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Fulltext Identification of circulating biomarkers in sera of Plasmodium knowlesi-infected malaria patients--comparison against Plasmodium vivax infection

Chen Y, Chan CK, Kerishnan JP, Lau YL, Wong YL, Gopinath SC

BMC Infect Dis, 2015;15:49.
PMID: 25656928 DOI: 10.1186/s12879-015-0786-2

Plasmodium knowlesi was identified as the fifth major malaria parasite in humans. It presents severe clinical symptoms and leads to mortality as a result of hyperparasitemia in a short period of time. This study aimed to improve the current understanding of P. knowlesi and identify potential biomarkers for knowlesi malaria.
In vitro and in vivo antifungal activity of Cassia surattensis flower against Aspergillus niger

Sumathy V, Zakaria Z, Jothy SL, Gothai S, Vijayarathna S, Yoga Latha L, et al.

Microb Pathog, 2014 Dec;77:7-12.
PMID: 25457794 DOI: 10.1016/j.micpath.2014.10.004

Invasive aspergillosis (IA) in immunocompromised host is a major infectious disease leading to reduce the survival rate of world population. Aspergillus niger is a causative agent causing IA. Cassia surattensis plant is commonly used in rural areas to treat various types of disease. C. surattensis flower extract was evaluated against the systemic aspergillosis model in this study. Qualitative measurement of fungal burden suggested a reduction pattern in the colony forming unit (CFU) of lung, liver, spleen and kidney for the extract treated group. Galactomannan assay assessment showed a decrease of fungal load in the treatment and positive control group with galactomannan index (GMI) value of 1.27 and 0.25 on day 28 but the negative control group showed high level of galactomannan in the serum with GMI value of 3.58. Histopathology examinations of the tissues featured major architecture modifications in the tissues of negative control group. Tissue reparation and recovery from infection were detected in extract treated and positive control group. Time killing fungicidal study of A. niger revealed dependence of the concentration of C. surattensis flower extract.
Fulltext Identification of host-immune response protein candidates in the sera of human oral squamous cell carcinoma patients

Chen Y, Azman SN, Kerishnan JP, Zain RB, Chen YN, Wong YL, et al.

PLoS One, 2014;9(10):e109012.
PMID: 25272005 DOI: 10.1371/journal.pone.0109012

One of the most common cancers worldwide is oral squamous cell carcinoma (OSCC), which is associated with a significant death rate and has been linked to several risk factors. Notably, failure to detect these neoplasms at an early stage represents a fundamental barrier to improving the survival and quality of life of OSCC patients. In the present study, serum samples from OSCC patients (n = 25) and healthy controls (n = 25) were subjected to two-dimensional gel electrophoresis (2-DE) and silver staining in order to identify biomarkers that might allow early diagnosis. In this regard, 2-DE spots corresponding to various up- and down-regulated proteins were sequenced via high-resolution MALDI-TOF mass spectrometry and analyzed using the MASCOT database. We identified the following differentially expressed host-specific proteins within sera from OSCC patients: leucine-rich α2-glycoprotein (LRG), alpha-1-B-glycoprotein (ABG), clusterin (CLU), PRO2044, haptoglobin (HAP), complement C3c (C3), proapolipoprotein A1 (proapo-A1), and retinol-binding protein 4 precursor (RBP4). Moreover, five non-host factors were detected, including bacterial antigens from Acinetobacter lwoffii, Burkholderia multivorans, Myxococcus xanthus, Laribacter hongkongensis, and Streptococcus salivarius. Subsequently, we analyzed the immunogenicity of these proteins using pooled sera from OSCC patients. In this regard, five of these candidate biomarkers were found to be immunoreactive: CLU, HAP, C3, proapo-A1 and RBP4. Taken together, our immunoproteomics approach has identified various serum biomarkers that could facilitate the development of early diagnostic tools for OSCC.
MicroRNAs: biogenesis, roles for carcinogenesis and as potential biomarkers for cancer diagnosis and prognosis

Kavitha N, Vijayarathna S, Jothy SL, Oon CE, Chen Y, Kanwar JR, et al.

