Displaying publications 21 - 40 of 151 in total

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  1. Li Tsu Chong, Mohd Nizam Kassim, Jane Ivanna Joss, Nurisrahwati Arif, Sherilviana Jukilin
    MyJurnal
    Introduction: The final year of the study period is the time students should be in the mood of ready to enter working life. There are concerned that newly graduated nurses do not have the necessary skills and competence once they enter the working life. The final year nursing students seldom have confidence because they were not getting enough experience in the clinical posting. The soft skill and not being able to perform in the clinical area and their readiness to work in real working life. Thus, this study is to assess final year and newly graduated students’ readiness to enter the real working life environment after graduated from the institution. Methods: This study using cross-sectional sur- vey design using convenience sampling method. Adapted questionnaire is used and distributed via on-line Google form to all final year nursing and newly graduated of nursing students Universiti Malaysia Sabah. Results: Total 71 respondents (63.38% third-year and 21.12% newly graduated students) responded to this survey. 68 students (95%) were ready to enter the real working life and there were two students (5%) that still not ready to perform on their own after the course finished. Majority 70 (98.59%) find that early exposure to a real working environment was important to polish student soft skill and enhance student performance skill in doing any procedure. 96% responded that early exposure will develop student competency in leadership qualities to guide their teamwork and adaptation from the real scenario on how they will perform in their work in the future. Complete facilities in the practical area can make the student feel excited to start working in clinical area is the possible factor rated in more than half of the responded (57.7%). Conclusion: Most of the participant is ready to apply their knowledge and skill in a real working situation.
  2. CHAN KHER ZHI, MOHD NIZAM LANI, MOHD NIZAM LANI, YUSNITA HAMZAH, FAUZIAH TUFAIL AHMAD, HAFIZAH NIK UBAIDILLAH
    MyJurnal
    Kefir is a fermented milk obtained by fermenting milk with kefir grains. The chemical composition ofdairy and non-dairy sources may affect the growth and characterisation of lactic acid bacteria (LAB). In this study, different sources of milk (cow milk) and non-dairy milk (soymilk and coconut milk) were used as the fermentation media for kefir products. The objectives of the study were to isolate and characterise LAB from kefir drink produced from dairy and non-dairy milk. LAB was isolated using different cultural methods, such as MRS Agar, MRS with 0.8% CaCO3, and M17 Agar. The characteristics of the LAB isolates were determined using morphological, biochemical tests and the API 50 CHL kit. The physicochemical composition of the samples was determined using titratable acidity and pH level. Sensory evaluation of the kefir drink samples was also carried out. Results confirmed that the isolates were identified as Lactobacillus buchneri, Lactobacillus brevis 1, Leuconostoc mesenteroides, Lactobacillus acidophilus 3and Lactobacillus plantarum 1. The L. buchneri, L. brevis, Leu. mesenteroides and L. acidophilus are heterofermentative bacteria, whereas L. plantarum is a homofermentative bacterium. Four LAB isolates have the potential to be used as probiotic strains due to their high resistant to low pH and bile salt. The sensory scores of these products range between 5.00 and 8.00 in the 9-point hedonic scale. Most of the sensory panelists preferred cow milk kefir (p < 0.05) compared with coconut milk kefir and soy milk kefir during the sensory evaluation of all attributes. Meanwhile, the preference between coconut milk kefir and soy milk kefir was similar (p>0.05) in all attributes. Therefore, this study will be useful for probiotic manufacturers in the production of alternative probiotic drinks using dairy and non-dairy milk.
  3. AGNES LEE CHIU NEE, MOHD NIZAM LANI, ROZILA ALIAS, ZAITON HASSAN
    MyJurnal
