Anticancer activity of isoobtusilactone A from Cinnamomum kotoense: involvement of apoptosis, cell-cycle dysregulation, mitochondria regulation, and reactive oxygen species

Chemistry and Bioactivity of the Genus Persea - A Review

This review provides the first comprehensive appraisal of bioactive compounds and their biological activities in Persea species from 1950 to 2023. Relevant articles from reputable databases, including PubMed, Web of Science, Science Direct and Google Scholar were collected, leading to the isolation of about 141 metabolite compounds, mainly flavonoids, terpenoids, fatty alcohols, lignoids, and γ-lactone derivatives. These compounds exhibit diverse biological activities, including insecticidal, antifeedant, nematicidal, antibacterial, antifungal, antiviral, cytotoxic, anti-inflammatory, and antioxidant properties. The review emphasizes the significant chemical and pharmacological potential of different Persea species, encouraging further research in various fields and medicine. Valuable insights into potential applications of Persea plants are provided.

Interaction of obtusilactone B and related butanolide lactones with the barrier-to-autointegration factor 1 (BAF1). A computational study

The barrier-to-autointegration factor 1 (BAF1) protein is a DNA-binding protein implicated in nuclear envelop repair and reformation after mitosis. This nuclear protein is frequently overexpressed in cancer cells and plays a role in the occurrence and development of different tumors. It is a potential therapeutic target for gastric cancer, breast cancer and other malignancies. For this reason, BAF1 inhibitors are searched. The butanolide lactone obtusilactone B (Ob-B) has been found to inhibit VRK1-dependent phosphorylation of BAF1, upon direct binding to the nuclear protein. Taking advantage of the known crystallographic structure of BAF1, we have elaborated molecular models of Ob-B bound to BAF1 to delimit the binding site and binding configuration. The long endoolefinic alkyl side chain of Ob-B extends into a small groove on the protein surface, and the adjacent exomethylene-γ-lactone moiety occupies a pocket comprising to the Ser-4 phosphorylation site of BAF1. Twenty butanolide lactones structurally close to ObB were screened for BAF1 binding. Several natural products with BAF1-binding capacity potentially superior to Ob-B were identified, including mahubanolide, kotomolide B, epilitsenolide D2, and a few other known anticancer plant natural products. Our study provides new ideas to guide the discovery and design of BAF1 inhibitors.

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Obtusilactone B (Ob-B) is an anticancer inhibitor of VRK1-mediated BAF1 phosphorylation.

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Molecular models of Ob-B bound to BAF1 have been constructed and the binding site determined.

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Screening of 20 butanolide lactones led to the identification of new potential BAF1 binders.

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Mahubanolide, kotomolide B and epilitsenolide D2 emerge as potential BAF1 inhibitors.

Cinnamomum Species: Bridging Phytochemistry Knowledge, Pharmacological Properties and Toxicological Safety for Health Benefits

The genus Cinnamomum includes a number of plant species largely used as food, food additives and spices for a long time. Different traditional healing systems have used these plants as herbal remedies to cure diverse ailments. The aim of this comprehensive and updated review is to summarize the biodiversity of the genus Cinnamomum, its bioactive compounds, the mechanisms that underlie the pharmacological activities and molecular targets and toxicological safety. All the data in this review have been collected from databases and recent scientific literature including Web of Science, PubMed, ScienceDirect etc. The results showed that the bioactive compounds of Cinnamomum species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer and neuroprotective effects. The preclinical (in vitro/in vivo) studies provided the possible molecular mechanisms of these action. As a novelty, recent clinical studies and toxicological data described in this paper support and confirm the pharmacological importance of the genus Cinnamomum. In conclusion, the obtained results from preclinical studies and clinical trials, as well as reduced side effects provide insights into future research of new drugs based on extracts and bioactive compounds from Cinnamomum plants.