Asian Pac J Cancer Prev, 2014;15(18):7489-97.
PMID: 25292018

MicroRNAs (miRNAs) are short non-coding RNAs of 20-24 nucleotides that play important roles in carcinogenesis. Accordingly, miRNAs control numerous cancer-relevant biological events such as cell proliferation, cell cycle control, metabolism and apoptosis. In this review, we summarize the current knowledge and concepts concerning the biogenesis of miRNAs, miRNA roles in cancer and their potential as biomarkers for cancer diagnosis and prognosis including the regulation of key cancer-related pathways, such as cell cycle control and miRNA dysregulation. Moreover, microRNA molecules are already receiving the attention of world researchers as therapeutic targets and agents. Therefore, in-depth knowledge of microRNAs has the potential not only to identify their roles in cancer, but also to exploit them as potential biomarkers for cancer diagnosis and identify therapeutic targets for new drug discovery.
Monitoring recombinant human erythropoietin abuse among athletes

Citartan M, Gopinath SCB, Chen Y, Lakshmipriya T, Tang TH

Biosens Bioelectron, 2015 Jan 15;63:86-98.
PMID: 25058943 DOI: 10.1016/j.bios.2014.06.068

The illegal administration of recombinant human erythropoietin (rHuEPO) among athletes is largely preferred over blood doping to enhance stamina. The advent of recombinant DNA technology allowed the expression of EPO-encoding genes in several eukaryotic hosts to produce rHuEPO, and today these performance-enhancing drugs are readily available. As a mimetic of endogenous EPO (eEPO), rHuEPO augments the oxygen carrying capacity of blood. Thus, monitoring the illicit use of rHuEPO among athletes is crucial in ensuring an even playing field and maintaining the welfare of athletes. A number of rHuEPO detection methods currently exist, including measurement of hematologic parameters, gene-based detection methods, glycomics, use of peptide markers, electrophoresis, isoelectric focusing (IEF)-double immunoblotting, aptamer/antibody-based methods, and lateral flow tests. This review gleans these different strategies and highlights the leading molecular recognition elements that have potential roles in rHuEPO doping detection.
MicroRNA pathways: an emerging role in identification of therapeutic strategies

Vijayarathna S, Oon CE, Jothy SL, Chen Y, Kanwar JR, Sasidharan S

Curr Gene Ther, 2014;14(2):112-20.
PMID: 24588707

For years researchers have exerted every effort to improve the influential roles of microRNA (miRNA) in regulating genes that direct mammalian cell development and function. In spite of numerous advancements, many facets of miRNA generation remain unresolved due to the perplexing regulatory networks. The biogenesis of miRNA, eminently endures as a mystery as no universal pathway defines or explicates the variegation in the rise of miRNAs. Early evidence in biogenesis ignited specific steps of being omitted or replaced that eventuate in the individual miRNAs of different mechanisms. Understanding the basic foundation concerning how miRNAs are generated and function will help with diagnostic tools and therapeutic strategies. This review encompasses the canonical and the non-canonical pathways involved in miRNA biogenesis, while elucidating how miRNAs regulate genes at the nuclear level and also the mechanism that lies behind circulating miRNAs.
Sensing strategies for influenza surveillance

Gopinath SC, Tang TH, Chen Y, Citartan M, Tominaga J, Lakshmipriya T

Biosens Bioelectron, 2014 Nov 15;61:357-69.
PMID: 24912036 DOI: 10.1016/j.bios.2014.05.024

Influenza viruses, which are RNA viruses belonging to the family Orthomyxoviridae, cause respiratory diseases in birds and mammals. With seasonal epidemics, influenza spreads all over the world, resulting in pandemics that cause millions of deaths. Emergence of various types and subtypes of influenza, such as H1N1 and H7N9, requires effective surveillance to prevent their spread and to develop appropriate anti-influenza vaccines. Diagnostic probes such as glycans, aptamers, and antibodies now allow discrimination among the influenza strains, including new subtypes. Several sensors have been developed based on these probes, efforts made to augment influenza detection. Herein, we review the currently available sensing strategies to detect influenza viruses.
Bacterial detection: from microscope to smartphone

