Cytotoxicity of Mahanimbine, Murryafoline A and S-Benzyldithiocarbazate on Human Leukemic Cell Line, CEM-SS

Mahanimbine, a carbazole alkaloid was isolated from an ether extract of the stem bark of Murraya koenigii whilst Murrayafoline A was isolated from petroleum ether extract of the roots of Murraya koenigii. S-Benzyldithiocarbazate is a dithiocarbazic acid Schiff base derived from S-alkyl esters. They were found to exhibit cytotoxic activity against CEM-SS human T-lymphoblastic leukemic cells. The cytotoxic activity of Mahanimbine, Murrayafoline A and S-Benzyldithiocarbazate that inhibit 50 % growth (IC₅₀) of CEM-SS were 6 µg/ml, S µg/ml and 7.S µg/ml respectively. For comparative purposes, the IC₅₀ of several commercial cytotoxic drugs against CEM-SS were determined. The inhibition effect of Mahanimbine, Murrayafoline A and SBenzyldithiocarbazate were better than Methotrexate (IC₅₀ > 30 µg/ml), Doxorubicine (IC₅₀ = 21 µg/ml), Cytarabine (IC₅₀ > 30 µg/ml) and Colchecine (IC₅₀ = 8 µg/ml).These compounds were found to be less active than cis-diamine dichloroplatinwn and Vinorelbine tartrate with a IC₅₀ value of 3 µg/ml. In contrast, these three compounds were found to be less active against normal mouse fibroblasts cell, 3T3 with the IC₅₀ value of 11 µg/ml (Mahanimbine), 17 µg/ml (Murrayafoline A) and 10 µg/ml (SBenzyldithiocarbazate) respectively. The study showed that the proliferation of cells was inhibited before the cells were being killed. In addition, Mahanimbine, MurrayafolineA and S-Benzyldithiocarbazate caused programmed cell death by showing apoptotic features such as nucleus fragmentation, cell shrinkage, membrane blebbing and formation of apoptotic bodies. These were further confirmed with DNA laddering in agarose gel electrophoresis assay due to DNA fragmentation. DNA laddering was obtained after 24 hours of treatment by these three compounds in a doseindependent but time-dependent way. Mahanimbine and Murrayafoline A were shown to arrest CEM-SS cells at G1 phase of cell cycle using flowcytometry method. As a result, Mahanimbine, Murrayafoline A and S-Benzyldithiocarbazate were found as potent antitumor agents

Toxicity Effects of Titanium Dioxide Nanoparticles in Marine Algae

Titanium dioxide nanoparticles (TiO2) are mineral compounds that had been manipulated to its nano-scale dimension, approximately 1 to 100nm. Nano-scaled TiO2 are claimed to have better chemical, physical and biological properties which make them enormously applied in industrial manufacturing. However, this has become a big threat to the environment due to the increase disposal of TiO2 into the environment whereby both human and other living organisms could be adversely affected. The aim of this study was to study the effects of TiO2 nanoparticles on two marine microalgae Dunaleilla tertiolecta and Pavlova gyrans. The change in photosynthetic pigments chlorophyll a and carotenoid content was used to measure the response of algae species towards the presence of TiO2 nanoparticle. The results showed Dunaleilla tertiolecta was more susceptible to TiO2 nanoparticles with lower effective concentration of 50% (EC50) at 31.25 mg/L compared to Pavlova gyrans. In addition, TiO2 was found to aggregate and adsorb on algal membrane and reduced its motility. In conclusion, TiO2 nanoparticles caused an impactful effect to the ecosystem and the post production wastes should be managed appropriately

Response of marine microalgae towards short single-walled carbon nanotubes

Nanoparticles have vast applications in industrial and consumer products such as household detergents, sunscreen, anti-bacterial clothing, electrical and telecommunication devices, sports equipment, medical treatment tools and others. The production of nanomaterials is increasing remarkably with an expected resultant increase in the distribution of nanoparticles in the environment. Many health problems have been correlated to the exposure of nanoparticles. For instance, engineered carbon nanotubes cause inflammation, fibrosis and oxidative stress in both in vitro and in vivo models and titanium dioxide nanoparticles could lead to chronic airflow obstruction. Marine microalgae play a pivotal role in all marine ecosystems as they form the food and energy base for all organisms living in lakes, ponds, streams and sea. They provide 75% of oxygen content in the atmosphere. Therefore, an effect on algal population may have an important impact on the whole ecosystem. The aim of this study is to assess the toxicity of short single-walled carbon nanotubes (SWCNT) and amount of reactive species oxygen (ROS) released in two marine microalgae Dunaliella tertiolecta and Isochrysis sp using pigment quantification method and H2DCFDA dye. We found that SWCNT reduced the algal cell number by 50% at 30 mg/L and 50 mg/L after 96 h of exposure in Isochrysis sp. and Dunaliella tertiolecta respectively. In addition, 6-10 folds of ROS were released by these marine microalgae when exposed to SWCNT (50 mg/L). In conclusion, the presence of nanoparticles in the environment causes ecotoxicity and its impact to biodata should not be neglected