Synergistic effect and ultrastructural changes in Trypanosoma cruzi caused by isoobtusilactone A in short exposure of time

Butanolides have shown a variety of biological effects including anti-inflammatory, antibacterial, and antiprotozoal effects against certain strains of Trypanosoma cruzi. Considering the lack of an effective drug to treat T. cruzi infections and the prominent results obtained in literature with this class of lactones, we investigated the anti-T. cruzi activity of five butanolides isolated from two species of Lauraceae, Aiouea trinervis and Mezilaurus crassiramea. Initially, the activity of these compounds was evaluated on epimastigote forms of the parasite, after a treatment period of 4 h, followed by testing on amastigotes, trypomastigotes, and mammalian cells. Next, the synergistic effect of active butanolides against amastigotes was evaluated. Further, metacyclogenesis inhibition and infectivity assays were performed for the most active compound, followed by ultrastructural analysis of the treated amastigotes and trypomastigotes. Among the five butanolides studied, majoranolide and isoobtusilactone A were active against all forms of the parasite, with good selectivity indexes in Vero cells. Both butanolides were more active than the control drug against trypomastigote and epimastigote forms and also had a synergic effect on amastigotes. The most active compound, isoobtusilactone A, which showed activity against all tested strains inhibited metacyclogenesis and infection of new host cells. In addition, ultrastructural analysis revealed that this butanolide caused extensive damage to the mitochondria of both amastigotes and trypomastigotes, resulting in severe morphological changes in the infective forms of the parasite. Altogether, our results highlight the potential of butanolides against the etiologic agent of Chagas disease and the relevance of isoobtusilactone A as a strong anti-T. cruzi drug, affecting different events of the life cycle and all evolutionary forms of parasite after a short period of exposure.

Antitrypanosomal butanolides from Aiouea trinervis

In a search for new antitrypanosomal agents in the Brazilian flora, the ethanol extract of the xylopodium from Aiouea trinervis (Lauraceae) exhibited in vitro activity against the epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. Bioassay-guided chromatographic fractionation of the ethanol extract afforded three butanolides, isoobtusilactone A (1), epilitsenolide C2 (2), and epilitsenolide C1 (3). Butanolides 1 and 3 were more active against T. cruzi epimastigotes than the reference drug benznidazole (by 8.9-fold and 3.2-fold, respectively), while 2 proved inactive. Compounds 1 and 3 showed low cytotoxicity in mammalian Vero cells (CC50> 156 μmol L-1) and high selectivity index (SI) values for epimastigotes (SI = 56.8 and 28.6, respectively), and 1 was more selective than benznidazole (SI = 46.5). Butanolide 1 at 24 μmol L-1 also led to cell cycle alterations in epimastigote forms, and inhibited the growth of amastigote cells in more than 70 %. In silico ADMET properties of 1 were also analyzed and predicted favorable drug-like characteristics. This butanolide also complied with Lipinski's rule of five and was not predicted as interference compound (PAINS). This is the first report on the isolation of these bioactive butanolides under the guidance of in vitro trypanocidal activity against T. cruzi.

Pharmacological properties and their medicinal uses of Cinnamomum: a review

OBJECTIVES

Cinnamomum (Family Lauraceae) is traditionally used for flavouring food and in pharmaceutical preparations against various ailments. Detailed literature on the ethnobotanical and pharmacological properties of Cinnamomum is segregated and not present in well-documented form. In the present review, we have been trying to gather its detailed medicinal as well as pharmacological properties. The ethnobotanical and pharmacological properties of Cinnamomum were collected by searching several scientific databases, that is PubMed, Elsevier, Google Scholar, Science Direct and Scopus.

KEY FINDINGS

The plant extracts have been reported to possess astringent, warming stimulant, carminative, blood purifier, digestive, antiseptic, antifungal, antiviral, antibacterial, antioxidant, anti-inflammatory and immunomodulatory properties and also help to reduce cholesterol and blood sugar levels. A wide range of phytochemical compounds including aldehydes, acetate, alcohol, terpinenes, flavonoids, alkaloids, anthraquinones, coumarins, phenols, saponins, tannins, carboxylic acid, hydrocarbons, camphene, spathulenol, fatty acids, actinodaphnine, butanolides, lignans, steroids, propenoids and kaempferol glycosides are found in various parts of plant.

SUMMARY

This review provides detailed information about history, traditional uses, phytochemistry and clinical impacts of cinnamon as a spice and medicine. So we recommend further study on the clinical, medicinal, purification and identification of the most effective antibacterial activity of cinnamon to cure various infectious diseases.

