Displaying publications 61 - 80 of 106 in total

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  1. Fulltext Enhanced caffeine degradation by immobilised cells of Leifsonia sp. strain SIU
    Ibrahim S, Shukor MY, Syed MA, Johari WL, Shamaan NA, Sabullah MK, et al.
    J Gen Appl Microbiol, 2016;62(1):18-24.
    PMID: 26923127 DOI: 10.2323/jgam.62.18
    In a previous study, we isolated Leifsonia sp. strain SIU, a new bacterium from agricultured soil. The bacterium was tested for its ability to degrade caffeine. The isolate was encapsulated in gellan gum and its ability to degrade caffeine was compared with the free cells. The optimal caffeine degradation was attained at a gellan gum concentration of 0.75% (w/v), a bead size of 4 mm diameter, and 250 beads per 100 mL of medium. At a caffeine concentration of 0.1 g/L, immobilised cells of the strain SIU degraded caffeine within 9 h, which is faster when compared to the case of free cells, in which it took 12 h to degrade. The immobilised cells degraded caffeine completely within 39 and 78 h at 0.5 and 1.0 g/L, while the free cells took 72 and 148 h at 0.5 and 1.0 g/L, respectively. At higher caffeine concentrations, immobilised cells exhibited a higher caffeine degradation rate. At concentrations of 1.5 and 2.0 g/L, caffeine-degrading activities of both immobilised and free cells were inhibited. The immobilised cells showed no loss in caffeine-degrading activity after being used repeatedly for nine 24-h cycles. The effect of heavy metals on immobilised cells was also tested. This study showed an increase in caffeine degradation efficiency when the cells were encapsulated in gellan gum.
  2. Fulltext Biosurfactant Production and Growth Kinetics Studies of the Waste Canola Oil-Degrading Bacterium Rhodococcuserythropolis AQ5-07 from Antarctica
    Ibrahim S, Abdul Khalil K, Zahri KNM, Gomez-Fuentes C, Convey P, Zulkharnain A, et al.
    Molecules, 2020 Aug 26;25(17).
    PMID: 32858796 DOI: 10.3390/molecules25173878
    With the progressive increase in human activities in the Antarctic region, the possibility of domestic oil spillage also increases. Developing means for the removal of oils, such as canola oil, from the environment and waste "grey" water using biological approaches is therefore desirable, since the thermal process of oil degradation is expensive and ineffective. Thus, in this study an indigenous cold-adapted Antarctic soil bacterium, Rhodococcus erythropolis strain AQ5-07, was screened for biosurfactant production ability using the multiple approaches of blood haemolysis, surface tension, emulsification index, oil spreading, drop collapse and "MATH" assay for cellular hydrophobicity. The growth kinetics of the bacterium containing different canola oil concentration was studied. The strain showed β-haemolysis on blood agar with a high emulsification index and low surface tension value of 91.5% and 25.14 mN/m, respectively. Of the models tested, the Haldane model provided the best description of the growth kinetics, although several models were similar in performance. Parameters obtained from the modelling were the maximum specific growth rate (qmax), concentration of substrate at the half maximum specific growth rate, Ks% (v/v) and the inhibition constant Ki% (v/v), with values of 0.142 h-1, 7.743% (v/v) and 0.399% (v/v), respectively. These biological coefficients are useful in predicting growth conditions for batch studies, and also relevant to "in field" bioremediation strategies where the concentration of oil might need to be diluted to non-toxic levels prior to remediation. Biosurfactants can also have application in enhanced oil recovery (EOR) under different environmental conditions.
  3. Fulltext A novel DNA nanosensor based on CdSe/ZnS quantum dots and synthesized Fe3O4 magnetic nanoparticles
    Hushiarian R, Yusof NA, Abdullah AH, Ahmad SA, Dutse SW
    Molecules, 2014 Apr 09;19(4):4355-68.
    PMID: 24722589 DOI: 10.3390/molecules19044355
    Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4) nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.
  4. Neuroprotective and antioxidant effect of Curcuma longa (Rhizome) methanolic extract on SH-SY5Y cells and Javanese medaka
    Hassan IM, Wan Ibrahim WN, Yusuf FM, Ahmad SA, Ahmad S
    Pak J Pharm Sci, 2021 Jan;34(1):47-56.
