Induction of cell cycle arrest and apoptosis by the ethyl acetate fraction of Kalopanax pictus leaves in human colon cancer cells

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Research on anti-hepatocellular carcinoma activity and mechanism of Polygala fallax Hemsl

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala fallax Hemsl. is a kind of traditional medicine of Yao Minority in China. In Chinese medicine practice, Polygala fallax Hemsl. is commonly prescribed to treat all kinds of acute and chronic hepatitis.

AIM OF THE STUDY

The present study aimed at investigating the effects and its possible mechanism of Polygala fallax Hemsl. on the proliferation and apoptosis of HepG2 cells (a kind of human hepatoma cell).

MATERIALS AND METHODS

Through a variety of experimental methods, including MTT technique and Hoechst staining to detect apoptosis in Hepatocyte HepG2 cells, flow cytometry to observe the pro-apoptotic and circulatory arrest effects as well as real-time fluorescence quantitative polymerase chain reaction (q-PCR) technique to examine the expression levels of Bcl-2/Bax gene and prote Western blot to examine the expression levels of bcl-2/bax,caspase3,8,9,CyclinA,p21,p27,ERK.Phospho-ERK and AKT, Phospho-AKT in HepG2 cells.

RESULTS

The results showed that compared with the control group, all polarity fractions of P. fallax had inhibitory effects on HepG2 cells, among which the inhibition effect of ethyl acetate fraction in 0.036 ± 0.001 mg/mL of IC₅₀ for 24 h was the most obvious (P < 0.01). And the HepG2 cells induced at the ethyl acetate fraction could up-regulate Bax gene and protein, while down-regulating Bcl-2 gene and protein (P < 0.05) during S phase in a dose-dependent manner. In addition, the ethyl acetate site of Larch can also down regulate the expression of ERK, AKT and activate caspase 3, 8 and 9.

CONCLUSION

It could be concluded that the ethyl acetate fraction of Polygala fallax Hemsl. can significantly prohibit the proliferation of HepG2 cells. The possible mechanism is to promote the expression of Bax, inhibit the expression of Bcl-2, and down regulate the expression of AKT and ERK.

Purified Astaxanthin from Haematococcus pluvialis Promotes Tissue Regeneration by Reducing Oxidative Stress and the Secretion of Collagen In Vitro and In Vivo

Intracellular reactive apoptosis and reactive oxygen species (ROS) play a crucial role in ultraviolet- (UV-) induced inflammation and aging reaction in human dermal tissues. This study determines the mechanism by which Haematococcus pluvialis extracts (HPE) and purified astaxanthin (HPA) to promote skin regeneration in the injured tissue in vitro and in vivo. The results show that HPE and HPA decrease the DNA damage and promote the secretion of collagen from the human normal fibroblast cell line (Hs68) in a dose-dependent manner. UV irradiation and HPA reduce oxidative stress damage due to phorbol-12-myristate-13-acetate (PMA). When skin cells are injured by free radicals, cells undergo a programmed cellular death. Cellular apoptotic death is determined using annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining to verify that there is no cell membrane asymmetry and that the nuclear membrane is broken. Inflammatory symptoms and apoptotic injuries to experimental rats in a group that is treated with HPA treated are decreased in a dose-dependent manner after UVB exposure (300 mJ/cm²) for 15 min in vivo, compared to the vehicle control group. These positive results show that HPA repairs UVB-triggered skin tissue injury and aging by conducting electrons out of cells to maintain a low level of oxidative stress so that collagen is synthesized in vitro and in vivo.

