Displaying publications 21 - 40 of 79 in total

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  1. Fulltext Soluble receptor for advanced glycation end-product (sRAGE)/pentosidine ratio: a potential risk factor determinant for type 2 diabetic retinopathy
    Ng ZX, Chua KH, Iqbal T, Kuppusamy UR
    Int J Mol Sci, 2013;14(4):7480-91.
    PMID: 23552832 DOI: 10.3390/ijms14047480
    This study aims to investigate potential diabetic retinopathy (DR) risk factors by evaluating the circulating levels of pentosidine, soluble receptor for advanced glycation end-product (sRAGE), advanced oxidation protein product (AOPP) as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in DR patients. A total of 235 healthy controls, 171 type 2 diabetic without retinopathy (DNR) and 200 diabetic retinopathy (DR) patients were recruited. Plasma was extracted for the estimation of pentosidine, sRAGE, AOPP levels and GPx activity whereas peripheral blood mononuclear cells were disrupted for SOD activity measurement. DNR and DR patients showed significantly higher levels of plasma pentosidine, sRAGE and AOPP but lower GPx and SOD activities when compared to healthy controls. The sRAGE/pentosidine ratio in DR patients was significantly lower than the ratio detected in DNR patients. Proliferative DR patients had significantly higher levels of plasma pentosidine, sRAGE, AOPP and sRAGE/pentosidine ratio than non-proliferative DR patients. High HbA1c level, long duration of diabetes and low sRAGE/pentosidine ratio were determined as the risk factors for DR. This study suggests that sRAGE/pentosidine ratio could serve as a risk factor determinant for type 2 DR as it has a positive correlation with the severity of DR.
  2. Receptor for advanced glycation end-product (RAGE) gene polymorphism 2245G/A is associated with pro-inflammatory, oxidative-glycation markers and sRAGE in diabetic retinopathy
    Ng ZX, Kuppusamy UR, Iqbal T, Chua KH
    Gene, 2013 Jun 1;521(2):227-33.
    PMID: 23545311 DOI: 10.1016/j.gene.2013.03.062
    Receptor for advanced glycation end-product (RAGE) gene polymorphism 2245G/A is associated with diabetic retinopathy (DR). However, the mechanism on how it affects the disease development is still unclear.
  3. Infections of Blastocystis hominis and microsporidia in cancer patients: are they opportunistic?
    Chandramathi S, Suresh K, Anita ZB, Kuppusamy UR
    Trans R Soc Trop Med Hyg, 2012 Apr;106(4):267-9.
    PMID: 22340948 DOI: 10.1016/j.trstmh.2011.12.008
    Chemotherapy can cause immunosuppression, which may trigger latent intestinal parasitic infections in stools to emerge. This study investigated whether intestinal parasites can emerge as opportunistic infections in breast and colorectal cancer patients (n=46 and n=15, respectively) undergoing chemotherapy treatment. Breast cancer patients were receiving a 5-fluorouracil/epirubicin/cyclophosphamide (FEC) regimen (6 chemotherapy cycles), and colorectal cancer patients were receiving either an oxaliplatin/5-fluorouracil/folinic acid (FOLFOX) regimen (12 cycles) or a 5-fluorouracil/folinic acid (Mayo) regimen (6 cycles). Patients had Blastocystis hominis and microsporidia infections that were only present during the intermediate chemotherapy cycles. Thus, cancer patients undergoing chemotherapy should be screened repeatedly for intestinal parasites, namely B. hominis and microsporidia, as they may reduce the efficacy of chemotherapy treatments.
  4. Effects of symptomatic and asymptomatic isolates of Blastocystis hominis on colorectal cancer cell line, HCT116
    Chan KH, Chandramathi S, Suresh K, Chua KH, Kuppusamy UR
    Parasitol Res, 2012 Jun;110(6):2475-80.