Bandwidth Widening Strategies for Piezoelectric Based Energy Harvesting from Ambient Vibration Sources

Due to the fact that the ambient vibration sources are random and unpredictable, therefore a vibration based energy harvesting device is desirable to be able to operate at wider bandwidth in an envelop of frequency range to generate maximum electrical output. In this paper, various ambient vibration from household appliances, machineries, vehicle and moving vehicle were measured and investigated. The second part of the paper will discuss the strategies to harvest these ambient vibration sources. An array of piezoelectric multi-cantilever is proposed to address the issue of single piezoelectric cantilever with high Q-factor. Two configurations of multi-cantilever were fabricated in a form that elevated from the substrate as freestanding structures. One with six cantilevers of constant width but different lengths and another with five cantilevers of constant length but different widths. The measurement and experimental results show a frequency band of 200 Hz to 300 Hz as a common bandwith between the vibration sources and the capability of miniature piezoelectric energy harvester in harvesting maximum electrical energy

Production of porous stainless steel using the space holder method

Metallic foams and porous materials can be produced by various methods. Among the methods that can produce metallic foams and porous materials, powder metallurgy is a promising method. This study investigates the production of a porous stainless steel by the space holder method in powder metallurgy. A novel space holder i.e. glycine and binder consisting of polymethylmethacrylate and stearic acid are used. Different amounts of glycine are added to the mixture of stainless-steel powder and binder. Subsequently, each mixture is cold-pressed at a pressure of 9-ton m-2. The samples are sintered at 1050 and 1150 °C with holding times of 30, 60, and 90 min. The microstructures and physical and mechanical properties of the sintered samples are investigated. A porous stainless steel with porosity ranging from 30.8 to 51.4% is successfully fabricated. Results show that the glycine content and sintering parameters influence the properties of the porous stainless steel. The sintering temperature significantly affects volumetric shrinkage. Volumetric shrinkage decreases as the volume fraction of glycine increases to 30% whereas sintering temperature 1150 °C and holding time 90 min will increase the volumetric shrinkage. The compressive yield strength and corresponding elastic modulus are in the ranges of 22.9 to 57.6 MPa and 6.3 to 26.8 GPa, respectively. The samples produced have potential biomedical applications because their mechanical properties, yield strength and elastic modulus match those of human bones

Physiologically Relevant Alternative Carbon Sources Modulate Biofilm Formation, Cell Wall Architecture and the Stress and Antifungal Resistance of Candida glabrata

Acknowledgments: This study was funded by Fundamental Research Grant Scheme (FRGS) from Ministry of Education (MOE), Malaysia (Grant number: 01-01-14-1456FR). S.Y.C. is a recipient of the MyBrain 15 Scholarship from MOE, Malaysia. AB was supported by the UK Medical Research Council (www.mrc.ac.uk: MR/M026663/1), the Medical Research Council Centre for Medical Mycology (MR/N006364/1), the Wellcome Trust (www.wellcome.ac.uk: 097377), and the European Commission (FunHoMic: H2020-MSCA-ITN-2018-812969)Peer reviewedPublisher PD

Glyoxylate cycle gene ICL1 is essential for the metabolic flexibility and virulence of Candida glabrata

We would like to acknowledge Professor Karl Kuchler from Medical University of Vienna for the kind gifts of C. glabrata strains used in this study. This study was funded by Fundamental Research Grant Scheme (FRGS) from Ministry of Education (MOE), Malaysia (Grant number: 01-01-14-1456FR). S.Y. is a recipient of the MyBrain 15 Scholarship from MOE, Malaysia. A.B. was supported by the Medical Research Council Centre for Medical Mycology at the University of Aberdeen (MR/N006364/1), by a programme grant from the UK Medical Research Council (MR/M026663/1), by a Strategic Award from the Wellcome Trust (097377) and by a grant from the UK Biotechnology and Biological Sciences Research Council (BB/P020119/1).Peer reviewedPublisher PD

Harnessing Diesel-Degrading Potential of an Antarctic Microalga from Greenwich Island and Its Physiological Adaptation

Phytoremediation is a plant-based approach to extract, stabilise, eliminate, or render pollutants into less harmful form. The study highlights the use of a native polar microalga as a means of phytoremediation in Antarctica where imported microbes are prohibited. Since 1959, Antarctica has been a protected region to preserve its dynamic ecosystems, but it is increasingly vulnerable to climate change and pollution. One of the anthropogenic disturbances in the continent is diesel spillage. Due to the extreme polar environment, natural attenuation of spilled diesel is severely hindered; hence, the problem calls for an effective and sustainable solution. This laboratory study proved that Antarctic microalga was capable of removing diesel (57.6%) through biodegradation and biosorption in the span of nine days. Meanwhile, mixotrophic cultivation triggered the vacuolar activities and potentially stimulated lipid assimilation in the cells. The microalgal-based process offers a cheap alternative in water decontamination while bearing the economic potential through the secretion of valuable products, such as biolipids

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities