Cytotoxic activity of two natural sesquiterpene lactones, isobutyroylplenolin and arnicolide D, on human colon cancer cell line HT-29

New Hydroxylactones and Chloro-Hydroxylactones Obtained by Biotransformation of Bicyclic Halolactones and Their Antibacterial Activity

The aim of this study was to obtain new halolactones with a gem-dimethyl group in the cyclohexane ring (at the C-3 or C-5 carbon) and a methyl group in the lactone ring and then subject them to biotransformations using filamentous fungi. Halolactones in the form of mixtures of two diasteroisomers were subjected to screening biotransformations, which showed that only compounds with a gem-dimethyl group located at the C-5 carbon were transformed. Strains from the genus Fusarium carried out hydrolytic dehalogenation, while strains from the genus Absidia carried out hydroxylation of the C-7 carbon. Both substrates and biotransformation products were then tested for antimicrobial activity against multidrug-resistant strains of both bacteria and yeast-like fungi. The highest antifungal activity against C. dubliniensis and C. albicans strains was obtained for compound 5b, while antimicrobial activity against S. aureus MRSA was obtained for compound 4a.

Arnicolide D: a multi-targeted anticancer sesquiterpene lactone-preclinical efficacy and mechanistic insights

Arnicolide D, a potent sesquiterpene lactone from Centipeda minima, has emerged as a promising anticancer candidate, demonstrating significant efficacy in inhibiting cancer cell proliferation, inducing apoptosis, and suppressing metastasis across various cancer models. This comprehensive study delves into the molecular underpinnings of Arnicolide D's anticancer actions, emphasizing its impact on key signaling pathways such as PI3K/AKT/mTOR and STAT3, and its role in modulating cell cycle and survival mechanisms. Quantitative data from preclinical studies reveal Arnicolide D's dose-dependent cytotoxicity against cancer cell lines, including nasopharyngeal carcinoma, triple-negative breast cancer, and human colon carcinoma, showcasing its broad-spectrum anticancer potential. Given its multifaceted mechanisms and preclinical efficacy, Arnicolide D warrants further investigation in clinical settings to validate its therapeutic utility against cancer. The evidence presented underscores the need for rigorous pharmacokinetic and toxicological studies to establish safe dosing parameters for future clinical trials.

Arnicolide D induces endoplasmic reticulum stress-mediated oncosis via ATF4 and CHOP in hepatocellular carcinoma cells

Endoplasmic reticulum (ER) stress can trigger various cell death mechanisms beyond apoptosis, providing promise in cancer treatment. Oncosis, characterized by cellular swelling and increased membrane permeability, represents a non-apoptotic form of cell death. In our study, we discovered that Arnicolide D (AD), a natural sesquiterpene lactone compound, induces ER stress-mediated oncosis in hepatocellular carcinoma (HCC) cells, and this process is reactive oxygen species (ROS)-dependent. Furthermore, we identified the activation of the PERK-eIF2α-ATF4-CHOP pathway during ER stress as a pivotal factor in AD-induced oncosis. Notably, the protein synthesis inhibitor cycloheximide (CHX) was found to effectively reverse AD-induced oncosis, suggesting ATF4 and CHOP may hold crucial roles in the induction of oncosis by AD. These proteins play a vital part in promoting protein synthesis during ER stress, ultimately leading to cell death. Subsequent studies, in where we individually or simultaneously knocked down ATF4 and CHOP in HCC cells, provided further confirmation of their indispensable roles in AD-induced oncosis. Moreover, additional animal experiments not only substantiated AD's ability to inhibit HCC tumor growth but also solidified the essential role of ER stress-mediated and ROS-dependent oncosis in AD's therapeutic potential. In summary, our research findings strongly indicate that AD holds promise as a therapeutic agent for HCC by its ability to induce oncosis.