    PMID: 22278727 DOI: 10.1007/s00436-011-2788-3
    The pathogenesis of Blastocystis hominis in human hosts has always been a matter of debate as it is present in both symptomatic and asymptomatic individuals. A recent report showed that B. hominis isolated from an asymptomatic individual could facilitate the proliferation and growth of existing cancer cells while having the potential to downregulate the host immune response. The present study investigated the differences between the effects of symptomatic and asymptomatic derived solubilized antigen of B. hominis (Blasto-Ag) on the cell viability and proliferation of colorectal cancer cells. Besides that, the gene expression of cytokine and nuclear transcriptional factors in response to the symptomatic and asymptomatic B. hominis antigen in HCT116 was also compared. In the current study, an increase in cell proliferation was observed in HCT116 cells which led to the speculation that B. hominis infection could facilitate the growth of colorectal cancer cells. In addition, a more significant upregulation of Th2 cytokines observed in HCT116 may lead to the postulation that symptomatic Blasto-Ag may have the potential in weakening the cellular immune response, allowing the progression of existing tumor cells. The upregulation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) was observed in HCT116 exposed to symptomatic Blasto-Ag, while asymptomatic Blasto-Ag exhibited an insignificant effect on NF-κB gene expression in HCT116. HCT116 cells exposed to symptomatic and asymptomatic Blasto-Ag caused a significant upregulation of CTSB which lead to the postulation that the Blasto-Ag may enhance the invasive and metastasis properties of colorectal cancer. In conclusion, antigen isolated from a symptomatic individual is more pathogenic as compared to asymptomatic isolates as it caused a more extensive inflammatory reaction as well as more enhanced proliferation of cancer cells.
  5. Urinary hyaluronidase activity in rats infected with Blastocystis hominis--evidence for invasion?
    Chandramathi S, Suresh KG, Mahmood AA, Kuppusamy UR
    Parasitol Res, 2010 May;106(6):1459-63.
    PMID: 20358228 DOI: 10.1007/s00436-010-1825-y
    The fact whether Blastocystis hominis can invade has always been in question. Apart from a few sporadic studies such as that done on gnotobiotic guinea pigs which showed surface invasion and mucosal inflammation of the host's intestine caused by B. hominis infection, no real documentation of invasion has been proven. Studies have shown that hyaluronidase is secreted during the penetration into the host's skin and gut by nematode parasites. Hyaluronidase activity in protozoa namely Entamoeba histolytica has also been described previously. This study attempts to determine hyaluronidase in urine samples of B. hominis-infected rats. The presence of hyaluronidase in urine provides an indirect evidence of invasion by B. hominis into colonic epithelium causing the degradation of extracellular matrix proteins namely hyaluronic acid (HA). HA is depolymerized by hyaluronidase which may be used by organisms to invade one another. In this study, the levels of urinary hyaluronidase of Sprague-Dawley rats infected with B. hominis were monitored for 30 days. Hyaluronidase levels in the infected rats were significantly higher on days 28 and 30 compared to the day before inoculation (P < 0.01 and P < 0.05, respectively). During this stage, parasitic burden in infected stools was also at a high level. Proinflammatory cytokines, interleukin-6 and interleukin-8, were also significantly higher (P < 0.05) in the serum of infected rats. The study demonstrates that since no other pathogen was present and that amoeboid forms of the parasites have been shown to exist previously, the elevated levels of hyaluronidase in this preliminary finding suggests that the organism is capable of having invasion or penetration activity in the hosts' intestine.
  6. Antioxidant capacity of fresh and processed fruit bodies and mycelium of Auricularia auricula-judae (Fr.) Quél
    Kho YS, Vikineswary S, Abdullah N, Kuppusamy UR, Oh HI
    J Med Food, 2009 Feb;12(1):167-74.
    PMID: 19298211 DOI: 10.1089/jmf.2007.0568
    Auricularia auricula-judae is currently grown in Malaysia. In the present study, the methanolic extracts from fruit bodies (fresh, oven-dried, and freeze-dried) and mycelium of A. auricula-judae were evaluated for their antioxidant capacities based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP) assay. The total phenolic content in the extracts were also measured. The extract of freeze-dried fruit bodies of A. auricula-judae had potent DPPH free radical scavenging activity with a 50% effective concentration of 2.87 mg/mL, whereas the FRAP value of A. auricula-judae mycelium was 5.22 micromol of FeSO(4).7H(2)O equivalents/g of mycelium sample. Further, a positive correlation (R(2) = 0.7668) between FRAP level of A. auricula-judae extracts and the total phenolic contents was observed. Thus the method of processing of fresh fruit bodies had an effect on the antioxidant potential of A. auricula-judae.
