Performance of NiO doped on alkaline sludge from waste photovoltaic industries for catalytic dry reforming of methane.

Alkali sludge (AS) is waste abundantly generated from solar photovoltaic (PV) solar cell industries. Since this potential basic material is still underutilized, a combination with NiO catalyst might greatly influence coke resentence, especially in high-temperature thermochemical reactions (Arora and Prasad, RSC Adv. 6:108,668-108688, 2016). This paper investigated alkaline sludge containing 3CaO-2SiO2 doped with well-known NiO to enhance the dry reforming of methane (DRM) reaction. The wet-impregnation method was used to prepare the xNiO/AS (x = 5-15%) catalysts. Subsequently, all catalysts were tested by using X-ray diffraction (XRD), nitrogen adsorption/desorption (BET), temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed desorption of carbon dioxide (TPD-CO2), field emission scanning electron microscopy (FESEM-EDX), and X-ray photoelectron spectroscopy (XPS). The spent catalysts were analyzed by thermogravimetric analysis (TGA/DTG), transmission electron microscopy (TEM), and temperature-programmed oxidation (TPO). The catalytic performance of xNiO/AS catalysts was investigated in a fixed bed reactor connected with gas chromatography thermal conductivity detector (GC-TCD) at a CH4:CO2 flow rate of 30 mL-1 during a 10-h reaction by following (Shamsuddin et al., Int. J. Energy Res. 45:15,463-15,480, 2021d). For optimization parameters, the effects of NiO concentration (5, 10, and 15%), reaction temperature (700, 750, 800, 850, and 900 °C), catalyst loading (0.1, 0.2, 0.3, 0.4, and 0.5 g), and gas hourly space velocity (GHSV) range from 3000, 6000, 9000, 12,000, and 15,000 h-1 were evaluated. The results showed that physical characteristics such as BET surface area and porosity do not significantly impact NiO percentages of dispersion, whereas chemical characteristics like reducibility are crucial for the catalysts' efficient catalytic activity. Due to the active sites on the catalyst surface being more accessible, increased NiO dispersion resulted in higher reactant conversion. The catalytic performance on various parameters that showed 15%NiO/AS exhibited high reactant conversion up to 98% and 40-60% product selectivity in 700 °C, 0.2 g catalyst loading, and 12,000 h-1 GHSV. According to spent catalyst analyses, the catalyst was stable even after the DRM reaction. Meanwhile, increased reducibility resulted in more and better active site formation on the catalyst. Synergetic effect of efficient NiO as active metal and medium basic sites from AS enhanced DRM catalytic activity and stability with low coke formation.

Mineralization of palm oil mill effluent by advanced oxidation processes: A review on current trends and the way forward.

Palm oil mill effluent (POME) is regarded as deleterious to the environment, primarily owing to the substantial volume of waste it produces during palm oil extraction. In terms of contaminant composition, POME surpasses the pollutant content typically found in standard municipal sewage, therefore releasing it without treatment into water bodies would do irreparable damage to the environment. Main palm oil mills are normally located in the proximity of natural rivers in order to take advantage of the cheap and abundant water source. The same rivers are also used as a water source for many villages situated along the river banks. As such, it is imperative to degrade POME before its disposal into the water bodies for obvious reasons. The treatment methods used so far include the biological processes such as open ponding/land application, which consist of aerobic as well as anaerobic ponds, physicochemical treatment including membrane technology, adsorption and coagulation are successful for the mitigation of contaminants. As the above methods require large working area and it takes more time for contaminant degradation, and in consideration of the strict environmental policies as well as palm oil being the most sort of vegetable oil in several countries, numerous researchers have concentrated on the emerging technologies such as advanced oxidation processes (AOPs) to remediate POME. Methods such as the photocatalysis, Fenton process, sonocatalysis, sonophotocatalysis, ozonation have attained special importance for the degradation of POME because of their efficiency in complete mineralization of organic pollutants in situ. This review outlines the AOP technologies currently available for the mineralization of POME with importance given to sonophotocatalysis and ozonation as these treatment process removes the need to transfer the pollutant while possibly degrading the organic matter sufficiently to be used in other industry like fertilizer manufacturing.