Gopinath SC, Tang TH, Chen Y, Citartan M, Lakshmipriya T

Biosens Bioelectron, 2014 Oct 15;60:332-42.
PMID: 24836016 DOI: 10.1016/j.bios.2014.04.014

The ubiquitous nature of bacteria enables them to survive in a wide variety of environments. Hence, the rise of various pathogenic species that are harmful to human health raises the need for the development of accurate sensing systems. Sensing systems are necessary for diagnosis and epidemiological control of pathogenic organism, especially in the food-borne pathogen and sanitary water treatment facility' bacterial populations. Bacterial sensing for the purpose of diagnosis can function in three ways: bacterial morphological visualization, specific detection of bacterial component and whole cell detection. This paper provides an overview of the currently available bacterial detection systems that ranges from microscopic observation to state-of-the-art smartphone-based detection.
Use of UV-vis-NIR spectroscopy to monitor label-free interaction between molecular recognition elements and erythropoietin on a gold-coated polycarbonate platform

Citartan M, Gopinath SC, Tominaga J, Chen Y, Tang TH

Talanta, 2014 Aug;126:103-9.
PMID: 24881539 DOI: 10.1016/j.talanta.2014.03.043

Label-free-based detection is pivotal for real-time monitoring of biomolecular interactions and to eliminate the need for labeling with tags that can occupy important binding sites of biomolecules. One simplest form of label-free-based detection is ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, which measure changes in reflectivity as a means to monitor immobilization and interaction of biomolecules with their corresponding partners. In biosensor development, the platform used for the biomolecular interaction should be suitable for different molecular recognition elements. In this study, gold (Au)-coated polycarbonate was used as a platform and as a proof-of-concept, erythropoietin (EPO), a doping substance widely abused by the athletes was used as the target. The interaction of EPO with its corresponding molecular recognition elements (anti-EPO monoclonal antibody and anti-EPO DNA aptamer) is monitored by UV-vis-NIR spectroscopy. Prior to this, to show that UV-vis-NIR spectroscopy is a suitable method for measuring biomolecular interaction, the interaction between biotin and streptavidin was demonstrated via this strategy and reflectivity of this interaction decreased by 25%. Subsequent to this, interaction of the EPO with anti-EPO monoclonal antibody and anti-EPO DNA aptamer resulted in the decrease of reflectivity by 5% and 10%, respectively. The results indicated that Au-coated polycarbonate could be an ideal biosensor platform for monitoring biomolecular interactions using UV-vis-NIR spectroscopy. A smaller version of the Au-coated polycarbonate substrates can be derived from the recent set-up, to be applied towards detecting EPO abuse among atheletes.
Current aspects in immunosensors

Gopinath SC, Tang TH, Citartan M, Chen Y, Lakshmipriya T

Biosens Bioelectron, 2014 Jul 15;57:292-302.
PMID: 24607580 DOI: 10.1016/j.bios.2014.02.029

Sensing applications can be used to report biomolecular interactions in order to elucidate the functions of molecules. The use of an analyte and a ligand is a common set-up in sensor development. For several decades, antibodies have been considered to be potential analytes or ligands for development of so-called "immunosensors." In an immunosensor, formation of the complex between antibody and antigen transduces the signal, which is measurable in various ways (e.g., both labeled and label-free based detection). Success of an immunosensor depends on various factors, including surface functionalization, antibody orientation, density of the antibody on the sensor platform, and configuration of the immunosensor. Careful optimization of these factors can generate clear-cut results for any immunosensor. Herein, current aspects, involved in the generated immunosensors, are discussed.
Detection of host-specific immunogenic proteins in the saliva of patients with oral squamous cell carcinoma

Mu AK, Chan YS, Kang SS, Azman SN, Zain RB, Chai WL, et al.