  7. Diabetes mellitus exacerbates advanced glycation end product accumulation in the veins of end-stage renal failure patients
    Nazratun N, Mahmood AA, Kuppusamy UR, Ahmad TS, Tan SY
    Vasc Med, 2006 Nov;11(4):245-50.
    PMID: 17390548
    The excess accumulation of advanced glycation end products (AGEs) contributes to the chronic complications of type 2 diabetes mellitus (DM) and renal failure. Biopsy specimens (n = 184) of arterial (n = 92) and venous (n = 92) tissues were obtained (radial artery and cephalic vein) from end-stage renal disease (ESRD) patients with or without DM and normal healthy subjects (n = 12) requiring surgery (trauma patients). Immunohistochemical assessment of the blood vessels revealed the presence of pentosidine (AGE marker) in both veins and arteries in 72% of the ESRD patients. The percentage of arteries and veins that showed positive pentosidine staining in ESRD patients with type 2 DM alone was 100% and 92% respectively, in the non-diabetic ESRD patients it was < 70% (for arteries and veins), and in the ESRD patients with hypertension as an additional co-morbidity to type 2 DM it was 70% and 82%, respectively. The veins of ESRD patients with DM showed a strong (+++) positive staining and very strong (++++) positive staining was observed in the patients with DM and hypertension. Only mild (+) or moderate (++) pentosidine staining intensity was observed in the arteries of ESRD patients without or with comorbidities, respectively. The accumulation of AGE in the vein rather than the artery may be a better reflection of the extent of complications of ESRD.
  8. The Medicinal Mushroom Ganoderma neo-japonicum (Agaricomycetes) from Malaysia: Nutritional Composition and Potentiation of Insulin-Like Activity in 3T3-L1 Cells
    Subramaniam S, Sabaratnam V, Heng CK, Kuppusamy UR
    Int J Med Mushrooms, 2020;22(1):65-78.
    PMID: 32463999 DOI: 10.1615/IntJMedMushrooms.2020033250
    Ganoderma neo-japonicum is an annual polypore mushroom that is consumed by Malaysian indigenous tribes to treat various ailments including diabetes. The present study aimed to investigate the nutritive composition and in vitro antihyperglycemic effects of G. neo-japonicum extracts on 3T3-L1 preadipocytes. Nutritional analysis of G. neo-japonicum basidiocarps indicated a predominant presence of carbohydrates, proteins, dietary fiber, and microelements. Hot aqueous extract (AE) and its isolated (1,3)(1,6)-β-D-glucan polysaccharide (GNJP) from basidiocarps of G. neo-japonicum were evaluated for their ability to stimulate insulin independent adipogenesis, glucose uptake, adiponectin secretion, and regulate gene expression in 3T3-L1 adipocytes. GNJP showed a dose dependent stimulation of glucose uptake and adiponectin secretion but attenuated lipid accumulation in 3T3-L1 adipocytes. It upregulated the expressions of adiponectin, Aktl (protein kinase B), PPARγ (peroxisome proliferator activated receptor gamma), PRKAG2 (protein kinase, AMP activated), and Slc2a4 (glucose transporter) genes to stimulate glucose uptake in 3T3-L1 cells, which may have contributed to the insulin-mimicking activities observed in this study. In summary, the nutritive compositions and significant glucose uptake stimulatory activities of GNJP indicated that it may have potential use in the formulation of functional food for the management of hyperglycemia, insulin resistance, and related complications.
  9. In vitro Anti-colorectal Cancer Potential of the Medicinal Mushroom Ganoderma neo-japonicum Imazeki in Hyperglycemic Condition: Impact on Oxidative Stress, Cell Cycle and Apoptosis
    Lau MF, Chua KH, Sabaratnam V, Kuppusamy UR
    Nutr Cancer, 2021 Jun 04.
    PMID: 34085886 DOI: 10.1080/01635581.2021.1931701
    Clinical efficacy of chemotherapy is often compromised by diabetogenic glucose on colorectal cancer (CRC). High glucose has been shown to diminish the cytotoxicity of anticancer drugs. The issue can potentially be addressed with natural products. Recently, we revealed that Ganoderma neo-japonicum exhibits inhibitory activities against human colonic carcinoma cells. In this study, the impacts of hexane fraction (Hex, sterol-enriched) and chloroform fraction (Chl, terpenoid-enriched) were further elucidated. The cellular responses, including oxidative stress, cell cycle, and apoptosis were compared between the presence of normal glucose (NG, 5.5 mM) and high glucose (HG, 25 mM). HG promoted cell viability with concomitant elevation of GSH level. Both Hex and Chl fractions stimulated NO production, in addition, induced cell cycle arrest. The apoptotic effect of Hex fraction was glucose-dependent, but Chl fraction triggered apoptosis with an equivalent extent in NG and HG conditions. Overall, the active fractions from G. neo-japonicum show therapeutic potential in managing hyperglycemia-associated CRC.