Catalytic, Theoretical, and Biological Investigations of Ternary Metal (II) Complexes Derived from L-Valine-Based Schiff Bases and Heterocyclic Bases.

A new series of ternary metal complexes, including Co(II), Ni(II), Cu(II), and Zn(II), were synthesized and characterized by elemental analysis and diverse spectroscopic methods. The complexes were synthesized from respective metal salts with Schiff's-base-containing amino acids, salicylaldehyde derivatives, and heterocyclic bases. The amino acids containing Schiff bases showed promising pharmacological properties upon complexation. Based on satisfactory elemental analyses and various spectroscopic techniques, these complexes revealed a distorted, square pyramidal geometry around metal ions. The molecular structures of the complexes were optimized by DFT calculations. Quantum calculations were performed with the density functional method for which the LACVP++ basis set was used to find the optimized molecular structure of the complexes. The metal complexes were subjected to an electrochemical investigation to determine the redox behavior and oxidation state of the metal ions. Furthermore, all complexes were utilized for catalytic assets of a multi-component Mannich reaction for the preparation of -amino carbonyl derivatives. The synthesized complexes were tested to determine their antibacterial activity against E. coli, K. pneumoniae, and S. aureus bacteria. To evaluate the cytotoxic effects of the Cu(II) complexes, lung cancer (A549), cervical cancer (HeLa), and breast cancer (MCF-7) cells compared to normal cells, cell lines such as human dermal fibroblasts (HDF) were used. Further, the docking study parameters were supported, for which it was observed that the metal complexes could be effective in anticancer applications.

Catalytic response and molecular simulation studies in the development of synthetic routes in trimeric triaryl pyridinium type ionic liquids.

Under conventional and silica-supported Muffle furnace methods, water-soluble substituted trimeric triaryl pyridinium cations with various inorganic counter anions are synthesized. The solvent-free synthesis method is superior to the conventional method in terms of non-toxicity, quicker reaction times, ease of workup, and higher yields. Trimeric substituted pyridinium salts acted as excellent catalytic responses for the preparation of Gem-bisamide derivatives compared with available literature. To evaluate the molecular docking, benzyl/4-nitrobenzyl substituted triaryl pyridinium salt compounds with VEGFR-2 kinase were used with H-bonds, π-π stacking, salt bridges, and hydrophobic contacts. The results showed that the VEGFR-2 kinase protein had the most potent inhibitory activity. Intriguingly, the compound [NBTAPy]PF6- had a strongly binds to VEGFR-2 kinase and controlled its activity in cancer treatment and prevention.

Environment-friendly deoxygenation of non-edible Ceiba oil to liquid hydrocarbon biofuel: process parameters and optimization study.

Non-edible Ceiba oil has the potential to be a sustainable biofuel resource in tropical countries that can replace a portion of today's fossil fuels. Catalytic deoxygenation of the Ceiba oil (high O/C ratio) was conducted to produce hydrocarbon biofuel (high H/C ratio) over NiO-CaO5/SiO2-Al2O3 catalyst with aims of high diesel selectivity and catalyst reusability. In the present study, response surface methodology (RSM) technique with Box-Behnken experimental designs (BBD) was used to evaluate and optimize liquid hydrocarbon yield by considering the following deoxygenation parameters: catalyst loading (1-9 wt. %), reaction temperature (300-380 °C) and reaction time (30-180 min). According to the RSM results, the maximum yield for liquid hydrocarbon n-(C8-C20) was found to be 77% at 340 °C within 105 min and 5 wt. % catalyst loading. In addition, the deoxygenation model showed that the catalyst loading-reaction time interaction has a major impact on the deoxygenation activity. Based on the product analysis, oxygenated species from Ceiba oil were successfully removed in the form of CO2/CO via decarboxylation/decarbonylation (deCOx) pathways. The NiO-CaO5/SiO2-Al2O3 catalyst rendered stable reusability for five consecutive runs with liquid hydrocarbon yield within the range of 66-75% with n-(C15 + C17) selectivity of 64-72%. Despite this, coke deposition was observed after several times of catalyst usage, which is due to the high deoxygenation temperature (> 300 °C) that resulted in unfavourable polymerization side reaction.