    Vinegars are most widely used as preservatives in food industry. Vinegars are known for their health benefits; however, the roles of vinegar-associated microflora in locally produced vinegars are not well established. The objectives of this study are to isolate and identify the lactic acid bacteria (LAB) from black rice vinegar and coconut vinegar, measure their pH and titratable acidity, and determine their antibacterial activity. LAB was isolated using cultural method. Phenotypic characterization of LAB was carried out using Gram-staining, oxidase test, catalase test and API 50 CHL Kit. Results from API 50 CHL Kit confirmed that BRV03M strain from black rice vinegar and CV03M strain from coconut vinegar were Lactobacillus paracaseissp. paracasei. The identified bacteria in both samples were consistent as L. paracaseiusing 16S rDNAgene sequences with 93% and 99% similarity, respectively. The pH and titratable acidity percentage of both vinegars were also determined. The stability of Cell Free Supernatant-Lactic Acid Bacteria (CFS-LAB) strains within 14 days on their inhibition against selected pathogenic bacteria was determined using agar well diffusion method. The CFS-LAB strain isolated from black rice vinegar (BRV03M) was more stable within 14 days than coconut vinegar in inhibiting tested bacteria, suggesting this strain has great potential as natural antibacterial agents.
  4. Nur Syazwani Mohd Nawi, Baba Md Deros, Mohd Nizam Ab. Rahman, Ezrin Hani Sukadarin, Norani Nordin
    MyJurnal
    Agricultural activities have always been associated with hazards and injuries. Most common injuries experienced by workers are health, safety and ergonomic injuries. It stems from many causes, such as the use of manual tools, incorrect working position, inadequate rest and overloading. This paper aims to reveal the daily hazardous work task of oil palm plantation workers with highlighting the ergonomics problems and risk of injury they faced. Observations of work tasks and distribution of Modified Nordic Questionnaire (MNQ) were performed for every work unit. Worker’s activities and posture while performing work tasks were recorded extensively using camera and video recordings for ergonomics analysis. Results from the observation and questionnaire survey conducted, showed that oil palm plantation workers are exposed to the risk of dangerous work every day. Fresh fruit bunches cutter and loose fruit collectors were having highest body pain complaints and almost from them are having low back pain problems. Therefore, it is necessary for an immediate action from the management in order to determine the current prevalence of ergonomic injuries. Using of manual tools should be avoided and plantation workers should be provided with ergonomics machines that can help them reduce their workload and injuries.
  5. Mohd Nizam Haron, Syahirah Zeti Azham, Lyanna Annura Sallehudin, Nur Firzanie Kamaruddin, Ezreen Elia Izzaty Afindi
    MyJurnal
    The purpose of this study is to retrospectively report the results of scoliosis patients who underwent chiropractic therapy and to evaluate their outcome by looking at the potential to alter the natural progression of scoliosis after therapy.
    Methods: Retrospective data collection was conducted at a private chiropractic centre in Kuala Lumpur. The data was collected from patients between the ages of 16 to 19 years old. A total of eight patients with 14 scoliotic curvatures (six thoracic, six lumbar and two thoracolumbar), who met the inclusion criteria, were selected as subjects for this study. All subjects received the same chiropractic therapy program. The outcome of the therapy was assessed by measuring the Cobb’s angle on the erect spine as captured on an x-ray. The Cobb’s angle was measured at the first presentation (to establish a baseline) after 6 and 24 months of therapy.
    Results: The mean baseline Cobb’s angle for thoracic, lumbar and thoracolumbar scoliosis were 30.70 ± 19.40, 31.70 ± 12.30 and 25.00 ± 18.40 respectively. After 24 months of chiropractic therapy, there was no discernible effect on the magnitude of the Cobb’s angles on the subjects overall.
    Conclusion: Our study showed no significant reduction in spine curvature in patients with scoliosis using chiropractic therapy after 24 months.
  6. Ahmad Sh. A. Lafi, Fahrul Huyop, Jacinta Santhanam, Tzar Mohd Nizam Khaithi
    MyJurnal
    Ergosterol, a component of fungal cell membrane, has been frequently detected as an indicator of fungal presence and mass
    in environmental samples like soil. However, its detection in major pathogenic fungal species has not been investigated.
    In this study, the ergosterol contents of ten pathogenic fungal species were determined. Liquid chromatography was used
    for the detection and quantification of ergosterol extracted from fungal broth cultures. Results showed that ergosterol
    eluted as a single, well resolved peak in the chromatogram profiles of all tested fungi. Based upon relative amounts of