Effects of preparation method on the biochemical characterization and cytotoxic activity of New Zealand surf clam extracts

Molluscan extracts confer a wide range of health promoting properties, one of them is cytotoxicity. Extraction and processing can affect the efficacy and properties of bioactive molecules. New Zealand (NZ) surf clams have never been thoroughly studied for bioactives until recently. However, the effect of cold and heat extraction procedure on biochemical composition and cytotoxic activities of NZ surf clam remains unanswered. The objective is to compare the effects on cytotoxicity of three NZ surf clams (Diamond shell, Crassula aequilatera; Storm shell, Mactra murchisoni; and Deepwater Tua tua, Paphies donacina) extracts via cold or heat process across cancer cell lines to find out which process can preserve bioactivity better. Fractions of extracts prepared via cold or heat procedures were tested for cell growth inhibition, apoptosis induction and cell cycle arrest in seven cancer cell lines. Apoptosis was induced through all cell lines, as further evidenced in Caspase-3/7 activities. Cell cycle arrest was focused on G2/M- and S- phases. Petroleum ether and ethyl acetate fractions, with the greatest bioactivity in this study, are rich in lipids and proteins, indicating likely bioactive sources. Cold preparation was responsible for the lowest cancer cell viability and induced greater apoptosis. Cold process retained better bioactivity/cytotoxicity than that of heat-processed extracts. This information may guide future health/nutraceutical clam product development.

C-glycosyl flavone from Urginea indica inhibits proliferation & angiogenesis & induces apoptosis via cyclin-dependent kinase 6 in human breast, hepatic & colon cancer cell lines

Background & objectives:

Search for novel compounds beneficial to the treatment of cancer attracts a great deal of attention. We earlier demonstrated the isolation of 5,7-dihydroxy-2-[4’-hydroxy-3’-(methoxymethyl)phenyl]-6-C-β-glucopyranosyl flavone, a novel C-glycosyl flavone from Urginea indica bulb. The present study was undertaken to investigate the effect of this novel compound on human normal epithelial and breast, hepatic and colon cancer cell lines.

Methods:

The maximum non-toxic concentration (MNTC) and cytotoxicity of C-glycosyl flavone were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell cycle was analyzed by flow cytometry. Docking studies were performed to predict possible targets. Levels of cyclin-dependent kinase 1 (CDK1) and CDK6, Bcl2 and BAX and cytochrome c were quantified by specific ELISA. Mitochondrial membrane potential was determined using JC-1 dye. Apoptosis was quantified by Annexin V ELISA method.

Results:

Flow cytometry analysis demonstrated G0/G1 arrest. In silico docking studies predicted CDK1 and CDK6 as a possible target of C-glycosyl flavone. In vitro study confirmed CDK6 as the main target in C-glycosyl flavone-treated cancer cell lines. C-glycosyl flavone treatment also induced membrane blebbing, chromatin fragmentation and nucleosome formation. C-glycosyl flavone treatment caused marked loss of mitochondrial membrane potential, decrease in Bcl2/BAX ratio and activation of caspase-3 and release of caspase-9 and cytochrome c. In addition, C-glycosyl flavone inhibited the tumour-induced angiogenesis and reduced the vascular endothelial growth factor levels. Similarly, CDK6 inhibitor significantly inhibited proliferation and angiogenesis and induced apoptosis in tested cell lines.

Interpretation & conclusions:

The results indicate that C-glycosyl flavone may exert induction of apoptosis, cell cycle arrest and inhibition of angiogenesis via CDK6. Thus, targeting CDK6 using C-glycosyl flavone may serve as a novel therapeutic approach for the treatment of breast, hepatic and colon cancers.

Cytotoxic effects of platinum nanoparticles obtained from pomegranate extract by the green synthesis method on the MCF-7 cell line

The study utilizes monodisperse platinum nanoparticles (Pt NPs) biosynthesized from Punica granatum crusts as anti-tumor agents on the human breast cancer cell line, MCF-7. The obtained Pt NPs were fully characterized using the UV-vis spectrum (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transformation infrared spectroscopy (FTIR). Effectiveness of the Pt NPs was determined by cell viability, propidium iodide staining test, flow cytometry and comet tests on the MCF-7 cancer cell line. Cell survival percentage was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The biosynthesized monodisperse platinum nanoparticles inhibited MCF-7 proliferation with an IC₅₀ of 17.84 μg/ml after 48 h of incubation. Propidium iodide staining demonstrated that the monodisperse Pt NPs induced apoptosis by means of molecular DNA fragmentation.