The Odyssey of Bioactive Compounds in Avocado (Persea americana) and Their Health Benefits

Persea americana, commonly known as avocado, has recently gained substantial popularity and is often marketed as a “superfood” because of its unique nutritional composition, antioxidant content, and biochemical profile. However, the term “superfood” can be vague and misleading, as it is often associated with unrealistic health claims. This review draws a comprehensive summary and assessment of research performed in the last few decades to understand the nutritional and therapeutic properties of avocado and its bioactive compounds. In particular, studies reporting the major metabolites of avocado, their antioxidant as well as bioavailability and pharmacokinetic properties, are summarized and assessed. Furthermore, the potential of avocado in novel drug discovery for the prevention and treatment of cancer, microbial, inflammatory, diabetes, and cardiovascular diseases is highlighted. This review also proposes several interesting future directions for avocado research.

The Apoptosis Effect on Liver Cancer Cells of Gold Nanoparticles Modified with Lithocholic Acid

Functionalized gold nanoparticles (AuNPs) have widely applied in many fields, due to their good biocompatibility, a long drug half-life, and their bioactivity is related to their size and the modified ligands on their surface. Here, we synthesized the AuNPs capped with ligands that possess polyethylene glycol (PEG) and lithocholic acid (LCA) linked by carboxyl groups (AuNP@MPA-PEG-LCA). Our cytotoxicity results indicated that AuNP@MPA-PEG-LCA have better cell selectivity; in other words, it could inhibit the growth of multiple liver cancer cells more effectively than other cancer cells and normal cells. Apoptosis plays a role in AuNP@MPA-PEG-LCA inhibition cell proliferation, which was convincingly proved by some apoptotic index experiments, such as nuclear staining, annexin V-FITC, mitochondrial membrane potential (MMP) analysis, and AO/EB staining experiments. The most potent AuNP@MPA-PEG-LCA were confirmed to efficiently induce apoptosis through a reactive oxygen species (ROS) mediating mitochondrial dysfunction. And AuNP@MPA-PEG-LCA could be more effective in promoting programmed cell death of liver cancer cells.

Cytotoxic and apoptosis-inducing activities against human lung cancer cell lines of cassaine diterpenoids from the bark of Erythrophleum fordii

A phytochemical investigation into the bark of Erythrophleum fordii yielded four new compounds, two new cassaine diterpenoids (erythrofordin T and U, 1 and 2) and two new cassaine diterpenoid amines (erythroformine A and B, 6 and 7), as well as nine known compounds. We report for the first time the isolation of erythrofordin V (3) from a natural source and that of the remaining eight known diterpenoids (4-5, 8-13) from E. fordii. All structures were elucidated using spectroscopic analysis. Cytotoxic activity of the isolated compounds (1-13) was examined in vitro against three non-small cell lung cancer cell lines (A549, NCI-H1975, and NCI-H1229) using the MTT assay. Cassaine diterpene amines (6-10, 12, 13) exhibited potent cytotoxic activity against all three cell lines with IC₅₀ values between 0.4μM and 5.9μM. Erythroformine B (7) significantly induced apoptosis in all three cancer cells in a concentration-dependent manner.

Tenuifolide B from Cinnamomum tenuifolium Stem Selectively Inhibits Proliferation of Oral Cancer Cells via Apoptosis, ROS Generation, Mitochondrial Depolarization, and DNA Damage