Hierarchical HZSM-5 for Catalytic Cracking of Oleic Acid to Biofuels.

Solid acid catalyzed cracking of waste oil-derived fatty acids is an attractive route to hydrocarbon fuels. HZSM-5 is an effective acid catalyst for fatty acid cracking; however, its microporous nature is susceptible to rapid deactivation by coking. We report the synthesis and application of hierarchical HZSM-5 (h-HZSM-5) in which silanization of pre-crystallized zeolite seeds is employed to introduce mesoporosity during the aggregation of growing crystallites. The resulting h-HZSM-5 comprises a disordered array of fused 10-20 nm crystallites and mesopores with a mean diameter of 13 nm, which maintain the high surface area and acidity of a conventional HZSM-5. Mesopores increase the yield of diesel range hydrocarbons obtained from oleic acid deoxygenation from ~20% to 65%, attributed to improved acid site accessibility within the hierarchical network.

Combustion and Emission Performance of CO/NOx/SOx for Green Diesel Blends in a Swirl Burner.

Green diesel is one of the alternative energy sources, which is found to be a second-generation biofuel. Green diesel has a similar molecular structure to petroleum diesel but has better diesel properties, sustainability, and environmental benignity. In this study, green diesel was synthesized from waste cooking oil via a deoxygenation reaction process and blended with petroleum diesel to assess the rate of greenhouse gas emissions. The fuel properties of the formed G100 (pure green diesel) were investigated, and the performance of G5 and G20 (a mixture of 5 and 20% green diesel in petroleum diesel) was tested for combustion in an oil burner. The overall test showed that the combustion of the blends of green diesel produced lower CO2 and SO2 emissions than that of petroleum diesel as a result of the rich oxygen-free fuel content. The obtained fuel properties of pure green diesel and blended green diesel are in compliance with ASTM D6751, ASTM D240-17, and EN 14214 standards. Based on these findings, it is shown that blended green diesel is a clean fuel for the environment and a promising alternative fuel for internal combustion engines.

Lewis acid Ni/Al-MCM-41 catalysts for H2-free deoxygenation of Reutealis trisperma oil to biofuels.

The activity of mesoporous Al-MCM-41 for deoxygenation of Reutealis trisperma oil (RTO) was enhanced via modification with NiO nanoparticles. Deoxygenation at atmospheric pressure and under H2 free conditions required acid catalysts to ensure the removal of the oxygenated fragments in triglycerides to form liquid hydrocarbons. NiO at different weight loadings was impregnated onto Al-MCM-41 and the changes of Lewis/Brønsted acidity and mesoporosity of the catalysts were investigated. The activity of Al-MCM-41 was enhanced when impregnated with NiO due to the increase of Lewis acidity originating from NiO nanoparticles and the mesoporosity of Al-MCM-41. Increasing the NiO loading enhanced the Lewis acidity but not Brønsted acidity, leading to a higher conversion towards liquid hydrocarbon yield. Impregnation with 10% of NiO on Al-MCM-41 increased the conversion of RTO to hydrocarbons via the deoxygenation pathway and reduced the products from cracking reaction, consequently enhancing the green diesel (C11-C18) hydrocarbon products.

Promoting dry reforming of methane via bifunctional NiO/dolomite catalysts for production of hydrogen-rich syngas.

