Displaying publications 1 - 20 of 225 in total

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  1. Chen Y, Ahmad M
    Future Oncol, 2018 Jun;14(15):1487-1496.
    PMID: 29767550 DOI: 10.2217/fon-2017-0671
    Psychotherapies were offered to alleviate psychological and physical symptoms; however, most psychological interventions were only delivered after cancer treatment. Newly diagnosed cancer patients experienced psychological distress while waiting for treatments. This review paper focused on randomized control trial studies, aimed to investigate the effectiveness of psychological intervention among newly diagnosed cancer patients. Eight randomized control trial papers were found in recent 10 year period through electronic database. A moderate to large effect size was detected on the outcomes, ranging from 0.43 to 0.89. This indicated that psychological-based prehabilitation with standard care yielded better outcomes than standard care alone. Psychological-based prehabilitation provides evidence in its effectiveness to reduce psychological distress, functional impairment, recurrence of cancer, numbers of immune reactivity and sleeping quality; however, inconsistent with longer survival result among cancer patients. In conclusion, psychological-based prehabilitation before cancer treatment is necessary for better treatment outcome, and future research is needed to investigate more directly the outcome.
  2. Chen YP, Sudderuddin KI
    PMID: 749224
    Toxicity tests carried out on the larvae of A. aegypti and C. quinquefasciatus showed the former to be more tolerant of all insecticides tested, the order of toxicity being temephos greater than DDT greater than DDVP greater than malathion greater than lindane greater than carbaryl; also the second instar larvae of A. aegypti were more susceptible than fourth instar larvae. Enzyme kinetic studies on the total non-specific esterases and CarEs of adults and larvae of both species showed the Km values for total esterases of adult A. aegypti to be 0.333 mM vs 0.233 mM for C. quinquefasciatus; for adult CarEs it was 0.250 mM vs 0.220 mM. For total larval esterases of A. aegypti it was 0.112 mM vs 0.175 mM for C. quinquefasciatus: and for larval CarES it was 0.159 mM vs 0.213 mM respectively. Although some correlation between in vivo toxicity (LD50 values) and in vitro esterase inhibition (I50 values) between species could be discerned, overall correlation could not be established.
  3. Shamsi S, Chen Y, Lim LY
    Int J Pharm, 2015 Nov 10;495(1):194-203.
    PMID: 26319630 DOI: 10.1016/j.ijpharm.2015.08.066
    Curcumin (CUR) has been formulated into a host of nano-sized formulations in a bid to improve its in vivo solubility, stability and bioavailability. The aim of this study was to investigate whether the encapsulation of CUR in nanocarriers would impede its biological interactivity, specifically its potential anti-cancer adjuvant activity via the modulation of CYP enzymes in vitro. NanoCUR, a micellar dispersion prepared via a thin film method using only Pluronic F127 as excipient, was amenable to lyophilization, and retained its nano-sized spherical dimensions (17-33 nm) upon reconstitution with water followed by dilution to 5 μM with HBSS or EMEM. NanoCUR was a weaker cytotoxic agent compared to CUR in solution (sCUR), affecting HepG2 cell viability only when the incubation time was prolonged from 4h to 48 h. Correlation with 2h uptake data suggests this was due to a lower cellular uptake rate of CUR from NanoCUR than from sCUR. The poorer CUR accessibility might also account for NanoCUR being a weaker inhibitor of CYP2C9 and CYP2D6 than sCUR. NanoCUR was, however, 1.76-fold more potent against the CYP3A4 (IC50 5.13 ± 0.91 μM) metabolic function. The higher activity against CYP3A4 might be attributed to the synergistic action of Pluronic F127, since the blank micellar dispersion also inhibited CYP3A4 activity. Both sCUR and NanoCUR had no effect on the CYP3A4 mRNA levels in the HepG2 cells. NanoCUR therefore, maintained most of the biological activities of CUR in vitro, albeit at a lower potency and response rate.
