The pharmacology of apoptosis

The role and molecular mechanism of Trametes Robiniophila Murr(Huaier) in tumor therapy

ETHNOPHARMACOLOGICAL RELEVANCE

Trametes Robiniophila Murr, commonly known as Huaier, has been extensively documented in ethnopharmacology research in China. Huaier has a long history of clinical usage spanning over 1000 years in China. Traditional clinical application records demonstrate the wide utilization of Huaier for treating various cancers and enhancing the autoimmunity of tumor patients.

AIM OF THE REVIEW

The present study provides a comprehensive review of the traditional uses, phytochemical constituents, pharmacological activities, anti-tumor mechanism, and potential applications of Huaier, thereby offering valuable insights for the further development and utilization of this natural product.

MATERIALS AND METHODS

This study employed the keywords "Trametes Robiniophila Murr" and "Huaier" to retrieve relevant information on Huaier from various databases, including PubMed, Web of Science, Springer, Science Direct, ACS, Wiley, CNKI, Baidu Scholar, Google Scholar, and ancient materia medica.

RESULTS

Trametes Robiniophila Murr (Huaier), a traditional Chinese medicine, has demonstrated significant efficacy in the clinical treatment of various tumors. The primary bioactive constituents of Huaier consist of fungal-derived compounds, including polysaccharides, proteins, ketones, alkaloids, and minerals. The research findings demonstrate that Huaier serves as a reliable adjunctive therapeutic agent by effectively inhibiting cancer cell proliferation, inducing apoptosis in cancer cells, suppressing tumor metastasis, regulating tumor stem cells and immune function. Therefore, it exerts a potent anti-tumor effect when used in conjunction with conventional anti-cancer therapies.

CONCLUSIONS

The analysis of traditional uses, phytochemical composition, and pharmacological activity reveals that Huaier exhibits significant potential as a medicinal plant with diverse pharmacological effects. Owing to its numerous advantages, Huaier holds immense promise for application in the domains of tumor prevention and treatment, enhancing both survival time and quality of life among cancer patients.

Comprehensive analysis of disulfidptosis-related genes: a prognosis model construction and tumor microenvironment characterization in clear cell renal cell carcinoma

BACKGROUND

Disulfidptosis, a form of cell death induced by abnormal intracellular accumulation of disulfides, is a newly recognized variety of cell death. Clear cell renal cell carcinoma (ccRCC) is a usual urological tumor that poses serious health risks. There are few studies of disulfidptosis-related genes (DRGs) in ccRCC so far.

METHODS

The expression, transcriptional variants, and prognostic role of DRGs were assessed. Based on DRGs, consensus unsupervised clustering analysis was performed to stratify ccRCC patients into various subtypes and constructed a DRG risk scoring model. Patients were stratified into high or low-risk groups by this model. We focused on assessing the discrepancy in prognosis, TME, chemotherapeutic susceptibility, and landscape of immune between the two risk groups. Finally, we validated the expression and explored the biological function of the risk scoring gene FLRT3 through in vitro experiments.

RESULTS

The different subtypes had significantly different gene expression, immune, and prognostic landscapes. In the two risk groups, the high-risk group had higher TME scores, more significant immune cell infiltration, and a higher probability of benefiting from immunotherapy, but had a worse prognosis. There were also remarkable differences in chemotherapeutic susceptibility between the two risk groups. In ccRCC cells, the expression of FLRT3 was shown to be lower and its overexpression caused a decrease in cell proliferation and metastatic capacity.

CONCLUSIONS

Starting from disulfidptosis, we established a new risk scoring model which can provide new ideas for doctors to forecast patient survival and determine clinical treatment plans.

Caspase-Linked Programmed Cell Death in Prostate Cancer: From Apoptosis, Necroptosis, and Pyroptosis to PANoptosis

Prostate cancer (PCa) is a complex disease and the cause of one of the highest cancer-related mortalities in men worldwide. Annually, more than 1.2 million new cases are diagnosed globally, accounting for 7% of newly diagnosed cancers in men. Programmed cell death (PCD) plays an essential role in removing infected, functionally dispensable, or potentially neoplastic cells. Apoptosis is the canonical form of PCD with no inflammatory responses elicited, and the close relationship between apoptosis and PCa has been well studied. Necroptosis and pyroptosis are two lytic forms of PCD that result in the release of intracellular contents, which induce inflammatory responses. An increasing number of studies have confirmed that necroptosis and pyroptosis are also closely related to the occurrence and progression of PCa. Recently, a novel form of PCD named PANoptosis, which is a combination of apoptosis, necroptosis, and pyroptosis, revealed the attached connection among them and may be a promising target for PCa. Apoptosis, necroptosis, pyroptosis, and PANoptosis are good examples to better understand the mechanism underlying PCD in PCa. This review aims to summarize the emerging roles and therapeutic potential of apoptosis, necroptosis, pyroptosis, and PANoptosis in PCa.

Simultaneous suppression of PKM2 and PHGDH elicits synergistic anti-cancer effect in NSCLC

Metabolic reprogramming is a hallmark of human cancer. Cancer cells exhibit enhanced glycolysis, which allows glycolytic intermediates to be diverted into several other biosynthetic pathways, such as serine synthesis. Here, we explored the anti-cancer effects of the pyruvate kinase (PK) M2 inhibitor PKM2-IN-1 alone or in combination with the phosphoglycerate dehydrogenase (PHGDH) inhibitor NCT-503 in human NSCLC A549 cells in vitro and in vivo. PKM2-IN-1 inhibited proliferation and induced cell cycle arrest and apoptosis, with increased glycolytic intermediate 3-phosphoglycerate (3-PG) level and PHGDH expression. The combination of PKM2-IN-1 and NCT-503 further suppressed cancer cell proliferation and induced G2/M phase arrest, accompanied by the reduction of ATP, activation of AMPK and inhibition of its downstream mTOR and p70S6K, upregulation of p53 and p21, as well as downregulation of cyclin B1 and cdc2. In addition, combined treatment triggered ROS-dependent apoptosis by affecting the intrinsic Bcl-2/caspase-3/PARP pathway. Moreover, the combination suppressed glucose transporter type 1 (GLUT1) expression. In vivo, co-administration of PKM2-IN-1 and NCT-503 significantly inhibited A549 tumor growth. Taken together, PKM2-IN-1 in combination with NCT-503 exhibited remarkable anti-cancer effects through induction of G2/M cell cycle arrest and apoptosis, in which the metabolic stress induced ATP reduction and ROS augmented DNA damage might be involved. These results suggest that the combination of PKM2-IN-1 and NCT-503 might be a potential strategy for the therapy of lung cancer.

Exosomes and their roles in the chemoresistance of pancreatic cancer

Pancreatic cancer (PC) remains one of the most lethal human malignancies worldwide. Due to the insidious onset and the rapid progression, most patients with PC are diagnosed at an advanced stage rendering them inoperable. Despite the development of multiple promising chemotherapeutic agents as recommended first-line treatment for PC, the therapeutic efficacy is largely limited by unwanted drug resistance. Recent studies have identified exosomes as essential mediators of intercellular communications during the occurrence of drug resistance. Understanding the underlying molecular mechanisms and complex signaling pathways of exosome-mediated drug resistance will contribute to the improvement of the design of new oncologic therapy regimens. This review focuses on the intrinsic connections between the chemoresistance of PC cells and exosomes in the tumor microenvironment (TME).

A new cell death program regulated by toll-like receptor 9 through p38 mitogen-activated protein kinase signaling pathway in a neonatal rat model with sepsis associated encephalopathy

Background:

Sepsis, a serious condition with high mortality, usually causes sepsis associated encephalopathy (SAE) that involves neuronal cell death. However, the cell death programs involved and their underlying mechanisms are not clear. This study aimed to explore the regulatory mechanisms of different cell death programs in SAE.

