pathway (HBP) and the synthesis of neutral lipids, possibly stored in detoxifying lipid droplets. Additionally, breast epithelial cells intensified pyruvate consumption and TCA cycle activity, possibly to compensate for oxidative impairment of pyruvate glycolytic production. This study provided novel insights into the metabolic effects of BA and UA in cancer and non-cancer breast cells, thus improving current understanding of the action of these compounds at the molecular level.

Synthesis of Gelatin-Based Dual-Targeted Nanoparticles of Betulinic Acid for Antitumor Therapy

Betulinic acid (BA) is a natural antitumor agent and has biological activity against multiple human tumor cell lines with low cytotoxicity to normal cells, while the high hydrophobicity and the short half-life of this compound limit its clinical application. Here, gelatin-based dual-targeted nanoparticles of BA are promising to solve this problem. Hydrophobic BA is loaded in cyclodextrin to increase its solubility and prolong the circulation time in vivo. The nanoscale drug delivery systems can further enhance the bioavailability and the antitumor effect of BA and are passively targeted to the tumor tissue sites by enhanced permeability and retention effect. The RGD sequence of gelatin specifically recognizes tumor cells and brings agents into tumor cells. The nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared, nuclear magnetic resonance, etc. In addition, we observed antitumor activity of the nanoparticles using both cell-based assays and mouse xenograft tumors, which proved that betulinic acid/gelatin-γ-cyclodextrin nanoparticles had a better tumor inhibition effect than betulinic acid/γ-cyclodextrin inclusion compound.

Betulinic Acid and Brosimine B Hybrid Derivatives as Potential Agents against Female Cancers

Background:

Cancer is a multifactorial disease, representing one of the leading causes of death worldwide. On a global estimate, breast cancer is the most frequently occurring cancer in women and cervical cancer, the fourth most common. Both types of cancer remain the major cause of cancer-related mortality in developing countries. A strategy for rational drug design is hybridization, which aims to bring together in one molecule, two or more pharmacophores in order to reach several biological targets.

Objective:

The objective of this work was to develop new hybrids based on natural pharmacophores: Betulinic acid (1) and brosimine b (2), active in female cancer cell lines.

Methods:

The coupling reactions were carried out by Steglich esterification. Different compounds were designed for the complete and simplified structural hybridization of molecules. The anticancer activities of the compounds were evaluated in human cervical adenocarcinoma (HeLa), human cervical metastatic epidermoid carcinoma (ME-180), and human breast adenocarcinoma (MCF-7) cell lines.

Results:

Hybrid 3 presented higher potency (IC50 = 9.2 ± 0.5μM) and SI (43.5) selectively in MCF-7 cells (in relation to Vero cells) with its cytotoxic effect occurring via apoptosis. In addition, compound 6 showed activity in MCF-7 and HeLa cells with intermediate potency, but with high efficacy, acting via apoptosis as well.

Conclusion:

In this context, we showed that the combination of two complex structures generated the development of hybrids with differing inhibitory profiles and apoptotic modes of action, thus representing potential alternatives in female cancer treatment.

Betulinic Acid Inhibits Endometriosis Through Suppression of Estrogen Receptor β Signaling Pathway

Endometriosis is an inflammatory gynecological disorder characterized by endometrial tissue growth located outside of the uterine cavity in addition to chronic pelvic pain and infertility. In this study, we aim to develop a potential therapeutic treatment based on the pathogenesis and mechanism of Endometriosis. Our preliminary data showed that the expression of estrogen receptor β (ERβ) was significantly increased, while ERα was significantly decreased, in endometriotic cells compared to normal endometrial cells. Further investigation showed that betulinic acid (BA) treatment suppressed ERβ expression through epigenetic modification on the ERβ promoter, while had no effect on ERα expression. In addition, BA treatment suppresses ERβ target genes, including superoxide dismutase 2 (SOD2), nuclear respiratory factor-1 (NRF1), cyclooxygenase 2 (COX2), and matrix metalloproteinase-1 (MMP1), subsequently increasing oxidative stress, triggering mitochondrial dysfunction, decreasing elevated proinflammatory cytokines, and eventually suppressing endometriotic cell proliferation, mimicking the effect of ERβ knockdown. On the other hand, gain of ERβ by lentivirus infection in normal endometrial cells resulted in increased cell proliferation and proinflammatory cytokine release, while BA treatment diminished this effect through ERβ suppression with subsequent oxidative stress and apoptosis. Our results indicate that ERβ may be a major driving force for the development of endometriosis, while BA inhibits Endometriosis through specific suppression of the ERβ signaling pathway. This study provides a novel therapeutic strategy for endometriosis treatment through BA-mediated ERβ suppression.