    PMID: 34248002
    Diseases caused by oxidative stress can be prevented by antioxidant. Current treatments for those neurodegenerative diseases are not effective and cause many side effects. Thus, the search for alternative medicines is in high demand. Therefore, the main purposed of this study is to evaluate the neuroprotective effects of Curcuma longa (rhizome) 80% methanol extract. Antioxidant using dichlorofuoresence diacetate (DCF-DA) assay on SH-SY5Y cells revealed high activities of Curcuma longa (rhizome) extract with IC50 of 105.9±0.8 µg/mL. Sub-acute and chronic toxicity tests of the plant extract on adult Javanese medaka (Oryzias javanicus) showed high toxicity effect with LC50 of 24.15±0.8 mg/L and 13.69±0.7 mg/L respectively. Neuroprotective tests using cholinesterase assay disclose significant differences at P<0.05 between the group that are exposed to arsenic and treated with the crude extract and the group that are exposed to only arsenic. Identification of vitexin and isovitexin justified the high antioxidant potential of this plant leaf and it highest benefit to be used as medicinal supplement.
  5. Fulltext Biochemical Constituent of Ginkgo biloba (Seed) 80% Methanol Extract Inhibits Cholinesterase Enzymes in Javanese Medaka (Oryzias javanicus) Model
    Hassan I, Wan Ibrahim WN, Yusuf FM, Ahmad SA, Ahmad S
    J Toxicol, 2020;2020:8815313.
    PMID: 33029137 DOI: 10.1155/2020/8815313
    Background: Pathophysiological changes leading to the death of nerve cells present in the brain and spinal cord are referred to as neurodegenerative diseases. Presently, treatment of these diseases is not effective and encounters many challenges due to the cost of drug and side effects. Thus, the search for the alternative agents to replace synthetic drugs is in high demand. Therefore, the aim of this study is to evaluate the anticholinesterase properties of Ginkgo biloba seed.

    Methods: The seed was extracted with 80% methanol. Toxicity studies and evaluation of anticholinesterase activities were carried out in adult Javanese medaka (Oryzias javanicus). Phytochemical study to identify the bioactive lead constituents of the crude extract was also carried out using high performance liquid chromatography (HPLC).

    Results: The result shows activities with high significant differences at P < 0.001 between the treated and nontreated groups. A bioactive compound (vitaxin) was identified with the aid of HPLC method.

    Conclusion: The presence of bioactive compound vitaxin is among the major secondary metabolites that contribute to increasing activities of this plant extract. High anticholinesterase activities and low toxicity effect of this plant show its benefit to be used as natural medicine or supplements.

  6. Fulltext Genotype-phenotype association of Hbe/β thalassemia disease and the role of genetic modifiers
    HanafI S, Abdullah WZ, Adnan RA, Bahar R, Johan MF, Azman NF, et al.
    Malaysian Journal of Paediatrics and Child Health, 2016;22(1):1-16.
    MyJurnal
    HbE/β-thalassemia is the most common severe form of thalassemia particularly in SEA region including Malaysia and globally, it comprised of a significant severe form of β-thalassemia disorder. It has various clinical manifestations ranging from very mild anemia to severe manifestation similar to beta thalassemia major. Many different syndromes are observed in HbE/β-thalassemia. Several genetic modifiers have been reported to play important role in contributing to phenotypic variability. The true reasons underlying this phenotypic variability remain unknown. The most reliable predictive factor of the disease phenotype is the nature of the beta globin gene mutation itself. However, the degree of severity is also believed to be affected by other genetic modifiers. For instance, high HbF level ameliorates the clinical severity of β thalassemia patients. Therefore, identification of these genetic modifiers is very important. The association of severe clinical manifestation and the specific β-globin gene mutation has been known. But the wide scope and other potential predictors have been only recently appreciated. This review therefore aimed to reveal the potential genetic modifiers of HbE/βthalassemia patients based on the previous reported studies. A better understanding on the mechanisms underlying the variety of phenotypes of this disease may lead to the direction for a better future management plans. This also promotes “personalized medicine” in patient care.
  7. Investigating the performance of an amplitude-independent algorithm for detecting the hand muscle activity of stroke survivors
    Hameed HK, Wan Hasan WZ, Shafie S, Ahmad SA, Jaafar H, Inche Mat LN
    J Med Eng Technol, 2020 Apr;44(3):139-148.
