Cell apoptosis induced by delta-elemene in colorectal adenocarcinoma cells via a mitochondrial-mediated pathway

Antimicrobial Activity the Essential Oil from Croton pluriglandulosus Carn. Leaves against Microorganisms of Clinical Interest

Multiresistant pathogens pose a serious threat to human health. The genus Candida is one class of human pathogenic yeasts responsible for infections affecting healthy and immunocompromised patients. In this context, plant essential oils emerged as a future natural alternative to control the diseases caused by these pathogens. Based on that, the present study aimed to evaluate the antimicrobial potential of essential oil from C. pluriglandulosus and understand the mechanism of action. Here, it highlighted antimicrobial activity and the mechanisms of action of the essential oil extracted from C. pluriglandulosus Carn.-Torres & Riina (CpEO) leaves on human pathogenic microorganisms in planktonic and biofilm lifestyles. In addition, for the first time, the oil composition was revealed by GC-MS analysis and the toxicity to human red blood cells (HRBC). Twenty-six chemical compounds were identified in CpEO, elemicin, bicyclogermacrene, caryophyllene, brevifolin, and 2,4,6-trimethoxy-styrene. Through hemolytic assay, it was shown that CpEO has no toxicity to human RBCs. At the concentration of 50 μg mL^-1, CpEO did not show great antibacterial potential. However, promising data were found for C. krusei and C. parapsilosis inhibiting by 89.3% and 80.7% of planktonic cell growth and 83.5% and 77.9% the biofilm formation, respectively. Furthermore, the mechanisms of action CpEO were elucidated by fluorescence. Scanning electron microscopy revealed damage to the cell membrane and pore formation, ROS overproduction, and induction of apoptosis in candida cells. Our results reinforce the potential of CpEO as an effective alternative molecule of pharmaceutical interest.

Daily Consumption of Lemon and Ginger Herbal Infusion Caused Tumor Regression and Activation of the Immune System in a Mouse Model of Breast Cancer

The Mediterranean diet includes the consumption of various fruits and vegetables. Lemon and ginger are highly popular in Mediterranean cuisine. The current study aims to evaluate both anticancer and immunomodulatory activities of lemon and ginger combination. The antiproliferative activities of the combination were tested against different cancer cell lines using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The degree of apoptosis induction and vascular endothelial growth factor expression were detected using ELISA. Balb/C mice were inoculated with the EMT6/P breast cancer cells and received combination water extract orally for 14 days. The effect of the water extract on splenocytes proliferation was measured using the mitogen proliferation assay. Macrophage function was evaluated using the nitro blue tetrazolium assay and pinocytosis was assessed using the neutral red method. Gas chromatography coupled to the tandem mass spectrometry was used to determine the composition of the combination. The lemon and ginger combination showed significant apoptosis induction and angiogenesis suppression effects. Fifty percent of the mice taking this combination did not develop tumors with a percentage of tumor reduction of 32.8%. This combination showed a potent effect in stimulating pinocytosis. Alpha-pinene and α-terpineol were detected in high percentages in the combination water extract. The lemon and ginger combination represents promising options to develop anticancer infusions for augmenting conventional anticancer therapies. Further testing is required to understand the exact molecular mechanisms of this combination.

A comprehensive review on phytochemistry, bioactivities, toxicity studies, and clinical studies on Ficus carica Linn. leaves

The leaves of Ficus carica Linn. (FC) have been widely used for medicine purposes since ancient times, and its decoction is consumed as tea. Many scientific papers have been published in the literature and the researchers across the world are still exploring the health benefits of FC leaves. In this review, we have collected the literature published since 2010 in the databases: Pubmed, Scopus, Web of Science, SciFinder, Google Scholar, Baidu Scholar and local classic herbal literature. The summary of the chemical constituents in FC leaves, biological activities, toxicity studies, and clinical studies carried out on FC leaves is provided in this review. In addition, the molecular mechanisms of the active constituents in FC leaves are also comprehended. FC leaves are reported to 126 constituents out of which the polyphenolic compounds are predominant. Many scientific studies have proven the antidiabetic, antioxidant, anti-inflammatory, anticancer, anticholinesterase, antimicrobial, hepatoprotective, and renoprotective activities. Many studies have carried out to provide the insights on molecular pathways involved in the biological activities of FC leaves. The toxicity studies have suggested that FC leaves exhibit toxicity only at very high doses. We believe this review serve as a comprehensive resource for those who are interested to understand the scientific evidence that support the medicinal values of FC leaves and also the research gaps to further improve the commercial value and health benefits of FC leaves.