Methods:

A neonatal rat model of SAE was established by cecal ligation and perforation. Survival rate and vital signs (mean arterial pressure and heart rate) were monitored, nerve reflexes were evaluated, and cortical pathological changes were observed by hematoxylin and eosin staining. The expression of pyroptosis, apoptosis, and necroptosis (PANoptosis)-related proteins, mitogen- activated protein kinase (MAPK), and its upstream regulator toll-like receptor 9 (TLR9) were detected. The expression of TLR9 in neurons was observed by immunofluorescence staining. The ultrastructure of neurons was observed by transmission electron microscope.

Results:

First, PANoptosis was found in cortical nerve cells of the SAE rats. Meanwhile, the subunits of MAPKs, p38 MAPK, Jun N- terminal kinase, and extracellular signal-regulated kinase (ERK) were activated. After pharmacologically inhibiting each of the subunits, only p38 MAPK was found to be associated with PANoptosis. Furthermore, blocking the p38 MAPK signaling pathway activated necroptosis but inhibited apoptosis and pyroptosis. When necroptosis was pharmacologically inhibited, apoptosis and pyroptosis were reactivated. Finally, we found that the expression of TLR9, a regulator of MAPKs, was significantly increased in this model. After down-regulation of TLR9, p38 MAPK, and ERK signaling pathways were inhibited, which led to the inhibition of PANoptosis. Further analysis found that down-regulation of TLR9 improved the survival rate and reduced the pathological changes in SAE rats.

Conclusions:

Our study showed that the programs comprising PANoptosis are activated simultaneously in SAE rats. TLR9 activated PANoptosis through the p38 MAPK signaling pathway. TLR9 may work as a potential target for SAE treatment.

Betulinic acid induces autophagy-dependent apoptosis via Bmi-1/ROS/AMPK-mTOR-ULK1 axis in human bladder cancer cells

Betulinic acid (BA), a pentacyclic triterpenoid isolated from tree bark, exhibits antitumor effects against solid malignancies and triggers autophagy and/or apoptosis in human cancer cells. Nonetheless, the relationship between autophagy and apoptosis and the potential modulatory actions of BA on autophagy-dependent bladder cancer cell death remain unclear. The present study showed that BA exposure significantly suppressed viability, proliferation, and migration of EJ and T24 human bladder cancer cells. These effects reflected caspase 3-mediated apoptosis and could be attenuated or abolished by inhibiting ROS production with N-acetyl-L-cysteine, inhibiting autophagy with chloroquine, or silencing ATG7 with targeted siRNA. BA-induced autophagy was evidenced by epifluorescence imaging of lentivirus-induced expression of mCherry-GFP-LC3B and increased expression of two autophagy-related proteins, LC3B-II and TEM. Moreover, enhanced AMPK phosphorylation and decreased mTOR and ULK-1 phosphorylation suggested BA activates autophagy via the AMPK/mTOR/ULK1 pathway. Accordingly, exposure to dorsomorphin (Compound C), an AMPK inhibitor, and AICAR, an AMPK activator, respectively inhibited and stimulated BA-induced autophagy in EJ and T24 cells. The effects of Bmi-1 overexpression in vitro and decreased Bmi-1 expression in BA-treated T24 cell xenografts in nude mice suggested that downregulation of Bmi-1 is the underlying mechanism in BA-mediated, autophagy-dependent apoptosis.

Trametes robiniophila Murr in the treatment of breast cancer

Breast cancer is the leading cause of cancer death among women across the world. Trametes robiniophila Murr (Huaier), a traditional herbal medicine, has been used in China to protect human health for about 1600 years. Recent years, Huaier had been proven to be effective for multiple types of malignancies. This systematic review focused on breast cancer treatment, summarizing the curative function of Huaier aqueous extract and polysaccharides in preclinical researches. Huaier could markedly inhibit breast cancer progression with low toxicity, enhance immune response and increase the sensitivity to radiation and chemotherapy. The therapeutic effect of Huaier granule in clinical studies was also included. This review amalgamated the current studies and highlighted the promising role of Huaier and its polysaccharides as complementary alternative medicine in breast cancer treatment.

Melognine, a novel monoterpenoid indole alkaloid from Melodinus fusiformis that induce apoptosis in BT549 cells

A novel monoterpenoid indole alkaloid, melognine (1) possessing an unprecedented skeleton with a 6/6/5/5/6/6 hexatomic rearranged ring system was isolated from the stems of Melodinus fusiformis. The structure with absolute configuration of 1 was established by extensive spectroscopic analyses and quantum ECD calculations. Melognine showed significant cytotoxicity on human breast cancer BT549 cells with an IC₅₀ value of 1.49 μM by MTT assay. Further mechanism of action study indicated that melognine demonstrated the ability to induce apoptosis by activation of caspase-3 and p53, and downregulation of Bcl-2 in BT549 cells.

Oxidative Stress Type Influences the Properties of Antioxidants Containing Polyphenols in RINm5F Beta Cells

The in vitro methods currently used to screen bioactive compounds focus on the use of a single model of oxidative stress. However, this simplistic view may lead to conflicting results. The aim of this study was to evaluate the antioxidant properties of two natural extracts (a mix of red wine polyphenols (RWPs) and epigallocatechin gallate (EGCG)) with three models of oxidative stress induced with hydrogen peroxide (H2O2), a mixture of hypoxanthine and xanthine oxidase (HX/XO), or streptozotocin (STZ) in RINm5F beta cells. We employed multiple approaches to validate their potential as therapeutic treatment options, including cell viability, reactive oxygen species production, and antioxidant enzymes expression. All three oxidative stresses induced a decrease in cell viability and an increase in apoptosis, whereas the level of ROS production was variable depending on the type of stress. The highest level of ROS was found for the HX/XO-induced stress, an increase that was reflected by higher expression antioxidant enzymes. Further, both antioxidant compounds presented beneficial effects during oxidative stress, but EGCG appeared to be a more efficient antioxidant. These data indicate that the efficiency of natural antioxidants is dependent on both the nature of the compound and the type of oxidative stress generated.

Isolation and purification of oligopeptides from Ruditapes philippinarum and its inhibition on the growth of DU‑145 cells in vitro

Ruditapes philippinarum is a member of the Veneridae family of marine bivalve molluscs. RPOI‑1 (Ruditapes philippinarum oligopeptide) is a tetrapeptide that can be extracted from Ruditapes philippinarum by means of enzymolysis. This study showed that RPOI‑1 strongly inhibits proliferation and induces apoptosis in DU‑145 human prostate cancer cells. When cells were treated with varying concentrations of RPOI‑1, significant inhibition of proliferation was detected by an MTT assay, and sub‑G1 and G2/M phase cell cycle arrest was observed using flow cytometric (FCM) analysis. Furthermore, morphological changes characteristic of apoptosis and an increase in the proportion of apoptotic cells were observed using double sequential acridine orange/ethidium bromide staining, FCM analysis and transmission election microscopy. FCM studies showed that exposing DU‑145 cells to 10, 20 and 30 mg/ml RPOI‑1 for 24 h increased the percentage of cells in the early‑stages of apoptotis in a dose‑dependent manner, with the numbers rising from 3.01% in the control group to 13.40% in the group treated with the highest dose.