Extensive effort has been focused on the advancement of an efficient catalyst for CO2 reforming of CH4 to achieve optimum catalytic activity together with cost-effectiveness and high resistance to catalyst deactivation. In this study, for the first time, a new catalytic support/catalyst system of bifunctional NiO/dolomite has been synthesized by a wet impregnation method using low-cost materials, and it shows unique performance in terms of amphoteric sites and self-reduction properties. The catalysts were loaded into a continuous micro-reactor equipped with an online GC-TCD system. The reaction was carried out with a gas mixture consisting of CH4 and CO2 in the ratio of 1 : 1 flowing 30 ml min-1 at 800 °C for 10 h. The physicochemical properties of the synthesized catalysts were determined by various methods including X-ray diffraction (XRD), N2 adsorption-desorption, H2 temperature-programmed reduction (H2-TPR), temperature-programmed desorption of CO2 (TPD-CO2), and temperature-programmed desorption of NH3 (TPD-NH3). The highest catalytic performance of the DRM reaction was shown by the 10% NiO/dolomite catalyst (CH4 & CO2 conversion, χCH4; χCO2 ∼ 98% and H2 selectivity, S H2 = 75%; H2/CO ∼ 1 : 1 respectively). Bifunctional properties of amphoteric sites on the catalyst and self-reduction behaviour of the NiO/dolomite catalyst improved dry reforming of the CH4 process by enhancing CH4 and CO2 conversion without involving a catalyst reduction step, and the catalyst was constantly active for more than 10 h.

Enhanced CO2 methanation at mild temperature on Ni/zeolite from kaolin: effect of metal-support interface.

Catalytic CO2 hydrogenation to CH4 offers a viable route for CO2 conversion into carbon feedstock. The research aimed to enhance CO2 conversion at low temperature and to increase the stability of Ni catalysts using zeolite as a support. NaZSM-5 (MFI), NaA (LTA), NaY (FAU), and NaBEA (BEA) synthesized from kaolin were impregnated with 15% Ni nanoparticles in order to elucidate the effect of surface area, porosity and basicity of the zeolite in increasing Ni activity at mild temperature of ∼200 °C. A highly dispersed Ni catalyst was produced on high surface area NaY meanwhile the mesoporosity of ZSM-5 has no significant effect in improving Ni dispersion. However, the important role of zeolite mesoporosity was observed on the stability of the catalyst. Premature deactivation of Ni/NaA within 10 h was due to the relatively small micropore size that restricted the CO2 diffusion, meanwhile Ni/NaZSM-5 with a large mesopore size exhibited catalytic stability for 40 h of reaction. Zeolite NaY enhanced Ni activity at 200 °C to give 21% conversion with 100% CH4 selectivity. In situ FTIR analysis showed the formation of hydrogen carbonate species and formate intermediates at low temperatures on Ni/NaY, which implied the efficiency of electron transfer from the basic sites of NaY during CO2 reduction. The combination of Ni/NaY interfacial interaction and NaY surface basicity promoted CO2 methanation reaction at low temperature.

Optimization and Characterization of Mesoporous Sulfonated Carbon Catalyst and Its Application in Modeling and Optimization of Acetin Production.

In this study, an optimized mesoporous sulfonated carbon (OMSC) catalyst derived from palm kernel shell biomass was developed using template carbonization and subsequent sulfonation under different temperatures and time conditions. The OMSC catalyst was characterized using acid-base titration, elemental analysis, XRD, Raman, FTIR, XPS, TPD-NH3, TGA-DTA, SEM, and N2 adsorption-desorption analysis to reveal its properties. Results proved that the OMSC catalyst is mesoporous and amorphous in structure with improved textural, acidic, and thermal properties. Both FTIR and XPS confirmed the presence of -SO3H, -OH, and -COOH functional groups on the surface of the catalyst. The OMSC catalyst was found to be efficient in catalyzing glycerol conversion to acetin via an acetylation reaction with acetic acid within a short period of 3 h. Response surface methodology (RSM), based on a two-level, three-factor, face-centered central composite design, was used to optimize the reaction conditions. The results showed that the optimized temperature, glycerol-to-acetic acid mole ratio, and catalyst load were 126 °C, 1:10.4, and 0.45 g, respectively. Under these optimum conditions, 97% glycerol conversion (GC) and selectivities of 4.9, 27.8, and 66.5% monoacetin (MA), diacetin (DA), and triacetin (TA), respectively, were achieved and found to be close to the predicted values. Statistical analysis showed that the regression model, as well as the model terms, were significant with the predicted R2 in reasonable agreement with the adjusted R2 (<0.2). The OMSC catalyst maintained excellent performance in GC for the five reaction cycles. The selectivity to TA, the most valuable product, was not stable until the fourth cycle, attributable to the leaching of the acid sites.