The development of drugs that selectively kill oral cancer cells but are less harmful to normal cells still provide several challenges. In this study, the antioral cancer effects of tenuifolide B (TFB), extracted from the stem of the plant Cinnamomum tenuifolium are evaluated in terms of their effects on cancer cell viability, cell cycle analysis, apoptosis, oxidative stress, and DNA damage. Cell viability of oral cancer cells (Ca9-22 and CAL 27) was found to be significantly inhibited by TFB in a dose-responsive manner in terms of ATP assay, yielding IC₅₀ = 4.67 and 7.05 μM (24 h), but are less lethal to normal oral cells (HGF-1). Dose-responsive increases in subG1 populations as well as the intensities of flow cytometry-based annexin V/propidium iodide (PI) analysis and pancaspase activity suggested that apoptosis was inducible by TFB in these two types of oral cancer cells. Pretreatment with the apoptosis inhibitor (Z-VAD-FMK) reduced the annexin V intensity of these two TFB-treated oral cancer cells, suggesting that TFB induced apoptosis-mediated cell death to oral cancer cells. Cleaved-poly (ADP-ribose) polymerase (PARP) and cleaved-caspases 3, 8, and 9 were upregulated in these two TFB-treated oral cancer cells over time but less harmful for normal oral HGF-1 cells. Dose-responsive and time-dependent increases in reactive oxygen species (ROS) and decreases in mitochondrial membrane potential (MitoMP) in these two TFB-treated oral cancer cells suggest that TFB may generate oxidative stress as measured by flow cytometry. N-acetylcysteine (NAC) pretreatment reduced the TFB-induced ROS generation and further validated that ROS was relevant to TFB-induced cell death. Both flow cytometry and Western blotting demonstrated that the DNA double strand marker γH2AX dose-responsively increased in TFB-treated Ca9-22 cells and time-dependently increased in two TFB-treated oral cancer cells. Taken together, we infer that TFB can selectively inhibit cell proliferation of oral cancer cells through apoptosis, ROS generation, mitochondrial membrane depolarization, and DNA damage.

Effects of hirami lemon, Citrus depressa Hayata, leaf meal in diets on the immune response and disease resistance of juvenile barramundi, Lates calcarifer (bloch), against Aeromonas hydrophila

The present study was conducted to evaluate the dietary supplementation of leaf meal from Citrus depressa Hayata on the growth, innate immune response, and disease resistance of juvenile barramundi, Lates calcarifer. Four diets were formulated to contain 0% (control), 1% (C1), 3% (C3), and 5% (C5) leaf meal, respectively. During a 56 d feeding trial, fish survival, growth performance, and feed efficiency were not significantly different among all groups. For immune response, respiratory burst, superoxide dismutase and lysozyme activities were not significantly different among all groups. However, fish fed the C5 diet for 56 d had significantly higher phagocytic activity. Also, fish fed C3 and C5 diets had significantly higher Mx gene expressions in spleens and head kidneys with nerve necrosis virus injections after 24 h. Disease resistance against Aeromonas hydrophila was increased by the C5 diet. In this study, barramundi fed on a diet containing 5% C. depressa Hayata leaf meal had significantly better innate immune response and disease resistance against A. hydrophila.

Chemical constituents and bioactivity of Formosan lauraceous plants

Taiwan is rich in lauraceous plants. A review of 197 references based on the chemical analysis and bioactivity of indigenous lauraceous plants carried out by native scientists from 1963 to 2014 has been compiled. About 303 new compounds and thousands of known compounds comprising alkaloids and non-alkaloids with diverse structures have been isolated or identified from indigenous plants belonging to the 11 lauraceous genera. The volatile components, however, have been excluded from this review. This review provides an overview of the past efforts of Taiwan scientists working on secondary metabolites and their bioactivity in native lauraceous plants. The potential of lauraceous plants worthy of further study is also noted. The contents will be helpful for the chemotaxonomy of Lauraceae and be of value for the development of native Formosan lauraceous plants.

Polyketide and benzopyran compounds of an endophytic fungus isolated from Cinnamomum mollissimum: biological activity and structure

OBJECTIVE

To study bioactivity and compounds produced by an endophytic Phoma sp. fungus isolated from the medicinal plant Cinnamomum mollissimum.

METHODS

Compounds produced by the fungus were extracted from fungal broth culture with ethyl acetate. This was followed by bioactivity profiling of the crude extract fractions obtained via high performance liquid chromatography. The fractions were tested for cytotoxicity to P388 murine leukemic cells and antimicrobial activity against bacteria and pathogenic fungi. Compounds purified from active fractions which showed antibacterial, antifungal and cytotoxic activities were identified using capillary nuclear magnetic resonance analysis, mass spectrometry and admission to AntiMarin database.