Morphine-induced apoptosis in the ventral tegmental area and hippocampus after the development but not extinction of reward-related behaviors in rats

Some data suggest that morphine induces apoptosis in neurons, while other evidences show that morphine could have protective effects against cell death. In this study, we suggested that there is a parallel role of morphine in reward circuitry and apoptosis processing. Therefore, we investigated the effect of morphine on modifications of apoptotic factors in the ventral tegmental area (VTA) and hippocampus (HPC) which are involved in the reward circuitry after the acquisition and extinction periods of conditioned place preference (CPP). In behavioral experiments, different doses of morphine (0.5, 5, and 10 mg/kg) and saline were examined in the CPP paradigm. Conditioning score and locomotor activity were recorded by Ethovision software after acquisition on the post-conditioning day, and days 4 and 8 of extinction periods. In order to investigate the molecular mechanisms in each group, we then dissected the brains and measured the expression of apoptotic factors in the VTA and HPC by western blotting analysis. All of the morphine-treated groups showed an increase of apoptotic factors in these regions during acquisition but not in extinction period. In the HPC, morphine significantly increased the ratio of Bax/Bcl-2, caspases-3, and PARP by the lowest dose (0.5 mg/kg), but, in the VTA, a considerable increase was seen in the dose of 5 mg/kg; promotion of apoptotic factors in the HPC and VTA insinuates that morphine can affect the molecular mechanisms that interfere with apoptosis through different receptors. Our findings suggest that a specific opioid receptor involves in modification of apoptotic factors expression in these areas. It seems that the reduction of cell death in response to high dose of morphine in the VTA and HPC may be due to activation of low affinity opioid receptors which are involved in neuroprotective features of morphine.

Effect of enoxaparin and onion extract on human skin fibroblast cell line - therapeutic implications for the treatment of keloids

CONTEXT

Keloids and hypertrophic scars are hyperproliferative skin disorders resulting in abnormal wound healing. In the prevention and treatment of keloids and hypertrophic scars, ointments containing heparin and onion extract are very popular. Their therapeutic effects, however, are still controversial and the mechanism of action is not fully understood.

OBJECTIVE

The aim of this study was to assess the effect of enoxaparin and dry onion extract on proliferation, apoptosis and β1 integrin expression in human fibroblasts.

MATERIALS AND METHODS

Fibroblast human cell lines (46 BR.1 N) were treated for 48 h with various concentrations of enoxaparin sodium (20, 100, 500 µg/mL) and/or onion [Allium cepa L. (Alliaceae)] extract (50, 250, 1000 µg/mL). The cell proliferation was evaluated by [(3)H]-thymidine incorporation assay. Furthermore, the expression of β1 integrin and apoptosis was determined by flow cytometry.

RESULTS AND DISCUSSION

The results demonstrate that enoxaparin and onion extract inhibited the proliferation of human fibroblasts. Almost complete inhibition of cell proliferation was achieved by enoxaparin in 500 µg/mL concentration (91.5% reduction). The onion extract at a concentration of 250 µg/mL also strongly inhibited the proliferation of cells (50.8% reduction). Depending on concentration, enoxaparin and onion extract induced apoptosis (500 and 1000 µg/mL, respectively) and, depending on concentration, downregulated the expression of β1 integrin on human fibroblasts.

CONCLUSION

This work points at possible mechanism of action of enoxaparin and onion extract, when administered in the treatment of patients with keloids and hypertrophic scars.

Do plants mediate their anti-diabetic effects through anti-oxidant and anti-apoptotic actions? an in vitro assay of 3 Indian medicinal plants

Background

Both experimental and clinical studies suggest that oxidative stress plays a major role in the pathogenesis of both types of diabetes mellitus. This oxidative stress leads to β-cell destruction by apoptosis. Hence exploring agents modulating oxidative stress is an effective strategy in the treatment of both Type I and Type II diabetes. Plants are a major source of anti-oxidants and exert protective effects against oxidative stress in biological systems. Phyllanthus emblica, Curcuma longa and Tinospora cordifolia are three such plants widely used in Ayurveda for their anti-hyperglycemic activity. Additionally their anti-oxidant properties have been scientifically validated in various experimental in vitro and in vivo models. Hence the present in vitro study was planned to assess whether the anti-hyperglycemic effects of the hydro-alcoholic extracts of Phyllanthus emblica (Pe) and Curcuma longa (Cl) and aqueous extract of Tinospora cordifolia (Tc) are mediated through their antioxidant and/or anti-apoptotic property in a streptozotocin induced stress model.

Methods

RINm5F cell line was used as a model of pancreatic β-cells against stress induced by streptozotocin (2 mM). Non-toxic concentrations of the plant extracts were identified using MTT assay. Lipid peroxidation through MDA release, modulation of apoptosis and insulin release were the variables measured to assess streptozotocin induced damage and protection afforded by the plant extracts.

Results

All 3 plants extracts significantly inhibited MDA release from RIN cells indicating protective effect against STZ induced oxidative damage. They also exhibited a dose dependent anti-apoptotic effect as seen by a decrease in the sub G0 population in response to STZ. None of the plant extracts affected insulin secretion from the cells to a great extent.

Conclusion

The present study thus demonstrated that the protective effect of the selected medicinal plants against oxidative stress induced by STZ in vitro, which was exerted through their anti-oxidant and anti-apoptotic actions.

Monoterpene bisindole alkaloids, from the African medicinal plant Tabernaemontana elegans, induce apoptosis in HCT116 human colon carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Tabernaemontana elegans is a medicinal plant used in African traditional medicine to treat several ailments including cancer. The aims of the present study were to identify anti-cancer compounds, namely apoptosis inducers, from Tabernaemontana elegans, and hence to validate its usage in traditional medicine.

METHODS AND MATERIALS

Six alkaloids, including four monomeric indole (1-3, and 6) and two bisindole (4 and 5) alkaloids, were isolated from the methanolic extract of Tabernaemontana elegans roots. The structures of these compounds were characterized by 1D and 2D NMR spectroscopic and mass spectrometric data. Compounds 1-6 along with compound 7, previously isolated from the leaves of the same species, were evaluated for in vitro cytotoxicity against HCT116 human colon carcinoma cells by the MTS metabolism assay. The cytotoxicity of the most promising compounds was corroborated by Guava-ViaCount flow cytometry assays. Selected compounds were next studied for apoptosis induction activity in HCT116 cells, by evaluation of nuclear morphology following Hoechst staining, and by caspase-3 like activity assays.

RESULTS

Among the tested compounds (1-7), the bisindole alkaloids tabernaelegantine C (4) and tabernaelegantinine B (5) were found to be cytotoxic to HCT116 cells at 20 µM, with compound 5 being more cytotoxic than the positive control 5-Fluorouracil (5-FU), at a similar dose. In fact, even at 0.5 µM, compound 5 was more potent than 5-FU. Compounds 4 and 5 induced characteristic patterns of apoptosis in HCT116 cancer cells including, cell shrinkage, condensation, fragmentation of the nucleus, blebbing of the plasma membrane and chromatin condensation. Further, general caspase-3-like activity was increased in cells exposed to compounds 4 and 5, corroborating the nuclear morphology evaluation assays.

CONCLUSIONS

Bisindole alkaloids tabernaelegantine C (4) and tabernaelegantinine B (5) were characterized as potent apoptosis inducers in HCT116 human colon carcinoma cells and as possible lead/scaffolds for the development of anti-cancer drugs. This study substantiates the usage of Tabernaemontana elegans in traditional medicine to treat cancer.

Antiapoptotic Effects of EGb 761

Ginkgo biloba extracts have long been used in Chinese traditional medicine for hundreds of years. The most significant extract obtained from Ginkgo biloba leaves has been EGb 761, a widely used phytopharmaceutical product in Europe. EGb 761 is a well-defined mixture of active compounds, which contains two main active substances: flavonoid glycosides (24-26%) and terpene lactones (6-8%). These compounds have shown antiapoptotic effects through the protection of mitochondrial membrane integrity, inhibition of mitochondrial cytochrome c release, enhancement of antiapoptotic protein transcription, and reduction of caspase transcription and DNA fragmentation. Other effects include the reduction of oxidative stress (which has been related to the occurrence of vascular, degenerative, and proliferative diseases), coupled to strong induction of phase II-detoxifying and cellular defense enzymes by Nrf2/ARE activation, in addition to the modulation of transcription factors, such as CREB, HIF-1 α , NF- κ B, AP-1, and p53, involved in the apoptosis process. This work reviews experimental results about the antiapoptotic effects induced by the standardized extract of Ginkgo biloba leaves (EGb 761).