Betulinic Acid Induces ROS-Dependent Apoptosis and S-Phase Arrest by Inhibiting the NF-κB Pathway in Human Multiple Myeloma

Betulinic acid (BA), as a prospective natural compound, shows outstanding antitumor bioactivities against many solid malignancies. However, its mechanism against multiple myeloma (MM) remains elusive. Herein, for the first time, we studied the antitumor activity of BA against MM both in vivo and in vitro. We showed that BA mediated cytotoxicity in MM cells through apoptosis, S-phase arrest, mitochondrial membrane potential (MMP) collapse, and overwhelming reactive oxygen species (ROS) accumulation. Moreover, when the ROS scavenger N-acetyl cysteine (NAC) effectively abated elevated ROS, the BA-induced apoptosis was partially reversed. Our results revealed that BA-mediated ROS overproduction played a pivotal role in anticancer activity. Molecularly, we found that BA resulted in marked inhibition of the aberrantly activated NF-κB pathway in MM. As demonstrated by using the NF-κB pathway-specific activator TNF-α and the inhibitor BAY 11-7082, BA-mediated inhibition of the NF-κB pathway directly promoted the overproduction of ROS and, ultimately, cell death. Furthermore, BA also exerted enormous tumor-inhibitory effects via repressing proliferation and inhibiting the NF-κB pathway in our xenograft model. Overall, by blocking the NF-κB pathway that breaks redox homeostasis, BA, as a potent NF-κB inhibitor, is a promising therapeutic alternative for MM.

New phosphate derivatives of betulin as anticancer agents: Synthesis, crystal structure, and molecular docking study

Betulin derivatives exhibit an antiproliferative activity and have been tested for many cancer cell lines. This paper describes a new series of 3-phosphate derivatives of betulin bearing different substituents at C28 position. The synthesized compounds were tested in vitro for their antiproliferative effect against human leukemia (MV-4-11 and CCRF/CEM), lung carcinoma (A549), prostate cancer (DU 145), melanoma (Hs 294T) cell lines, and murine leukemia P388. To explore the possible mechanism of anticancer activity for the most in vitro active compounds (4, 5, 7 and 8) and betulin, molecular docking was performed to the binding sites of potential anticancer targets, described for the various triterpene derivatives, including topoisomerase I and II, epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGFR), transcription factor NF-κB, anti-apoptotic protein Bcl-2 and peroxisome proliferator-activated receptor (PPARγ). According to the results of the docking, the best fit to the binding pocket of PPARγ was shown by compound 4.

Betulinic acid induces apoptosis and inhibits metastasis of human colorectal cancer cells in vitro and in vivo

Betulinic acid (BA) is a pentacyclic triterpenoids extracted from birch with a wide range of biological properties. Recent studies have shown that BA has significant cytotoxicity to various types of human cancer cells, and shows potential in cancer treatment. However, the efficacy of BA on human colorectal cancer tumor cells is still unclear. The purpose of our study was to evaluate the anti-cancer activity of BA in human colorectal cancer cells in vitro and in vivo to investigate the possible mechanism. In this experiment, we found that BA inhibited colorectal cancer cell lines in vitro with a time-dependent and dose-dependent manner. Moreover, BA could induce cell apoptosis by upregulating expression of Bax and cleaved caspase-3 and downregulating protein of Bcl-2. BA could increase the production of reactive oxygen species and reduce mitochondrial membrane potential of cancer cell, suggesting that BA induced cancer cells apoptosis by mitochondrial mediated pathways. Furthermore, BA significantly inhibited the migration and invasion of colorectal cancer cells, reduced the expression of matrix metalloproteinase (MMPs) and increased the expression of MMPs inhibitor (TIMP-2). In addition, the growth of tumor was significantly suppressed by intraperitoneal administration of 20 mg/kg/day of BA in a xenograft tumor mouse model of HCT-116. Histopathological and immunohistochemical analysis showed that MMP-2+ cells and Ki-67+ cells were reduced and cleaved caspase-3+ cells were increased in tumor tissues of mice after BA administration. The results showed that BA not only promoted the apoptosis of colorectal cancer cells, but also inhibited the metastasis of cancer cells. Our results suggest that BA can be a potential natural drug to inhibit the growth and metastasis of colorectal cancer.