Mechanism of ferroptosis in breast cancer and research progress of natural compounds regulating ferroptosis

Breast cancer is the most prevalent cancer worldwide and its incidence increases with age, posing a significant threat to women's health globally. Due to the clinical heterogeneity of breast cancer, the majority of patients develop drug resistance and metastasis following treatment. Ferroptosis, a form of programmed cell death dependent on iron, is characterized by the accumulation of lipid peroxides, elevated levels of iron ions and lipid peroxidation. The underlying mechanisms and signalling pathways associated with ferroptosis are intricate and interconnected, involving various proteins and enzymes such as the cystine/glutamate antiporter, glutathione peroxidase 4, ferroptosis inhibitor 1 and dihydroorotate dehydrogenase. Consequently, emerging research suggests that ferroptosis may offer a novel target for breast cancer treatment; however, the mechanisms of ferroptosis in breast cancer urgently require resolution. Additionally, certain natural compounds have been reported to induce ferroptosis, thereby interfering with breast cancer. Therefore, this review not only discusses the molecular mechanisms of multiple signalling pathways that mediate ferroptosis in breast cancer (including metastasis, invasion and proliferation) but also elaborates on the mechanisms by which natural compounds induce ferroptosis in breast cancer. Furthermore, this review summarizes potential compound types that may serve as ferroptosis inducers in future tumour cells, providing lead compounds for the development of ferroptosis-inducing agents. Last, this review proposes the potential synergy of combining natural compounds with traditional breast cancer drugs in the treatment of breast cancer, thereby suggesting future directions and offering new insights.

A Review of the Research Applications of Centipeda minima

Centipeda minima is a traditional Chinese medicine with wide applications and diverse pharmacological effects. Scholars have conducted extensive studies on its relevant clinical applications, especially its remarkable efficacy in cancer treatment. This paper thoroughly investigates the chemical composition and identification, pharmacological effects, and toxicity, along with the safety of Centipeda minima, so as to lay the foundation for corresponding clinical applications and product development. Furthermore, as global scholars have conducted extensive research on such clinical applications and made significant progress, the future development and utilization of Centipeda minima's active ingredients to create novel drugs are of great clinical significance.

Brevilin A exerts anti-colorectal cancer effects and potently inhibits STAT3 signaling invitro

Colorectal cancer (CRC) is the third most common cause of cancer-related morbidity worldwide, with an estimated of 1.85 million new cases and 850,000 deaths every year. Nevertheless, the current treatment regimens for CRC have many disadvantages, including toxicities and off-targeted side effects. STAT3 (signal transducer and activator of transcription 3) has been considered as a promising molecular target for CRC therapy. Brevilin A, a sesquiterpene lactone compound rich in Centipedae Herba has potent anticancer effects in nasopharyngeal, prostate and breast cancer cells by inhibiting the STAT3 signaling. However, the anti-CRC effect of brevilin A and the underlying mechanism of action have not been fully elucidated. In this study, we aimed to investigate the involvement of STAT3 signaling in the anti-CRC action of brevilin A. Here, HCT-116 and CT26 cell models were used to investigate the anti-CRC effects of brevilin A in vitro. HCT-116 cells overespressing with STAT3 were used to evaluate the involvement of STAT3 signaling in the anti-CRC effect of brevilin A. Screening of 49 phosphorylated tyrosine kinases in the HCT-116 cells after brevilin A treatment was performed by using the human phospho-receptor tyrosine kinase (phospho-RTK) array. Results showed that brevilin A inhibited cell proliferation and cell viability, induced apoptosis, reduced cell migration and invasion, inhibited angiogenesis, lowered the protein expression levels of phospho-Src (Tyr416), phospho-JAK2 (Y1007/1008) and phospho-STAT3 (Tyr705), and inhibited STAT3 activation and nuclear localization. Brevilin A also significantly reduced the protein expression levels of STAT3 target genes, such as MMP-2, VEGF and Bcl-xL. More importantly, over-activation of STAT3 diminished brevilin A's effects on cell viability. All these results suggest that brevilin A exerts potent anti-CRC effects, at least in part, by inhibiting STAT3 signaling. Our findings provide a strong pharmacological basis for the future exploration and development of brevilin A as a novel STAT3-targeting phytotherapeutic agent for CRC treatment.

Two sesquiterpene lactones, arnicolide B and arnicolide C, isolated from Centipeda minima, exert anti-inflammatory effects in LPS stimulated RAW 264.7 macrophages via inactivation of the MAPK pathway

Arnicolide B and arnicolide C are two sesquiterpene lactones isolated and identified from Centipeda minima, but the anti-inflammatory effects and mechanisms of these two compounds have not been reported. In this study, LPS was used to establish RAW 264.7 macrophages inflammatory response model. Griess, ELISA, Western blot were used to investigate the anti-inflammatory effects in vitro and the molecular mechanisms of these two active compounds. The results showed that arnicolide B and arnicolide C could not only inhibit the production of inflammatory mediators NO, PGE2, TNF-α and IL-6, but also down-regulate the high expression of inflammatory proteins iNOS and COX-2. Furthermore, arnicolide B and arnicolide C inhibited the phosphorylation of ERK, JNK, p38 proteins in the MAPK signaling pathway, but had no effect on the degradation of IκB-α protein and the activation of the NF-κB pathway. As conclusion, these two compounds exert anti-inflammatory effects by inactivation of the MAPK pathway.