Recent Advances in Characterizing Natural Products that Regulate Autophagy

Autophagy, an intricate response to nutrient deprivation, pathogen infection, Endoplasmic Reticulum (ER)-stress and drugs, is crucial for the homeostatic maintenance in living cells. This highly regulated, multistep process has been involved in several diseases including cardiovascular and neurodegenerative diseases, especially in cancer. It can function as either a promoter or a suppressor in cancer, which underlines the potential utility as a therapeutic target. In recent years, increasing evidence has suggested that many natural products could modulate autophagy through diverse signaling pathways, either inducing or inhibiting. In this review, we briefly introduce autophagy and systematically describe several classes of natural products that implicated autophagy modulation. These compounds are of great interest for their potential activity against many types of cancer, such as ovarian, breast, cervical, pancreatic, and so on, hoping to provide valuable information for the development of cancer treatments based on autophagy.

Inhibition of β-elemene on the expressions of HIF-lα, VEGF and iNOS in diabetic rats model

AIM

To evaluate the effect of β-elemene on the expressions of hypoxia-inducible factor (HIF)-lα, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) in a streptozotocin (STZ) induced diabetic Sprague-Dawley (SD) rat model.

METHODS

SD rats were administered an abdominal injection of STZ and induced to a diabetic model. After 6wk course of diabetes, the treatment groups were given β-elemene through periocular and intravitreous injection separately and the control groups were given blank emulsion injection. HE staining was used to observe the morphology of retina. The mRNA expressions of HIF-1α, VEGF and iNOS was assayed by real-time polymerase chain reaction (PCR) and the protein expression was measured by Western blot and immunocytochemistry methods.

RESULTS

The results indicated that the protein and mRNA expressions of HIF-1α, VEGF and iNOS after treated by β-elemene periocularly and intravitreally injections were all found to be reduced compared with the levels in the diabetic rats group (P<0.05). The inhibitory effect of intravitreal injection was more remarkable.

CONCLUSION

The results show β-elemene protect the retina of diabetic rats from high glucose damage by downregulating the expression of HIF-1α, VEGF and iNOS.

Elemene injection as adjunctive treatment to platinum-based chemotherapy in patients with stage III/IV non-small cell lung cancer: A meta-analysis following the PRISMA guidelines

BACKGROUND

Elemene injection is an anticancer Chinese patent medicine that is widely used for the treatment of advanced lung cancer. Its active ingredients are β-, γ- and δ-elemene, which are extracted from Curcumaaromatica Salisb. (Curcumawenyujin Y.H. Chen & C. Ling).

PURPOSE

To evaluate the effects of Elemene injection as adjunctive treatment to platinum-based chemotherapy (PBC) in patients with stage III/IV non-small cell lung cancer.

STUDY DESIGN

A systematic review and meta-analysis of randomized clinical trials (RCTs).

MATERIALS AND METHODS

A systematic review and meta-analysis were conducted following the PRISMA (Preferred Reported Items for Systematic Review and Meta-analysis) guidelines. Analyses were performed using Review Manager 5.3, Comprehensive Meta-Analysis 3.0 and Trial Sequential Analysis software. All RCTs comparing Elemene injection combined with PBC vs. PBC alone were selected and assessed for inclusion. The disease control rate (DCR) was defined as the primary endpoint, and the objective Response rate (ORR), survival rate, quality of life (QOL), cellular immune function and toxicities were the secondary outcomes.

