Papers by Keyword: Apoptosis

Abstract: Luvunga scandens (“Mengkurat Jakun”) is one of the medicinal plant that produce triterpenoid compounds. A number of studies have reported that the compounds possess anti-proliferative activities against various type of cancer cells. The present study aims for anticancer potential of two triterpenoids derived from L. scandens namely flindissol (compound-1) and 3-oxotirucalla-7,24-dien-21-oic-acid (compound-2) on human oral cancer HSC-3 cells. Cytotoxic activities of the triterpenoids were assessed by MTT assay. Apoptosis activities were determined by flow cytometry and caspase 3/7 assay. The MTT assay showed that compounds-1 and -2 markedly induced cytotoxicity on HSC-3 cells with IC50 10.7 μM and 8.3 μM, respectively. Flow-cytometry analysis demonstrated that both compounds increase the percentage of apoptotic cells by 18.2 % and 16.6 % respectively. Moreover, the caspase 3/7 assay confirmed that compounds-1 and -2 markedly induced caspase 3/7 activities in HSC-3 cells. These results suggest that triterpenoids extracted from L. scandens could be a potential candidate for oral cancer treatment.

Abstract: Andrographolide (AG) is a diterpenoid lactone found in Andrographis paniculata leaves and stems. It has excellent activity against various cancer cells, for example, skin cancer cells. However, application of AG for skin cancer treatment in clinical trials is limited due to its poor water solubility. To overcome this problem, oil in water AG-loaded nanoemulsion (AG-NE) would be prepared. The objectives of this study were to investigate physicochemical properties of AG-NE and to determine its activity against non-melanoma skin cancer cells. Nanoemulsion (NE) without AG (NE base) and NE containing AG (0.1%w/w) were prepared by high-pressure homogenization technique. They contained a mixture of Tween 80 and Span 80 (5:1) (10% w/w) as an emulsifier. Their droplet size, zeta potential and physical stability were evaluated. Cytotoxicity of AG and AG-NE to non-melanoma skin cancer cells (A-431 cells) and normal skin fibroblast cells (HFF-1 cells) were investigated. The results showed that NE base and AG-NE had droplet size in a nanometer range. They had low viscosity with the flow behavior consistent with Newtonian liquids. Although their zeta potential values were slightly low, they showed good physical stability against centrifugal force. AG and AG-NE were not toxic to HFF-1 cells, but they could induce apoptosis of A-431 cells with IC50 of 25.83 μg/ml and 58.32 mg/ml, respectively. Therefore, AG-NE has become possible to use for investigation of its efficacy and safety in animal models and clinical trials.

Abstract: Wnt-β Catenin pathway has an important role in many cancers. Wnt-1 protein from the Wnt protein family, which regulates this pathway, has a special effect on the development of breast cancer. Monoclonal antibodies attaching to metal nanoparticles have an important role in the diagnosis and treatment of cancers.In this study, the anti-Wnt-1monoclonal antibody was conjugated to the gold nanoparticles synthesized by theTurkevichmethod. Conjugation was achieved using the EDC-NHS method. The density of the monoclonal antibodies bonded to gold nanoparticles was measured by Roche Cobas Integra 400 Plus device. MCF-7 and MDA-MB-231 breast cancer cell lines were treated with conjugated nanoparticles for 48 h, followed by performing a double-staining method to detect apoptosis cells.The results showed that inhibition of Wnt-1 protein in extracellular matrix causes apoptosis and gold nanoparticles to have a positive effect on Anti-Wnt-1monoclonal antibodies, leading to an increase in the number of conjugating nanoparticles.

Abstract: The aim of this study was to investigate the relation between the amount of glycosaminoglycans (GAGs) secreted and the level of apoptosis induced by hydrogen peroxide (H₂O₂) in porcine chondrocytes cultured on two different biodegradable PCL/PHBV scaffolds: one had primary pores solely, while the other possessed both primary and secondary pores, namely PCL/PHBV/0%NaCl and PCL/PHBV/50%NaCl scaffolds, respectively. The scaffolds with an average primary pore size of 200 μm were primarily fabricated by a fused deposition modeling (FDM) machine, and secondary pores on the material surface were then generated after NaCl leaching in a sodium hydroxide solution. The investigation was performed comparatively under static and dynamic environments. In static culture study, more pronounced GAG accumulation was found on the PCL/PHBV/50%NaCl scaffold, suggesting that the secondary pores could promote the chondrogenic function of chondrocytes, and the primary pores could further accommodate the cells to grow and function more productively. Meanwhile, the significant reductions in the levels of apoptosis of chondrocytes, studied in a H₂O₂-dose dependent manner (0-2 mM), were observed with a use of a flow cytometer when the chondrocytes were cultured on the PCL/PHBV/50%NaCl scaffold in which more GAG content was found. In dynamic culture study, although the total GAG content detected on the PCL/PHBV/50%NaCl scaffold was still significantly higher than that measured on the PCL/PHBV/0%NaCl scaffold, these GAG accumulations were tremendously greater than those found in the static culture. As a consequence, far less oxidative stress-induced apoptotic death was observed in the cells cultured under the dynamic culture. Moreover, cells seemed to be well protected from apoptosis, in the presence of considerable amounts of GAGs; similar degrees of apoptosis (~25%) were observed on the cells cultured on each scaffold at all H₂O₂ concentrations studied. The obtained results had demonstrated that the degree of chondrocyte apoptosis was somehow related to the level of GAG accumulation.