Ultrathin Assembles of Porous Array for Enhanced H2 Evolution.

Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H2) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UV-visible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh-1 which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water.

Synthesis of bifunctional nanocatalyst from waste palm kernel shell and its application for biodiesel production.

The potential of bifunctional nanocatalysts obtained from waste palm kernel shell (PKS) was investigated for one-step transesterification-esterification under mild conditions. State-of-the-art characterization illustrated that the synthesized catalyst has high stability through the thermal test, high BET surface area of 438.08 m2 g-1, pore volume of 0.367 cm3 g-1 and pore width of 3.8 nm. The high amount of basicity (8.866 mmol g-1) and acidity (27.016 mmol g-1) promoted the successfulness of simultaneous transesterification-esterification. The investigation revealed that the combination of potassium and copper on activated carbon surface showed good catalytic activity by giving 95.0% FAME yield and 97.3% FFA conversion at a relatively mild condition of 5 wt% catalyst loading, 12 : 1 methanol to oil molar ratio at 80 °C for 4 hours with FAME yield > 80% after 5 reaction cycles. Characterization of the spent catalyst showed that the amount of basicity was reduced to 3.106 mmol g-1, which validated the reduction of the catalytic performance. The usage of waste material was successfully discovered in producing an effective bifunctional catalyst for biodiesel production from waste cooking oil (WCO) and has high potential for commercialization in the future.

Application of Plasmonic Metal Nanoparticles in TiO2-SiO2 Composite as an Efficient Solar-Activated Photocatalyst: A Review Paper.

Over the last decade, interest in the utilization of solar energy for photocatalysis treatment processes has taken centre-stage. Researchers had focused on doping TiO2 with SiO2 to obtain an efficient degradation rate of various types of target pollutants both under UV and visible-light irradiation. In order to further improve this degradation effect, some researchers resorted to incorporate plasmonic metal nanoparticles such as silver and gold into the combined TiO2-SiO2 to fully optimize the TiO2-SiO2's potential in the visible-light region. This article focuses on the challenges in utilizing TiO2 in the visible-light region, the contribution of SiO2 in enhancing photocatalytic activities of the TiO2-SiO2 photocatalyst, and the ability of plasmonic metal nanoparticles (Ag and Au) to edge the TiO2-SiO2 photocatalyst toward an efficient solar photocatalyst.

Facile Recoverable and Reusable Macroscopic Alumina Supported Ni-based Catalyst for Efficient Hydrogen Production.

A γ-NA5 catalyst in the form of pellet was first to be reported and was pioneering in gasification to accelerate the production of syngas through biomass (palm empty fruit brunch) conversion. The synthesised γ-NA5 pellet possesses a high surface area of 212.32 m2 g-1, which renders more active sites for hydrocarbon cracking, subsequently leading to high H2 production (0.0716 m3 kg-1). Additionally, the pellet exhibits remarkable reversibility and reusability with 91% H2 production efficiency being retained after five consecutive gasification cycles. Distinctively, the feature of the synthesised γ-NA5 pellet from the conventional powder-like catalyst is that it eases the separation of the used catalyst from the biomass ash, and subsequently facilitates regeneration solely by calcination process. The loading of 20 wt.% optimised amount of catalyst itself has successfully shorten the completion of gasification process up to 135 min, which is highly feasible for a large scale industrial usage after considering the cost of the catalyst, facile preparation method, and catalyst's effectiveness towards gasification.

Production of green biofuel by using a goat manure supported Ni-Al hydrotalcite catalysed deoxygenation process.