Apoptosis inducing activity of benzophenanthridine-type alkaloids and 2-arylbenzofuran neolignans in HCT116 colon carcinoma cells

Thirteen compounds belonging to different classes of alkaloids (1-9) and lignans (10-13), isolated from the methanol extract of roots of the African medicinal plant Zanthoxylum capense, were assayed for their ability as apoptosis inducers in HCT116 colon carcinoma cells. The cytotoxicity of these compounds was evaluated in HCT116 colon carcinoma cells by the MTS assay. Out of the tested compounds, three benzophenanthridine alkaloids (1, 4, and 7), a dibenzyl butyrolactone lignan (10), and two 2-arylbenzofuran neolignans (12 and 13) displayed significant cytotoxicity to HCT116 cells, confirmed by the Guava ViaCount viability assay. The selected compounds (1, 4, 7, 10, 12, and 13) were further tested for apoptosis induction activity in HCT116 cells, by evaluation of nuclear morphology following Hoechst staining, and by caspase-3 like activity assays. Morphologic evaluation of HCT116 nuclei following Hoechst staining and fluorescence microscopy revealed that compounds 1, 4, 7, 10, 12, and 13 induced apoptosis in HCT116 colon carcinoma cells, producing similar, or higher, apoptosis levels when compared with 5-fluorouracil (5-FU), the cornerstone cytotoxic used in colon cancer treatment for several decades. In fact, HCT116 cells developed morphological changes characteristic of apoptosis, including chromatin condensation, nuclear fragmentation and formation of apoptotic bodies. Importantly, compounds 4 and 13 at 20 μM were the most promising in this study, inducing respectively ∼11- and 7-fold increases in apoptotic cells as compared to vehicle control, whereas 5-FU increased apoptosis by ∼2-fold. Apoptosis induction for compounds 4 and 13 was further confirmed by caspase-3-like activity assays, which showed respectively ∼2- and 1.5-fold increases in caspase-3-like activity compared to vehicle control. These results suggested that specific benzophenanthridine alkaloids and 2-arylbenzofuran neolignans isolated from Zanthoxylum capense show strong anticancer activity in HCT116 colon carcinoma cells.

Quercetin-induced apoptosis of HL-60 cells by reducing PI3K/Akt

To explore the effect and mechanism of quercetin on proliferation and apoptosis of leukemia cells, and provide a theoretical basis for its clinical application. HL-60 leukemia cell lines was treated with different dose quercetin, the proliferation activity of leukemia cells was assessed by MTT method; the morphological changes of apoptosis of HL-60 cells, including nuclear condensation and DNA fragmentation, were observed by Hoechst 33258 fluorescence staining, the apoptosis rate and caspase 2,3 activation were assessed by flow cytometry, and the cell signal pathway including phosphatidylinositol 3-kinase (PI3K), phosphorylated protein kinase B (pAkt), Bcl-2, Bax were detected by western blotting. Quercetin could significantly decrease the proliferation activity of HL-60 cells through the blockade of G(0)/G(1) phase, and induce the apoptosis of HL-60 cells in a time- and dose-dependent manner. Quercetin caused leukemia cells apoptosis by decreasing the protein expression of PI3K and Bax, the inhibitory phosphorylation of Akt, the decreased levels of Bcl-2 protein and increased activations of caspase-2 and -3, and increased poly(ADP-ribose) polymerase cleavage. Our results indicate that the apoptotic processes caused by quercetin are mediated by the decrease of pAkt and Bcl-2 levels, the increase of Bax level, and the activation of caspase families in HL-60 cells.

Tehranolide inhibits proliferation of MCF-7 human breast cancer cells by inducing G0/G1 arrest and apoptosis

Tehranolide, a novel natural sesquiterpene lactone with an endoperoxide group, bears a structural similarity to artemisinin and has been shown to inhibit cell growth. However, the underlying mechanisms of these activities remain obscure. The purpose of this study was to investigate the fundamental mechanisms by which tehranolide inhibits growth in MCF-7 cells. Cell growth was determined by using the MTT viability assay and counting cells. Apoptosis and cell-cycle progression were evaluated by means of Hoechst 33258 staining, flow cytometry with annexin-V/propidium iodide double staining, and ROS formation. The protein expression of Bax and Bcl-2 was demonstrated by Western blotting. Moreover, to determine the molecular mechanism whereby tehranolide mediates G0/G1 arrest, the expression of PI3K, p-PI3K, Akt, p-Akt, p27kip1, cyclin D1, and CDK4 was monitored. Cell proliferation was significantly inhibited by tehranolide in a dose- and time-dependent manner. This compound inhibited cell proliferation and induced G0/G1 arrest through the PI3K/Akt/cyclin D1 pathway. It also induced apoptosis and an increase in ROS. In addition, an increase in cytochrome c and Bax, as well as a decrease in Bcl-2, was observed. Moreover, blocking the CD95 receptor with an anti-CD95 antibody (ZB4) had no effect on tehranolide-mediated apoptosis. This study has yielded promising results, which show for the first time that tehranolide does inhibit the growth of cancer cells. The selective inhibition of cancer cell growth, the apoptosis induction via the mitochondrial pathway, and the G0/G1 arrest by modulating the PI3K/AKT signaling pathway and downregulating cyclin D1, which leads to the release of p27kip1 and the association of this inhibitor with the cyclin E/CDK2 complex, ultimately preventing cell-cycle progression from G1 to S phase, all serve to provide support for further studies of tehranolide as a possible anticancer drug in the clinical treatment of cancer.

Selectively induced apoptosis in human neutrophils in the presence of oxidative phenoxazines, 2-amino-4,4α-dihydryo-4α-7H-phenoxazine-3-one and 2-aminophenoxazine-3-one, preceded by decrease of intracellular pH, depolarization of the mitochondria, and inhibition of superoxide generation

The present research investigated the effect of the oxidative phenoxazines, 2-amino-4,4α-dihydryo-4α-7H-phenoxazine-3-one (Phx-1) and 2-amino-phenoxazine-3-one (Phx-3) on apoptosis induction and apoptosis-related early events in human neutrophils. When Phx-1 or Phx-3 was administered to freshly drawn human blood for 18 h, these phenoxazines caused apoptotic cell death morphologically characterized by condensation of the nucleus in neutrophils, without causing it in lymphocytes and monocytes. Apoptosis, which was detectable by microscopic analysis and by using flow-cytometry, occurred significantly in human neutrophils isolated from freshly drawn blood, 6 h after the administration of 50 µM Phx-1 and Phx-3. After 24 h, every isolated neutrophil treated with Phx-1 or Phx-3 fell into apoptosis or lost its morphology, while many of the neutrophils without these phenoxazines remained alive, with normal morphology. Apoptosis-related early events including a decrease in intracellular pH (pHi) and depolarization of the mitochondria occurred in the isolated neutrophils, 30 min and 6 h after the administration of Phx-1 or Phx-3, respectively. Superoxide generation from the isolated neutrophils mimicked by phorbol myristate acetate (PMA) was very markedly inhibited by 100 µM Phx-1 or Phx-3. This result could be explained, in part, by the fact that the insufficient supply of NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) was caused by pHi decrease in neutrophils treated with Phx-1 or Phx, because NADPH is necessary for NADPH oxidase responsible for generating superoxide in the cells. The present results suggest that Phx-1 and Phx-3 have the capacity of selectively inducing apoptosis in human neutrophils and that these phenoxazines may be useful as specific drugs to induce apoptotic cell death of human neutrophils and thereby prevent inflammation caused by these phagocytic cells.