  4. Sasidharan S, Chen Y, Saravanan D, Sundram KM, Yoga Latha L
    PMID: 22238476
    Natural products from medicinal plants, either as pure compounds or as standardized extracts, provide unlimited opportunities for new drug leads because of the unmatched availability of chemical diversity. Due to an increasing demand for chemical diversity in screening programs, seeking therapeutic drugs from natural products, interest particularly in edible plants has grown throughout the world. Botanicals and herbal preparations for medicinal usage contain various types of bioactive compounds. The focus of this paper is on the analytical methodologies, which include the extraction, isolation and characterization of active ingredients in botanicals and herbal preparations. The common problems and key challenges in the extraction, isolation and characterization of active ingredients in botanicals and herbal preparations are discussed. As extraction is the most important step in the analysis of constituents present in botanicals and herbal preparations, the strengths and weaknesses of different extraction techniques are discussed. The analysis of bioactive compounds present in the plant extracts involving the applications of common phytochemical screening assays, chromatographic techniques such as HPLC and, TLC as well as non-chromatographic techniques such as immunoassay and Fourier Transform Infra Red (FTIR) are discussed.
  5. Chen Y, Lim BK, Hashim OH
    J Hematol Oncol, 2009;2:37.
    PMID: 19709441 DOI: 10.1186/1756-8722-2-37
    The general enhanced expression of alpha1-antichymotrypsin (ACT), clusterin (CLU), alpha1-antitrypsin (AAT), haptoglobin beta-chain (HAP), and leucine rich glycoprotein (LRG) in the sera of patients with epithelial ovarian carcinoma (EOCa) was recently reported. In the present study, we compared the expression of the serum acute-phase proteins (APPs) in the patients according to their stages of cancer.
  6. Shanmugapriya, Chen Y, Kanwar JR, Sasidharan S
    Nutr Cancer, 2017 10 25;69(8):1308-1324.
    PMID: 29068745 DOI: 10.1080/01635581.2017.1367944
    This study was conducted to investigate the anticancer effects and mechanism of Calophyllum inophyllum fruit extract against MCF-7 cells. C. inophyllum fruit extract was found to have markedly cytotoxic effect against MCF-7 cells in a dose-dependent manner with the IC50 for 24 h of 23.59 µg/mL. Flow cytometry analysis revealed that C. inophyllum fruit extract mediated cell cycle at G0/G1 and G2/M phases, and MCF-7 cells entered the early phase of apoptosis. The expression of anti-apoptotic proteins Bcl-2 was decreased whereas the expression of the pro-apoptotic protein Bax, cytochrome C and p53 were increased after treatment. C. inophyllum fruit extract led to apoptosis in MCF-7 cells via the mitochondrial pathway in a dose dependent manner. This is evidenced by the elevation of intracellular ROS, the loss of mitochondria membrane potential (Δψm), and activation of caspase-3. Meanwhile, dose-dependent genomic DNA fragmentation was observed after C. inophyllum fruits extract treatment by comet assay. This study shows that C. inophyllum fruits extract-induced apoptosis is primarily p53 dependent and mediated through the activation of caspase-3. C. inophyllum fruit extract could be an excellent source of chemopreventive agent in the treatment of breast cancer and has potential to be explored as green anticancer agent.
  7. Kirubakari B, Chen Y, Sasidharan S
    PMID: 31113347 DOI: 10.2174/1871523018666190522112902
    BACKGROUND: Polyalthia longifolia is a popular medicinal plant and have been widely used as traditional remedy for centuries in curing of various ailments. The purpose of this study was conducted to determine the in situ antimicrobial synergistic effects between Polyalthia longifolia leaf ethyl acetate fraction (PLEAF) and ampicillin against MRSA local isolate by using modern microscopy technique.

    METHODS: Hence, the evaluation of synergistic activity of PLEAF and ampicillin against MRSA local isolate was conducted with scanning electron microscopy (SEM).