The high oxygen content in natural biomass resources, such as vegetable oil or biomass-pyrolysed bio oil, is the main constraint in their implementation as a full-scale biofuel for the automotive industry. In the present study, renewable fuel with petrodiesel-like properties was produced via catalytic deoxygenation of oleic acid in the absence of hydrogen (H2). The deoxygenation pathway of oleic acid to bio-hydrocarbon involves decarboxylation/decarbonylation of the oxygen content from the fatty acid structure in the form of carbon dioxide (CO2)/carbon monoxide (CO), with the presence of a goat manure supported Ni-Al hydrotalcite (Gm/Ni-Al) catalyst. Goat manure is an abundant bio-waste, containing a high mineral content, urea as well as cellulosic fiber of plants, which is potentially converted into activated carbon. Synthesis of Gm/Ni-Al was carried out by incorporation of pre-activated goat manure (GmA) during co-precipitation of Ni-Al catalyst with 1 : 3, 1 : 1 and 3 : 1 ratios. The physico-chemical properties of the catalysts were characterized by X-ray diffractometry (XRD), Brunauer-Emmet-Teller (BET) surface area, field emission surface electron microscopy (FESEM) and temperature program desorption ammonia (TPD-NH3) analysers. The catalytic deoxygenation reaction was performed in a batch reactor and the product obtained was characterized by using gas chromatography-mass spectroscopy (GCMS) for compound composition identification as well as gas chromatography-flame ionisation detector (GC-FID) for yield and selectivity determination. The optimization and evaluation were executed using response surface methodology (RSM) in conjunction with central composite design (CCD) with 5-level-3-factors. From the RSM reaction model, it was found that the Gm/Ni-Al 1 : 1 catalysed deoxygenation reaction gives the optimum product yield of 97.9% of hydrocarbon in the range of C8-C20, with diesel selectivity (C17: heptadecane and heptadecene compounds) of 63.7% at the optimal reaction conditions of: (1) reaction temperature: 327.14 °C, (2) reaction time: 1 h, and (3) catalyst amount: 5 wt%.

Nanolayered composite with enhanced ultraviolet ray absorption properties from simultaneous intercalation of sunscreen molecules.

INTRODUCTION: The potential of layered double hydroxide (LDH) as a host of multiple ultraviolet-ray absorbers was investigated by simultaneous intercalation of benzophenone 4 (B4) and Eusolex® 232 (EUS) in Zn/Al LDH. METHODS: The nanocomposites were prepared via coprecipitation method at various molar ratios of B4 and EUS. RESULTS: At equal molar ratios, the obtained nanocomposite showed an intercalation selectivity that is preferential to EUS. However, the selectivity ratio of intercalated anions was shown to be capable of being altered by adjusting the molar ratio of intended guests during synthesis. Dual-guest nanocomposite synthesized with B4:EUS molar ratio 3:1 (ZEB [3:1]) showed an intercalation selectivity ratio of B4:EUS =53:47. Properties of ZEB (3:1) were monitored using powder X-ray diffractometer to show a basal spacing of 21.8 Å. Direct-injection mass spectra, Fourier transform infrared spectra, and ultraviolet-visible spectra confirmed the dual intercalation of both anions into the interlayer regions of dual-guest nanocomposite. The cytotoxicity study of dual-guest nanocomposite ZEB (3:1) on human dermal fibroblast cells showed no significant toxicity until 25 µg/mL. CONCLUSION: Overall, the findings demonstrate successful customization of ultraviolet-ray absorbers composition in LDH host.

Anticancer effect of dentatin and dentatin-hydroxypropyl-ß-cyclodextrin complex on human colon cancer (HT-29) cell line.