RESULTS

Three known compounds, namely 4-hydroxymellein, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one and 1-(2,6-dihydroxyphenyl) ethanone, were isolated from the fungus. The polyketide compound 4-hydroxymellein showed high inhibitory activity against P388 murine leukemic cells (94.6%) and the bacteria Bacillus subtilis (97.3%). Meanwhile, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one, a benzopyran compound, demonstrated moderate inhibitory activity against P388 murine leukemic cells (48.8%) and the fungus Aspergillus niger (56.1%). The second polyketide compound, 1 (2,6-dihydroxyphenyl) ethanone was inactive against the tested targets.

CONCLUSIONS

These findings demonstrate the potential of endophytes as producers of pharmacologically important compounds, including polyketides which are major secondary metabolites in fungi.

Isophilippinolide A arrests cell cycle progression and induces apoptosis for anticancer inhibitory agents in human melanoma cells

Three new butanolides, isophilippinolide A, philippinolide A, and philippinolide B, and an amide, cinnaretamine, were isolated from the roots of Cinnamomum philippinense to be identified by spectroscopic analysis. Four isolated compounds were screened to examine their radical-scavenging ability, metal-chelating power, and ferric-reducing antioxidant power assay (FRAP). Cinnaretamine showed powerful antioxidative properties in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and a reducing activity; all compounds presented minor inhibition of metal-chelating capacities. The effects of anti-tyrosinase of C. philippinense constituents were determined by the level of the suppression of hydroxylation that turned from L-tyrosine to L-dopa through an in vitro mushroom tyrosinase assay, and all testing samples illustrated slight mushroom tyrosinase inhibitory properties. Isophilippinolide A exhibited inhibitory effectivenesses against the A375.S2 melanoma cell line in a cell viability assay at concentrations ranging from 0 to 200 μM for 24 h. Propidium iodide staining and flow cytometry analyses were applied to assess cell cycle accumulative distribution. It was discovered that isophilippinolide A caused sub-G1 phase accumulation in positive correlation for apoptosis to inhibit cell growth. Further investigation revealed that isophilippinolide A induced A375.S2 cells with an increase of caspase-dependent apoptotic proteins to trigger correlated pathway mechanisms according to Western blotting results. Finally, isophilippinolide A displayed only low cytotoxicities to human normal epidermal cells (melanocytes) and dermal cells (fibroblasts). Altogether, the results implied C. philippinense compounds could be considered functional ingredients in cosmetics, foods, and pharmaceutical products, particularly for their anticancer ability on human skin melanoma cells.

Antioxidant treatment promotes prostate epithelial proliferation in Nkx3.1 mutant mice

Discordant results in preclinical and clinical trials have raised questions over the effectiveness of antioxidants in prostate cancer chemoprevention. Results from the large-scale Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed that antioxidants failed to prevent, and in some cases promoted, prostate cancer formation in men without a history of the disease. One possible explanation for these alarming results is the notion that the effects of antioxidant treatment on the prostate are modified by specific, intrinsic genetic risk factors, causing some men to respond negatively to antioxidant treatment. Loss of expression of the homeobox transcription factor NKX3.1 in the prostate is frequently associated with human prostate cancer. Nkx3.1 mutant mice display prostatic hyperplasia and dysplasia and are used as a model of the early stages of prostate cancer initiation. While the mechanisms by which Nkx3.1 loss promotes prostate tumorigenicity are not completely understood, published data have suggested that elevated reactive oxygen species (ROS) associated with Nkx3.1 loss may be a causative factor. Here we have tested this hypothesis by treating Nkx3.1 mutant mice with the antioxidant N-acetylcysteine (NAC) for 13 weeks post-weaning. Surprisingly, while NAC treatment decreased ROS levels in Nkx3.1 mutant mouse prostates, it failed to reduce prostatic epithelial hyperplasia/dysplasia. Rather, NAC treatment increased epithelial cell proliferation and promoted the expression of a pro-proliferative gene signature. These results show that ROS do not promote proliferation in the Nkx3.1-null prostate, but instead inhibit proliferation, suggesting that antioxidant treatment may encourage prostate epithelial cell proliferation early in prostate tumorigenesis. Our findings provide new insight that may help explain the increased prostate cancer risk observed with vitamin E treatment in the SELECT trial and emphasize the need for preclinical studies using accurate models of cancer.