Biological Activity and In Silico Study of 3-Modified Derivatives of Betulin and Betulinic Aldehyde

A series of 3-substituted derivatives of betulin and betulinic aldehyde were synthesized as promising anticancer agents. The newly triterpenes were tested against five human cancer cell lines like biphenotypic B myelomonocytic leukaemia (MV-4-11), adenocarcinoma (A549), prostate (Du-145), melanoma (Hs294T), breast adenocarcinoma (MCF-7) and normal human mammary gland (MCF-10A). The compound 9 showed towards Du-145, MCF-7 and Hs294T cells significant antiproliferative activity with IC₅₀ ranging from 7.3 to 10.6 μM. The evaluation of ADME properties of all compounds also includes their pharmacokinetic profile. The calculated TPSA values for synthetized derivatives are in the range between 43.38 Ų and 55.77 Ų suggesting high oral bioavailability. The molecular docking calculations showed that triterpene 9 fits the active site of the serine/threonine protein kinase Akt.

Antitumor Activity of Betulinic Acid and Betulin in Canine Cancer Cell Lines

BACKGROUND/AIM

Betulinic acid (BA) and betulin (BT) exhibit a variety of pharmacological properties including anti-cancer, anti-inflammatory and anti-oxidant ones. Canine lymphoma and osteosarcoma have a high mortality rate and need more effective therapeutic approaches. In this study, the anti-proliferative and pro-apoptotic effects of BA and BT were investigated in canine T-cell lymphoma (CL-1), canine B-cell lymphoma (CLBL-1) and canine osteosarcoma (D-17) cell lines.

MATERIALS AND METHODS

The cultured cells were treated with several concentrations of BA or BT for 24, 48 and 72 h, and cell proliferation was assessed by the MTT assay. Cell apoptotic rate and cell cycle were analyzed using flow cytometry.

RESULTS

Anti-proliferative effect of BT and BA was concentration- and time-dependent. Moreover, BA and BT arrested cell cycle in S phase in CL-1 and D-17 cells, and in G₀/G₁ phase in CLBL-1 cells.

CONCLUSION

Both compounds showed an antitumor activity, and the effects of BA were stronger than that of BT.

Therapeutic applications of betulinic acid nanoformulations

Betulinic acid (BA), a naturally occurring plant-derived pentacyclic triterpenoid, has gained attention in recent years owing to its broad-spectrum biological and medicinal properties. Despite the pharmacological activity of BA, it has been associated with some drawbacks, such as poor aqueous solubility and short half-life in vivo, which limit therapeutic application. To solve these problems, much work in recent years has focused on enhancing BA's aqueous solubility, half-life, and efficacy by using nanoscale drug delivery systems. Several different kinds of nanoscale delivery systems-including polymeric nanoparticles, magnetic nanoparticles, liposomes, polymeric conjugates, nanoemulsions, cyclodextrin complexes, and carbon nanotubes-have been developed for the delivery of BA. Here, we focus on the recent developments of novel nanoformulations used to deliver BA in order to improve its efficacy.

Plant Secondary Metabolites as Anticancer Agents: Successes in Clinical Trials and Therapeutic Application

Cancer is a multistage process resulting in an uncontrolled and abrupt division of cells and is one of the leading causes of mortality. The cases reported and the predictions for the near future are unthinkable. Food and Drug Administration data showed that 40% of the approved molecules are natural compounds or inspired by them, from which, 74% are used in anticancer therapy. In fact, natural products are viewed as more biologically friendly, that is less toxic to normal cells. In this review, the most recent and successful cases of secondary metabolites, including alkaloid, diterpene, triterpene and polyphenolic type compounds, with great anticancer potential are discussed. Focusing on the ones that are in clinical trial development or already used in anticancer therapy, therefore successful cases such as paclitaxel and homoharringtonine (in clinical use), curcumin and ingenol mebutate (in clinical trials) will be addressed. Each compound’s natural source, the most important steps in their discovery, their therapeutic targets, as well as the main structural modifications that can improve anticancer properties will be discussed in order to show the role of plants as a source of effective and safe anticancer drugs.