J Immunoassay Immunochem, 2014;35(2):183-93.
PMID: 24295181 DOI: 10.1080/15321819.2013.836535

The main purpose of this article is to develop a new and reliable saliva-based clinical diagnostic method for the early detection of oral squamous cell carcinoma (OSCC). This study used an immunoproteomic approach which allowed the detection of immunogenic host proteins in patients' samples using pooled human antibodies. In an attempt to investigate potential biomarkers of OSCC, two-dimensional electrophoresis (2-DE) followed by immunoblotting of saliva from patients and controls were compared. The protein spots of interest were analyzed using 2-DE image analyzer and subsequently subjected to MALDI-TOF/TOF and then matched against NCBI database. The result showed that four protein clusters, namely Human Pancreatic Alpha-amylase (HPA), Human Salivary Amylase (sAA), keratin-10 (K-10), and Ga Module Complexed with Human Serum Albumin (GA-HSA), had exhibited immunoreactivity in western blot. The results are suggestive of the potential use of the differentially expressed saliva protein as tumor biomarkers for the detection of OSCC. However, further studies are recommended to validate this finding.
Fulltext Antioxidant activity of methanol extracts of different parts of Lantana camara

Mahdi-Pour B, Jothy SL, Latha LY, Chen Y, Sasidharan S

Asian Pac J Trop Biomed, 2012 Dec;2(12):960-5.
PMID: 23593576 DOI: 10.1016/S2221-1691(13)60007-6

To investigate the antioxidant activity of methanolic extracts of Lantana camara (L. camara) various parts and the determination of their total phenolics content.
In vitro antioxidant activity potential of lantadene A, a pentacyclic triterpenoid of Lantana plants

Grace-Lynn C, Darah I, Chen Y, Latha LY, Jothy SL, Sasidharan S

Molecules, 2012 Sep 19;17(9):11185-98.
PMID: 22992785

Lantadenes are pentacyclic triterpenoids present in the leaves of the plant Lantana camara. In the present study, in vitro antioxidant activity and free radical scavenging capacity of lantadene A was 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•), superoxide anion scavenging activities and ferrous ion chelating assay. Interestingly, lantadene A showed considerable in vitro antioxidant, free radical scavenging capacity activities in a dose dependant manner when compared with the standard antioxidant in nitric oxide scavenging, superoxide anion radical scavenging and ferrous ion chelating assay. These findings show that the lantadene A possesses antioxidant activity with different mechanism of actions towards the different free radicals tested. Since lantadene A is a very popular drug in modern medicine, it is a promising candidate for use as an antioxidant and hepatoprotective agent.
Fulltext Bioassay-directed isolation of active compounds with antiyeast activity from a Cassia fistula seed extract

Jothy SL, Zakaria Z, Chen Y, Lau YL, Latha LY, Shin LN, et al.

Molecules, 2011 Sep 05;16(9):7583-92.
PMID: 21894090 DOI: 10.3390/molecules16097583

BACKGROUND AND OBJECTIVE: Cassia fistula L belongs to the family Leguminosae, and it is one of the most popular herbal products in tropical countries. C. fistula seeds have been used as a herbal medicine and have pharmacological activity which includes anti-bacterial, anti-fungal, and antioxidant properties. The goal of this study was to identify compounds from C. fistula seeds which are responsible for anti-Candida albicans activity using bioassay-directed isolation.
RESULTS: The preliminary phytochemical screening of the plant seed revealed the presence of anthraquinones, flavonoids, saponins, tannins and terpenoids. The isolation of active compounds was carried out in four steps: multiple extractions, fractionation using column chromatography and purification using preparative thin-layer chromatography (TLC) and liquid chromatography/mass spectrometry (LC/MS). The structure of separated compounds was determined on the basis of mass spectrometry data. One compound was identified is roseanone.
CONCLUSIONS: The MS analysis on the active fraction from seed extract of C. fistula confirmed the presence of roseanone with antiyeast activity.
Fulltext Acute oral toxicity of methanolic seed extract of Cassia fistula in mice

Jothy SL, Zakaria Z, Chen Y, Lau YL, Latha LY, Sasidharan S

Molecules, 2011 Jun 23;16(6):5268-82.
PMID: 21701437 DOI: 10.3390/molecules16065268