Isoobtusilactone A sensitizes human hepatoma Hep G2 cells to TRAIL-induced apoptosis via ROS and CHOP-mediated up-regulation of DR5

Hepatoma cells are relatively resistant to TRAIL. We have previously shown that isoobtusilactone A (IOA), a potent anticancer agent isolated from Cinnamomum kotoense, induced mitochondria-mediated apoptosis in hepatoma cells. Here, we report that IOA could potentiate TRAIL-induced apoptosis in Hep G2 cells. The combined treatment with IOA and TRAIL significantly induced caspase-dependent apoptosis. This correlated with the up-regulation of C/EBP homologous protein (CHOP) and death receptor 5 (DR5) protein levels. Gene silencing of the DR5 by small interfering RNA abrogated the apoptosis induced by the combined regimen of IOA and TRAIL, suggesting that the sensitization to TRAIL was mediated through DR5. By analyzing the DR5 promoter, we found that IOA induced a CHOP-dependent DR5 transactivation. DR5 expression after IOA treatment was accompanied by provoking intracellular reactive oxygen species (ROS) generation. Pretreatment with N-acetyl-L-cysteine (NAC) attenuated IOA-induced CHOP and DR5 expression and inhibited TRAIL-induced apoptosis. Taken together, our data suggested that ROS-dependent and CHOP-regulated DR5 expression played a pivotal role in the synergistic enhancement of TRAIL-induced apoptosis instigated by IOA in Hep G2 cells.

Cytotoxic and Antifungal Activities of 5-Hydroxyramulosin, a Compound Produced by an Endophytic Fungus Isolated from Cinnamomum mollisimum

An endophytic fungus isolated from the plant Cinnamomum mollissimum was investigated for the bioactivity of its metabolites. The fungus, similar to a Phoma sp., was cultured in potato dextrose broth for two weeks, followed by extraction with ethyl acetate. The crude extract obtained was fractionated by high-performance liquid chromatography. Both crude extract and fractions were assayed for cytotoxicity against P388 murine leukemic cells and inhibition of bacterial and fungal pathogens. The bioactive extract fraction was purified further and characterized by nuclear magnetic resonance, mass spectral and X-ray crystallography analysis. A polyketide compound, 5-hydroxyramulosin, was identified as the constituent of the bioactive fungal extract fraction. This compound inhibited the fungal pathogen Aspergillus niger (IC₅₀ 1.56 μg/mL) and was cytotoxic against murine leukemia cells (IC₅₀ 2.10 μg/mL). 5-Hydroxyramulosin was the major compound produced by the endophytic fungus. This research suggests that fungal endophytes are a good source of bioactive metabolites which have potential applications in medicine.

A novel homosesquiterpenoid from the stems of Cinnamomum burmanii

A novel homosesquiterpenoid, burmanol (1), along with 16 known compounds, including one triterpenoid, one quinol, two chlorophylls, two coumarins, two steroids, three lignans and five benzenoids were obtained from the stems of Cinnamomum burmanii (Lauraceae). The structures of these compounds were determined on the basis of spectroscopic analysis.

A new benzodioxocinone from the leaves of Cinnamomum tenuifolium

Investigation of the leaves' extract of Cinnamomum tenuifolium (Lauraceae) led to the isolation of one novel benzodioxocinone, 2,3-dihydro-6,6-dimethylbenzo-[b][1,5]dioxocin-4(6 H)-one (1). The structure was determined through in-depth spectroscopic and mass-spectrometric analyses. The antioxidant potential was evaluated using the following in vitro method: scavenging of 1,1-diphenyl-2-picrylhydrazyl radical. We also detected the anti-proliferative effect of 1 on human oral cancer cells and its IC(50) is 107.7 µM.

Subamolide A, a component isolated from Cinnamomum subavenium, induces apoptosis mediated by mitochondria-dependent, p53 and ERK1/2 pathways in human urothelial carcinoma cell line NTUB1

ETHNOPHARMACOLOGICAL RELEVANCE

Cinnamomum subavenium has long been used as a traditional Chinese medicine to treat carcinomatous swelling, abdominal pain and other diseases.

AIM OF THE STUDY

The goal of this work was to study the cytotoxic effect of subamolide A, a constituent isolated from the stems of Cinnamomum subavenium Miq., and to extend its traditional use for clinical applications in treating human urothelial carcinoma.