  10. In vitro and in silico anticancer evaluation of a medicinal mushroom, Ganoderma neo-japonicum Imazeki, against human colonic carcinoma cells
    Lau MF, Chua KH, Sabaratnam V, Kuppusamy UR
    Biotechnol Appl Biochem, 2021 Aug;68(4):902-917.
    PMID: 32856730 DOI: 10.1002/bab.2013
    Ganoderma neo-japonicum is a well-known medicinal mushroom in Asian countries. However, scientific validations on its curative activities are confined to cirrhosis and diabetes. In this study, the anticancer properties of G. neo-japonicum were evaluated using cellular and computational models. The ethanolic extract (EtOH) with a promising inhibitory effect was fractionated into four different fractions: hexane (Hex), chloroform (Chl), butanol (Btn), and aqueous (Aq). The active fractions were then subjected to cell apoptosis assessment and phytochemical profiling. Molecular docking was conducted to elucidate the affinity of selected constituents towards antiapoptotic Bcl-2 protein. The butanol fraction showed the highest antioxidant activities as well as total phenolic content. Both hexane and chloroform fractions exerted a potent cytotoxic effect on colonic carcinoma cells through the induction of apoptosis. Phytochemical analysis revealed that the chloroform fraction is terpenoid enriched whereas the hexane fraction comprises predominantly sterol constituents. Stellasterol and 1,25-dihydroxyvitamin D3 3-glycoside were demonstrated to have a high affinity towards Bcl-2 protein. Overall, G. neo-japonicum can be considered as a compelling therapeutic candidate for cancer treatment.
  11. Cell Proliferation and DNA Repair Ability of Ganoderma neo-japonicum (Agaricomycetes): An Indigenous Medicinal Mushroom from Malaysia
    Tan WC, Kuppusamy UR, Phan CW, Sabaratnam V
    Int J Med Mushrooms, 2018;20(2):155-163.
    PMID: 29773007 DOI: 10.1615/IntJMedMushrooms.2018025445
    Ganoderma neo-japonicum is an annual polypore that grows on decaying bamboo in the forests of Malaysia. The indigenous Temuan tribe uses this species as a medicinal mushroom to cure fever and epilepsy and to improve body strength. The potential use of G. neo-japonicum in genoprotection and DNA repair was established using a single-cell gel electrophoresis (comet) assay. The effects of the ethanol and hot aqueous extracts from wild and cultivated basidiocarps, solid substrate-fermented (SSF) wheat grains, and mycelia via submerged culture on H2O2-damaged murine RAW264.7 macrophages were investigated. An ethanol extract from wild basidiocarps showed the most significant protective effect on murine RAW264.7 macrophages, followed by ethanol and hot water extracts of cultivated basidiocarps, and this effect was dose dependent. However, only the ethanol extracts from SSF and submerged culture showed significant protective effects compared with the control. As for DNA repair ability, only the ethanol extract from wild and cultivated basidiocarps showed significant results when compared with the negative control. The findings suggest the potential therapeutic use of G. neo-japonicum in genome protection and as a DNA repair stimulator.
  12. Functional Properties of Partially Characterized Polysaccharide from the Medicinal Mushroom Ganoderma neo-japonicum (Agaricomycetes)
    Subramaniam S, Raman J, Sabaratnam V, Heng CK, Kuppusamy UR
    Int J Med Mushrooms, 2017;19(10):849-859.