    PMID: 32396756 DOI: 10.1080/03091902.2020.1753838
    To make robotic hand devices controlled by surface electromyography (sEMG) signals feasible and practical tools for assisting patients with hand impairments, the problems that prevent these devices from being widely used have to be overcome. The most significant problem is the involuntary amplitude variation of the sEMG signals due to the movement of electrodes during forearm motion. Moreover, for patients who have had a stroke or another neurological disease, the muscle activity of the impaired hand is weak and has a low signal-to-noise ratio (SNR). Thus, muscle activity detection methods intended for controlling robotic hand devices should not depend mainly on the amplitude characteristics of the sEMG signal in the detection process, and they need to be more reliable for sEMG signals that have a low SNR. Since amplitude-independent muscle activity detection methods meet these requirements, this paper investigates the performance of such a method on people who have had a stroke in terms of the detection of weak muscle activity and resistance to false alarms caused by the involuntary amplitude variation of sEMG signals; these two parameters are very important for achieving the reliable control of robotic hand devices intended for people with disabilities. A comparison between the performance of an amplitude-independent muscle activity detection algorithm and three amplitude-dependent algorithms was conducted by using sEMG signals recorded from six hemiparesis stroke survivors and from six healthy subjects. The results showed that the amplitude-independent algorithm performed better in terms of detecting weak muscle activity and resisting false alarms.
  8. Fulltext Hexavalent molybdenum reduction to mo-blue by a sodium-dodecyl-sulfate-degrading Klebsiella oxytoca strain DRY14
    Halmi MI, Zuhainis SW, Yusof MT, Shaharuddin NA, Helmi W, Shukor Y, et al.
    Biomed Res Int, 2013;2013:384541.
    PMID: 24383052 DOI: 10.1155/2013/384541
    Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant.
  9. Fulltext Production of Lipopeptide Biosurfactant by a Hydrocarbon-Degrading Antarctic Rhodococcus
    Habib S, Ahmad SA, Wan Johari WL, Abd Shukor MY, Alias SA, Smykla J, et al.
    Int J Mol Sci, 2020 Aug 26;21(17).
    PMID: 32858859 DOI: 10.3390/ijms21176138
    Rhodococci are renowned for their great metabolic repertoire partly because of their numerous putative pathways for large number of specialized metabolites such as biosurfactant. Screening and genome-based assessment for the capacity to produce surface-active molecules was conducted on Rhodococcus sp. ADL36, a diesel-degrading Antarctic bacterium. The strain showed a positive bacterial adhesion to hydrocarbon (BATH) assay, drop collapse test, oil displacement activity, microplate assay, maximal emulsification index at 45% and ability to reduce water surface tension to < 30 mN/m. The evaluation of the cell-free supernatant demonstrated its high stability across the temperature, pH and salinity gradient although no correlation was found between the surface and emulsification activity. Based on the positive relationship between the assessment of macromolecules content and infrared analysis, the extracted biosurfactant synthesized was classified as a lipopeptide. Prediction of the secondary metabolites in the non-ribosomal peptide synthetase (NRPS) clusters suggested the likelihood of the surface-active lipopeptide production in the strain's genomic data. This is the third report of surface-active lipopeptide producers from this phylotype and the first from the polar region. The lipopeptide synthesized by ADL36 has the prospect to be an Antarctic remediation tool while furnishing a distinctive natural product for biotechnological application and research.
  10. Fulltext Evaluation of conventional and response surface level optimisation of n-dodecane (n-C12) mineralisation by psychrotolerant strains isolated from pristine soil at Southern Victoria Island, Antarctica
    Habib S, Ahmad SA, Johari WLW, Shukor MYA, Alias SA, Khalil KA, et al.
    Microb Cell Fact, 2018 Mar 17;17(1):44.
    PMID: 29549881 DOI: 10.1186/s12934-018-0889-8
    BACKGROUND: Biodegradation of hydrocarbons in Antarctic soil has been reported to be achieved through the utilisation of indigenous cold-adapted microorganisms. Although numerous bacteria isolated from hydrocarbon-contaminated sites in Antarctica were able to demonstrate promising outcomes in utilising hydrocarbon components as their energy source, reports on the utilisation of hydrocarbons by strains isolated from pristine Antarctic soil are scarce. In the present work, two psychrotolerant strains isolated from Antarctic pristine soil with the competency to utilise diesel fuel as the sole carbon source were identified and optimised through conventional and response surface method.