BACKGROUND AND OBJECTIVE: Cassia fistula is widely used in traditional medicine to treat various types of ailments. The evaluation of toxic properties of C. fistula is crucial when considering public health protection because exposure to plant extracts can result in undesirable effects on consumers. Hence, in this study the acute oral toxicity of C. fistula seeds extract was investigated in mice.
RESULTS: Oral administration of crude extract at the highest dose of 5000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that C. fistula in nontoxic. Throughout 14 days of the treatment no changes in behavioural pattern, clinical sign and body weight of mice in both control and treatment groups. Also there were no any significant elevations observed in the biochemical analysis of the blood serum. Further, histopathological examination revealed normal architecture and no significant adverse effects observed on the kidney, heart, liver, lung and spleen.
CONCLUSIONS: Overall, the results suggest that, the oral administration of C. fistula methanolic seeds extract did not produce any significant toxic effect in mice. Hence, the extract can be utilized for pharmaceutical formulations.
Fulltext Hepatoprotective potential of Clitoria ternatea leaf extract against paracetamol induced damage in mice

Nithianantham K, Shyamala M, Chen Y, Latha LY, Jothy SL, Sasidharan S

Molecules, 2011 Dec 06;16(12):10134-45.
PMID: 22146374 DOI: 10.3390/molecules161210134

BACKGROUND AND AIM: Clitoria ternatea, a medicinal herb native to tropical equatorial Asia, is commonly used in folk medicine to treat various diseases. The aim of the present study is to evaluate the hepatoprotective and antioxidant activity of C. ternatea against experimentally induced liver injury.
METHODS: The antioxidant property of methanolic extract (ME) of C. ternatea leaf was investigated by employing an established in vitro antioxidant assay. The hepatoprotective effect against paracetamol-induced liver toxicity in mice of ME of C. ternatea leaf was also studied. Activity was measured by monitoring the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and billirubin along with histopathological analysis.
RESULTS: The amount of total phenolics and flavonoids were estimated to be 358.99 ± 6.21 mg/g gallic acid equivalent and 123.75 ± 2.84 mg/g catechin equivalent, respectively. The antioxidant activity of C. ternatea leaf extract was 67.85% at a concentration of 1 mg/mL and was also concentration dependant, with an IC(50) value of 420.00 µg/mL. The results of the paracetamol-induced liver toxicity experiments showed that mice treated with the ME of C. ternatea leaf (200 mg/kg) showed a significant decrease in ALT, AST, and bilirubin levels, which were all elevated in the paracetamol group (p < 0.01). C. ternatea leaf extract therapy also protective effects against histopathological alterations. Histological studies supported the biochemical findings and a maximum improvement in the histoarchitecture was seen.
CONCLUSIONS: The current study confirmed the hepatoprotective effect of C. ternatea leaf extract against the model hepatotoxicant paracetamol. The hepatoprotective action is likely related to its potent antioxidative activity.
A phone-counseling smoking-cessation intervention for male Chinese restaurant workers

Burton D, Zeng XX, Chiu CH, Sun J, Sze NL, Chen Y, et al.

J Community Health, 2010 Dec;35(6):579-85.
PMID: 20186474 DOI: 10.1007/s10900-010-9244-7

We sought to develop a smoking-cessation intervention for male Chinese restaurant workers in New York City that required no seeking out by participants; provided support over a relatively long period of time; and was responsive to participants' cultural backgrounds and daily lives. The resulting intervention consisted of a minimum of 9 proactive phone counseling sessions within a 6-month period for each participant recruited at his worksite. All activities were conducted in Chinese languages. The efficacy of this proactive phone-counseling intervention was assessed in a pretest/posttest design comparing baseline smoking with smoking 6 months after the intervention ended. Of 137 male employees recruited at their restaurants, 101 (median age 40.5) participated in the phone-counseling intervention in 2007-2008, with 75 completing the program with at least 9 counseling calls. We found a linear increase in smoking cessation from 0% at Call 1 to 50.7% at Call 9 for 75 men who completed the program, and we found for all 101 participants a 32.7% intent-to-treat cessation rate for 6 months post-end of program, adjusted to 30.8% by saliva cotinine assessments. The results indicate that combining field outreach with phone counseling over an extended period of time can facilitate smoking cessation for population groups whose environments do not support efforts to quit smoking.
Fulltext Profiling of serum and tissue high abundance acute-phase proteins of patients with epithelial and germ line ovarian carcinoma