    ergosterol produced per fungal mycelial dry weight, three groups of fungal pathogens were identified, namely low ergosterol
    (Aspergillus niger, Candida albicans and Cryptococcus neoformans at 4.62, 6.29 and 7.08 µg/mg, respectively), medium
    ergosterol (Fusarium solani, Aspergillus fumigatus, Mucor sp., Penicillium sp., Cryptococcus gattii and Rhizopus sp.
    at 9.40, 10.79, 10.82, 11.38, 12.60 and 13.40 µg/mg, respectively), and high ergosterol (Candida tropicalis at 22.84 µg/
    mg), producers. Ergosterol was not detectable in bacterial samples, which were included as controls. This first report on
    ergosterol detection in major pathogenic fungal species indicates that ergosterol may be used as a biomarker to diagnose
    invasive fungal infections in clinical samples.
  7. Jacinta Santhanam, Mohd Hanif Jainlabdin, Ang LC, Tzar Mohd Nizam
    Sains Malaysiana, 2018;47:489-498.
    Invasive fungal infections (IFIs) have risen dramatically in recent years among high risk immunocompromised patients.
    Rapid detection of fungal pathogens is crucial to timely and accurate antifungal therapy. Two multiplex polymerase
    chain reaction (PCR) assays were developed to detect major fungal species that cause invasive infections and identify
    resistant species. Genus specific primers for Candida, Aspergillus, Fusarium and species specific primers for Candida
    glabrata, Candida krusei and Aspergillus terreus which are known to be clinically resistant species, were designed from
    the internal transcribed spacer (ITS) regions of ribosomal ribonucleic acid (rRNA) gene complex. Both assays were
    performed simultaneously to promote rapid detection of fungal isolates based on distinct amplicon sizes. Inclusion of the
    universal fungal primers ITS 1 and ITS 4 in the genus specific assay produced a second amplicon for each isolate which
    served to confirm the detection of a fungal target. The limit of detection for the genus specific assay was 1 nanogram
    (ng) deoxyribonucleic acid (DNA) for Aspergillus fumigatus and Candida albicans, 0.1 ng DNA for Fusarium solani, while
    the species-specific assay detected 0.1 ng DNA of A. terreus and 10 picogram (pg) DNA of C. krusei and C. glabrata. The
    multiplex PCR assays, apart from universal detection of any fungal target, are able to detect clinically important fungi
    and differentiate resistant species rapidly and accurately, which can contribute to timely implementation of effective
    antifungal regime.
  8. Lee-Hoon Ho, Nor Fadhilah Ramli, Norlia Muhamad, Mohd Nizam Haron, Thuan-Chew Tan
    Sains Malaysiana, 2018;47:99-107.
    The objective of the present study was to determine the total phenolic content (TPC), total flavonoid content (TFC) and
    antioxidant properties, i.e. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferric reducing
    antioxidant potential (FRAP) assay, of red- and yellow-fleshed watermelon rind powders prepared using different drying
    conditions (hot-air oven drying at 40 and 60°C and freeze drying). All the samples were subjected to four different
    solvent extract using water, methanol, ethanol and acetone prior analyses. Water extract from red- and yellow-fleshed
    watermelon rind powders presented highest value for TPC and TFC. However, methanol extract samples showed highest
    value for antioxidant properties (DPPH and FRAP) followed by acetone, ethanol and water extract. By comparing the
    drying conditions, all samples dried using hot-air dryer at 40 and 60°C had significantly higher (p<0.05) in TPC value
    than the samples dried using freeze dryer. However, samples dried using freeze dryer showed highest in DPPH and
    FRAP values. The present obtained results would be useful to the food and pharmaceutical industries for developing of
    functional ingredients.
  9. Nazrun AS, Tzar MN, Mokhtar SA, Mohamed IN
    Ther Clin Risk Manag, 2014;10:937-48.
    PMID: 25429224 DOI: 10.2147/TCRM.S72456
    PURPOSE:
    Osteoporotic fracture is the main complication of osteoporosis. The current management is to discharge patients as early as possible so they can get back to their daily activities. Once discharged, there are three main issues relating to morbidity, mortality, and risk of a subsequent fracture that need to be addressed and discussed. Therefore, the aim of this systematic review was to summarize and evaluate the evidence from published literature, to determine the outcome of osteoporotic fracture patients after their hospital discharge.