    RESULTS: The combinational effect of PLEAF fraction and ampicillin exhibited a significant antibacterial activity against MRSA. Bacterial cells observations showed invagination, impaired cell division, extensive wrinkles, cell shrinkage, appearance of rougher cell with fibrous matrix and clustered cells which confirmed synergistic effect of PLEAF and ampicillin against MRSA local isolate by SEM.

    CONCLUSION: Conclusively, the in situ SEM observation was proved the synergistic antimicrobial activity between PLEAF fraction and ampicillin to destroy the MRSA resistance bacteria which is an important aspect of PLEAF fraction to be used in the future combinational therapy.

  8. Sumathy V, Zakaria Z, Chen Y, Latha LY, Jothy SL, Vijayarathna S, et al.
    Eur Rev Med Pharmacol Sci, 2013 Jun;17(12):1648-54.
    PMID: 23832733
    Cassia (C.) surattensis Burm. f. (Leguminosae), a medicinal herb native to tropical equatorial Asia, was commonly used in folk medicine to treat various diseases. The aim of the present study is to investigate the effects of methanolic flower extract of C. surattensis against Aspergillus (A.) niger.
  9. Jothy SL, Aziz A, Chen Y, Sasidharan S
    PMID: 23243455 DOI: 10.1155/2012/561284
    In the present study, in vitro antioxidant, free radical scavenging capacity, and hepatoprotective activity of methanol extracts from Polyalthia longifolia and Cassia spectabilis were evaluated using established in vitro models such as ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH(•)), hydroxyl radical (OH(•)), nitric oxide radical (NO(•)) scavenging, metal chelating, and antilipidperoxidation activities. Interestingly, all the extracts showed considerable in vitro antioxidant and free radical scavenging activities in a dose-dependent manner when compared to the standard antioxidant which verified the presence of strong antioxidant compound in leaf extracts tested. Phenolic and flavonoid content of these extracts is significantly correlated with antioxidant capacity. Since P. longifolia extract was exhibited better in vitro antioxidant activities, it was subjected for in vivo hepatoprotective activity in paracetamol-intoxicated mice. Therapy of P. longifolia showed the liver protective effect on biochemical and histopathological alterations. Moreover, histological studies also supported the biochemical finding, that is, the maximum improvement in the histoarchitecture of the liver. Results revealed that P. longifolia leaf extract could protect the liver against paracetamol-induced oxidative damage by possibly increasing the antioxidant protection mechanism in mice. Our findings indicated that P. longifolia and C. spectabilis have potential as good sources of natural antioxidant/antiaging compounds.
  10. Palaeya V, Lau YL, Mahmud R, Chen Y, Fong MY
    Malar. J., 2013;12:182.
    PMID: 23734702 DOI: 10.1186/1475-2875-12-182
    Plasmodium knowlesi is the fifth species identified to cause malaria in humans and is often misdiagnosed as Plasmodium malariae due to morphological similarities. The development of an inexpensive, serological detection method utilizing antibodies specific to P. knowlesi would be a valuable tool for diagnosis. However, the identification of specific antigens for these parasites remains a major challenge for generating such assays. In this study, surface protein containing an altered thrombospondin repeat domain (SPATR) was selected as a potentially specific antigen from P. knowlesi. Its multistage expression by sporozoites, asexual erythrocytic forms and gametocytes, along with its possible role in liver cell invasion, suggests that SPATR could be used as a biomarker for diagnosis of P. knowlesi.
  11. Jothy SL, Zakariah Z, Chen Y, Sasidharan S
    Molecules, 2012 Jun 07;17(6):6997-7009.