Promising anticancer activities and mechanisms of action of active compounds from the medicinal herb Centipeda minima (L.) A. Braun & Asch

BACKGROUND

Centipeda minima (L.) A. Braun & Asch (C. minima) has been used as a traditional Chinese herbal medicine to treat multiple diseases, including sinusitis, rhinitis, headache, and allergy. To date, the anticancer properties of C. minima have drawn considerable attention owing to the anticancer potential of C. minima extracts, the identification of active components, and the elucidation of underlying molecular mechanisms. However, the anticancer properties and significance of active components in C. minima have rarely been summarized.

PURPOSE

This review presents a comprehensive summary of the anticancer properties exhibited by active components of C. minima.

METHODS

An extensive search for published articles on the anticancer activities and active components of C. minima was performed using Web of Science, PubMed, Science Direct, and Google Scholar.

RESULTS

C. minima extracts exhibited both anticancer and chemosensitizing effects. Phytochemical studies have identified the active anticancer components of C. minima extracts. Sesquiterpene lactones, such as 6-O-angeloylplenolin (6-OAP, or brevilin A) and arnicolide D, have similar structures and anticancer mechanisms. As the most abundant sesquiterpene lactone in C. minima, 6-OAP exhibits anticancer activities mainly by targeting Skp1-Cullin1-F-box protein (SCF) E3 ubiquitin ligase and signal transducers and activators of transcription 3 (STAT3). Clinical trials have assessed the potential of 6-OAP in patients with vertex balding and alopecia areata, given its effect on JAK-STATs signaling. Chlorogenic acid, a representative organic acid in C. minima, reportedly possesses anticancer potential and inhibits tumor growth by affecting tumor microenvironment and has been approved for phase II clinical trials in patients with glioma in China.

CONCLUSION

In the present review, we highlight intriguing anticancer properties mediated by active compounds isolated from C. minima extracts, particularly sesquiterpene lactones, which might provide clues for developing novel anticancer drugs. Relevant clinical trials on chlorogenic acid and 6-OAP can promote anticancer clinical applications. Therefore, it is worth comprehensively elucidating underlying anticancer mechanisms and conducting clinical trials on C. minima and its active components.

Deoxyelephantopin Induces Apoptosis and Enhances Chemosensitivity of Colon Cancer via miR-205/Bcl2 Axis

Colon cancer (CC) is one of the major causes of cancer death in humans. Despite recent advances in the management of CC, the prognosis is still poor and a new strategy for effective therapy is imperative. Deoxyelephantopin (DET), extracted from an important medicinal plant, Elephantopus scaber L., has been reported to exhibit excellent anti-inflammatory and -cancer activities, while the detailed anti-cancer mechanism remains unclear. Herein, we found that DET showed a significant CC inhibiting effect in vitro and in vivo without obvious organ toxicity. Mechanistically, DET inhibited CC cells and tumor growth by inducing G2/M phase arrest and subsequent apoptosis. DET-mediated cell cycle arrest was caused by severe DNA damage, and DET decreased the Bcl2 expression level in a dose-dependent manner to promote CC cell apoptosis, whereas restoring Bcl2 expression reduced apoptosis to a certain extent. Moreover, we identified a microRNA complementary to the 3'-UTR of Bcl2, miR-205, that responded to the DET treatment. An inhibitor of miR-205 could recover Bcl2 expression and promoted the survival of CC cells upon DET treatment. To further examine the potential value of the drug, we evaluated the combinative effects of DET and 5-Fluorouracil (5FU) through Jin's formula and revealed that DET acted synergistically with 5FU, resulting in enhancing the chemotherapeutic sensitivity of CC to 5FU. Our results consolidate DET as a potent drug for the treatment of CC when it is used alone or combined with 5FU, and elucidate the importance of the miR-205-Bcl2 axis in DET treatment.