3,4-Disubstituted oxazolidin-2-ones as constrained ceramide analogs with anticancer activities

Heterocyclic analogs of ceramide as 3-alkanoyl or benzoyl-4-(1-hydroxy-2-enyl)-oxazolidin-2-ones were designed by binding of primary alcohol and amide in sphinogosine backbone as a carbamate. They were synthesized by addition of acyl halide to the common ring 4-(1-t-butyldimethylsilyloxyhexadec-2-enyl)-oxazolidin-2-one which was elaborated from chiral aziridine-2-carboxylate including stereoselective reduction and ring opening reactions as key steps. Other analogs with different carbon frame at C4 position which is corresponding to the sphingoid backbone were prepared from 3-cyclopentanecarbonyl-4-(1-t-butyldimethylsilyloxybut-2-enyl)-oxazolidin-2-one and straight and cyclic alkenes by cross metathesis. All compounds were tested as antileukemic drugs against human leukemia HL-60 cells. Many of them including propionyl, cyclopentanoyl and p-nitrobenzoyl-4-(1-hydroxyhexadec-2-enyl)-oxazolidin-2-ones showed better antileukemic activities than natural C2-ceramide with good correlation between cell death and DNA fragmentation. There is a drastic change of the activities by the carbon chain lengths at C4 position. Cytotoxicity was induced by caspase activation without significant accumulation of endogenous ceramide concentration or any perturbation of ceramide metabolism.

Hypoglycemic activity of C-glycosyl flavonoid from Enicostemma hyssopifolium

CONTEXT

Enicostemma hyssopifolium Verdoon (Gentianaceae) has been documented for various therapeutic effects in traditional systems of medicine; the hypoglycemic and hypolipidemic activities are also well reported.

OBJECTIVE

Bioactivity guided fractionation of methanol extract of E. hyssopifolium to test the hypothesis that E. hyssopifolium and its constituents influence cells and systemic glucose homeostasis.

MATERIALS AND METHODS

Derived fraction and isolated compounds were studied for (1) aldose reductase (AR) inhibition, (2) α-glucosidase inhibition, (3) effect on gluconeogenesis in rat hepatoma, (4) cytoprotection against streptozotocin (STZ)-induced toxicity on RINm5F cells, (5) normalization of glycemic control in acute hyperglycemic rat model, and (6) insulin-releasing effect both in vitro and in vivo.

RESULTS

The results indicated that E. hyssopifolium can modify the glucose homeostasis at the cellular level. Two bioactive constituents were identified. Swertisin was found to inhibit AR (IC(50) 1.23 μg/mL) and α-glucosidase (IC(50) 1.89 μg/mL). It also possessed a significant cytoprotective action of RINm5F cell line against toxicant STZ. Swertiamarin was found to have hepatic gluconeogenesis inhibiting and insulin-releasing effect on rat hepatoma and RINm5F cells, respectively. The results of the in vivo study showed that swertiamarin, unlike the in vitro effect, produced no significant raise of insulin secretion. Swertisin normalized the serum glucose 60 min after high dose of glucose (2 g/kg, i.p.) in rats.

DISCUSSION AND CONCLUSION

These findings demonstrate that the fraction derived from the aerial part of E. hyssopifolium achieve normoglycemic status in hyperglycemic conditions via various mechanisms. The constituents swertiamarin and swertisin are responsible for bioactivity.

Small-molecule inhibitors of c-Myc transcriptional factor suppress proliferation and induce apoptosis of promyelocytic leukemia cell via cell cycle arrest

c-Myc plays a decisive role in the proliferation of HL-60 promyelocytic leukemia cells. In the present study, we demonstrated that an inhibitor of c-Myc/Max/DNA complex formation has a high potentiality as a suppressor of c-Myc-involved cell signaling. We prepared recombinant c-Myc and Max proteins encompassing the human-origin DNA binding and dimerization domains, and tested a chemical library of 6480 small molecules for their inhibitory effect on the in vitro formation of the c-Myc/Max/DNA complex as well as their influence on DMSO-differentiated HL-60 cells. We found several hit compounds through in vitro and cell-based screening tests, and also confirmed these compounds significantly inhibited the formation of the recombinant c-Myc/Max/DNA complex in the low micromolar range. Indeed, these inhibitors effectively blocked c-Myc-associated gene expression in cancer cell line, suppressed the proliferation and induced the apoptosis of HL-60 promyelocytic leukemia cells via cell cycle arrest without altering the expression level of c-Myc in the DMSO-differentiated HL-60 cells. These successive results suggest that our c-Myc/Max/DNA complex inhibitors potently contribute to the suppression of the Myc-dependent proliferation of leukemia cells and to the induction of apoptosis. Accordingly, we would expect that these compounds could serve as lead compounds in the development of novel anticancer drugs.

Cytotoxicity, apoptosis-inducing effects and structure-activity relationships of four natural xanthones from Gentianopsis paludosa Ma in HepG2 and HL-60 cells

Four xanthones were isolated from Gentianopsis paludosa Ma and were identified by modern spectroscopic methods. Cytotoxicity of the four xanthones was tested on HepG2 cells and HL-60 cells by sulphorhodamine B (SRB) assay. Clonogenic survival assay, trypan blue exclusion method, AO/EB staining and DNA fragmentation assay were conducted to investigate the effect on growth inhibition and apoptosis in the two cell lines in vitro. At the same time, structure-activity relationships (SARs) of the xanthones were investigated. The results showed that the xanthones had significant cytotoxicity and inhibition of proliferation in both HepG2 cells and HL-60 cells, and could induce apoptosis in these two cell lines. SARs indicated that the methoxy group had more cytotoxic contribution than the hydroxyl group at site C-8 in the structural scaffold of xanthone. The glycosidea at site C-1 may aggravate the stereospecific blockade of compound 4 and reduced its cytotoxic activity.

The role of strain variation in BAX and BCL-2 expression in murine bleomycin-induced pulmonary fibrosis

This study hypothesized that the expression of apoptosis-regulatory genes, such as BCL-2 and BAX may be affected by genetic variation in bleomycin-induced pulmonary fibrosis in C57BL/6 and NMRI mice. Pulmonary fibrosis induced by single intratracheal dose of bleomycin (3 U kg(-1)). After 2 weeks, lung samples were analyzed for collagen deposition, pathological changes and expression of BCL-2 and BAX. The fibrotic lung changes were similar in both strains. The immunohistochemical assay using a biotin-streptavidin technique showed no significant difference in immunoreactivity for BCL-2 protein between the controls and bleomycin-treated C57BL/6 mice. However, in NMRI mice, the expression of BCL-2 was significantly (p<0.05) upregulated in myofibroblasts and neutrophils. The expression of BAX protein was significantly (p<0.05) upregulated in alveolar epithelial cells of both strains and downregulated in myofibroblasts and lymphocytes of the lung tissues of C57BL/6 mice and also in lymphocytes of NMRI mice at 2 weeks after bleomycin instillation. These results confirm the role of BCL-2 and BAX proteins in the pathogenesis of pulmonary fibrosis and suggest that the expression of apoptotic regulatory genes may be specific in different cell types in various strains.

Cell death serum biomarkers are early predictors for survival in severe septic patients with hepatic dysfunction

INTRODUCTION

Severe sepsis, septic shock, and resulting organ failure represent the most common cause of death in intensive care medicine, with mortality ranging from 40% to 70%. It is still unclear whether necrosis or apoptosis plays the predominant role in severe sepsis. Determining the prevalent mode of cell death would be valuable, as new therapeutic agents (eg, antiapoptotic drugs such as caspase inhibitors) may improve unsatisfactory outcomes in patients with severe sepsis. Furthermore, the prognostic value of newly developed cell death serum biomarkers is of great interest.

METHODS

In total, 147 patients (101 patients with severe sepsis, 28 postoperative patients after major abdominal surgery, 18 healthy volunteers) were enrolled. Baseline and clinical data were evaluated. Blood samples from patients with severe sepsis were collected at the time of sepsis diagnosis, and 48 and 120 hours later; samples from healthy volunteers were collected once, and from postoperative patients, once immediately after surgery. We measured caspase-cleaved and uncleaved cytokeratin-18 (CK-18, intermediate filament protein) as a marker of cell death, isolated CK-18 fragments as a marker of apoptosis, as well as IL-6, soluble vascular cell adhesion molecule, and soluble intercellular adhesion molecule.