Chen Y, Lim BK, Peh SC, Abdul-Rahman PS, Hashim OH

Proteome Sci, 2008;6:20.
PMID: 18637207 DOI: 10.1186/1477-5956-6-20

Acute-phase response involves the simultaneous altered expression of serum proteins in association to inflammation, infection, injury or malignancy. Studies of the acute-phase response usually involve determination of the levels of individual acute-phase serum proteins. In the present study, the acute-phase response of patients with epithelial (EOCa) and germ-line (GOCa) ovarian carcinoma was investigated using the gel-based proteomic approach, a technique which allowed the simultaneous assessment of the levels of the acute-phase serum high abundance proteins. Data obtained were validated using ELISA and immunostaining of biopsy samples.
Fulltext Evaluation of the hepatoprotective Effects of Lantadene A, a pentacyclic triterpenoid of Lantana plants against acetaminophen-induced liver damage

Grace-Lynn C, Chen Y, Latha LY, Kanwar JR, Jothy SL, Vijayarathna S, et al.

Molecules, 2012 Nov 23;17(12):13937-47.
PMID: 23178309 DOI: 10.3390/molecules171213937

The aim of the present study was to evaluate the hepatoprotective activity of lantadene A against acetaminophen-induced liver toxicity in mice was studied. Activity was measured by monitoring the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and bilirubin, along with histo-pathological analysis. Silymarin was used as positive control. A bimodal pattern of behavioural toxicity was exhibited by the lantadene A-treated group at the beginning of the treatment. However, treatment with lantadene A and silymarin resulted in an increase in the liver weight compared with the acetaminophen treated group. The results of the acetaminophen-induced liver toxicity experiments showed that mice treated with lantadene A (500 mg/kg) showed a significant decrease in the activity of ALT, AST and ALP and the level of bilirubin, which were all elevated in the acetaminophen treated group (p < 0.05). Histological studies supported the biochemical findings and a maximum improvement in the histoarchitecture was seen. The lantadene A-treated group showed remarkable protective effects against histopathological alterations, with comparable results to the silymarin treated group. The current study confirmed the hepatoprotective effects of lantadene A against the model hepatotoxicant acetaminophen, which is likely related to its potent antioxidative activity.
Fulltext Decreased expression of alpha-2-HS glycoprotein in the sera of rats treated with Eurycoma longifolia extract

Chen Y, Phang WM, Mu AK, Chan CK, Low BS, Sasidharan S, et al.

Front Pharmacol, 2015;6:211.
PMID: 26441666 DOI: 10.3389/fphar.2015.00211

Eurycoma longifolia is a Malaysian native herb that has been widely used as an aphrodisiac and a remedy for andropause. Although the physiological effects of the plant extract were predicted as a result of the alterations in protein expression, the key protein(s) involved in these alterations are still unclear. In the present study, we have investigated the effect of standardized E. longifolia extract on serum protein expression up to 28 days following oral administration in rats. Serum protein profiles were analyzed by 2-dimensional electrophoresis, and altered proteins were identified via mass spectrometry. We observed that alpha-2-HS glycoprotein (AHS) was significantly decreased in the serum of experimentally treated rats compared to pre-treated animals. Moreover, reduction in AHS was confirmed using competitive enzyme-linked immunosorbent assay. AHS expression is known to be associated with insulin resistance and diabetes. Our data indicated that serum AHS was reduced in rats treated with standardized E. longifolia extract, and therefore form a prelude for further investigation into the effects of this natural extract in animal models involving infertility and diabetes.

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