Centipeda minima extract sensitizes lung cancer cells to DNA-crosslinking agents via targeting Fanconi anemia pathway

BACKGROUND

Intrinsic and acquired chemoresistance remains a critical challenge in lung cancer chemotherapy. Fanconi anemia (FA) pathway plays an important role in antagonizing the cytotoxic effects of chemotherapeutics by repairing DNA damage. We recently demonstrated that the traditional Chinese medicinal herb, Centipeda minima (C. minima), possessed anti-inflammatory and antioxidant properties. However, the potential anticancer application of C. minima and the underlying mechanisms remain unclear.

PURPOSE

We aimed to investigate the combined anticancer effects of the ethanol extract of C. minima (ECM) and DNA-crosslinking agents on non-small cell lung cancer (NSCLC) and elucidate the underlying mechanisms.

METHODS

Cell viability and flow cytometry assay were performed to determine the synergistic cytotoxicity of ECM and DNA-crosslinking agents, cisplatin (CDDP) or mitomycin C (MMC), in NSCLC cells. Western blotting and immunofluorescence were conducted to examine the effects of ECM on protein expression in DNA damage repair pathway. Comet assay was applied to evaluate DNA damage levels. Subcutaneous xenografts of NSCLC were established to evaluate the combined anticancer effects of ECM and CDDP.

RESULTS

Combined treatments with ECM and DNA-crosslinking agents exhibited synergistic cytotoxic effects against A549 and H1299 cells. FANCD2 was highly expressed in NSCLC that correlates with poor prognosis of NSCLC patients, based on the online database analysis. ECM significantly inhibited DNA damage-induced monoubiquitination and nuclear foci formation of FANCD2, thereby sensitizing NSCLC to CDDP- or MMC-induced DNA damage and apoptosis, as evidenced by increased expression of γ-H2AX, increased cleavage of caspases-3 and PARP, and enhanced Annexin V-FITC/PI staining. Further, ECM can also decrease the protein level of FANCD2 that contributes to the chemosensitizing effects. Moreover, ECM significantly attenuated CDDP-mediated S-phase arrest by antagonizing the activation of ATR/Chk1 pathway in NSCLC cells. Animal experiments further demonstrated that ECM and CDDP combination treatment synergistically inhibited tumor growth by decreasing FANCD2 protein level in tumor tissues.

CONCLUSION

Our results demonstrated that ECM can inhibit DNA-crosslinking agents-induced activation of FA pathway by attenuating both the expression and monoubiquitination of FANCD2. ECM and CDDP combination therapy exhibited synergistic anticancer effects both in vitro and in vivo, indicating that ECM and its active components might serve as novel anticancer drugs in the combination chemotherapy.

Medicinal Plant Centipeda Minima: A Resource of Bioactive Compounds

BACKGROUND

Centipeda minima (the family Asteraceae) is an annual herbaceous plant native to the tropical regions, especially in eastern tropical Asia. C. minima is well-known in the list of medicinal plants with capacities in treatment of whooping cough, nasal allergy, malaria, and asthma. More than sixty reports on phytochemical and pharmacological aspects of this plant are now available, but a supportive review is insufficient.

OBJECTIVE

The current review aims to make a compilation of almost all of the isolated compounds from the title plant, together with their pharmacological activities.

METHODOLOGY

Centipeda minima is a meaningful keyword to search for previous references, while the reliable databases, such as Sci-Finder, Google Scholar, Pub Med, Science Direct, the Web of Science, Scopus, Bentham science, Taylor Francis, Springer, IOP Science were utilized at most.

CONCLUSION

More than one hundred secondary metabolites, classifying as terpenoids, flavonoids, mono-phenols, fatty acids, amides, and other types, were isolated from this plant. Among them, sesquiterpene lactones are dominant in either C. minima species or numerous plants of genus Centipeda. These phytochemical groups also possessed various biological results like anti-cancer, anti-bacteria, anti-allergy, anti-virus, anti-inflammation, and hepatoprotective activities. With many kinds of bioactive results such as anti-cancer and anti-inflammation, the use of C. minima plant extracts and isolated compounds for drug development seems to be a futuristic strategy.