MATERIALS AND METHODS

Cytotoxic effect of subamolide A was determined by the MTT assay in NTUB1, T24, PC3 and SV-HUC-1 cells treated with various concentrations of subamolide A for three days. Apoptosis was detected by the change of cell morphology and flow cytometry analysis. The reactive oxygen species (ROS) level and mitochondria membrane potential (Δψm) were determined by flow cytometry. Western blot analysis was used to quantify the expression of apoptosis-related and stress-induced signaling molecules.

RESULTS

Subamolide A selectively induced apoptosis in two cancerous human urothelial carcinoma cell lines (NTUB1 and T24) in comparison with normal immortalized uroepithelial cells (SV-HUC-1). Subamolide A reduced mitochondrial membrane potential (Δψm) and caused apoptosis of NTUB1 cells. Subamolide A increased Bax/Bcl-2 ratios, the amount of cytochrome c released from the mitochondria, caspase-3 and PARP cleavage, activated p53 and ERK1/2 and ultimately led to apoptosis in NTUB1 cells. Furthermore, a higher dose (10μM) of subamolide A synergistically enhanced the cytotoxicity of cisplatin and gemcitabine in NTUB1 cells.

CONCLUSIONS

The current study demonstrated that subamolide A triggered the mitochondria-dependent apoptotic pathways and p53 and ERK1/2 activation in the human urothelial carcinoma cell line NTUB1. In addition, subamolide A synergistically enhanced cytotoxic effect of CDDP and Gem in NTUB1. These data suggested that subamolide A exhibited a potent anti-proliferation activity. This study supports the traditional use of Cinnamomum subavenium stems with a therapeutic potential for the treatment of human urothelial carcinoma.

Amides from the Stems of Cinnamomum burmannii

A novel amide, cinnabutamine (1), along with five known amides, cinnaretamine (2), N-trans-caffeoyl-5-hydroxytyramine (3), N-trans-feruloyltyramine (4), N-trans-feruloyl-5-methoxytyramine (5) and N-cis-feruloyl-5-methoxytyramine (6), were isolated from the stems of Cinnamomum burmannii (Lauraceae). Their structures were characterized and identified by spectral analysis.

The effect of N-acetylcysteine on the antitumor activity of ifosfamide

Ifosfamide-induced nephrotoxicity is a serious adverse effect in children undergoing chemotherapy. Our previous cell and rodent models have shown that the antioxidant N-acetylcysteine (NAC), used extensively as an antidote for acetaminophen poisoning, protects renal tubular cells from ifosfamide-induced nephrotoxicity at a clinically relevant concentration. For the use of NAC to be clinically relevant in preventing ifosfamide nephrotoxicity, we must ensure there is no effect of NAC on the antitumor activity of ifosfamide. Common pediatric tumors that are sensitive to ifosfamide, human neuroblastoma SK-N-BE(2) and rhabdomyosarcoma RD114-B cells, received either no pretreatment or pretreatment with 400 µmol/L of NAC, followed by concurrent treatment with NAC and either ifosfamide or the active agent ifosfamide mustard. Ifosfamide mustard significantly decreased the growth of both cancer cell lines in a dose-dependent manner (p < 0.001). The different combined treatments of NAC alone, sodium 2-mercaptoethanesulfonate alone, or NAC plus sodium 2-mercaptoethanesulfonate did not significantly interfere with the tumor cytotoxic effect of ifosfamide mustard. These observations suggest that NAC may improve the risk/benefit ratio of ifosfamide by decreasing ifosfamide-induced nephrotoxicity without interfering with its antitumor effect in cancer cells clinically treated with ifosfamide.

Involvement of mitochondrial pathway in NCTD-induced cytotoxicity in human hepG2 cells

BACKGROUND

Norcantharidin, the demethylated analog of cantharidin derived from a traditional Chinese medicine, Mylabris, has been used in the treatment of anti-cancer effects. However, the detailed mechanisms underlying this process are generally unclear. The aim of this study was to investigate the mechanism of NCTD-induced apoptosis in HepG2 cells.