    PMID: 29256840 DOI: 10.1615/IntJMedMushrooms.2017024355
    This study was conducted to evaluate the mycochemical composition and antiglycemic and antioxidant activities of Ganoderma neo-japonicum hot aqueous extracts, prepared at different boiling durations, and polysaccharides isolated from them. Ground basidiocarps of G. neo-japonicum were double-boiled at 100°C for 0.5, 3, or 4 hours, and the antiglycemic activity was assessed by α-amylase and α-glucosidase enzyme inhibition assays. The antioxidant capacity of the crude hot aqueous extracts (AE-1, AE-2, AE-3) was assessed by DPPH and ABTS radical scavenging and ferric-reducing antioxidant power assays. The total phenolics, protein, and sugar in the crude extracts were also determined. The hot aqueous extract (AE-3) containing a significant amount of total sugar and having enhanced antiglycemic and antioxidant activities was selected for polysaccharide isolation. The isolated crude polysaccharide was separated and purified using diethylaminoethyl-cellulose-52 and Sepharose 6B column chromatography. Fourier transform infrared spectroscopy studies of the purified polysaccharide fraction (PF) showed the presence of typical bands corresponding to polysaccharides. The estimated β-glucan concentration in the PF was 39.26%. In general, the PF exhibited significantly lower antioxidant activity than AE-3. Nevertheless, its potency in inhibiting carbohydratehydrolyzing enzymes may have potential in the management of diabetes mellitus.
  13. Fulltext Ergothioneine and its prospects as an anti-ageing compound
    Apparoo Y, Phan CW, Kuppusamy UR, Sabaratnam V
    Exp Gerontol, 2022 Dec;170:111982.
    PMID: 36244584 DOI: 10.1016/j.exger.2022.111982
    Healthy ageing is a crucial process that needs to be highlighted as it affects the quality of lifespan. An increase in oxidative stress along with ageing is the major factor related to the age-associated diseases, especially neurodegenerative disorders. An antioxidant-rich diet has been proven to play a significant role in the ageing process. Targeting ageing mechanisms could be a worthwhile approach to improving health standards. Ergothioneine (EGT), a hydrophilic compound with specific transporter known as OCTN1, has been shown to exert anti-ageing properties. In addition to its antioxidant effect, EGT has been reported to have anti-senescence, anti-inflammatory and anti-neurodegenerative properties. This review aims to define the pivotal role of EGT in major signalling pathways in ageing such as insulin/insulin-like growth factor (IGF) signalling (IIS), sirtuin 6 (SIRT6) and mammalian target of rapamycin complex (mTOR) pathways. The review further discusses evidence of EGT on neurodegeneration in its therapeutic context in various model organisms, providing new insights into improving health. In conclusion, an ergothioneine-rich diet may be beneficial in preventing age-related diseases, resulting in a healthy ageing population.
  14. Blastocystis sp. reduces the efficacy of 5-fluorouracil as a colorectal cancer chemotherapeutic treatment
    Kumarasamy V, Kuppusamy UR, Jayalakshmi P, Govind SK
    Exp Parasitol, 2023 Aug;251:108564.
    PMID: 37308003 DOI: 10.1016/j.exppara.2023.108564
    Blastocystis is an enteric protozoan parasite with extensive genetic variation and unclear pathogenicity. It is commonly associated with gastrointestinal symptoms such as nausea, diarrhea, vomiting and abdominal pain in immunocompromised individuals. In this study, we explored the in vitro and in vivo effects of Blastocystis on the activity of a commonly used CRC chemotherapeutic agent, 5-FU. The cellular and molecular effects of solubilized antigen of Blastocystis in the presence of 5-FU were investigated using HCT116, human CRC cell line and CCD 18-Co, normal human colon fibroblast cells. For the in vivo study, 30 male Wistar rats were divided into six groups, as follows; Control Group: oral administration of 0.3 ml Jones' medium, Group A: rats injected with azoxymethane (AOM), Group A-30FU: Rats injected with AOM and administered 30 mg/kg 5-FU, Group B-A-30FU: rats inoculated with Blastocystis cysts, injected with AOM and administered 30 mg/kg 5-FU, Group A-60FU: rats injected with AOM and administered 60 mg/kg 5-FU and Group B-A-60FU: rats inoculated with Blastocystis cysts, injected with AOM and administered 60 mg/kg 5-FU. The in vitro study revealed that the inhibitory potency of 5-FU at 8 μM and 10 μM was reduced from 57.7% to 31.6% (p 
  15. Fulltext Rosiglitazone enhances the apoptotic effect of 5-fluorouracil in colorectal cancer cells with high-glucose-induced glutathione
    Lau MF, Chua KH, Sabaratnam V, Kuppusamy UR
    Sci Prog, 2020;103(1):36850419886448.