    RESULTS: Two potent hydrocarbon-degraders (ADL15 and ADL36) were identified via partial 16S rRNA gene sequence analysis, and revealed to be closely related to the genus Pseudomonas and Rhodococcus sp., respectively. Factors affecting diesel degradation such as temperature, hydrocarbon concentration, pH and salt tolerance were studied. Although strain ADL36 was able to withstand a higher concentration of diesel than strain ADL15, both strains showed similar optimal condition for the cell's growth at pH 7.0 and 1.0% (w/v) NaCl at the conventional 'one-factor-at-a-time' level. Both strains were observed to be psychrotrophs with optimal temperatures of 20 °C. Qualitative and quantitative analysis were performed with a gas chromatograph equipped with a flame ionisation detector to measure the reduction of n-alkane components in diesel. In the pre-screening medium, strain ADL36 showed 83.75% of n-dodecane mineralisation while the reduction of n-dodecane by strain ADL15 was merely at 22.39%. The optimised condition for n-dodecane mineralisation predicted through response surface methodology enhanced the reduction of n-dodecane to 99.89 and 38.32% for strain ADL36 and strain ADL15, respectively.

    CONCLUSIONS: Strain ADL36 proves to be a better candidate for bioaugmentation operations on sites contaminated with aliphatic hydrocarbons especially in the Antarctic and other cold regions. The results obtained throughout strongly supports the use of RSM for medium optimisation.

  11. Fulltext Inertial Sensor-Based Instrumented Cane for Real-Time Walking Cane Kinematics Estimation
    Fernandez IG, Ahmad SA, Wada C
    Sensors (Basel), 2020 Aug 19;20(17).
    PMID: 32825029 DOI: 10.3390/s20174675
    Falls are among the main causes of injuries in elderly individuals. Balance and mobility impairment are major indicators of fall risk in this group. The objective of this research was to develop a fall risk feedback system that operates in real time using an inertial sensor-based instrumented cane. Based on inertial sensor data, the proposed system estimates the kinematics (contact phase and orientation) of the cane. First, the contact phase of the cane was estimated by a convolutional neural network. Next, various algorithms for the cane orientation estimation were compared and validated using an optical motion capture system. The proposed cane contact phase prediction model achieved higher accuracy than the previous models. In the cane orientation estimation, the Madgwick filter yielded the best results overall. Finally, the proposed system was able to estimate both the contact phase and orientation in real time in a single-board computer.
  12. Fulltext The Mechanistic Action of Biosynthesised Silver Nanoparticles and Its Application in Aquaculture and Livestock Industries
    De Silva C, Nawawi NM, Abd Karim MM, Abd Gani S, Masarudin MJ, Gunasekaran B, et al.
    Animals (Basel), 2021 Jul 14;11(7).
    PMID: 34359224 DOI: 10.3390/ani11072097
    Nanotechnology is a rapidly developing field due to the emergence of various resistant pathogens and the failure of commercial methods of treatment. AgNPs have emerged as one of the best nanotechnology metal nanoparticles due to their large surface-to-volume ratio and success and efficiency in combating various pathogens over the years, with the biological method of synthesis being the most effective and environmentally friendly method. The primary mode of action of AgNPs against pathogens are via their cytotoxicity, which is influenced by the size and shape of the nanoparticles. The cytotoxicity of the AgNPs gives rise to various theorized mechanisms of action of AgNPs against pathogens such as activation of reactive oxygen species, attachment to cellular membranes, intracellular damage and inducing the viable but non-culturable state (VBNC) of pathogens. This review will be centred on the various theorized mechanisms of actions and its application in the aquaculture, livestock and poultry industries. The application of AgNPs in aquaculture is focused around water treatment, disease control and aquatic nutrition, and in the livestock application it is focused on livestock and poultry.
  13. Fulltext Antarctic heavy metal pollution and remediation efforts: state of the art of research and scientific publications
    Darham S, Zakaria NN, Zulkharnain A, Sabri S, Khalil KA, Merican F, et al.
    Braz J Microbiol, 2023 Sep;54(3):2011-2026.