RESULTS

15 RCTs recruiting 1,410 patients with stage III/IV NSCLC were included. The methodological quality of most included trials was low to moderate. Compared with PBC alone, Elemene injection plus PBC can improve DCR (RR = 1.23, 95% CI 1.16 to 1.31, p < 0.00001), ORR (RR = 1.62, 95% CI 1.44 to 1.82, p < 0.00001), 1- and 2-year survival rates (RR = 1.33, 95% CI 1.11 to 1.59, p = 0.002; RR = 1.73, 95% CI 1.21 to 2.46, p = 0.002, respectively), QOL (RR = 1.91, 95% CI 1.58 to 2.32, p < 0.00001), CD₄⁺T cell counts (WMD = 10.43, 95% CI 8.25 to 12.62, p < 0.00001), and the CD₄⁺/CD₈⁺ratio (WMD = 0.78, 95% CI 0.42 to 1.14, p < 0.0001) and can reduce severe toxicities by 58% (RR = 0.42, 95% CI 0.34 to 0.52, p < 0.00001).

CONCLUSION

Elemene injection is a safe and effective adjunctive treatment to platinum-based chemotherapy in patients with stage III/IV NSCLC. Elemene injection can improve clinical efficacy, enhance cellular immune function and alleviate the toxicity of chemotherapy. High-quality RCTs with significant survival outcomes and longer follow-ups are warranted to confirm the results further.

Effects of ebv-miR-BART7 on tumorigenicity, metastasis, and TRAIL sensitivity of non-small cell lung cancer

OBJECTIVE

To investigate how the Epstein-Barr virus (EBV) encoded microRNA BART7 (miR-BART7) affects tumorigenicity, metastasis, and TRAIL sensitivity of non-small cell lung cancer (NSCLC).

METHODS

Real time-polymerase chain reaction was performed to detect miR-BART7 expression in NSCLC cell lines. A549 and Calu-1 cells transfected with miR-BART7 inhibitors/mimics were used to do the in-vitro experiments, including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Annexin V-fluorescein isothiocyanate/PI, wound-healing, transwell, clonogenic assays, Western blot analysis, and anchorage-independent growth assay. Additionally, mice were used to inject A549 cells infected with miR-BART7 inhibitors to observe the tumorigenicity and metastasis of NSCLC.

RESULTS

TRAIL-resistant NSCLC cell lines (H460R, A549, Calu-1, and H1299) exhibited higher miR-BART7 rather than sensitive H460 and H292 cells. After transfected with miR-BART7 inhibitors, we observed an inhibition in proliferation, migration, invasion, and colony formation, but an enhancement in apoptosis as well as expressions of caspase-3 and caspase-8 in A549 and Calu-1 cells. Besides, TRAIL elevated the migration, invasion, and anchorage-independent growth of A549 cells, which was reversed by silencing DR4 and DR5 (siDRs). However, miR-BART7 inhibitors could reduce migration, invasion, and transformation potential of TRAIL treated A549 cells. Moreover, the expression of transforming growth factor-beta 1 (TGFβ1) could be decreased by miR-BART7 inhibitors with or without TRAIL treatment. Moreover, the tumor growth, epithelial-to-mesenchymal transition, and metastasis was suppressed and tumor-free survival was extended after injection of A549-miR-BART7 inhibitors.

CONCLUSION

Inhibition of miR-BART7 exerted inhibitory effects on cell proliferation, migration, invasion, and colony formation, consequently facilitating cell apoptosis and raising TRAIL sensitivity, providing a new therapeutic target in NSCLC.

Autophagy and its potent modulators from phytochemicals in cancer treatment

Autophagy is a ubiquitous catabolic process by which damaged or harmful intracellular components are delivered to the lysosomes for self-digestion and recycling. It is critical in cancer treatment. Therapy-induced autophagy predominantly acts as a pro-survival mechanism, but progressive autophagy can lead to non-apoptotic cell death, also known as autophagic cell death. Plants or herbs contain various natural compounds that are widely used in the treatment of many types of malignancies. Emerging evidence indicates that phytochemicals targeting the autophagic pathway are promising agents for cancer treatment. However, these compounds play different roles in autophagy. In this review, we discussed the role of autophagy in cancer development and therapy, and focussed on elucidating the anti-cancer activities of autophagic modulators, especially phytochemicals. Notably, we described a novel premise that the dynamic role of phytochemicals should be evaluated in regulation of autophagy in cancer.