A Comprehensive Overview of Colon Cancer- A Grim Reaper of the 21st Century

A few decades ago, the incidence of colorectal cancer (CRC) was low and is now the fourth in the list of deadly cancers producing nearly a million deaths annually. A population that is aging along with risk factors such as smoking, obesity, sedentary lifestyle with little or no physical activity, and non-healthy food habits of developed countries can increase the risk of colorectal cancer. The balance in gut microbiota and the metabolites produced during bacterial fermentation within the host plays a significant role in regulating intestinal diseases as well as colorectal cancer development. Recent progress in the understanding of illness resulted in multiple treatment options such as surgery, radiation, and chemotherapy, including targeted therapy and multitherapies. The treatment plan for CRC depends on the location, stage and grade of cancer as well as genomic biomarker tests. Despite all the advancements made in the genetic and molecular aspects of the disease, the knowledge seems inadequate as the drug action as well as the wide variation in drug response did not appear strongly correlated with the individual molecular and genetic characteristics, which suggests the requirement of comprehensive molecular understanding of this complex heterogeneous disease. Furthermore, multitherapies or a broad spectrum approach, which is an amalgamation of the various promising as well as effective therapeutic strategies that can tackle heterogeneity and act on several targets of the disease, need to be validated in clinical studies. The latest treatment options have significantly increased the survival of up to three years in the case of advanced disease. The fact that colorectal cancer is developed from a polypoid precursor, as well as the symptoms of the disease that occur at an advanced stage, underlines how screening programs can help early detection and decrease mortality as well as morbidity from CRC.

Guaianolides from Tanacetopsis karataviensis (Kovalevsk.) Kovalevsk

In continuation of our phytochemical study on the aerial part of Tanacetopsis karataviensis (Kovalevsk.) Kovalevsk, three new guaiane-type sesquiterpene lactones were isolated namely karatanolide (1), 11,13β-dihydrokaratanolide (2) and 11,13α-dihydrokaratanolide (3), in addition to the two known sesquiterpene lactones 1β,10α-dihydroxyarglabin (4) and artefin (5). The structures of the isolated sesquiterpene lactones were elucidated by IR and NMR spectroscopy. Single crystal X-ray diffraction allowed to unambiguously confirm the structure of the isolated sesquiterpene lactones. Quantum chemical calculations of the guaianolides 1-3 suggested the existence of two conformations for the seven-membered cycle. All sesquiterpene lactones from Tanacetopsis karataviensis were isolated for the first time.

Sesquiterpenes and their derivatives-natural anticancer compounds: An update

Sesquiterpenes belong to the largest group of plant secondary metabolites, which consist of three isoprene building units. These compounds are widely distributed in various angiosperms, a few gymnosperms and bryophytes. Sesquiterpenes and their allied derivatives are bio-synthesized in various plant parts including leaves, fruits and roots. These plant-based metabolites are predominantly identified in the Asteraceae family, wherein up to 5000 complexes have been documented to date. Sesquiterpenes and their derivatives are characteristically associated with plant defence mechanisms owing to their antifungal, antibacterial and antiviral activities. Over the last two decades, these compounds have been reportedly demonstrated health promoting perspectives against a wide range of metabolic syndromes i.e. hyperglycemia, hyperlipidemia, cardiovascular complications, neural disorders, diabetes, and cancer. The high potential of sesquiterpenes and their derivatives against various cancers like breast, colon, bladder, pancreatic, prostate, cervical, brain, liver, blood, ovarium, bone, endometrial, oral, lung, eye, stomach and kidney are the object of this review. Predominantly, it recapitulates the literature elucidating sesquiterpenes and their derivatives while highlighting the mechanistic approaches associated with their potent anticancer activities such as modulating nuclear factor kappa (NF-kB) activity, inhibitory action against lipid peroxidation and retarding the production of reactive oxygen & nitrogen species (ROS&RNS).

Arnicolide D Inhibits Triple Negative Breast Cancer Cell Proliferation by Suppression of Akt/mTOR and STAT3 Signaling Pathways

Triple-Negative Breast Cancer (TNBC) is a most dangerous breast cancer subtype. The naturally occurring sesquiterpene lactone, arnicolide D (AD), has proven effective against a variety of tumors, however, the inhibitory effects of AD against TNBC and the underlying mechanisms remain unclear. In the present study, two TNBC cell lines (MDA-MB-231 and MDA-MB-468) and an MDA-MB-231 xenograft mouse model were employed to investigate the anti-TNBC effects of AD in vitro and in vivo. Cell viability was assessed by MTT assay. Cell cycle arrest and apoptosis were analyzed by flow cytometry. Protein levels were determined by immunoblotting. In vitro studies demonstrated that AD significantly decreased cell viability, and induced G2/M cell cycle arrest and apoptosis. In vivo assays showed that oral administration of 25 or 50 mg/kg AD for 22 days led to a reduction of tumor weights by 24.7% or 41.0%, without appreciable side effects. Mechanistically, AD inhibited the activation of Akt/mTOR and STAT3 signaling pathways. Based on our findings, AD is a promising candidate for development as an adjunctive therapeutic drug for TNBC.

