Abdah Md Akim

Molecular mechanisms of apoptosis and cell selectivity of zinc dithiocarbamates functionalized with hydroxyethyl substituents.

In the solid state each of three binuclear zinc dithiocarbamates bearing hydroxyethyl groups, {Zn[S2CN(R)CH2CH2OH]2}2 for R = iPr (1), CH2CH2OH (2), and Me (3), and an all alkyl species, [Zn(S2CNEt2)2]2 (4), features a centrosymmetric {ZnSCS}2 core with a step topology; both 1 and 3 were isolated as monohydrates. All compounds were broadly cytotoxic, specifically against human cancer cell lines compared with normal cells, with greater potency than cisplatin. Notably, some selectivity were indicated with 2 being the most potent against human ovarian carcinoma cells (cisA2780), and 4 being more cytotoxic toward multidrug resistant human breast carcinoma cells (MCF-7R), human colon adenocarcinoma cells (HT-29), and human lung adenocarcinoma epithelial cells (A549). Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis in HT-29 cells is demonstrated via both extrinsic and intrinsic pathways. Compounds 2-4 activate the p53 gene while 1 activates both p53 and p73. Cell cycle arrest at the S and G2/M phases correlates with inhibition of HT-29 cell growth. Cell invasion is also inhibited by 1-4 which is correlated with down-regulation of NF-κB.

A bismuth diethyldithiocarbamate compound promotes apoptosis in HepG2 carcinoma, cell cycle arrest and inhibits cell invasion through modulation of the NF-κB activation pathway

The compound with R=CH2CH3 in Bi(S2CNR2)3 (1) is highly cytotoxic against a range of human carcinoma, whereas that with R=CH2CH2OH (2) is considerably less so. Both 1 and 2 induce apoptosis in HepG2 cells with some evidence for necrosis induced by 2. Based on DNA fragmentation, caspase activities and human apoptosis PCR-array analysis, both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. While both compounds activate mitochondrial and FAS apoptotic pathways, compound 1 was also found to induce another death receptor-dependent pathway by induction of CD40, CD40L and TNF-R1 (p55). Further, 1 highly expressed DAPK1, a tumour suppressor, with concomitant down-regulation of XIAP and NF-κB. Cell cycle arrest at the S and G2/M phases correlates with the inhibition of the growth of HepG2 cells. The cell invasion rate of 2 is 10-fold higher than that of 1, a finding correlated with the down-regulation of survivin and XIAP expression by 1. Compounds 1 and 2 interact with DNA through different binding motifs with 1 interacting with AT- or TA-specific sites followed by inhibition of restriction enzyme digestion; 2 did not interfere with any of the studied restriction enzymes.

In vitro cytotoxicity of Strobilanthes crispus ethanol extract on hormone dependent human breast adenocarcinoma MCF-7 cell

BackgroundStrobilanthes crispus has been traditionally used as antidiabetic, anticancer, diuretic, antilytic and laxative agent. However, cytotoxicity and antiproliferative effect of S. crispus is still unclear.ResultsStrobilanthes cripus was able to reduce cell viability and proliferation in MTT and BrdU assays. Both cell cycle progression and Tunel assay suggested that IC50 of S. crispus ethanol extract induced sub-G1 cell cycle phase, and DNA fragmentation. On the other hand, translocation of mitochondria cytochrome c release, induction of caspase 3/7 and p53 while suppress XIAP on treated MCF-7 cell were also observed in this study.ConclusionOur findings suggest that S. crispus ethanol extract induced apoptosis and DNA fragmentation on hormone dependent breast cancer cell line MCF-7 via mitochondria dependent p53 apoptosis pathway.

The influence of R substituents in triphenylphosphinegold(I) carbonimidothioates, Ph3PAu[SC(OR)=NPh] (R = Me, Et and iPr), upon in vitro cytotoxicity against the HT-29 colon cancer cell line and upon apoptotic pathways.

The Ph3PAu[SC(OR)=NPh], R=Me (1), Et (2) and iPr (3), compounds are significantly cytotoxic to the HT-29 cancer cell line with 1 being the most active. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis is demonstrated and both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. Compound 1 activates the p73 gene, whereas each of 2 and 3 activates the p53 gene. An additional apoptotic mechanism is exhibited by 2, that is, via the JNK/MAP pathway.