    PMID: 36973583 DOI: 10.1007/s42770-023-00949-9
    In Antarctica, human activities have been reported to be the major cause of the accumulation of heavy metal contaminants. A comprehensive bibliometric analysis of publications on heavy metal contamination in Antarctica from year 2000 to 2020 was performed to obtain an overview of the current landscape in this line of research. A total of 106 documents were obtained from Scopus, the largest citation database. Extracted data were analysed, and VOSviewer software was used to visualise trends. The result showed an increase in publications and citations in the past 20 years indicating the rising interest on heavy metal contamination in the Antarctic region. Based on the analysis of keywords, the publications largely discuss various types of heavy metals found in the Antarctic water and sediment. The analysis on subject areas detects multiple disciplines involved, wherein the environmental science was well-represented. The top countries and authors producing the most publication in this field were from Australia, China, Brazil and Chile. Numerous efforts have been exercised to investigate heavy metal pollution and its mitigation approaches in the region in the past decades. This paper not only is relevant for scholars to understand the development status and trends in this field but also offers clear insights on the future direction of Antarctic heavy metal contamination and remediation research.
  14. A proposed aerobic granules size development scheme for aerobic granulation process
    Dahalan FA, Abdullah N, Yuzir A, Olsson G, Salmiati, Hamdzah M, et al.
    Bioresour Technol, 2015 Apr;181:291-6.
    PMID: 25661308 DOI: 10.1016/j.biortech.2015.01.062
    Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.
  15. Chicken feather valorization by thermal alkaline pretreatment followed by enzymatic hydrolysis for protein-rich hydrolysate production
    Cheong CW, Lee YS, Ahmad SA, Ooi PT, Phang LY
    Waste Manag, 2018 Sep;79:658-666.
    PMID: 30343798 DOI: 10.1016/j.wasman.2018.08.029
    A huge amount of feathers is generated as a waste every year. Feathers can be a protein source if it is treated with an appropriate method. The present study investigates feasibility of autoclave alkaline and microwave alkaline pretreatments to be combined with enzymatic treatment for feather solubilization and protein production. Hydrolysis of chicken feather by autoclave alkaline pretreatment followed by an enzymatic method (AAS) or microwave alkaline pretreatment followed by an enzymatic method (MAS) was optimized by response surface methodology. Various NaOH concentrations for autoclave alkaline pretreatment (0.01-0.1 M) and microwave-alkaline pretreatment (0.01-0.05 M) were applied. The holding time for both pretreatments ranged from 1 to 10 min. The pretreated feathers were subjected to enzymatic hydrolysis using a commercial enzyme prior to analysis of protein content, feather solubilization, functional groups, and elemental composition (carbon, hydrogen, nitrogen and sulfur) of the treated feathers. The results revealed that both autoclave alkaline pretreatment and microwave alkaline pretreatment under optimized conditions of 0.068 M NaOH, 2 min holding time, 105 °C and 450 W, 0.05 M NaOH for 10 min, respectively, enhanced the subsequent Savinase hydrolysis of chicken feathers to achieve more than 80% degradation and more than 70% protein recovery. Fourier transform infrared spectroscopy results showed that both thermal-alkaline pretreatments weakened the structure of the feather. Reduction of carbon, nitrogen, and sulfur occurred in both thermal-alkaline pretreatments of feathers indicating degradation of the feather as well as protein release. Thermal-alkaline pretreatment may be a promising method for enhancing the enzymatic hydrolysis of chicken feathers and for producing a protein-rich hydrolysate.
  16. Characterization of surface electromyography using time domain features for determining hand motion and stages of contraction
    Bin Ahmad Nadzri AA, Ahmad SA, Marhaban MH, Jaafar H
    Australas Phys Eng Sci Med, 2014 Mar;37(1):133-7.
    PMID: 24443218 DOI: 10.1007/s13246-014-0243-3
    Surface electromyography (SEMG) signals can provide important information for prosthetic hand control application. In this study, time domain (TD) features were used in extracting information from the SEMG signal in determining hand motions and stages of contraction (start, middle and end). Data were collected from ten healthy subjects. Two muscles, which are flexor carpi ulnaris (FCU) and extensor carpi radialis (ECR) were assessed during three hand motions of wrist flexion (WF), wrist extension (WE) and co-contraction (CC). The SEMG signals were first segmented into 132.5 ms windows, full wave rectified and filtered with a 6 Hz low pass Butterworth filter. Five TD features of mean absolute value, variance, root mean square, integrated absolute value and waveform length were used for feature extraction and subsequently patterns were determined. It is concluded that the TD features that were used are able to differentiate hand motions. However, for the stages of contraction determination, although there were patterns observed, it is determined that the stages could not be properly be differentiated due to the variability of signal strengths between subjects.
  17. Fulltext HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia
    Baskaran G, Salvamani S, Ahmad SA, Shaharuddin NA, Pattiram PD, Shukor MY
    Drug Des Devel Ther, 2015;9:509-17.