RESULTS

Age and sex of patients with severe sepsis and postoperative patients were comparable, whereas healthy volunteers were significantly younger. In healthy volunteers, the mode of cellular turnover was primarily apoptotic cell death. Postoperative patients showed comparable levels of apoptotic activity, but necrotic cell death was markedly increased, probably due to surgical tissue injury. In contrast, patients with severe sepsis, and especially non-survivors of the septic group showed increased levels of markers for both apoptotic and necrotic cell death. In severe septic patients with liver dysfunction, necrosis is increased relative to severe septic patients with intact hepatic function. For severe septic patients with liver dysfunction, a cut-off value for caspase-cleaved and uncleaved cytokeratin-18 could be calculated, in order to identify patients at high risk for death due to severe sepsis.

CONCLUSIONS

The measurement of caspase-cleaved and uncleaved cytokeratin-18 appears to be an early predictor for survival in severe septic patients with hepatic dysfunction. Furthermore, the loss of parenchymal cells due to necrosis may be the primary mode of cell death in these patients. This may limit possible therapeutic options.

Purification, characterization and cytotoxicity of malanin, a novel plant toxin from the seeds of Malania oleifera

Malanin, a novel plant toxin with a molecular weight of 61,875 Da and an isoelectric point of 5.5, was isolated from Malania oleifera seeds by homogenization, ammonium sulfate precipitation and hydrophobic interaction chromatography (HIC). It is a glycoprotein with two chains, chain-A and chain-B, which are crosslinked by one or more disulfide bonds. The N-terminal amino-acid sequences of malanin are DETXTDEEFN (X was commonly C) in chain-B, and DYPKLTFTTS in chain-A. Malanin exhibited highly cytotoxic activities against cancer cell lines (HeLa, PC-12, MCF-7, K562) and non-cancer cell lines (Vero and MDCK), producing IC(50) values of 0.15+/-0.08, 7.71+/-0.24, 11.20+/-0.02, 15.80+/-0.09, 2.79+/-0.05 and 3.92+/-0.01 nM, respectively. It significantly inhibited the growth of HeLa cells through cell-cycle arrest at S phase and induced an apoptotic response. LD(50) values were determined in ICR mice, which were found to be 26.22 microg/kg and 43.11 mg/kg by i.p. and i.g. respectively. Thus, malanin is amongst the most potent toxin of plant origin.

Anti-proliferation, cell cycle arrest and apoptosis induced by a natural xanthone from Gentianopsis paludosa Ma, in human promyelocytic leukemia cell line HL-60 cells

1-hydroxy-3,7,8-trimethoxyxanthone (xanthone 1) was isolated from Gentianopsis paludosa Ma and identified by MS and NMR in our laboratory. In this study, the results showed that xanthone 1 is a potent inducer of anti-proliferation and apoptosis in HL-60 cells. When the cells treated with lower concentrations of xanthone 1 (12.4-74.4microM), significant proliferation inhibition was detected by cell viability assay and morphological analyses, and conspicuous G1 and G2/M cell cycle arrest were observed by flow cytometric (FCM) analysis. However, when the cells treated with higher doses of xanthone 1 (82.7-330.8microM), significant apoptosis was observed by double sequential AO/EB staining, DNA fragmentation assay and FCM analysis. In addition, conspicuous DNA damage was detected by comet assay. In short, all the results showed that xanthone 1 had a significant cytotoxic effect and could induce proliferation inhibition and apoptosis in HL-60 cells in a time- and dose-dependent manner. It was possible that xanthone 1 could induce DNA damage in HL-60 cells, which resulted in G1 phase arrest at the lower concentrations and G2/M phase arrest at the higher concentrations, thus inhibiting the cell proliferation, and irreparable DNA damage at the higher concentrations might be responsible for the occurrence of apoptosis.

Lupane-type triterpenoids from Microtropis fokienensis and Perrottetia arisanensis and the apoptotic effect of 28-hydroxy-3-oxo-lup-20(29)-en-30-al

Seven new lupane triterpenoids were isolated from bioactive methanol extracts of Microtropis fokienensis (1- 4) and Perrottetia arisanensis (4-7), along with 18 known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic data analysis. All triterpenoids were evaluated for their in vitro cytotoxicity toward seven human cancer cell lines. Compound 8 (28-hydroxy-3-oxo-lup-20(29)-en-30-al) was among the most cytotoxic substances obtained and was found to induce apoptosis of human leukemia HL60 cells and mediate cleavage of PARP and up-regulation of Bax proteins.

Cytoprotective Effects of KIOM-79 on Streptozotocin Induced Cell Damage by Inhibiting ERK and AP-1

The present study investigated the potential cytoprotective properties of a combination of plant extracts (KIOM-79) obtained from Magnolia officinalis, Pueraria lobata, Glycyrrhiza uralensis, and Euphorbia pekinensis, against the oxidative stresses induced by streptozotocin (STZ) in a rat pancreatic beta-cells (RINm5F). KIOM-79 was found to scavenge intracellular reactive oxygen species (ROS), thereby preventing DNA damage and lipid peroxidation. The KIOM-79 inhibited apoptosis of the beta-cells exposed to STZ via radical scavenging activity and activation of antioxidant enzymes. KIOM-79 inhibited activation of extracellular regulated kinase (ERK) induced by STZ and inhibited DNA binding activity of an activator protein-1 (AP-1), a downstream transcription factor of ERK. Taken together, these findings suggest that KIOM-79 protects against STZ induced cell death in RINm5F cells by inhibiting ROS generation and the ERK pathway.

Induction of cell apoptosis in 3T3-L1 pre-adipocytes by flavonoids is associated with their antioxidant activity

Obesity is biologically characterized at the cellular level by an increase in the number and size of adipocytes differentiated from fibroblastic pre-adipocytes in adipose tissue. In this study, we focused on the relationship between the influence of flavonoids on cell population growth and their antioxidant activity. The results showed that the inhibition of flavonoids (naringenin, rutin, hesperidin, resveratrol, naringin and quercetin) on 3T3-L1 pre-adipocytes was 28.3, 8.1, 11.1, 33.2, 5.6 and 71.5%, respectively. In oxygen radical absorbance capacity (ORAC) assay, quercetin had the highest ORAC(ROO) value among the six flavonoids tested. Apoptosis assays showed that quercetin increased apoptotic cells in time- and dose-dependent manner. Treatment of cells with quercetin decreased the mitochondrial membrane potential in the courses of time and dose. The cell apoptosis/necrosis assay showed that quercetin increased the number of apoptotic cells, but not necrotic cells. Quercetin treatment of cells caused a significant time- and dose-dependent increase in the caspase-3 activity. Western analysis indicated that treatment of quercetin markedly down-regulated PARP and Bcl-2 proteins, and activated caspase-3, Bax, and Bak proteins. These results indicate that quercetin efficiently inhibits cell population growth and induction of apoptosis in 3T3-L1 pre-adipocytes.

Apoptosis and caspases regulate death and inflammation in sepsis

Although the prevailing concept has been that mortality in sepsis results from an unbridled hyper-inflammatory cytokine-mediated response, the failure of more than 30 clinical trials to treat sepsis by controlling this cytokine response requires a 'rethink' of the molecular mechanism underpinning the development of sepsis. As we discuss here, remarkable new studies indicate that most deaths from sepsis are actually the result of a substantially impaired immune response that is due to extensive death of immune effector cells. Rectification of this apoptotic-inflammatory imbalance using modulators of caspases and other components of the cell-death pathway have shown striking efficacy in stringent animal models of sepsis, indicating an entirely novel path forward for the clinical treatment of human sepsis.