Modulation of dysregulated cancer metabolism by plant secondary metabolites: A mechanistic review

Several signaling pathways and basic metabolites are responsible for the control of metabolism in both normal and cancer cells. As emerging hallmarks of cancer metabolism, the abnormal activities of these pathways are of the most noticeable events in cancer. This altered metabolism expedites the survival and proliferation of cancer cells, which have attracted a substantial amount of interest in cancer metabolism. Nowadays, targeting metabolism and cross-linked signaling pathways in cancer has been a hot topic to investigate novel drugs against cancer. Despite the efficiency of conventional drugs in cancer therapy, their associated toxicity, resistance, and high-cost cause limitations in their application. Besides, considering the numerous signaling pathways cross-linked with cancer metabolism, discovery, and development of multi-targeted and safe natural compounds has been a high priority. Natural secondary metabolites have exhibited promising anticancer effects by targeting dysregulated signaling pathways linked to cancer metabolism. The present review reveals the metabolism and cross-linked dysregulated signaling pathways in cancer. The promising therapeutic targets in cancer, as well as the critical role of natural secondary metabolites for significant anticancer enhancements, have also been highlighted to find novel/potential therapeutic agents for cancer treatment.

Arnicolide D exerts anti-melanoma effects and inhibits the NF-κB pathway

BACKGROUND

Melanoma is a lethal cancer. NF-κB has been validated as a molecular target for melanoma treatment. Current therapies for melanoma have limitations. Novel targeted therapeutics are needed. Arnicolide D (Ar-D), a sesquiterpene lactone isolated from the dried whole plant of Centipeda minima (L.) A. Br. et Aschers., has been reported to inhibit NF-κB activity in colorectal cancer cells.

PURPOSE

To investigate the anti-melanoma effects of Ar-D in vitro and in vivo; and to determine whether Ar-D inhibits the NF-κB pathway in melanoma cells.

METHODS

A B16F10 allograft mouse model and two melanoma cell lines (A375 and B16F10) were used to investigate the anti-melanoma effects of Ar-D in vivo and in vitro. Dacarbazine was used as a positive control. Cell viability was assessed by MTT and crystal violet staining assays. Cell cycle arrest and apoptosis were analyzed by flow cytometry. Protein levels were determined by Immunoblotting.

RESULTS

In vivo assays showed that the average tumor weight in Ar-D-treated group (4 mg/kg, i.p, 15 days) was reduced by 53.7%, when compared with the control group. In vitro studies demonstrated that Ar-D reduced cell viability, induced G2/M cell cycle arrest and apoptosis, elevated levels of cell cycle regulatory proteins p53 and p21, and lowered levels of G2/M checkpoint proteins Cdc2 and Cyclin B1 in melanoma cells. Mechanistically, Ar-D inhibited the activity of IKKα/β, the degradation of IκBα, and the phosphorylation and expression of NF-κB p65 in melanoma cells.

CONCLUSION

Ar-D has anti-melanoma effects, and inhibition of the IKK/IκBα/NF-κB p65 pathway is involved in the effects.