    METHODS:
    The MEDLINE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were searched, using the terms "osteoporosis", "fracture", "osteoporotic fracture", "hip fracture", and "vertebral fracture". We included only human studies published in English between 2004 and 2014. The reference lists of included studies were thoroughly reviewed in search for other relevant studies.

    RESULTS:
    A total of 18 studies met the selection criteria. Most were observational and cohort studies. Out of all the studies, five studies looked into the morbidity, six studies looked into the risk of subsequent fractures, and seven studies looked into mortality. Vertebral fracture caused the greatest health burden, but hip fracture patients were the main users of informal care after hospital discharge. There was an increased risk of a subsequent fracture after a primary fracture compared with the control group, a cohort comparison, or the general population. Osteoporotic fractures, especially hip fractures, are associated with higher mortality rate despite the advances in the management of osteoporotic fracture cases.

    CONCLUSION:
    There is strong evidence to show that after hospital discharge, osteoporotic fracture patients are faced with higher morbidity, subsequent fractures, and mortality.

    KEYWORDS:
    hip fracture; osteoporosis; vertebral fracture
  10. Goh TB, Koh RY, Mordi MN, Mansor SM
    Asian Pac J Cancer Prev, 2014;15(14):5659-65.
    PMID: 25081682
    BACKGROUND: To investigate the antioxidant value and anticancer functions of mitragynine (MTG) and its silane-reduced analogues (SRM) in vitro.

    MATERIALS AND METHODS: MTG and SRM was analyzed for their reducing power ability, ABTS radical inhibition and 1,1-diphenyl-2-picryl hydrazylfree radicals scavenging activities. Furthermore, the antiproliferation efficacy was evaluated using MTT assay on K 562 and HCT116 cancer cell lines versus NIH/3T3 and CCD18-Co normal cell lines respectively.

    RESULTS: SRM and MTG demonstrate moderate antioxidant value with ABTS assay (Trolox equivalent antioxidant capacity (TEAC): 2.25±0.02 mmol trolox / mmol and 1.96±0.04 mmol trolox / mmol respectively) and DPPH (IC50=3.75±0.04 mg/mL and IC50=2.28±0.02 mg/mL respectively). Both MTG and SRM demonstrate equal potency (IC50=25.20±1.53 and IC50= 22.19±1.06 respectively) towards K 562 cell lines, comparable to control, betulinic acid (BA) (IC5024.40±1.26). Both compounds showed concentration-dependent cytototoxicity effects and exert profound antiproliferative efficacy at concentration > 100 μM towards HCT 116 and K 562 cancer cell lines, comparable to those of BA and 5-FU (5-Fluorouracil). Furthermore, both MTG and SRM exhibit high selectivity towards HCT 116 cell lines with selective indexes of 3.14 and 2.93 respectively compared to 5-FU (SI=0.60).

    CONCLUSIONS: These findings revealed that the medicinal and nutitional values of mitragynine obtained from ketum leaves that growth in tropical forest of Southeast Asia and its analogues does not limited to analgesic properties but could be promising antioxidant and anticancer or chemopreventive compounds.