Elemene inhibits osteosarcoma growth by suppressing the renin‑angiotensin system signaling pathway

Osteosarcoma remains the most prevalent primary malignant bone tumor in children and young adults globally. Therefore, novel and highly effective antitumor agents are urgently required. Elemene is a natural plant compound extracted from the medicinal Chinese herb, Rhizomazedoariae, which has been employed as an antitumor agent for the treatment of a number of tumors, including osteosarcoma. However, the mechanisms underlying its antitumor effect are currently unclear. The human osteosarcoma cell lines, MG‑63 and U2OS, were employed in the present study. MTT, migration, transwell invasion and terminal deoxynucleotidyltransferase‑mediated deoxy‑UTP‑fluorescein nick end‑labeling assays were performed to evaluate cell viability, migration, invasion and apoptosis, respectively. Western blotting and immunohistochemistry analyses were performed to measure the levels of renin‑angiotensin system (RAS) components. In order to evaluate the effect of elemene on tumor weight and volume, MG‑63 and U2OS cells were injected into mice. Treatment of osteosarcoma cell lines, MG‑63 and U2OS, with elemene led to the inhibition of cell viability, migration and invasion, as well as induction of cell apoptosis. In addition, elemene treatment downregulated the expression of a number of RAS components. The growth of osteosarcoma cell‑transplanted tumors in nude mice and angiotensin II expression were inhibited by elemene treatment. The results of the present study indicate that the antitumor effects of elemene may partly be due to downregulation of the RAS signaling pathway, and that RAS may be a putative pharmacological target for osteosarcoma therapy.

Chemical constituents and biological research on plants in the genus Curcuma

Curcuma, a valuable genus in the family Zingiberaceae, includes approximately 110 species. These plants are native to Southeast Asia and are extensively cultivated in India, China, Sri Lanka, Indonesia, Peru, Australia, and the West Indies. The plants have long been used in folk medicine to treat stomach ailments, stimulate digestion, and protect the digestive organs, including the intestines, stomach, and liver. In recent years, substantial progress has been achieved in investigations regarding the chemical and pharmacological properties, as well as in clinical trials of certain Curcuma species. This review comprehensively summarizes the current knowledge on the chemistry and briefly discusses the biological activities of Curcuma species. A total of 720 compounds, including 102 diphenylalkanoids, 19 phenylpropene derivatives, 529 terpenoids, 15 flavonoids, 7 steroids, 3 alkaloids, and 44 compounds of other types isolated or identified from 32 species, have been phytochemically investigated. The biological activities of plant extracts and pure compounds are classified into 15 groups in detail, with emphasis on anti-inflammatory and antitumor activities.

Development of Certain Protein Kinase Inhibitors with the Components from Traditional Chinese Medicine

Traditional Chinese medicines (TCMs) have been used in China for more than two thousand years, and some of them have been confirmed to be effective in cancer treatment. Protein kinases play critical roles in control of cell growth, proliferation, migration, survival, and angiogenesis and mediate their biological effects through their catalytic activity. In recent years, numerous protein kinase inhibitors have been developed and are being used clinically. Anticancer TCMs represent a large class of bioactive substances, and some of them display anticancer activity via inhibiting protein kinases to affect the phosphoinositide 3-kinase, serine/threonine-specific protein kinases, pechanistic target of rapamycin (PI3K/AKT/mTOR), P38, mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) pathways. In the present article, we comprehensively reviewed several components isolated from anticancer TCMs that exhibited significantly inhibitory activity toward a range of protein kinases. These components, which belong to diverse structural classes, are reviewed herein, based upon the kinases that they inhibit. The prospects and problems in development of the anticancer TCMs are also discussed.

Composition and cytotoxic and antioxidant activities of the oil of Piper aequale Vahl

Background

Piper aequale Vahl is a small shrub that grows in the shadow of large trees in the Carajás National Forest, Municipality of Parauapebas, Para state, Brazil. The local people have used the plant against rheumatism and inflammation.

Methods

The essential oil of the aerial parts was extracted and analyzed by GC and GC-MS. The MTT colorimetric assay was used to measuring the cytotoxic activity of the oil against human cancer lines. The determination of antioxidant activity of the oil was conducted by DPPH radical scavenging assay.