In Vitro Antioxidant and Antiproliferative Activities of Methanolic Plant Part Extracts of Theobroma cacao

The aims of this study were to determine the antioxidant and antiproliferative activity of the following Theobroma cacao plant part methanolic extracts: leaf, bark, husk, fermented and unfermented shell, pith, root, and cherelle. Antioxidant activity was determined using 2,2-diphenyl-2-picrylhydrazyl (DPPH), thiobarbituric acid-reactive substances (TBARS), and Folin-Ciocalteu assays; the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT) assay was used to determine antiproliferative activity. The root extract had the highest antioxidant activity; its median effective dose (EC50) was 358.3 ± 7.0 µg/mL and total phenolic content was 22.0 ± 1.1 g GAE/100 g extract as compared to the other methanolic plant part extracts. Only the cherelle extract demonstrated 10.4% ± 1.1% inhibition activity in the lipid peroxidation assay. The MTT assay revealed that the leaf extract had the highest antiproliferative activity against MCF-7 cells [median inhibitory concentration (IC50) = 41.4 ± 3.3 µg/mL]. Given the overall high IC50 for the normal liver cell line WRL-68, this study indicates that T. cacao methanolic extracts have a cytotoxic effect in cancer cells, but not in normal cells. Planned future investigations will involve the purification, identification, determination of the mechanisms of action, and molecular assay of T. cacao plant extracts.

G2/M cell cycle arrest on HT-29 cancer cells and toxicity assessment of triphenylphosphanegold(I) carbonimidothioates, Ph3PAu[SC(OR)=NPh], R=Me, Et, and iPr, during zebrafish development.

Phosphanegold(I) thiolates, Ph3PAu[SC(OR)=NPh], R=Me (1), Et (2) and iPr (3), were previously shown to be significantly cytotoxic toward HT-29 cancer cells and to induce cell death by both intrinsic and extrinsic apoptotic pathways whereby 1 activated the p73 gene, and each of 2 and 3 activated p53; 2 also caused apoptotic cell death via the c-Jun N-terminal kinase/mitogen-activated protein kinase pathway. Apoptosis pathways have been further evaluated by mitochondrial cytochrome c measurements and annexin V screening, confirming apoptotic pathways of cell death. Cell cycle analysis showed the majority of treated HT-29 cells were arrested at the G2/M checkpoint after 24h; results of both assays were confirmed by changes in populations of relevant genes (PCR array analysis). Cell invasion studies showed inhibition of metastasis through Matrigel™ matrix to 17-22% cf. untreated cells. LC50 values were determined in zebrafish (8.36, 8.17, and 7.64μM for 1-3). Finally, the zebrafish tolerated doses of 1 and 2 up to 0.625μM, and 3 was tolerated at even higher doses of up to 1.25μM.

In vitro evaluation of Pandanus amaryllifolius ethanol extract for induction of cell death on non-hormone dependent human breast adenocarcinoma MDA-MB-231 cell via apoptosis.

BackgroundOur previous study had shown that P. amaryllifolius was able to selectively inhibit cell proliferation of hormone independent breast cancer cell line MDA-MB-231. To understand the mode of killing and mechanism of action for P. amaryllifolius, the ethanol extract was evaluated for their alteration of cell cycle progression, PS externalization, DNA fragmentation and expression of anti/pro-apoptotic related protein.ResultsCell cycle progression analysis, Annexin V and Tunel assays suggested that IC50 of P. amaryllifolius ethanol extract induced G0/G1 cell cycle arrest, PS externalization and DNA fragmentation. On the other hand, ELISA for cytochrome c, caspase-3/7, 8 and 9 indicated that apoptosis was contributed by mitochondrial cytochrome c release via induction of caspase 3/7, 9, and p53 was associated with the suppression of XIAP in P. amaryllifolius treated MDA-MB-231 cells.ConclusionOur findings suggest that P. amaryllifolius ethanol extract induced apoptosis on hormone independent breast cancer cell line MDA-MB-231.

Two New Acridone Alkaloids from Glycosmis macrantha

Extraction and chromatographic separation of the extracts of dried stem barks of Glycosmis macrantha lead to isolation of two new acridone alkaloids, macranthanine (1) and 7-hydroxynoracronycine (2), and a known acridone, atalaphyllidine (3). The structures of these alkaloids were determined by detailed spectral analysis and also by comparison with reported data.