    PMID: 25609924 DOI: 10.2147/DDDT.S75056
    The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.
  18. Fulltext Hypocholesterolemic and Antiatherosclerotic Potential of Basella alba Leaf Extract in Hypercholesterolemia-Induced Rabbits
    Baskaran G, Salvamani S, Azlan A, Ahmad SA, Yeap SK, Shukor MY
    Evid Based Complement Alternat Med, 2015;2015:751714.
    PMID: 26697097 DOI: 10.1155/2015/751714
    Hypercholesterolemia is the major risk factor that leads to atherosclerosis. Nowadays, alternative treatment using medicinal plants gained much attention since the usage of statins leads to adverse health effects, especially liver and muscle toxicity. This study was designed to investigate the hypocholesterolemic and antiatherosclerotic effects of Basella alba (B. alba) using hypercholesterolemia-induced rabbits. Twenty New Zealand white rabbits were divided into 5 groups and fed with varying diets: normal diet, 2% high cholesterol diet (HCD), 2% HCD + 10 mg/kg simvastatin, 2% HCD + 100 mg/kg B. alba extract, and 2% HCD + 200 mg/kg B. alba extract, respectively. The treatment with B. alba extract significantly lowered the levels of total cholesterol, LDL, and triglycerides and increased HDL and antioxidant enzymes (SOD and GPx) levels. The elevated levels of liver enzymes (AST and ALT) and creatine kinase were noted in hypercholesterolemic and statin treated groups indicating liver and muscle injuries. Treatment with B. alba extract also significantly suppressed the aortic plaque formation and reduced the intima: media ratio as observed in simvastatin-treated group. This is the first in vivo study on B. alba that suggests its potential as an alternative therapeutic agent for hypercholesterolemia and atherosclerosis.
  19. In vivo and in vitro effects on cholinesterase of blood of Oreochromis mossambicus by copper
    Basirun AA, Ahmad SA, Sabullah MK, Yasid NA, Daud HM, Khalid A, et al.
    3 Biotech, 2019 Feb;9(2):64.
    PMID: 30729088 DOI: 10.1007/s13205-019-1592-0
    The present study is aimed to evaluate the effects of sub-acute toxicity testing of copper sulphate (CuSO4), on behavioural, histological and biochemical changes of the Oreochromis mossambicus (black tilapia) blood tissues. The effects were assessed according to the previous results on sub-acute toxicity test after exposing fish to several concentrations (0.0, 2.5, 5.0, and 10.0 mg/L). The observations of scanning electron microscope, and transmission electron microscope studies revealed severe histopathological changes on the surface and the cellular changes in blood tissues, respectively. The morphological alterations in blood involved irregular structure of red blood cell and blood clot formation. CuSO4 affected the biochemical alteration of the blood cholinesterase also known as serum cholinesterase (ChE). Blood ChE inhibited up to 80% of activity when exposed to 10.0 mg/L CuSO4. The findings from this study can further improve the quality standards of aquaculture industry and the fundamental basis in selecting suitable strains among freshwater fish species to be used as bioindicator.
  20. Fulltext Enhancement the electrochemical conductivity of a modified reduced graphene oxide/calixarene screen-printed electrode using response surface methodology
    Azman NZM, Zainal PNS, Alang Ahmad SA
    PLoS One, 2020;15(6):e0234148.
    PMID: 32502185 DOI: 10.1371/journal.pone.0234148
    In this paper, Response Surface Methodology with central composite design (RSM/CCD) was used to optimize a modified electrode for improved electron transfer rate and electrochemical performance. The modification was done on a screen-printed carbon electrode (SPCE) with reduced graphene oxide (ERGO)/calix [4] arene (ERGOC4-SPCE). The properties of the modified electrodes were analyzed via cyclic voltammetry, Raman spectroscopy, and Fourier-Transform Infrared (FT-IR) spectroscopy. Then, different variables were optimized, namely, the concentration of graphene oxide, GO (A), the number of scan cycles of graphene oxide (B), and the deposition time (C). The effect of the optimized variables on the reduction-oxidation peak current response of the potassium ferricyanide redox system was analyzed. By using statistical analysis, it shows a significant effect of the concentration of GO, the deposition time, and the number of scans cycles on the peak current response. The coefficient of determination (R2) value of 0.9987 produced indicated a good fit of the model with experimental finding.
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