    PMID: 31795844 DOI: 10.1177/0036850419886448
    Colorectal cancer is one of the most prevalent noncommunicable diseases worldwide. 5-Fluorouracil is the mainstay of chemotherapy for colorectal cancer. Previously, we have demonstrated that high glucose diminishes the cytotoxicity of 5-fluorouracil by promoting cell cycle progression. The synergistic impact of rosiglitazone on 5-fluorouracil-induced apoptosis was further investigated in this study. Besides control cell lines (CCD-18Co), two human colonic carcinoma cell lines (HCT 116 and HT 29) were exposed to different treatments containing 5-fluorouracil, rosiglitazone or 5-fluorouracil/rosiglitazone combination under normal glucose (5.5 mM) and high-glucose (25 mM) conditions. The cellular oxidative stress level was evaluated with biomarkers of nitric oxide, advanced oxidation protein products, and reduced glutathione. The cell apoptosis was assessed using flow cytometry technique. High glucose caused the production of reduced glutathione in HCT 116 and HT 29 cells. Correspondingly, high glucose suppressed the apoptotic effect of 5-fluorouracil and rosiglitazone. As compared to 5-fluorouracil alone (2 µg/mL), addition of rosiglitazone significantly enhanced the apoptosis (increment rate of 5-20%) in a dose-dependent manner at normal glucose and high glucose levels. This study indicates that high-glucose-induced reduced glutathione confers resistance to apoptosis, but it can be overcome upon treatment of 5-fluorouracil and 5-fluorouracil/rosiglitazone combination. Rosiglitazone may be a promising antidiabetic drug to reduce the chemotherapeutic dose of 5-fluorouracil for colorectal cancer complicated with hyperglycemia.
  16. Protective effect of myricetin derivatives from Syzygium malaccense against hydrogen peroxide-induced stress in ARPE-19 cells
    Arumugam B, Palanisamy UD, Chua KH, Kuppusamy UR
    Mol Vis, 2019;25:47-59.
    PMID: 30820141
    Purpose: Oxidative stress is implicated in the etiology of diabetes and its debilitating complications, such as diabetic retinopathy (DR). Various flavonoids have been reported to be useful in reducing DR progression. Myricetin derivatives (F2) isolated from leaf extract of Syzygium malaccense have the potential to serve as functional food as reported previously. The present study was performed with the aim of determining the antioxidant potential and protective effect of myricetin derivatives (F2) isolated from leaf extract of S. malaccense against glucose oxidase (GO)-induced hydrogen peroxide (H2O2) production that causes oxidative stress in ARPE-19 (RPE) cells.

    Methods: Antioxidant properties were assessed through various radical (DPPH, ABTS, and nitric oxide) scavenging assays and determination of total phenolic content and ferric reducing antioxidant power level. ARPE-19 cells were preincubated with samples before the addition of GO (to generate H2O2). Cell viability, change in intracellular reactive oxygen species (ROS), H2O2 levels in cell culture supernatant, and gene expression were assessed.

    Results: F2 showed higher antioxidant levels than the extract when assessed for radical scavenging activities and ferric reducing antioxidant power. F2 protected the ARPE-19 cells against GO-H2O2-induced oxidative stress by reducing the production of H2O2 and intracellular reactive oxygen species. This was achieved by the activation of nuclear factor erythroid 2-related factor 2 (Nrf2/NFE2L2) and superoxide dismutase (SOD2), as well as downregulation of nitric oxide producer (NOS2) at the transcriptional level.

    Conclusions: The results showed that myricetin derivatives from S. malaccense have the capacity to exert considerable exogenous antioxidant activities and stimulate endogenous antioxidant activities. Therefore, these derivatives have excellent potential to be developed as therapeutic agents for managing DR.

  17. Fulltext Gene regulation in β-sitosterol-mediated stimulation of adipogenesis, glucose uptake, and lipid mobilization in rat primary adipocytes
    Chai JW, Lim SL, Kanthimathi MS, Kuppusamy UR
    Genes Nutr, 2011 May;6(2):181-8.