Crosstalk between reactive oxygen species and pro-inflammatory markers in developing various chronic diseases: a review

The inflammation process in the human body plays a central role in the pathogenesis of many chronic diseases. In addition, reactive oxygen species (ROS) exert potentially a decisive role in human body, particularly in physiological and pathological process. The chronic inflammation state could generate several types of diseases such as cancer, atherosclerosis, diabetes mellitus and arthritis, especially if it is concomitant with high levels of pro-inflammatory markers and ROS. The respiratory burst of inflammatory cells during inflammation increases the production and accumulation of ROS. However, ROS regulate various types of kinases and transcription factors such nuclear factor-kappa B which is related to the activation of pro-inflammatory genes. The exact crosstalk between pro-inflammatory markers and ROS in terms of pathogenesis and development of serious diseases is still ambitious. Many studies have been attempting to determine the mechanistic mutual relationship between ROS and pro-inflammatory markers. Therefore hereby, we review the hypothetical relationship between ROS and pro-inflammatory markers in which they have been proposed to initiate cancer, atherosclerosis, diabetes mellitus and arthritis.

Total Phenolic Content, Antioxidant, Cytotoxicity and Hepatoprotective Activities of Aqueous Extract of Channa striatus (Haruan)

Antioxidant has been the important approaches to reduce the development of cancer disease and play a role as a protective against liver toxicity. Channastriatus (haruan) have been used traditionally oral remedy for wound healing among women after child birth. However, there is little scientific evidence or research yet regarding the cytotoxicity and hepatoprotective activity of C.striatus. Thus, the aims of this study are to determine potential total phenolic content (TPC), antioxidant, cytotoxicity and hepatoprotective effect of C.striatus (Haruan) extract. For this present study, aqueous and lipid extract of was prepared using chloroform and methanol solvent in a ratio of 2:1. Folin-Ciocalteu was used to quantify TPC and three antioxidant assays were used to determine antioxidant activity, including 2,2-diphenyl-picrylhydrazyl (DPPH) assay, azino-bis(3- ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing ability of power (FRAP). For cell viability assay, HepG2 cell lines were seeded in 96-well plates and were treated with various concentration of aqueous extract of C.striatus, AECS (0, 0.00001, 0.0001, 0.001, 0.01, 0.1, 1, and 10 mg/ml) at 24, 48 and 72 hours. MTT assay has been used to measure HepG2 viability by using ELISA microplate reader. For hepatoprotective study, thirty six of adult male Sprague-Dawley rats will be divided into six groups of six rats each (n=6): G1:control (10%DMSO), G2:negative control (10% DMSO), G3:positive control (silymarin-100 mg/kg),G4: C.striatus (50mg/kg), G5:C.striatus (150mg/kg) and G6:C.striatus (450 mg/kg). The extract was given orally for 1 week. Acetaminophen,AAP (3g/kg) was induced orally from group 2 to 6 after 7 days of treatment. Blood collection was analyzed for liver function test and then the rats were sacrificed for histopathologically study. In TPC assay, AECS was observed to have higher content of phenolic (12799.33±237.90) compared to lipid extract of C.striatus, LECS (515.33±160.75). This indicates that, AECS has higher scavenging activity in DPPH and ABTS assay with EC50 (64.93±10.78) and (4687±0.67)respectively in comparison to LECS with EC50 (0.1513±0.046) and (93333.33±11.25) respectively. Additionally, AECS also consists of reducing potency since it has higher ability to reduce ferric ion compared to lipid extract of Channa striatus.For MTT assay, a significant decrease the percentage of HepG2 viability in a dose dependent manner was observed after HepG2 treated with various concentration of AECS at 24, 48 and 72 hours. The result showed no IC50 value of HepG2 obtained at 24 hours while IC50 value of AECS were 0.85 ± 0.26 and 0.1 ± 0.04mg/ml at 48 and 72 hours respectively. In vivo study, all groups pretreated of rats with AECS has shown significant decrease (p <0.05) in the level of ALT, AST, AST and histological scoring of liver when comparing with acetaminophen group. In conclusion, AECS has higher TPC and antioxidant activity than LECS. Besides that, AECS exhibited potential cytotoxicity effect towards HepG2 cell lines in both dose and time dependent manner and also hepatoprotective effect at lowest dose of AECS (50 mg/kg). Further studies are required for fully elucidation on the mechanism of cytotoxicity and hepatoprotective activity of AECS.