Fatty acids, inhibitors for the DNA binding of c-Myc/Max dimer, suppress proliferation and induce apoptosis of differentiated HL-60 human leukemia cell

c-Myc is instrumental in the progression of Burkitt's lymphoma including HL-60 human leukemia cells. We tested fatty acids for their inhibitory effect on the DNA binding of c-Myc/Max dimeric proteins of human origin, prepared as recombinant proteins encompassing DNA binding (basic) and dimerization (HLHZip) domain, and found that those suppress proliferation and induce apoptosis of DMSO-differentiated HL-60 cells. The analyzed IC50 values of myristic acid, stearic acid, gamma-linolenic acid, linoleic acid, linolenic acid and arachidonic acid by EMSA were 97(+/-3), 2.2(+/-1.2), 55(+/-5), 32(+/-2), 62(+/-12), 22(+/-2)microM for DNA binding of recombinant c-Myc/Max, respectively. According to the results shown by XTT assay, their influence on proliferation was quite different from the rank order of IC50. Whereas the degree of influence of the unsaturated fatty acids on the proliferation of DMSO-differentiated HL-60 cells was similar, the influence of saturated fatty acids, stearic acid in particular, was very weak at same concentrations. In addition, we confirmed that these fatty acids have no influence on the expression of c-Myc in DMSO-differentiated HL-60 cells. Our experiments demonstrated that the inhibitors for the DNA binding of c-Myc/Max contribute to the downregulation of Myc-dependent proliferation and to the inducement of apoptosis, and serve as an exploration of potent new inhibitors.

Lipids and lipidomics in brain injury and diseases

Lipidomics is systems-level analysis and characterization of lipids and their interacting moieties. The amount of information in the genomic and proteomic fields is greater than that in the lipidomics field, because of the complex nature of lipids and the limitations of tools for analysis. The main innovation during recent years that has spurred advances in lipid analysis has been the development of new mass spectroscopic techniques, particularly the "soft ionization" techniques electrospray ionization and matrix-assisted laser desorption/ionization. Lipid metabolism may be of particular importance for the central nervous system, as it has a high concentration of lipids. The crucial role of lipids in cell signaling and tissue physiology is demonstrated by the many neurological disorders, including bipolar disorders and schizophrenia, and neurodegenerative diseases such as Alzheimer's, Parkinson's, and Niemann-Pick diseases, that involve deregulated lipid metabolism. Altered lipid metabolism is also believed to contribute to cerebral ischemic (stroke) injury. Lipidomics will provide a molecular signature to a certain pathway or a disease condition. Lipidomic analyses (characterizing complex mixtures of lipids and identifying previously unknown changes in lipid metabolism) together with RNA silencing, using small interfering RNA (siRNA), may provide powerful tools to elucidate the specific roles of lipid intermediates in cell signaling and open new opportunities for drug development.

Antidiabetic, Antioxidant and Antihyperlipidemic Status of Heliotropium zeylanicum Extract on Streptozotocin-Induced Diabetes in Rats

The potential role of the methanolic extract of Heliotropium zeylanicum (BURM.F) LAMK (MEHZ) in the treatment of diabetes along with its antioxidant and antihyperlipidemic effects was studied in streptozotocin-induced diabetic rats. Oral administration of (MEHZ) 150 and 300 mg/kg/d for 14 d significantly decreased the blood glucose level and considerably increased the body weight, food intake, and liquid intake of diabetic-induced rats. MEHZ significantly decreased thiobarbituric acid reactive substances and significantly increased reduced glutathione, superoxide dismutase and catalase in streptozotocin-induced diabetic rats at the end of 14 d of treatment. The study also investigated the antihyperlipidemic potential of MEHZ. The results show that the active fraction of MEHZ is promising for development of a standardized phytomedicine for the treatment of diabetes mellitus.

Genomic and non-genomic effects of different glucocorticoids on mouse thymocyte apoptosis

Glucocorticoids, widely used therapeutic agents for several pathologies, act upon diverse cells and tissues, including the lympho-haemopoietic system. Glucocorticoid-mediated apoptosis has been described as one of the mechanisms underlying their pharmacological and physiological effects. Glucocorticoids induce apoptosis in thymocytes through genomic and non-genomic signals. We tested thymocyte apoptosis rates as induced by a panel of glucocorticoids. Using four glucocorticoids that are widely adopted in clinical practice we compared their induction of thymocyte apoptosis and activation of non-genomic and genomic signals, including phosphatidylinositol-specific phospholipase C (PI-PLC), caspase-8, -9 and -3, and Glucocorticoid-Induced Leucine Zipper (GILZ). GILZ is a protein that is rapidly induced by glucocorticoids treatment and involved in apoptosis modulation. Results indicate different glucocorticoids have different apoptotic activity which is related to their ability to induce both genomic, evaluated as caspases activation and GILZ expression, and non-genomic effects, evaluated as PI-PLC phosphorylation.

Molecular imaging of apoptosis in cancer

Apoptosis plays an important role in cancer. Mechanisms hindering its action are implicated in a number of malignancies. Also, the induction of apoptosis plays a pivotal role in non-surgical cancer treatment regimes such as irradiation, chemotherapy, or hormones. Recent advanced in imaging science have made it now possible for us to detect and visualize previously inaccessible and even unrecognized biological phenomena in cells and tissue undergoing apoptosis in vivo. Not only are these imaging techniques painting an intriguing picture of the spatiotemporal characteristics and metabolic and biophysical of apoptosis in situ, but they are expected to have an ever increasing impact in preclinical testing and design of new anticancer agents as well. Rapid and accurate visualization of apoptotic response in the clinical settings can also be of significant diagnostic and prognostic worth. With the advent of molecular medicine and patient-tailored treatment options and therapeutic agents, such monitoring techniques are becoming paramount.

Elevated serum levels of epithelial cell apoptosis-specific cytokeratin 18 neoepitope m30 in critically ill patients

Apoptosis of the epithelium is deemed to play a pivotal role in the pathogenesis of sepsis. A neoepitope in cytokeratin 18 (CK18), termed M30 neoantigen, becomes available at an early caspase cleavage event during apoptosis of epithelium-derived cells and is not detectable in vital or necrotic epithelial cells. A monoclonal antibody, M30, specifically recognizes a fragment of CK18 cleaved at Asp396 (M30 neoantigen). We used an enzyme-linked immunosorbent assay (ELISA) to measure M30 antigen levels in the sera of 15 septic patients. Healthy humans and critical ill patients suffering from severe trauma served as controls. Mann-Whitney U test was used to calculate significance, and a P value of <0.01 was considered to be statistically significant. Serum levels of the CK18 neoepitope M30 were significantly increased in septic patients (236.88 +/- 47.4 U/L) versus trauma (97.2 +/- 17.1 U/L) and healthy controls (66.9 +/- 9.2 U/L) (P < 0.01 and P < 0.008, respectively). The increased serum level of the CK18 neoepitope in septic patients indicates a heightened apoptotic turnover in epithelial cells as compared with trauma patients and healthy controls. Interestingly, nonsurviving trauma patients exhibited a significant increase in the M30 neoantigen as compared with survivors and healthy controls (P < 0.003 and P < 0.002, respectively). The detection of CK18 neoepitope M30 in the serum might be a useful marker in tracing apoptotic epithelium in septic patients.