Abstract: We showed the results of immunohistochemical investigation of outbred albino rat’s neural tissue exposed to 9-day exposure of nanobiocomposite, which consist silver nanoparticles encapsulated in natural biopolymer matrix - arabinogalactan. Investigation of white rats was composed of 2 stages: half of the rats in each group were sacrificed immediately after exposure (early period) and other rats – through 6 months after end of exposure (distant period). We showed that test substance causes functional changes in nervous tissue. After subacute administration of nanobiocomposite - argentumarabinogalaktan (nAG) we have observed changes of content of apoptotic and anti-apoptotic proteins caspase-3 and bcl-2 in nervous tissue of white rats. number of normal neurons producing the protein caspase-3 was increased sharply and number of immunonegative normal neurons was significantly reduced. Along with this there was a high level of bcl – 2, one function of which is to prevent apoptosis trigger. We revealed in samples a significant increase in number of neurons with bcl-2, but protective effect of this protein not fully realized, which leads to significant increase of amount ofdamaged hyperchromatic cells. Assessment of results of immunohistochemical study of white rat’s nervous tissue, according to the expression of the protein caspase-3 and bcl – 2, may lead conclusion about ability of nanosilver encapsulated in a polymer matrix to penetrate blood-brain barrier and induced start apoptotic cascade in cortical neurons.

Abstract: The novel TiO₂/graphene sheet (TiO₂/GSs) nanocomposites were synthesized using graphene oxide sheets and TiCl₃. All target composites were characterized by transmission electron microscopy (TEM), X-ray electron diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectra (EDX), and the surface areas were tested with the Brunauer-Emmett-Teller (BET) method. We studied the cytotoxicity of TiO₂/GSs nanoparticles on A549 cells by examining the influence of TiO₂/GSs on cell morphology and viability by methyl thiazolyl tetrazolium (MTT) assay. We also determined membrane integrity and apoptosis of A549 cells after different doses of TiO₂/GSs exposure by LDH assay and flow cytometry. Assay of A549 cell viability showed regular reductions with a time-and dose-dependent tendency after exposure to pure TiO₂, TiO₂/4.2wt% GSs and TiO₂/6wt% GSs for 24 hrs or 48 hrs. The LDH released and cellular apoptosis also had a dose-dependent effect, which was associated with the surface area of TiO₂/4.2wt% GSs. Our results provide essential knowledge of the acceptable biocompatibility of TiO₂/GSs nanocomposites, and only when cells were exposed at a high concentration (≥50 μg/mL), and for a prolonged period of time did TiO₂/GSs nanoparticles exhibit minimal cytotoxicity against A549 cells.

Abstract: In this study, we used the well in the well (WIW) culture system to study the effect of granulosa cells apoptosis on the cumulus expansion and the developmental competence of bovine oocytes. Results: The apoptosis of granulosa cells affect the cumulus expansion of bovine oocytes significantly. Especially when the percentage of granulosa cells apoptosis exceed 40%, the cumulus expansion was worse. The cumulus expansion affect the oocyte developmental competence of bovine oocytes significantly. The developmental competence of bovine oocyte increases with the increasing of cumulus expansion.

Abstract: Numerous studies have reported the association between fine particle matter (PM) and lung diseases. Alveolar macrophages (AM) are the key lung cells with strong capability of eliminating external particle pollutant. Therefore the prevention of AM from apoptosis induced by fine PM is vital for clinical treatment of increased pulmonary diseases. This study aims to investigate the ultrastructural changes in cultured AM induced by fine PM, which can directly reflect the effect of fine PM on AM apoptosis. In addition, Standard Reference Material for fine PM (SRM 2786) was used in current study due to its relative uniform composition. The results in this study suggested that SRM 2786 induced morphology changes in AM in a dose-dependent manner by transmission electron microscope observation, including nuclear fragmentation, chromatin aggregation, increased numbers of lysosomes and so forth. Consequently, this study provides reliable evidence for us to further investigate the apoptotic mechanism of AM induced by fine PM treatment in the future.

Abstract: In order to search for new structural modification strategies on quercetin, we have designed and synthesized a series of quercetin derivatives. Several novel quercetin derivatives displayed potent protect effect on H₂O₂-induced injury in PC12 cells. In the recent study, we investigated the effect of 3,3',4',5,7-pentahydroxyflavone 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one (HPS5) on the apoptosis of PC12 cells in vitro. We used neuronal PC12 cell line to study the regulation role of HPS5 in H₂O₂ induced cell apoptosis. MTT assay was used for detection the proliferation of PC12 cells upon H₂O₂ treatment. PC12 cell nuclear morphological change was detected with Hoechst 33258 staining. The antioxidative capacity was judged by SOD determinations. The protein levels of Bax and Bcl-2 were deteanined by Western blotting. Our results demonstrated that Quercetin derivatives HPS5 can prevent and protect against H₂O₂-induced injury in PC12 cells. Together, our studies provided new insights activities of quercetin, and may contribute to pharmacological study of quercetin in future research.

Abstract: We cloned a new serine protease gene from the marine annelid, Arenicola cristata by rapid amplification of cDNA ends. The full-length cDNA of 901bp contained an open reading frame of 774bp encoding 258 amino acids. Sequence analysis of the deduced amino acids indicated that this protease belonged to serine protease family and contained highly conserved sequence GDSGGP. An expression vector, harboring the mature peptide of Arenicola cristata protease, was constructed and transformed into E.coli. The purified recombinant protein could inhibit proliferation of cancer cells in a dose-dependant way and induce apoptosis. These results indicated that the recombinant protease of Arenicola cristata, as a new member of serine protease family, might be valuable in developing anti-tumor agents.