Betulinic acid impairs metastasis and reduces immunosuppressive cells in breast cancer models

Breast cancer is the most common female cancer with considerable metastatic potential, explaining the need for new candidates that inhibit tumor metastasis. In our study, betulinic acid (BA), a kind of pentacyclic triterpenoid compound derived from birch trees, was evaluated for its anti-metastasis activity in vitro and in vivo. BA decreased the viability of three breast cancer cell lines and markedly impaired cell migration and invasion. In addition, BA could inhibit the activation of stat3 and FAK which resulted in a reduction of matrix metalloproteinases (MMPs), and increase of the MMPs inhibitor (TIMP-2) expression. Moreover, in our animal experiment, intraperitoneal administration of 10 mg/kg/day BA suppressed 4T1 tumor growth and blocked formation of pulmonary metastases without obvious side effects. Furthermore, histological and immunohistochemical analyses showed a decrease in MMP-9 positive cells, MMP-2 positive cells and Ki-67 positive cells and an increase in cleaved caspase-3 positive cells upon BA administration. Notably, BA reduced the number of myeloid-derived suppressor cells (MDSCs) in the lungs and tumors. Interestingly, in our caudal vein model, BA also obviously suppressed 4T1 tumor pulmonary metastases. These findings suggested that BA might be a potential agent for inhibiting the growth and metastasis of breast cancer.

Betulinic acid induces apoptosis and ultrastructural changes in MDA-MB-231 breast cancer cells

The aim of this study is to investigate the effects of betulinic acid (BA) on triple-negative breast cancer MDA-MB-231 cells and observe the ultrastructural changes. The concentration of BA required to induce apoptosis in MDA-MB-231 cells has been previously reported. In this study, a cell counting kit-8 proliferation assay was used to measure cell viability and the apoptosis rate. Western blotting was performed to observe the protein expression levels of Bcl-2. Cell morphology and changes in cell density were observed by microscopy. Electron microscopy revealed pyknotic nuclei as well as vacuoles. Collectively, our results showed the morphological mechanisms by which BA impairs the ultrastructure of MDA-MB-231 cells.

Estrogenic terpenes and terpenoids: Pathways, functions and applications

Terpenes are made of the isoprene unit (C₅), and along with their derivatives, terpenoids, they are widely distributed in plants as active ingredients involved in anti-inflammation, anti-carcinogenesis and neuroprotection. Estrogenic terpenes and terpenoids are an important category of phytoestrogens and have been used as traditional medicines. The comprehensive list of estrogenic terpenes and terpenoids includes hemi-, mono-, sesqui-, di-, tri-, tetra- and polyterpenes, their derivatives, and meroterpenes, along with the signaling pathways and cellular functions on which their estrogenicity is exerted. Signaling pathways are further classified as bidirectional or unidirectional, the latter being further divided into two types depending upon the presence of both ligands, or the absence of one or both ligands. Although estrogenic activity of terpenes and terpenoids was evaluated by ligand-binding assays, yeast two-hybrid assays, reporter-gene assays, transcription assays, protein assays, cell assays and animal testing, the mechanism of estrogenic activity is still not fully understood. Applications of estrogenic terpenes and terpenoids are categorized into cancer treatment and prevention, cardioprotection, endocrine toxicity/reproductive dysfunction, food/supplement/traditional medicine, immunology/inflammation, menopausal syndromes and neuroprotection, where their benefits are discussed based on their availability, stability and variations.

A novel oncolytic adenovirus targeting Wnt signaling effectively inhibits cancer-stem like cell growth via metastasis, apoptosis and autophagy in HCC models

Cancer stem cells (CSCs), which are highly differentiated and self-renewing, play an important role in the occurrence, therapeutic resistant and metastasis of hepatacellular carcinoma (HCC). Oncolytic adenoviruses have targeted killing effect on tumor cells, and are invoked as candidate drugs for cancer treatment. We designed a dual-regulated oncolytic adenovirus Ad.wnt-E1A(△24bp)-TSLC1 that targets Wnt and Rb signaling pathways respectively, and carries the tumor suppressor gene, TSLC1. Previous studies have demonstrated that oncolytic adenovirus mediated TSLC1can target liver cancer and exhibit significant cytotoxicity. However, whether Ad.wnt-E1A(△24bp)-TSLC1 can effectively eliminate liver CSCs remains to be explored. We first used the spheroid culture to enrich the liver CSCs-like cells, and detected the self-renewal capacity, differentiation, drug resistance and tumorigenicity. The results showed that Ad-wnt-E1A(△24bp)-TSLC1 could effectively lead to autophagic death. In addition, recombinant adenovirus effectively induced the apoptosis, inhibit metastasis of hepatic CSCs-like cells in vivo. Further animal experiments indicated that Ad-wnt-E1A(△24bp)-TSLC1could effectively inhibit the growth of transplanted tumor of hepatic CSCs and prolong the survival time of mice. Therefore, the novel oncolytic adenovirus Ad.wnt-E1A(△24bp)-TSLC1 has potential application as a therapeutic target for HCC stem cells.