    PMID: 22678414 DOI: 10.3390/molecules17066997
    Cassia fistula seeds have many therapeutic uses in traditional medicine practice. The present investigation was undertaken to demonstrate the anticandidal activity of the C. fistula seed extract at ultra-structural level through transmission electron microscope (TEM) and scanning electron microscope (SEM) observations. The effect of seed extract on the growth profile of the Candida albicans was examined via time-kill assays and in vivo efficacy of the extract was tested in an animal model. In addition, the anticandidal effect of seed extract was further evaluated by microscopic observations using SEM and TEM to determine any major alterations in the ultrastructure of C. albicans. The complete inhibition of C. albicans growth was shown by C. fistula seed extract at 6.25 mg/mL concentration. The time-kill assay suggested that C. fistula seed extract had completely inhibited the growth of C. albicans and also exhibited prolonged anti-yeast activity. The SEM and TEM observations carried out to distinguish the metamorphosis in the morphology of control and C. fistula seed extract-treated C. albicans cells revealed the notable effect on the outer cell wall and cytoplasmic content of the C. albicans and complete collapse of yeast cell exposed to seed extract at concentration 6.25 mg/mL at 36 h. The in vitro time-kill study performed using the leaf extract at 1/2, 1 or 2 times of the MIC significantly inhibited the yeast growth with a noticeable drop in optical density (OD) of yeast culture, thus confirming the fungicidal effect of the extract on C. albicans. In addition, in vivo antifungal activity studies on candidiasis in mice showed a 6-fold decrease in C. albicans in kidneys and blood samples in the groups of animals treated with the extract (2.5 g/kg body weight). The results suggested that the C. fistula seed extract possessed good anticandidal activity and is a potential candidate for the development of anticandidal agents.
  12. Goh KL, Chen Y, Chou SM, Listrat A, Bechet D, Wess TJ
    Animal, 2010 Sep;4(9):1613-7.
    PMID: 22444710 DOI: 10.1017/S1751731110000698
    The basic mechanism of reinforcement in tendons addresses the transfer of stress, generated by the deforming proteoglycan (PG)-rich matrix, to the collagen fibrils. Regulating this mechanism involves the interactions of PGs on the fibril with those in the surrounding matrix and between PGs on adjacent fibrils. This understanding is key to establishing new insights on the biomechanics of tendon in various research domains. However, the experimental designs in many studies often involved long sample preparation time. To minimise biological degradation the tendons are usually stored by freezing. Here, we have investigated the effects of commonly used frozen storage temperatures on the mechanical properties of tendons from the tail of a murine model (C57BL6 mouse). Fresh (unfrozen) and thawed samples, frozen at temperatures of -20°C and -80°C, respectively, were stretched to rupture. Freezing at -20°C revealed no effect on the maximum stress (σ), stiffness (E), the corresponding strain (ε) at σ and strain energy densities up to ε (u) and from ε until complete rupture (up). On the other hand, freezing at -80°C led to higher σ, E and u; ε and up were unaffected. The results implicate changes in the long-range order of radially packed collagen molecules in fibrils, resulting in fibril rupture at higher stresses, and changes to the composition of extrafibrillar matrix, resulting in an increase in the interaction energy between fibrils via collagen-bound PGs.
  13. Ping KY, Darah I, Chen Y, Sasidharan S
    Asian Pac J Trop Biomed, 2013 Sep;3(9):692-6.
    PMID: 23998008 DOI: 10.1016/S2221-1691(13)60140-9
    To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta (E. hirta) in MCF-7 cell line model using comet assay.
  14. Jothy SL, Chen Y, Kanwar JR, Sasidharan S
    PMID: 23878610 DOI: 10.1155/2013/925380
    Medicinal plants have been used in medicoculturally diverse countries around the world, where it is a part of a time-honoured tradition that is respected even today. Polyalthia longifolia leaf extract has been previously reported as an efficient antioxidant in vitro. Hence, the genotoxic effects of P. longifolia leaf were investigated by using plasmid relation, comet, and Allium cepa assay. In the presence of   (∙) OH radicals, the DNA in supercoil was start nicked into open circular form, which is the product of the single-stranded cleavage of supercoil DNA and quantified as fragmented separate bands on agarose gel in plasmid relation assay. In the plasmid relation and comet assay, the P. longifolia leaf extract exhibited strong inhibitory effects against H2O2-mediated DNA damage. A dose-dependent increase of chromosome aberrations was also observed in the Allium cepa assay. The abnormalities scored were stickiness, c-mitosis, bridges, and vagrant chromosomes. Micronucleated cells were also observed at the interphase. The results of Allium cepa assay confirmed that the methanol extracts of P. longifolia exerted no significant genotoxic or mitodepressive effects at 100  μ g/mL. Thus, this study demonstrated that P. longifolia leaf extract has a beneficial effect against oxidative DNA damage. This experiment is the first report for the protective effect of P. longifolia on DNA damage-induced by hydroxyl radicals. Additionally in acute oral toxicity study, female rats were treated at 5000 mg/kg body weight of P. longifolia leaf extract and observed for signs of toxicity for 14 days. P. longifolia leaf extract did not produce any treatment-related toxic effects in rats.