  11. Ramli SR, Francis AL, Yusof Y, Khaithir TM
    Case Rep Infect Dis, 2013;2013:851875.
    PMID: 24377053 DOI: 10.1155/2013/851875
    A 52-year-old man with diabetes developed a unilateral central corneal ulcer after accidental foreign body inoculation. He complained of pain and loss of visual acuity in the injured eye, which displayed redness and edema and eventually discharged pus. A corneal scraping from the left eye orbit revealed fungal elements, and cultures of the material grew a fungus. The isolate was identified as Arthrographis kalrae based on gross and microscopic morphologies. The patient received amphotericin B intravenously and itraconazole orally. The wound healed following surgical intervention, but the patient lost the use of his left eye.
  12. Ramli R, Abd Rashid AH, Phang KS, Khaithir TM
    Malays J Pathol, 2009 Dec;31(2):143-5.
    PMID: 20514859 MyJurnal
    Sporotrichosis is a mycosis caused by a saprophytic dimorphic fungus named Sporothrix schenckii. Infections occur following traumatic inoculation of fungus from plants and infected cat bites and scratches. We report a case of a farmer who presented with a solitary subcutaneous nodule initially diagnosed as a soft tissue tumour. A history of agricultural activity and feline contact should draw the clinician's attention to sporotrichosis, as the diagnosis can be easily missed in atypical cases. The diagnosis, microbiology and management of the case are discussed.
  13. Ding CH, Wahab AA, Muttaqillah NA, Tzar MN
    J Pak Med Assoc, 2014 Dec;64(12):1375-9.
    PMID: 25842581
    To determine the proportion of albicans and non-albicans candiduria in a hospital setting and to ascertain if fluconazole is still suitable as empirical antifungal therapy based on antifungal susceptibility patterns of Candida species.
  14. Zainuddin N, Jaafart H, Isa MN, Abdullah JM
    Neurol Res, 2004 Jan;26(1):88-92.
    PMID: 14977064
    Recent advances in neuro-oncology have revealed different pathways of molecular oncogenesis in malignant gliomas including loss of heterozygosity on chromosomal regions harboring tumor suppressor genes. In the present study, we performed polymerase chain reaction-loss of heterozygosity (PCR-LOH) analysis using microsatellite markers to identify loss of heterozygosity on chromosomes 10q, 9p, 17p and 13q in the Malays with malignant gliomas. Of 12 cases with allelic losses, seven (58.3%) cases showed LOH on chromosome 10q, three (25.0%) cases showed LOH on chromosome 9p, four (33.3%) cases showed LOH on chromosome 17p and two (16.7%) cases showed LOH on chromosome 13q. The cases include five (41.7%) cases of glioblastoma multiforme, three (25.0%) cases of anaplastic astrocytoma, three (25.0%) cases of anaplastic oligodendroglioma and one (8.3%) case of anaplastic ependymoma. Four cases showed loss of heterozygosity on more than one locus. Our findings showed that loss of heterozygosity on specific chromosomal regions contributes to the molecular pathway of glioma progression in Malay population. In addition, these data provide useful evidence of molecular genetic alterations of malignant glioma in South East Asian patients, particularly in the East Coast of Malaysia.
  15. Zahari N, Mat Bah MN, A Razak H, Thong MK
    Eur J Pediatr, 2019 Aug;178(8):1267-1274.
    PMID: 31222391 DOI: 10.1007/s00431-019-03403-x
    Limited data are available on the survival of patients with Down syndrome and congenital heart disease (CHD) from middle-income countries. This retrospective cohort study was performed to determine the trends in the prevalence and survival of such patients born from January 2006 to December 2015 in Malaysia. Among 754 patients with Down syndrome, 414 (55%) had CHD, and no significant trend was observed during the 10 years. Of these 414 patients, 30% had lesions that closed spontaneously, 35% underwent surgery/intervention, 9% died before surgery/intervention, and 10% were treated with comfort care. The overall mortality rate was 23%, the median age at death was 7.6 months, and no significant changes occurred over time. The early and late post-surgery/intervention mortality rates were 0.7% and 9.0%, respectively. Most deaths were of non-cardiac causes. The overall 1-, 5-, and 10-year survival rates were 85.5%, 74.6%, and 72.9%, respectively. Patients with severe lesions, persistent pulmonary hypertension of the newborn, atrioventricular septal defect, and pulmonary hypertension had low survival at 1 year of age.Conclusion: The prevalence of CHD in patients with Down syndrome is similar between Malaysia and high-income countries. The lower survival rate is attributed to limited expertise and resources which limit timely surgery. What is Known: • The survival of patients with Down syndrome with congenital heart disease (CHD) has improved in high-income countries. However, little is known about the survival of patients with Down syndrome with CHD from middle-income countries. • In the Caucasian population, atrioventricular septal defect is the most common type of CHD associated with Down syndrome. What is New: • In middle-income countries, the prevalence of CHD is the same as in high-income countries, but with a lower survival rate. • In the Asian population, ventricular septal defect is the most common type of CHD in patients with Down syndrome.
  16. Mat Bah MN, Sapian MH, Alias EY
    Ann Pediatr Cardiol, 2020 09 17;13(4):320-326.
    PMID: 33311920 DOI: 10.4103/apc.APC_35_20
    Aims: There are limited data regarding critical congenital heart disease (CCHD) from middle-income countries (MIC). This study aims to determine the birth prevalence, rate of late diagnosis, and influence of timing of diagnosis on the outcome of CCHD.