Results

The main constituents were δ-elemene (18.92 %), β-pinene (15.56 %), α-pinene (12.57 %), cubebol (7.20 %), β-atlantol (5.87 %), and bicyclogermacrene (5.51 %), totalizing 65.63 % of the oil. The oil displayed a strong in vitro cytotoxic activity against the human cancer cell lines HCT-116 (colon) and ACP03 (gastric) with IC₅₀values of 8.69 μg/ml and 1.54 μg/ml, respectively. The oil has induced the apoptosis in a gastric cancer cells in all tested concentration (0.75–3.0 μg/ml), after 72 h of treatment, when compared to negative control (p < 0.001). Also, the oil showed a significant antioxidant activity (280.9 ± 22.2 mg TE/ml), when analyzed as Trolox equivalent, and a weak acetylcholinesterase inhibition, with a detection limit of 100 ng, when compared to the physostigmine standard (1.0 ng).

Conclusion

The higher cell growth inhibition induced by the oil of P. aequale is probably due to its primary terpene compounds, which were previously reported in the proliferation inhibition, in stimulation of apoptosis and induction of cell cycle arrest in malignant cells.

Inhibition of tumor growth by β-elemene through downregulation of the expression of uPA, uPAR, MMP-2, and MMP-9 in a murine intraocular melanoma model

This paper explores the underlying mechanism through which β-elemene inhibits the growth of intraocular melanoma in a mouse model. C57BL/6J mice were administered a subretinal injection of B16F10 melanoma cells and divided into two groups: treatment and control. The treatment group was administered β-elemene through an intravitreal injection and the control group was injected with a blank emulsion. After 21 days of continuous treatment, tumor masses were removed and weighed. The mRNA expression levels of the urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), matrix metalloproteinase (MMP)-2, and MMP-9 were assayed by real-time PCR, and the protein expression levels of uPA, uPAR, MMP-2, and MMP-9 were assayed by immunocytochemistry and western blotting. Tumor size was inhibited by β-elemene in the treatment group, and the expressions of uPA, uPAR, MMP-2, and MMP-9 were all downregulated at both the mRNA and the protein level compared with the control group. In a mouse model of intraocular melanoma, β-elemene inhibits tumor growth by downregulating the expression of uPA, uPAR, MMP-2, and MMP-9.

Meta-Analysis of Oxaliplatin-Based Chemotherapy Combined With Traditional Medicines for Colorectal Cancer: Contributions of Specific Plants to Tumor Response

This meta-analysis evaluates the clinical evidence for the addition of traditional medicines (TMs) to oxaliplatin-based regimens for colorectal cancer (CRC) in terms of tumor response rate (TRR). Eight electronic databases were searched for randomized controlled trials of oxaliplatin-based chemotherapy combined with TMs compared to the same oxaliplatin-based regimen. Data on TRR from 42 randomized controlled trials were analyzed using Review Manager 5.1. Studies were conducted in China or Japan. Publication bias was not evident. The meta-analyses suggest that the combination of the TMs with oxaliplatin-based regimens increased TRR in the palliative treatment of CRC (risk ratio [RR] 1.31 [1.20-1.42], I(2) = 0%). Benefits were evident for both injection products (RR 1.36 [1.18-1.57], I(2) = 0%) and orally administered TMs (RR 1.27 [1.15-1.41], I(2) = 0%). Further sensitivity analysis of specific plant-based TMs found that Paeonia, Curcuma, and Sophora produced consistently higher contributions to the RR results. Compounds in each of these TMs have shown growth-inhibitory effects in CRC cell-line studies. Specific combinations of TMs appeared to produce higher contributions to TRR than the TMs individually. Notable among these was the combination of Hedyotis, Astragalus, and Scutellaria.

NG as a novel nitric oxide donor induces apoptosis by increasing reactive oxygen species and inhibiting mitochondrial function in MGC803 cells