Interaction of silver and gold nanoparticles in mammalian cancer: as real topical bullet for wound healing- A comparative study

The present study evaluates in vitro cytotoxic effects and the mode of interaction of biologically synthesized Ag and Au nanoparticles (NPs) using Brassica oleracea L. var. capitata f. rubra (BOL) against HT-1080 cancer cells and bacterial cells as well as their wound healing efficacy using a mouse model. UV-visible spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray analysis have ascertained the formation of nano-sized Ag and Au particles. Fourier transform infrared analysis has confirmed that polyphenol and amide groups in BOL act as capping as well as reducing agents. The free radical scavenging activity under in vitro conditions is found to be higher for the Ag NPs when compared to the Au NPs. Acridine orange-ethidium bromide dual staining and comet assay have indicated that the cytotoxic effects are mediated through nuclear morphological changes and DNA damage. The intracellular localization of Ag and Au NPs in HT-1080 cells and their subsequent effect on apoptosis and necrosis were analyzed by flow cytometry while the mode of interaction was established by scanning electron microscopy under field emission mode and by bio-transmission electron microscopy. These methods of analysis clearly revealed that the Ag and Au NPs have easily entered and accumulated into the cytosol and nucleus, resulting in activation of inflammatory and apoptosis pathways, which in turn cause damage in DNA. Further, mRNA and protein expression of caspase-3 and caspase-7, TNF-α, and NF-κB have provided sufficient clues for induction of intrinsic and extrinsic apoptosis and inflammatory pathways in Ag NP- and Au NP-treated cells. Evaluation of wound healing properties of Ag and Au NPs using a mouse model indicates rapid healing of wounds. In addition, no clear toxic effects and no nuclear abnormalities in peripheral blood cells are observed. Ag NPs appear to be a better anticancer therapeutic agent than Au NPs. Nonetheless, both Ag NPs and Au NPs show potential for promoting topical wound healing without any toxic effects. Graphical abstract Schematic representation of biological synthesis of Ag and Au NPs and its application on cancer and wound healing.

Methylferulate from Tamarix aucheriana inhibits growth and enhances chemosensitivity of human colorectal cancer cells: possible mechanism of action

Background

Natural products are valuable sources for anticancer agents. In the present study, methylferulate (MF) was identified for the first time from Tamarix aucheriana. Spectral data were used for identification of MF. The potential of MF to control cell growth, cell cycle, apoptosis, generation of reactive oxygen species (ROS), cancer cell invasion, nuclear factor kappa B (NFkB) DNA-binding activity and proteasomal activities, as well as the enhancement of chemosensitivity in human colorectal cancer cells, were evaluated. The possible molecular mechanism of MF’s therapeutic efficacy was also assessed.

Methods

Column chromatography and spectral data were used for isolation and identification of MF. MTT, immunofluorescence, flow cytometry, in vitro invasion, fluoremetry, EIA and Real time qPCR were used to measure antiproliferative, chemo-sensitizing effects and other biochemical parameters.

Results

MF showed a dose-dependent anti-proliferative effect on colorectal cancer cells (IC₅₀ = 1.73 – 1.9 mM) with a nonsignificant cytotoxicity toward normal human fibroblast. Colony formation inhibition (P ≤ 0.001, 0.0001) confirmed the growth inhibition by MF. MF arrested cell cycle progression in the S and G2/M phases; induced apoptosis and ROS generation; and inhibited NF-kB DNA-binding activity, proteasomal activities and cell invasion in colorectal cancer cells. MF up-regulated cyclin-dependent kinase inhibitors (p19 ^INK4D, p21^WAF1/CIP1, p27^KIP1), pro-apoptotic gene expression (Bax, Bad, Apaf1, Bid, Bim, Smac) and caspases (caspase 2, 3, 6, 7, 8, 9). Moreover, MF down-regulated cyclin-dependent kinases (Cdk1, Cdk2) and anti-apoptotic gene expression (c-IAP-1, c-IAP-2, Bcl2,FLIP). In addition, MF differentially potentiated the sensitivity of colorectal cancer cells to standard chemotherapeutic drugs.