  15. Yap SF, Wong PW, Chen YC, Rosmawati M
    PMID: 12118437
    A retrospective study was carried out to determine the frequency of the pre-core stop codon mutant virus in a group of chronic hepatitis B carriers: 81 cases were considered [33 hepatits B e antigen (HBe) positive and 48 HBe negative]. All of the HBe positive cases had detectable viral DNA by hybridization analysis; in the case of the HBe negative cases, one third had detectable viral DNA by hybridization analysis and two thirds had HBV DNA detectable by polymerase chain reaction (PCR) amplification. Pre-core stop codon mutant detection was carried out on all specimens using allele-specific oligonucleotide hybridization following PCR amplification of the target sequence. The pre-core mutant was detected in 13/33 (39.4%) of HBe positive cases and in 32/48 (66.7%) of HBe negative cases. Sequence analysis was carried out on 8 of the 16 HBe negative specimens that did not carry the pre-core mutant virus to determine the molecular basis for the HBe minus phenotype in these cases: the 1762/1764 TA paired mutation in the second AT rich region of the core promoter was detected in five cases; a start codon mutation was detected in one case. The predominant mutation resulting in the HBe minus phenotype in our isolates was the 1896A pre-core ("pre-core stop codon") mutation; other mutations responsible for the phenotype included the core promoter paired mutation and pre-core start codon mutation. In view of the high frequency of the pre-core mutant virus, sequence analysis was performed to determine the virus genotype on the basis of the nucleotide sequence of codon 15. The sequences of 21 wild type virus (14 HBe positive and 7 HBe negative cases) were examined: 15 were found to be codon 15 CCT variants (71.4%); the frequency in the HBe positive group was 12/14 (85.7%), while that in the HBe negative group was 3/7 (42.9%). The high frequency of the codon 15 CCT variant in association with the frequent occurrence of the pre-core mutant in our isolates concurs with the results of other studies.
  16. Liam CK, Chen YC, Yap SF, Srinivas P, Poi PJ
    Respirology, 1998 Jun;3(2):125-9.
    PMID: 9692522
    The objective of this study was to evaluate the utility of a polymerase chain reaction (PCR) assay in detecting Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) specimens of patients suspected of having active pulmonary tuberculosis (TB) but who were sputum smear-negative. Patients undergoing investigation for suspected pulmonary TB at the University Hospital, Kuala Lumpur, and who were sputum smear-negative underwent fibreoptic bronchoscopy and BAL. One portion of each lavage specimen was submitted for smear examination for acid-fast bacilli and mycobacterial culture and the other portion assayed by PCR for the presence of a 562-base pair DNA segment belonging to the insertion sequence IS986, unique to the M. tuberculosis complex. As controls, lavage specimens from patients with other lung lesions were also similarly tested. The PCR assay gave a positivity rate of 80.9% (55 of 68) compared with 8.8% of smear examination and 7.4% of culture for detecting M. tuberculosis in BAL specimens. The assay was positive in two of 45 BAL specimens from 35 control subjects. The PCR assay was more sensitive than smear and culture in detecting M. tuberculosis in BAL specimens of patients with sputum smear-negative pulmonary TB.
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