NG, O(2)-(2,4-dinitro-5-{[2-(12-en-28-β-D-galactopyranosyl-oleanolate-3-yl)-oxy-2-oxoethyl] amino} phenyl) 1-(N-hydroxyethylmethylamino) diazen-1-ium-1,2-diolate, was identified in our laboratory as a novel nitric oxide-releasing prodrug with antitumor effects. A previous study showed that NG inhibited cell growth, and induced apoptosis in HepG2 cells. In this study, the inhibitory effects of NG on the viability of MGC803 cells were examined using methylthiazolyl tetrazolium biomide (MTT) assay, neutral red assay and trypan blue exclusion test. The results showed that NG had strong cytotoxicity to induce apoptosis, which was characterized by a significant externalization of phosphatidylserine, nuclear morphological changes and enhanced Bax-to-Bcl-2 ratio. Moreover, the release of cytochrome c (Cyt c) from mitochondria and the activation of caspase-9/3 were also detected, indicating that NG may induce apoptosis through a mitochondrial-mediated pathway. NG induced mitochondrial dysfunction in MGC803 cells by altering membrane potential (△Ψm), the inhibition of complexes I, II and IV consequently decreasing ATP level. Furthermore, the treatment of MGC803 cells with NG caused a marked rise in oxidative stress as characterized by accumulation of reactive oxygen species (ROS), excessive malondialdehyde (MDA) production and a reduction in glutathione hormone (GSH) level and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. In addition, pretreatment with N-acetylcysteine (NAC), a GSH synthesis precursor, was partially protective against the NG-induced ROS generation and cell apoptosis. In contrast, pretreatment of MGC803 cells with L-buthionine-S, R-sulfoximine (BSO), a GSH synthesis inhibitor, increased the ROS levels, and aggravated cell apoptosis by NG. These results suggest that NG-induced apoptosis in MGC803 cells is mediated, at least in part, by the increase in ROS production, oxidative stress and mitochondrial dysfunction.

Curcumin-free turmeric exhibits anti-inflammatory and anticancer activities: Identification of novel components of turmeric

Turmeric, a dried powder derived from the rhizome of Curcuma longa, has been used for centuries in certain parts of the world and has been linked to numerous biological activities including antioxidant, anti-inflammatory, anticancer, antigrowth, anti-arthritic, anti-atherosclerotic, antidepressant, anti-aging, antidiabetic, antimicrobial, wound healing, and memory-enhancing activities. One component of turmeric is curcumin, which has been extensively studied, as indicated by more than 5600 citations, most of which have appeared within the past decade. Recent research has identified numerous chemical entities from turmeric other than curcumin. It is unclear whether all of the activities ascribed to turmeric are due to curcumin or whether other compounds in turmeric can manifest these activities uniquely, additively, or synergistically with curcumin. However, studies have indicated that turmeric oil, present in turmeric, can enhance the bioavailability of curcumin. Studies over the past decade have indicated that curcumin-free turmeric (CFT) components possess numerous biological activities including anti-inflammatory, anticancer, and antidiabetic activities. Elemene derived from turmeric is approved in China for the treatment of cancer. The current review focuses on the anticancer and anti-inflammatory activities exhibited by CFT and by some individual components of turmeric, including turmerin, turmerone, elemene, furanodiene, curdione, bisacurone, cyclocurcumin, calebin A, and germacrone.

β-elemene induces glioma cell apoptosis by downregulating survivin and its interaction with hepatitis B X-interacting protein

β-elemene, extracted from the ginger plant, possesses antitumor activity against a broad range of cancers clinically. However, the mechanism underlying β-elemene-induced cytotoxicity remains incompletely understood. Here, we show that β-elemene promoted apoptotic cell death in human glioma cells, downregulated survivin gene expression, and induced caspase-9, -3 and -7 activities. Induction of apoptosis was associated with inhibition of survivin gene expression, and restoration of survivin levels remarkably attenuated β-elemene-induced glioma cell death. Moreover, we found that the interaction between surviving and HBXIP, a critical regulator of caspase-9 activity, was impaired by β-elemene treatment. The results, therefore, reveal a caspase-mediated apoptotic pathway induced by β-elemene in human glioma cells, which is associated with downregulation of survivin itself and the interaction between survivin and HBXP.

Anti-cancer properties of terpenoids isolated from Rhizoma Curcumae--a review

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Curcumae is a popular type of traditional Chinese medicine whose essential oils are widely used in the treatment of cancer in China. This review aims to systematically summarize and analyze the anti-cancer properties of terpenoids, the main components of essential oils in Rhizoma Curcumae, and thus enable the development of new anti-cancer drugs.

MATERIALS AND METHODS

Information on the recent progress of anti-cancer studies on terpenoids isolated from Rhizoma Curcumae, including β-elemene, δ-elemene, furanodiene, furanodienone, curcumol, and germacrone, was gathered and analyzed.