    PMID: 21484150 DOI: 10.1007/s12263-010-0196-4
    The nutraceutical benefits of β-sitosterol (SIT) are well documented. The present study investigated the in vitro effects of SIT on adipogenesis, glucose transport, and lipid mobilization in rat adipocytes. Primary cultures of rat preadipocytes and differentiated adipocytes were used in this study. Glucose uptake was measured by the uptake of radio-labeled glucose. Adipogenesis and lipolysis were measured by oil-red-O and glycerol quantification methods, respectively. The expression of protein kinase B (Akt), glucose transporter 4 (GLUT4), hormone sensitive lipase (HSL), and phosphatidylinositol-3-kinase (PI3 K) genes in SIT-treated adipocytes were assessed by real-time reverse transcription polymerase chain reaction (RT-PCR). The data showed that SIT induced glucose uptake in adipocytes. It also stimulated adipogenesis in differentiating preadipocytes. Interestingly, although SIT displayed general insulin-mimetic activity by stimulating glucose uptake and adipogenesis, it also induced lipolysis in adipocytes. Furthermore, the SIT-induced lipolysis was not attenuated by insulin and co-incubation of SIT with epinephrine improved epinephrine-induced lipolysis. GLUT4 gene expression was highly down-regulated in SIT-treated adipocytes, compared to insulin-treated adipocytes, which was up-regulated. Insulin- and SIT-treated adipocytes showed similar levels of Akt, HSL, and PI3 K gene down-regulation. These observations suggest that the elevation of glucose uptake in SIT-treated adipocytes was unrelated to de novo synthesis of GLUT4 and the SIT-induced lipolysis is associated with the down-regulation of Akt and PI3K genes. The unique effects of SIT on the regulation of glucose uptake, adipogenesis, and lipolysis in adipocytes show that it has potential to be utilized in diabetes and weight management.
  18. Fulltext Attenuation of hydrogen peroxide and ferric reducing/antioxidant power serum levels in colorectal cancer patients with intestinal parasitic infection
    Chandramathi S, Suresh KG, Anita ZB, Kuppusamy UR
    Malays J Med Sci, 2009 Apr;16(2):15-20.
    PMID: 22589653 MyJurnal
    This study assessed several common oxidative indices in subjects infected with intestinal parasites, as well as in colorectal cancer (CRC) patients both with and without intestinal parasites.
  19. Fulltext Lentinus squarrosulus (Mont.) mycelium enhanced antioxidant status in rat model
    Mhd Omar NA, Abdullah S, Abdullah N, Kuppusamy UR, Abdulla MA, Sabaratnam V
    Drug Des Devel Ther, 2015;9:5957-64.
    PMID: 26604694 DOI: 10.2147/DDDT.S90746
    Lentinus squarrosulus is an edible wild mushroom commonly found in Asia. This species has several interesting features such as rapid mycelial growth, and hence has the potential to be used as food, functional food, and nutraceuticals. Our previous study shows that L. squarrosulus contains potent antioxidant compounds in vitro. This study aims to investigate the in vivo bioavailability of L. squarrosulus mycelium extract and its antioxidant effect on biomarkers of antioxidant defense and oxidative stress.
  20. Fulltext Intrastrain comparison of the chemical composition and antioxidant activity of an edible mushroom, Pleurotus giganteus, and its potent neuritogenic properties
    Phan CW, David P, Tan YS, Naidu M, Wong KH, Kuppusamy UR, et al.
    ScientificWorldJournal, 2014;2014:378651.
    PMID: 25121118 DOI: 10.1155/2014/378651
    Two strains of Pleurotus giganteus (commercial and wild) were tested for their ability to induce neurite outgrowth in rat pheochromocytoma (PC12) and mouse neuroblastoma-2a (N2a) cells. Treatment with the mushroom extracts resulted in neuronal differentiation and neuronal elongation, but not nerve growth factor (NGF) production. Linoleic acid (4.5-5.0%, w/w) which is a major fatty acid present in the ethanol extract promoted NGF biosynthesis when augmented with low concentration of NGF (5 ng/mL). The two strains of mushroom were found to be high in protein (154-192 g kg(-1)), total polysaccharides, phenolics, and flavonoids as well as vitamins B1, B2, and B3. The total phenolics present in the mushroom extracts were positively correlated to the antioxidant activity (free radical scavenging, ferric reducing power, and lipid peroxidation inhibition). To conclude, P. giganteus could potentially be used in well-balanced diet and as a source of dietary antioxidant to promote neuronal health.
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