INTRODUCTION: Dentatin (DEN) (5-methoxy-2, 2-dimethyl-10-(1, 1-dimethyl-2propenyl) dipyran-2-one), a natural compound present in the roots of Clausena excavata Burm f, possesses pro-apoptotic and antiproliferative effects in various cancer cells. Because of its hydrophobicity, it is believed that its complexation with hydroxy-ß-cyclodextrin (HPßCD) will make it a potent inhibitor of cancer cell growth. In the current work, the molecular mechanisms of apoptosis induced by DEN and DEN-HPßCD complex were demonstrated in human colon HT-29 cancer cells. MATERIALS AND METHODS: After the human colon HT-29 cancer cells were treated with DEN and DEN-HPßCD complex, their effects on the expression of apoptotic-regulated gene markers in mitochondria-mediated apoptotic and death receptor pathways were detected by Western blot analysis and reverse transcription polymerase chain reaction. These markers included caspases-9, 3, and 8, cytochrome c, poly (ADP-ribose) polymerase, p53, p21, cyclin A as well as the Bcl-2 family of proteins. RESULTS: At 3, 6, 12, and 24 µg/mL exposure, DEN and DEN-HPßCD complex significantly affected apoptosis in HT-29 cells through the down-regulation of Bcl-2 and cyclin A in turn, and up-regulation of Bax, p53, p21, cytochrome c at both protein and mRNA levels. DEN and DEN-HPßCD complex also decreased cleaved poly (ADP-ribose) polymerase and induced caspases-3, -8, and -9. CONCLUSION: Results of this study indicate that the apoptotic pathway caused by DEN and DEN-HPßCD complex are mediated by the regulation of caspases and Bcl-2 families in human colon HT-29 cancer cells. The results also suggest that DEN-HPßCD complex may have chemotherapeutic benefits for colon cancer patients.

Therapeutic uses of epicatechin in diabetes and cancer.

Epicatechin is a natural flavonoid found in green tea. It has been reported to possess an immense antioxidant effect which contributes to its therapeutic effect against a handful of ailments. In this review, we discuss its therapeutic role in the management of two of the most important human diseases; diabetes and cancer. The consumption of epicatechin has been shown to reduce blood glucose levels in diabetic patients, while is anticancer effect was attributed to its antioxidant properties, antiangiogenic and direct cytotoxicity to cancer cells. Although the exact mechanism of action of epicatechin is still being explored, there is no doubt that it is a promising candidate as an alternative. The significance of this review is to highlight the importance of the usage of natural products (in this case, epicatechin) as an alternative for the treatment of two potentially fatal diseases which is diabetes and cancer. The aim of this review is to educate the scientific community on the role of epicatechin in ameliorating the effects of diabetes and cancers on human while understanding the potential mechanisms of these aforementioned effects.

Inducing G2/M Cell Cycle Arrest and Apoptosis through Generation Reactive Oxygen Species (ROS)-Mediated Mitochondria Pathway in HT-29 Cells by Dentatin (DEN) and Dentatin Incorporated in Hydroxypropyl-ß-Cyclodextrin (DEN-HPßCD).

Dentatin (DEN), purified from the roots of Clausena excavata Burm f., has poor aqueous solubility that reduces its therapeutic application. The aim of this study was to assess the effects of DEN-HPßCD (hydroxypropyl-ß-cyclodextrin) complex as an anticancer agent in HT29 cancer cell line and compare with a crystal DEN in dimethyl sulfoxide (DMSO). The exposure of the cancer cells to DEN or DEN-HPßCD complex leads to cell growth inhibition as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. To analyze the mechanism, in which DEN or DEN-HPßCD complex causes the death in human colon HT29 cancer cells, was evaluated by the enzyme-linked immunosorbent assay (ELIZA)-based assays for caspase-3, 8, 9, and reactive oxygen species (ROS). The findings showed that an anti-proliferative effect of DEN or DEN-HPßCD complex were via cell cycle arrest at the G2/M phase and eventually induced apoptosis through both mitochondrial and extrinsic pathways. The down-regulation of poly(ADP-ribose) polymerase (PARP) which leaded to apoptosis upon treatment, was investigated by Western-blotting. Hence, complexation between DEN and HPßCD did not diminish or eliminate the effective properties of DEN as anticancer agent. Therefore, it would be possible to resolve the conventional and current issues associated with the development and commercialization of antineoplastic agents in the future.