RESULTS

Among these terpenoids, β-elemene is the most widely studied, whereas δ-elemene, furanodiene, furanodienone, curcumol, and germacrone have just recently attracted the attention of researchers. The anti-cancer effects of these terpenoids are related to the retardation of cell cycle arrest, the induction of apoptosis, and the inhibition of metastasis or tissue invasion, among others.

CONCLUSIONS

Most studies have focused on the in vitro data, and in vivo data is urgently needed. Further insight into the anti-cancer activity and the molecular basis of these compounds, combined with efforts in pharmaceutical chemistry and/or pharmaceutics, will potentially enable the development of new anti-cancer agents.

Induction of apoptosis by casticin in cervical cancer cells: reactive oxygen species-dependent sustained activation of Jun N-terminal kinase

Casticin, a polymethoxyflavone from Fructus viticis used as an anti-inflammatory agent in Chinese traditional medicine, has been reported to have anti-cancer activity. The purpose of this study was to examine the apoptotic activity of casticin on human cervical cancer cells and its molecular mechanism. We revealed a novel mechanism by which casticin-induced apoptosis occurs and showed for the first time that the apoptosis induced by casticin is mediated through generation of reactive oxygen species (ROS) and sustained activation of c-Jun N-terminal kinase (JNK) in HeLa cells. Casticin markedly increased the levels of intracellular ROS and induced the expression of phosphorylated JNK and c-Jun protein. Pre-treatment with N-acetylcysteine and SP600125 effectively attenuated induction of apoptosis by casticin in HeLa cells. Moreover, casticin induced ROS production and apoptotic cell death in other cervical cancer cell lines, such as CasKi and SiHa. Importantly, casticin did not cause generation of ROS or induction of apoptosis in normal human peripheral blood mononuclear cells and embryonic kidney epithelium 293 cells. These results suggest that ROS generation and sustained JNK activation by casticin play a role in casticin-induced apoptosis and raise the possibility that treatment with casticin might be promising as a new therapy against human cervical cancer.

Lysosomal membrane permeabilization contributes to elemene emulsion-induced apoptosis in A549 cells

Elemene is a broad-spectrum antitumor agent. In the present study, lysosomal membrane permeabilization (LMP) was detected after short elemene emulsion--exposure (12 h) that preceded a decrease of the mitochondrial membrane potential and DNA damage (24 h) in A549 cells. At later time points (36 h) elemene emulsion caused the appearance of A549 cells with apoptotic features, including apoptotic morphology, phosphatidylserine exposure, and caspase-3 activation. A significant increase in protein expression for cathepsin D was also observed utilizing Western blot analysis after exposure to elemene emulsion for 12 h. The present study showed that elemene emulsion induced the increased levels of reactive oxygen species (ROS) and depletion of glutathione (GSH) in A549 cells. Cells treated with pepstatin A, an inhibitor for cathepsin D, showed a significant inhibition in DNA damage, mitochondrial membrane permeabilization, caspase-3 activation, and phosphatidylserine exposure. These results demonstrated that apoptosis induced by elemene emulsion in A549 cells is mediated in part through LMP and lysosomal protease cathepsin D.

β-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis

Background

β-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.

Results

β-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.

Conclusions

Our data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.

Mechanisms of inhibition of elemene on human lens epithelial cell proliferation in vitro

AIM

To study the effects of elemene (Ele) on proliferation and cell cycle of human lens epithelial cells B3 (HLE-B3) and the mechanisms of its signal transduction.

METHODS

Recombinant human basic fibroblast growth factor (rhbFGF) was used to induce proliferation of HLE-B3 cells, which were incubated with 80mg/L Ele for 24 hours. The inhibitory effects of Ele on the proliferation of HLE-B3 cells were evaluated by MTT method. The effect of Ele on HLE-B3 cell cycle was analyzed by flow cytometry(FCM). The expressions of protein kinase A (PKA) and protein kinase G (PKG) of HLE-B3 were also analyzed by FCM.

RESULTS

Ele altered the cell cycle of HLE-B3 and effectively inhibited HLE-B3 cell proliferation induced by rhbFGF. Ele up-regulated PKA and down-regulated the expression of PKG in HLE-B3 cell.

CONCLUSION

Ele inhibits HLE-B3 proliferation, making it an attractive potential agent in regimens to treat after-cataracts.