    Setting and Design: Retrospective observational cohort study in the State of Johor, Malaysia.

    Subjects and Methods: All infants born between January 2006 and December 2015 with a diagnosis of CCHD, defined as infants with duct-dependent lesions or cyanotic heart disease who may die without early intervention. The late diagnosis was defined as a diagnosis of CCHD after 3 days of age.

    Results: Congenital heart disease was diagnosed in 3557 of 531,904 live-born infants and were critical in 668 (18.7%). Of 668, 347 (52%) had duct-dependent pulmonary circulation. The birth prevalence of CCHD was 1.26 (95% confidence interval: 1.16-1.35) per 1000 live births, with no significant increase over time. The median age of diagnosis was 4 days (Q1 1, Q3 26), with 61 (9.1%) detected prenatally, and 342 (51.2%) detected late. The highest rate of late diagnosis was observed in coarctation of the aorta with a rate of 74%. Trend analysis shows a statistically significant reduction of late diagnosis and a significant increase in prenatal detection. However, Cox regression analysis shows the timing of diagnosis does not affect the outcome of CCHD.

    Conclusions: Due to limited resources in the MIC, the late diagnosis of CCHD is high but does not affect the outcome. Nevertheless, the timing of diagnosis has improved over time.

  17. Mat Bah MN, Syed Mohamed SA, Abdullah N, Alias EY
    Pediatr Crit Care Med, 2020 11;21(11):e959-e966.
    PMID: 32590834 DOI: 10.1097/PCC.0000000000002406
    OBJECTIVES: To study the rate of unplanned PICU readmission, determine the risk factors and its impact on mortality.

    DESIGN: A single-center retrospective cross-sectional study.

    SETTING: Tertiary referral PICU in Johor, Malaysia.

    PATIENTS: All children admitted to the PICU over 8 years were included. Patients readmitted into PICU after the first PICU discharge during the hospitalization period were categorized into "early" (within 48 hr) and "late" (after 48 hr), and factors linked to the readmissions were identified. The mortality rate was determined and compared between no, early, and late readmission.

    INTERVENTIONS: None.

    MEASUREMENTS AND MAIN RESULTS: There were 2,834 patients in the study with 70 early and 113 late readmissions. Therefore, the rate of early and late PICU readmission was 2.5% (95% CI, 1.9-3.0%) and 3.9% (95% CI, 3.2-4.7%), respectively. The median length of stay of the second PICU admission for early and late readmissions was 2.7 days (interquartile range, 1.1-7.0 d) and 3.2 days (interquartile range, 1.2-7.5 d), respectively. The majority of early and late readmissions had a similar diagnosis with their first PICU admission. Multivariable multinomial logistic regression revealed a Pediatric Index Mortality 2 score of greater than or equal to 15, chronic cardiovascular condition, and oxygen supplement upon discharge as independent risk factors for early PICU readmission. Meanwhile, an infant of less than 1 year old, having cardiovascular, other congenital and genetic chronic conditions and being discharged between 8 AM and 5 PM was an independent risk factor for late readmission. There was no significant difference in the mortality rate of early (12.9%), late (13.3%), and no readmission (10.7%).