Conclusion

MF showed a multifaceted anti-proliferative and chemosensitizing effects. These results suggest the chemotherapeutic and co-adjuvant potential of MF.

Luffa echinata Roxb. Induced Apoptosis in Human Colon Cancer Cell (SW-480) in the Caspase-dependent Manner and Through a Mitochondrial Apoptosis Pathway

BACKGROUND

Luffa echinata Roxb. (LER) (Cucurbitaceae) showed tremendous medicinal importance and are being used for the treatment of different ailments.

OBJECTIVE

In this study, the antiproliferative properties and cell death mechanism induced by the extract of the fruits of LER were investigated.

MATERIALS AND METHODS

MTT and LDH assay were used to test the antiproliferative and cytotoxicity of LER extract, respectively. The intracellular ROS were measured by a fluorometric assay. The expression of several apoptotic-related proteins in SW-480 cells treated by LER was evaluated by Western blot analysis.

RESULTS

The methanolic extract of LER fruits inhibited the proliferation of human colon cancer cells (SW-480) in both dose- and time-dependent manners. The LER-treated cells showed obvious characteristics of cell apoptosis, including cell shrinkage, destruction of the monolayer, and condensed chromatin. In addition, treatments of various concentrations of LER extracts caused the release of lactate dehydrogenase as a dose-dependent manner via stimulation of the intracellular metabolic system. LER induced apoptosis, DNA fragmentation, and cellular ROS accumulation in SW-480 cells. Treatment of LER on SW-480 cells promoted the expression of caspases, Bax, Bad, and p53 proteins and decreased the levels of Bcl-2 and Bcl-XL.

CONCLUSIONS

These results indicated that treatment with LER-induced cell death in mitochondrial apoptosis pathway by regulating pro-apoptotic proteins via the up regulation of the p53 protein. These findings highlight the potentials of LER in the treatment of human colon cancer.

SUMMARY

LER induced apoptosis, DNA fragmentation, and cellular ROS accumulation in SW-480 cells. Treatment of LER on SW-480 cells promoted the expression of caspases, Bax, Bad, and p53 proteins and decreased the levels of Bcl-2 and Bcl-XL.

Morusin suppresses breast cancer cell growth in vitro and in vivo through C/EBPβ and PPARγ mediated lipoapoptosis

Background

Breast cancer is the most fatal malignant cancer among women, the conventional therapeutic modalities of it are limited. Morusin possesses cytotoxicity against some cancer cells in vitro. The purpose of this study is to test the growth inhibition effect of morusin on human breast cancer growth in vitro and in vivo and to explore the potential mechanism of its action.

Methods

The growth inhibition effect of morusin on human breast cancer cells in vitro and in vivo were tested by cell cytotoxicity, colony formation inhibition, adipogenic differentiation, apoptosis induction, and tumor growth inhibition in vivo assays. The potential molecular mechanisms underlying the growth inhibition effect of morusin on human breast cancer cells in vitro and in vivo were investigated with Western blotting evaluation of expression levels of transcription factors, C/EBPβ and PPARγ, adipogenic and apoptotic proteins in morusin treated breast cancer cells and tumor tissues.

Results

Morusin inhibited breast cancer cells growth in vitro and in vivo; it induced adipogenic differentiation, apoptosis and lipoapoptosis of cancer cells.

Conclusions

Morusin has the potential to inhibit human breast cancer cell growth in vitro and in vivo through C/EBPβ and PPARγ mediated lipoapoptosis.

Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells

Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry.