METHODS

The cytotoxicity was measured by MTT assay for cellular viability and by flow cytometry. The mitochondrial membrane potential and reactive oxygen species production was evaluated by flow cytometry analysis. The role of caspase activities were assayed using caspase apoptosis detection kit . Western blot analysis was used to evaluate the level of Cyto-C, Bcl-2, Bax, Bid, caspase 3, -9, -8 and PARP expression

RESULTS

After treatment with NCTD, a decrease in the viability of HepG2 cells and increase in apoptosis were observed. NCTD-induced apoptosis was accompanied by an increase in ROS production, loss of mitochondrial membrane potential and release of cytochrome c(cyto-c) from the mitochondria to the cytosol and down-regulation of anti-apoptotic protein Bcl-2 levels with concurrent up-regulation in pro-apoptotic protein Bax levels. However, another pro-apoptotic molecule, Bid, showed no change in such same treatment. NCTD-increased activity of caspase 9,caspase 3 and the subsequent cleavage caspase substrate PARP were also observed. The expression levels of pro-caspase-8 were not changed after NCTD treatment.

CONCLUSION

These results indicate that NCTD induced cytotoxicity in HepG2 cells by apoptosis, which is mediated through ROS generation and mitochondrial pathway.

Mechanisms by which the antitumor compound di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) induces apoptosis and the mitochondrial-mediated signaling pathway in human cancer SGC-7901 cells

The mechanisms by which the strong antitumor diorganotin(IV) compound di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) (DBDCT) induces apoptosis of SGC-7901 cells were first investigated. Inhibition of proliferation of four cancer cell lines compared with normal human hepatic L-O2 cells, cancer cell apoptosis, and expression of related mRNA and protein were detected using the methyl thiazolyl tetrazolium (MTT), flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), Western blot, and DNA ladder assays, and electron microscopy and immunocytochemistry. DBDCT decreased cancer cell proliferation rates in a dose- and time-dependent manner and changed the cycle distribution of SGC-7901 cells; the proportion of cells in G(0)-G(1) phase was increased, whereas the numbers in S and G(2)-M phases were decreased. Blockade of the cell cycle was perhaps associated with increased levels of p21, p27, p53 and the decreased level of proliferating cell nuclear antigen (PCNA). Apoptosis was characterized by DNA fragmentation, chromosomal condensation, apoptotic bodies, sub-G(1) peaks, and an increased apoptotic rate, as shown using the annexin V-FITC method. Pretreatment of cells with N-acetylcysteine and caspase-9 inhibitor could reduce growth inhibition and DBDCT-induced apoptosis. The results showed that DBDCT-mediated cell-cycle arrest might occur through the induction of p21 in a p53-dependent manner and that DBDCT induction of the mitochondrial apoptotic signaling pathway is perhaps mediated by increasing Bax/Bcl-2 ratios, which result in the loss of DeltaPsi(m), release of cytochrome c into the cytoplasm, activation of caspase-3 and -9, and increased reactive oxygen species (ROS) generation.

Induction of G(2)/M phase arrest and apoptosis by oridonin in human laryngeal carcinoma cells

Oridonin (1), an active component isolated from the plant Rabdosia rubescens, has been reported to exhibit antitumor effects. In this study, the mechanism involved in 1-induced growth inhibition, including apoptosis and G(2)/M phase arrest, in human laryngeal carcinoma HEp-2 cells deficient in functional p53, was investigated for the first time. Compound 1 triggered the mitochondrial apoptotic pathway, as indicated by increased Bax/Bcl-2 ratios, reduction of mitochondrial membrane potential (DeltaPsi(m)), and substantial increase in apoptosis-inducing factor (AIF) and cytochrome c. Inhibition of caspase-9 in HEp-2 cells did not protect the cells from 1-induced apoptosis, and cleaved caspase-9 was not detected, indicating that apoptosis occurred via a caspase-9-independent pathway. The results also suggested that G(2)/M phase arrest and apoptosis mediated by 1 occurred via a p53-independent but in a p21/WAF1-dependent manner in HEp-2 cells. In addition, the generation of reactive oxygen species (ROS) was found to be a critical mediator in growth inhibition induced by 1. Taken together, the results indicate that oridonin (1) is a potentially effective agent for the treatment of laryngeal squamous cell carcinoma.