Effects of lycorine on HL-60 cells via arresting cell cycle and inducing apoptosis

As a natural anti-cancer alkaloid extracted from Amaryllidaceae, lycorine shows various biological effects on tumor cells. The survival rate of HL-60 cells exposed to lycorine was decreased in a dose-dependent manner with 1 microM as the 50% inhibitory concentration (IC50), cell growth was slowed down by arresting cell cycle at G2/M phase, and cell regeneration potential was inhibited. HL-60 cells exhibited typical apoptotic morphological changes, apoptotic DNA "ladder" pattern, and sub-G1 peak in cell phase distribution, showing apoptosis of HL-60 cells. To further understand the apoptotic molecular mechanism of lycorine on HL-60 cells, caspase activity was tested by colorimetric assay, and the expression of Bcl-2 and Bax proteins was examined by Western blotting. The increase of caspase-8, -9, -3 activities demonstrated that caspase was a key mediator of apoptotic pathways induced by lycorine. Under-expression of Bcl-2 and increase of Bax:Bcl-2 ratio showed that Bcl-2 family proteins were involved in apoptosis. Our finding suggests that lycorine can suppress leukemia growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.

Scoparia dulcis, a traditional antidiabetic plant, protects against streptozotocin induced oxidative stress and apoptosis in vitro and in vivo

Oxidative stress is implicated in the pathogenesis of diabetic complications. The experiments were performed on normal and experimental male Wistar rats treated with Scoparia dulcis plant extract (SPEt). The effect of SPEt was tested on streptozotocin (STZ) treated Rat insulinoma cell lines (RINm5F cells) and isolated islets in vitro. Administration of an aqueous extract of Scoparia dulcis by intragastric intubation (po) at a dose of 200 mg/kg body weight significantly decreased the blood glucose and lipid peroxidative marker thiobarbituric acid reactive substances (TBARS) with significant increase in the activities of plasma insulin, pancreatic superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in streptozotocin diabetic rats at the end of 15 days treatment. Streptozotocin at a dose of 10 mug/mL evoked 6-fold stimulation of insulin secretion from isolated islets indicating its insulin secretagogue activity. The extract markedly reduced the STZ-induced lipidperoxidation in RINm5F cells. Further, SPEt protected STZ-mediated cytotoxicity and nitric oxide (NO) production in RINm5F cells. Treatment of RINm5F cells with 5 mM STZ and 10 mug of SPEt completely abrogated apoptosis induced by STZ, suggesting the involvement of oxidative stress. Flow cytometric assessment on the level of intracellular peroxides using fluorescent probe 2'7'-dichlorofluorescein diacetate (DCF-DA) confirmed that STZ (46%) induced an intracellular oxidative stress in RINm5F cells, which was suppressed by SPEt (21%). In addition, SPEt also reduced (33%) the STZ-induced apoptosis (72%) in RINm5F cells indicating the mode of protection of SPEt on RIN m5Fcells, islets, and pancreatic beta-cell mass (histopathological observations). Present study thus confirms antihyperglycemic effect of SPEt and also demonstrated the consistently strong antioxidant properties of Scoparia dulcis used in the traditional medicine.

Role of apoptotic cell death in sepsis

Sepsis is the leading cause of morbidity and mortality in critically ill patients in many intensive care units. The pathophysiology of organ failure and death in patients with sepsis remain elusive. This review focuses on recent advances in our understanding of the mechanisms of cell death in sepsis, the types of cells that are dying and the consequences on immunity. Extensive apoptotic death results in immune cell depletion and may compromise the ability of the patient to eradicate the primary infection and predispose to secondary nosocomial infections. Peripheral circulating lymphocyte apoptosis is also increased in patients with sepsis and correlates with the severity of the disease. In addition, recent evidence indicates that uptake of apoptotic cells impairs the immune function of surviving cells and contributes to immunosuppression. This new understanding of sepsis may lead to novel therapeutic approaches including pharmacological agents that block apoptosis.

Loss of mitochondrial transmembrane potential and caspase-9 activation during apoptosis induced by the novel styryl-lactone goniothalamin in HL-60 leukemia cells

Styryl-lactones such as goniothalamin represent a new class of compounds with potential anti-cancer properties. In this study, we investigated the mechanisms of goniothalamin (GTN), a plant styryl-lactone induced apoptosis in human promyelocytic leukemia HL-60 cells. This plant extract resulted in apoptosis in HL-60 cells as assessed by the externalisation of phosphatidylserine. Using the mitochondrial membrane dye (DIOC(6)) in conjunction with flow cytometry, we found that GTN treated HL-60 cells demonstrated a loss of mitochondrial transmembrane potential (Deltapsi(m)). Further immunoblotting on these cells showed activation of initiator caspase-9 and the executioner caspases-3 and -7. Pretreatment with the pharmacological caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD.FMK) abrogated apoptosis as assessed by all of the apoptotic features in this study. In summary, our results demonstrate that goniothalamin-induced apoptosis occurs via the mitochondrial pathway in a caspase dependent manner.

Ceramide analogues in apoptosis: a new strategy for anticancer drug development

A survey on the role played by ceramide within the sphingolmyelin pathway is here reported, taking into account its importance as an intracellular effector molecule in apoptosis. Recently, several analogs of ceramide, able to pass the cell membrane and then to induce apoptosis, have been developed as a new potential approach in anticancer therapy.

Techniques: Visualizing apoptosis using nuclear magnetic resonance

Apoptosis plays a key role in tumour biology, and the induction of apoptosis forms a cornerstone of most anticancer therapies. New developments in nuclear magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) have taken these techniques far beyond their original roles as the workhorses of structural and pharmaceutical chemistry and clinical imaging to the detection of previously inaccessible and unrecognized biological phenomena in living cells and tissues undergoing apoptosis. These new MR techniques can be used in the development of new drugs and in the improved detection of treatment responses in the clinic.

Protective effect of Mangifera indica L. extract (Vimang) on the injury associated with hepatic ischaemia reperfusion

The effect of Mangifera indica L. extract (Vimang) on treatment of injury associated with hepatic ischaemia/reperfusion was tested. Vimang protects from the oxidative damage induced by oxygen-based free radicals as shown in several in vitro test systems conducted. The ability of Vimang to reduce liver damage was investigated in rats undergoing right-lobe blood fl ow occlusion for 45 min followed by 45 min of reperfusion. The ischaemia/reperfusion model leads to an increase of transaminase (ALT and AST), membrane lipid peroxidation, tissue neutrophil in filtration, DNA fragmentation, loss of protein -SH groups, cytosolic Ca2+ overload and a decrease of catalase activity. Oral administration of Vimang (50, 110 and 250 mg/kg, b.w.) 7 days before reperfusion, reduced transaminase levels and DNA fragmentation in a dose dependent manner (p < 0.05). Vimang also restored the cytosolic Ca2+ levels and inhibited polymorphonuclear migration at a dose of 250 mg/kg b.w., improved the oxidation of total and non protein sulfhydryl groups and prevented modification in catalase activity, uric acid and lipid peroxidation markers (p < 0.05). These data suggest that Vimang could be a useful new natural drug for preventing oxidative damage during hepatic injury associated with free radical generation.

Massive cell death of cerebellar granule neurons accompanied with caspase-3-like protease activation and subsequent motor discoordination after intracerebroventricular injection of vincristine in mice

Vincristine, a microtubule-depolymerizing agent, is known to induce neuronal cell damage. Biochemical, histological and behavioral alterations were investigated after intracerebroventricular injection of vincristine in mice. Intracerebroventricular injection of vincristine caused caspase-3-like protease activation followed by nucleosomal release in the cerebellum. Histological examinations showed that vincristine-induced damage was relatively specific to granule cells in the cerebellum, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling-positive cells were observed among these cells. Chromatin condensation, one of the criteria for apoptosis, was seen on electron microscopy. Behavioral changes, namely head movements, pivoting and backward walking, were observed in parallel with the increase of caspase-3-like protease activity and nucleosomal release. Furthermore, motor function tests (bulb balance test and rotating rod test) showed deficits of motor coordination ability. These observations suggest that intracerebroventricular vincristine causes massive apoptosis of cerebellar granule cells accompanied with caspase-3-like protease activation, leading to motor dysfunction, in this model. These vincristine-treated mice should be a useful in vivo model for examination of neuronal apoptosis, which might be involved in a variety of neurodegenerative diseases.