Antiproliferative activity and induction of apoptosis by Annona muricata (Annonaceae) extract on human cancer cells

Background

Annona muricata (A. muricata) is widely distributed in Asia, Africa and South America. Different parts of this plant are used to treat several diseases in Cameroon. The aim of this study is to determine the in vitro anti-proliferative effects and apoptotic events of A. muricata extracts on HL-60 cells as well as to quantify its phenols content.

Methods

The cell viability was measured by using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay while the changes in morphology of HL-60 cells, membrane mitochondrial potential (MMP) and the cell cycle were used for assessment apoptosis induction.

Results

The results show that the concentration of phenols, flavonoids and flavonols in the extracts varied depending on the part of the plant. All the extracts tested inhibited the proliferation of HL-60 cells in a concentration dependent manner with IC₅₀ varied from 6–49 μg/mL. The growth inhibition of the cells by extracts was associated with the disruption of MMP, reactive oxygen species (ROS) generation and the G0/G1 cell arrest.

Conclusion

These findings suggest that the extracts from A. muricata have strong antiproliferation potential and can induce apoptosis through loss of MMP and G0/G1 phase cell arrest.

Phloroglucinol induces apoptosis via apoptotic signaling pathways in HT-29 colon cancer cells

Phloroglucinol is a polyphenolic compound that is used to treat and prevent several human diseases, as it exerts beneficial biological activities, including anti-oxidant, anti-inflammatory and anticancer properties. The aim of the present study was to investigate the effects of phloroglucinol on apoptotic signaling pathways in HT-29 colon cancer cells. The results indicated that phloroglucinol suppressed cell viability and induced apoptosis in HT-29 cells in a concentration-dependent manner. Phloroglucinol treatment of HT-29 cells resulted in characteristic apoptosis-related changes: altered Bcl-2 family proteins, cytochrome c release, and activation of caspase-3 and caspase-8. This study also showed that proteins involved in apoptosis were stimulated by treatment with phloroglucinol. These findings demonstrated that phloroglucinol exerts anticancer activity in HT-29 colon cancer cells through induction of apoptosis.

Phloroglucinol induces apoptosis through the regulation of insulin-like growth factor 1 receptor signaling pathways in human colon cancer HT-29 cells

Phloroglucinol is a polyphenol compound with free radical scavenging, anti-inflammatory and antitumor activity. In this study, we investigated the anticancer effects of phloroglucinol on insulin-like growth factor-1 receptor (IGF-1R) signaling in HT-29 human colon cancer cells. Apoptosis was evaluated using 4′,6-diamidino-2-phenylindole (DAPI) staining, which clearly demonstrated cell shrinkage and condensed nuclei. Treatment with a pan-caspase inhibitor reduced the expression of phosphatidylinositol-3-kinase (PI3K)/Akt, which could induce apoptosis through IGF-1R signaling pathways. Treatment with phloroglucinol significantly inhibited the expression of Ras, Raf, mitogen-activated protein kinase (MEK), extracellular-signal regulated kinase (ERK) phosphorylation, PI3K and Akt. Phloroglucinol also decreased mammalian target of rapamycin (mTOR) and expression of its downstream effectors p70S6 kinase and translation initiation factors elF4B and RPS6. These results demonstrate that IGF-1R activates PI3K/Akt/mTOR and Ras/ERK-MAPK downstream signaling pathways, which has important implications for understanding the roles of cell growth pathways in colon cancer cell tumorigenesis.

Antioxidant properties and neuroprotective effects of isocampneoside II on hydrogen peroxide-induced oxidative injury in PC12 cells