Brevilin A Induces Cell Cycle Arrest and Apoptosis in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most common malignant cancers in Southeast Asia and Southern China. Centipeda minima extract (CME) had previously demonstrated anti-cancer effects in human NPC. Brevilin A, a sesquiterpene lactone isolated from C. minima, has been reported to exhibit biological activities. In this study, we investigated its anti-NPC effect and further explored its molecular mechanisms. The effects of brevilin A were tested in the NPC cell lines CNE-1, CNE-2, SUNE-1, HONE1, and C666-1. Effects of brevilin A on cell viability were determined by MTT assay, and cell cycle and apoptosis were detected by flow cytometry. The molecular mechanism of cell cycle regulation and apoptosis were investigated via Western blot. Results showed that brevilin A inhibited NPC cell viability in a concentration- and time-dependent manner. Brevilin A induced cell cycle arrest at G2/M and induced apoptosis. Western blot results demonstrated that brevilin A could down-regulate cyclin D3, cdc2, p-PI3K, p-AKT, p-mTOR, and p-STAT3, while up-regulating cleaved PARP, cleaved caspase 9, and Bax. Regulation of cyclin B1, cdk6, and Bcl-2 expression by brevilin A showed dynamic changes according to dose and time. In the tumor xenograft model, brevilin A could reduce tumor growth, at a similar magnitude to cisplatin. However, notably, whereas cisplatin treatment led to significant weight loss in treated mice, treatment with brevilin A did not, indicating its relative lack of toxicity. Taken together, brevilin A regulated cell cycle, activated the caspase signaling pathway, and inhibited PI3K/AKT/mTOR and STAT3 signaling pathways in vitro, and exhibited similar efficacy to the common chemotherapeutic cisplatin in vivo, without its associated toxicity. These findings provide a framework for the preclinical development of brevilin A as a chemotherapeutic for NPC.

Arnicolide D, from the herb Centipeda minima, Is a Therapeutic Candidate against Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a high morbidity and mortality cancer with an obvious racial and geographic bias, particularly endemic to Southeast China. Our previous studies demonstrated that Centipeda minima extract (CME) exhibited anti-cancer effects in human NPC cell lines. Arnicolide C and arnicolide D are sesquiterpene lactones isolated from Centipeda minima. In this study, for the first time, we investigated their anti-NPC effects and further explored the related molecular mechanisms. The effects of both arnicolide C and arnicolide D were tested in NPC cells CNE-1, CNE-2, SUNE-1, HONE1, and C666-1. The results showed that the two compounds inhibited NPC cell viability in a concentration- and time-dependent manner. As the inhibitory effect of arnicolide D was the more pronounced of the two, our following studies focused on this compound. Arnicolide D could induce cell cycle arrest at G₂/M, and induce cell apoptosis. The molecular mechanism of cell cycle regulation and apoptosis induction was investigated, and the results showed that arnicolide D could downregulate cyclin D3, cdc2, p-PI3K, p-AKT, p-mTOR, and p-STAT3, and upregulate cleaved PARP, cleaved caspase 9, and Bax. Regulation of cyclin B1, cdk6, and Bcl-2 expression by arnicolide D showed dynamic changes according to dose and time. Taken together, arnicolide D modulated the cell cycle, activated the caspase signaling pathway, and inhibited the PI3K/AKT/mTOR and STAT3 signaling pathways. These findings provide a solid base of evidence for arnicolide D as a lead compound for further development, and act as proof for the viability of drug development from traditional Chinese medicines.

Chemopreventive effects of some popular phytochemicals on human colon cancer: a review

The present review summarizes (1) the epidemiology and etiology of colon cancer, (2) generalized cancer chemoprotective mechanisms, and (3) the chemopreventive properties of some popular phytochemicals as well as some phytochemicals developed by our research group recently.

Terpenoids as anti-colon cancer agents - A comprehensive review on its mechanistic perspectives

Multistep model of colon carcinogenesis has provided the framework to advance our understanding of the molecular basis of colon cancer. This multistage process of carcinogenesis takes a long period to transform from a normal epithelial cell to invasive carcinoma. Thus, it provides enough time to intervene the process of carcinogenesis especially through dietary modification. In spite of the in-depth understanding of the colon cancer etiology and pathophysiology and its association with diet, colon cancer remains a major cause of cancer mortality worldwide. Phytochemicals and their derivatives are gaining attention in cancer prevention and treatment strategies because of cancer chemotherapy associated adverse effects. Being the largest group of phytochemicals traditionally used for medicinal purpose in India and China, terpenoids are recently being explored as anticancer agents. Anticancer properties of terpenoids are associated with various mechanisms like counteraction of oxidative stress, potentiating endogenous antioxidants, improving detoxification potential, disrupting cell survival pathways and inducing apoptosis. This review gives a comprehensive idea of naturally occurring terpenoids as useful agents for the prevention of colon cancer with reference to their classes, sources and molecular targets. Based on the explored molecular targets further research in colon cancer chemoprevention is warranted.