    CONCLUSIONS: Despite the lack of resources and expertise in lower- and middle-income countries, the rate and factors for PICU readmission are similar to those in high-income countries. However, PICU readmission has no statistically significant association with mortality.

  18. Ayipo YO, Mordi MN, Mustapha M, Damodaran T
    Eur J Pharmacol, 2021 Feb 15;893:173837.
    PMID: 33359647 DOI: 10.1016/j.ejphar.2020.173837
    Neuropsychiatric disorders are diseases of the central nervous system (CNS) which are characterised by complex pathomechanisms that including homeostatic failure, malfunction, atrophy, pathology remodelling and reactivity anomaly of the neuronal system where treatment options remain challenging. β-Carboline (βC) alkaloids are scaffolds of structurally diverse tricyclic pyrido[3,4-b]indole alkaloid with vast occurrence in nature. Their unique structural features which favour interactions with enzymes and protein receptor targets account for their potent neuropharmacological properties. However, our current understanding of their biological mechanisms for these beneficial effects, especially for neuropsychiatric disorders is sparse. Therefore, we present a comprehensive review of the scientific progress in the last two decades on the prospective pharmacology and physiology of the βC alkaloids in the treatment of some neuropsychiatric conditions such as depression, anxiety, Alzheimer's disease, Parkinson's disease, brain tumour, essential tremor, epilepsy and seizure, licking behaviour, dystonia, agnosia, spasm, positive ingestive response as demonstrated in non-clinical models. The current evidence supports that βC alkaloids offer potential therapeutic agents against most of these disorders and amenable for further drug design.
  19. Al-Qattan MN, Mordi MN, Mansor SM
    Comput Biol Chem, 2016 10;64:237-249.
    PMID: 27475235 DOI: 10.1016/j.compbiolchem.2016.07.007
    BACKGROUND: Glutathione-s-transferases (GSTs) are enzymes that principally catalyze the conjugation of electrophilic compounds to the endogenous nucleophilic glutathione substrate, besides, they have other non-catalytic functions. The Plasmodium falciparum genome encodes a single isoform of GST (PfGST) which is involved in buffering the toxic heme, thus considered a potential anti-malarial target. In mammals several classes of GSTs are available, each of various isoforms. The human (human GST Pi-1 or hGSTP1) and mouse (murine GST Mu-1 or mGSTM1) GST isoforms control cellular apoptosis by interaction with signaling proteins, thus considered as potential anti-cancer targets. In the course of GSTs inhibitors development, the models of ligands interactions with GSTs are used to guide rational molecular modification. In the absence of X-ray crystallographic data, enzyme kinetics and molecular docking experiments can aid in addressing ligands binding modes to the enzymes.

    METHODS: Kinetic studies were used to investigate the interactions between the three GSTs and each of glutathione, 1-chloro-2,4-dinitrobenzene, cibacron blue, ethacrynic acid, S-hexyl glutathione, hemin and protoporphyrin IX. Since hemin displacement is intended for PfGST inhibitors, the interactions between hemin and other ligands at PfGST binding sites were studied kinetically. Computationally determined binding modes and energies were interlinked with the kinetic results to resolve enzymes-ligands interaction models at atomic level.

    RESULTS: The results showed that hemin and cibacron blue have different binding modes in the three GSTs. Hemin has two binding sites (A and B) with two binding modes at site-A depending on presence of GSH. None of the ligands were able to compete hemin binding to PfGST except ethacrynic acid. Besides bind differently in GSTs, the isolated anthraquinone moiety of cibacron blue is not maintaining sufficient interactions with GSTs to be used as a lead. Similarly, the ethacrynic acid uses water bridges to mediate interactions with GSTs and at least the conjugated form of EA is the true hemin inhibitor, thus EA may not be a suitable lead.

    CONCLUSIONS: Glutathione analogues with bulky substitution at thiol of cysteine moiety or at γ-amino group of γ-glutamine moiety may be the most suitable to provide GST inhibitors with hemin competition.

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