Oxidative stress has been considered as a major cause of cell damage in various neurodegenerative disorders. One of the reasonable strategies for delaying the disease's progression is to prevent reactive oxygen species (ROS) mediated cellular injury by dietary or pharmaceutical augmentation of free radical scavengers. Isocampneoside II (ICD) is an active phenylethanoid glycoside isolated from the medicinal hardwood genus Paulownia. This study was designed to explore free radical scavenging potential of ICD in different in vitro systems and its protective role in hydrogen peroxide (H₂O₂)-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. The results showed ICD eliminated approximately 80.75% superoxide radical at the concentration of 0.1mg/ml and inhibited metal chelating by 22.07% at 8 mg/ml. Additionally, ICD showed a strong ability on reducing power and provided protection against oxidative protein damage induced by hydroxyl radicals. Pretreatment of PC12 cells with ICD prior to H₂O₂ exposure elevated cell viability, enhanced activity of superoxide dismutase and catalase, and decreased levels of malondialdehyde and intracellular ROS. Furthermore, ICD inhibited cell apoptosis and Bax/Bcl-2 ratio induced by H₂O₂. These findings suggested ICD may be considered as a potential antioxidant agent and should encourage for further research in neurodegenerative diseases.

In vitro and in vivo anticancer activity of a novel puerarin nanosuspension against colon cancer, with high efficacy and low toxicity

The present study aims to evaluate the anticancer activity of puerarin nanosuspensions in human colon cancer HT-29 cell line in vitro and in vivo. Puerarin nanosuspensions were prepared by the high-pressure homogenization (HPH) technique. The HT-29 cells were incubated with increasing concentrations of puerarin solution and nanosuspensions for indicated times. MTT evaluated cellular viability and investigated the effect of puerarin on cell proliferation of HT-29. Annexin V-FITC/PI staining method was conducted to determine the influences of the puerarin nanosuspensions on cell cycle and apoptosis. The in vivo anticancer activity of the puerarin nanosuspensions was observed in HT-29 cancer bearing mice. The puerarin nanosuspensions were well re-dispersed in aqueous media a mean diameter about 400-500 nm. Cytotoxicity assay, observation of morphological changes and early apoptosis revealed that the puerarin nanosuspensions could significantly enhance the in vitro anti-proliferation against HT-29 cells compared to the puerarin free solution. The prepared puerarin nanosuspensions in vivo evaluation showed higher anticancer efficacy and lower toxicity compared to the free solution, as shown by changes in tumor volumes, body weights, and survival rates. Based on these data, the potential of the puerarin nanosuspensions to serve as a cancer chemotherapeutic agent for colon cancer could be suggested.

Anticancer potential of aqueous extract of alocasia macrorrhiza against hepatic cancer in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Alocasia macrorrhiza has been used as a folk medicine for cancer treatment in the Southwest of China.

AIM OF THE STUDY

The purpose of this study is to confirm the anticancer activity of aqueous extract of alocasia macrorrhiza against hepatic cancer and to elucidate its mechanism of action.

MATERIALS AND METHODS

Human normal liver cells and hepatocellular carcinoma cells were tested in vitro for cytotoxicity, colony formation inhibition, EdU incorporation, AO/EB staining apoptotic cells, apoptotic DNA fragmentation, and cell cycle distribution in response to alocasia macrorrhiza extract. The mRNA and protein expressions of PPARγ, Cyclin D1, Rb, P21, Bax, Bcl-2 and caspase-3 were detected through RT-PCR and Western blotting; the tumor growth inhibition in vivo was tested by oral administration of the extract.

RESULTS

Alocasia macrorrhiza aqueous extract exhibited proliferation inhibition and apoptosis effects on human hepatocellular carcinoma cells in vitro, inhibited hepatoma growth in vivo.

CONCLUSION

Alocasia macrorrhiza extract has potential cytotoxic and apoptotic effect on human hepatocellular carcinoma cells and inhibits hepatoma growth in vivo, its mechanism of action might be associated with the inhibition of DNA synthesis, cell cycle (G(0)/G(1)) arrest, apoptosis induction through up-regulation the mRNA and protein expressions of PPARγ, Rb, Bax and capase-3genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes.

Luffa echinata Roxb. induces human colon cancer cell (HT-29) death by triggering the mitochondrial apoptosis pathway

The antiproliferative properties and cell death mechanism induced by the extract of the fruits of Luffa echinata Roxb. (LER) were investigated. The methanolic extract of LER inhibited the proliferation of human colon cancer cells (HT-29) in both dose-dependent and time-dependent manners and caused a significant increase in the population of apoptotic cells. In addition, obvious shrinkage and destruction of the monolayer were observed in LER-treated cells, but not in untreated cells. Analysis of the cell cycle after treatment of HT-29 cells with various concentrations indicated that LER extracts inhibited the cellular proliferation of HT-29 cells via G2/M phase arrest of the cell cycle. The Reactive oxygen species (ROS) level determination revealed that LER extracts induced apoptotic cell death via ROS generation. In addition, LER treatment led to a rapid drop in mitochondrial membrane potential (MMP) as a decrease in fluorescence. The transcripts of several apoptosis-related genes were investigated by RT-PCR analysis. The caspase-3 transcripts of HT-29 cells significantly accumulated and the level of Bcl-XL mRNA was decreased after treatment with LER extract. Furthermore, the ratio of mitochondria-dependent apoptosis genes (Bax and Bcl-2) was sharply increased from 1.6 to 54.1. These experiments suggest that LER has anticancer properties via inducing the apoptosis in colon cancer cells, which provided the impetus for further studies on the therapeutic potential of LER against human colon carcinoma.

Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells

Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects.

Cell cycle arrest and apoptosis induced by methyl 3,5-dicaffeoyl quinate in human colon cancer cells: Involvement of the PI3K/Akt and MAP kinase pathways

Methyl 3,5-dicaffeoyl quinate (MDQ) is a flavonoid glucoside found in several plants that scavenges 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and peroxynitrite, and inhibits the formation of cholesteryl ester hydroperoxide during the copper ion-induced oxidation of blood plasma in rats. In this study, MDQ inhibited proliferation and induced apoptosis in HT-29 cells in a dose-dependent manner as detected by 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), trypan blue exclusion, and flow cytometric assays. Western blot analysis showed that apoptosis was dependent on caspase-3 activity. PARP cleavage and the cytosolic release of cytochrome c from mitochondria increased significantly. In addition, these events were accompanied by a collapse in the mitochondrial membrane potential and a decreased Bcl-2/Bax ratio. Furthermore, the MDQ-induced G(0)/G(1) arrest was correlated with an increase in p27 and a decrease in cyclin D1 and p53. MDQ also inhibited the phosphorylation of PI3K/Akt and ERK; significantly reduced NF-κB; and in general displayed a significant anti-proliferative effect via a cell cycle arrest and apoptotic induction in HT-29 cells. These results suggest that MDQ has therapeutic potential against human colon carcinoma.

Antioxidant and antiproliferative properties of water extract from Mahonia bealei (Fort.) Carr. leaves

Mahonia bealei (Fort.) Carr. (Berberidaceae) leaves have been widely used as a tea leaf beverage south of the Qinling Mountains of China. In this study, the antioxidant and antiproliferative properties of M. bealei leaves were investigated. Our data showed that the water extract of M. bealei leaves (WML) exhibited extremely high antioxidant properties, which were demonstrated by its ability to scavenge 50% of 1,1-diphenyll-2-2-pricylhydrazyl (DPPH) free radicals at 60.46 μg/ml, and it eliminated approximately 71.19% of superoxide radicals at 500 μg/ml. In addition, the WML showed strong reducing abilities and provided protection against oxidative protein damage induced by hydroxyl radicals. Cellular proliferation and the induction of apoptosis were also examined by cellular proliferation assay, flow cytometry, and mRNA expression analysis. These results demonstrate that WML significantly inhibited the growth of human colon cancer (HT-29) cells in a concentration-dependent manner, and it gradually increased the proportion of apoptotic cells and reduced the expression of the survivin gene. The bioactivity-guided study of WML resulted in the isolation and identification of berberine, a known isoquinoline alkaloid. Berberine exhibited strong antiproliferative activity on HT-29 cells, with IC(50) values of 36.54 μM, suggesting it is, in part, responsible of the anticancer activity of WML.