Displaying publications 1 - 20 of 22 in total

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  1. Cytotoxic and Apoptotic Effects of Ethyl Acetate Extract of Elephantopus mollis Kunth. in Human Liver Carcinoma HepG2 Cells Through Caspase-3 Activation
    Ooi KL, Tengku Muhammad TS, Lam LY, Sulaiman SF
    Integr Cancer Ther, 2014 May;13(3):NP1-9.
    PMID: 22336595 DOI: 10.1177/1534735411433203
    Previous cytotoxic (anticancer) evaluations ofElephantopus molliswere mainly focused on its elephantopin derivatives neglecting the combined effect of the phytochemicals in its traditionally used extracts. In this study, the cytotoxic mechanism of its extracts was investigated using methylene blue assay. The cytotoxic screening results revealed the ethyl acetate extract as the most potent extract by displaying prominent dose-dependent and time-dependent growth inhibitions in human liver carcinoma HepG2 cells with the lowest EC50value of 9.38 ± 0.43 µg/mL after 72 hours of treatment. Acute exposure of the HepG2 cells to the ethyl acetate extract produced a significant regulation of caspase-3 with the peak expression at 8 hours of treatment (P< .05). DNA fragmentation indicated by DeadEnd Apoptosis Detection System-labeled nuclei cells confirmed that the extract induced apoptotic cell death through caspase-3-dependent pathway in HepG2 cells.
  2. Apoptotic effects of Physalis minima L. chloroform extract in human breast carcinoma T-47D cells mediated by c-myc-, p53-, and caspase-3-dependent pathways
    Ooi KL, Tengku Muhammad TS, Lim CH, Sulaiman SF
    Integr Cancer Ther, 2010 Mar;9(1):73-83.
    PMID: 20150224 DOI: 10.1177/1534735409356443
    The chloroform extract of Physalis minima produced a significant growth inhibition against human T-47D breast carcinoma cells as compared with other extracts with an EC(50) value of 3.8 microg/mL. An analysis of cell death mechanisms indicated that the extract elicited an apoptotic cell death. mRNA expression analysis revealed the coregulation of apoptotic genes, that is, c-myc , p53, and caspase-3. The c-myc was significantly induced by the chloroform extract at the earlier phase of treatment, followed by p53 and caspase-3. Biochemical assay and ultrastructural observation displayed typical apoptotic features in the treated cells, including DNA fragmentation, blebbing and convolution of cell membrane, clumping and margination of chromatin, and production of membrane-bound apoptotic bodies. The presence of different stages of apoptotic cell death and phosphatidylserine externalization were further reconfirmed by annexin V and propidium iodide staining. Thus, the results from this study strongly suggest that the chloroform extract of P. minima induced apoptotic cell death via p53-, caspase-3-, and c-myc-dependent pathways.
  3. Interleukin-6 inhibits human peroxisome proliferator activated receptor alpha gene expression via CCAAT/enhancer-binding proteins in hepatocytes
    Chew CH, Chew GS, Najimudin N, Tengku-Muhammad TS
    Int J Biochem Cell Biol, 2007;39(10):1975-86.
    PMID: 17616429
    Peroxisome proliferator activated receptor alpha has been implicated as a regulator of acute phase response genes in hepatocytes. Interleukin-6 is widely known as a major cytokine responsible in the regulation of acute phase proteins and, therefore, acute phase response. Unfortunately, to date, very little is understood about the molecular mechanisms by which interleukin-6 regulates the gene expression of peroxisome proliferator activated receptor alpha. Here, we report the molecular mechanisms by which peroxisome proliferator activated receptor alpha was regulated by interleukin-6 in human HepG2 cells. Interleukin-6 was shown to down-regulate the peroxisome proliferator activated receptor alpha gene expression at the level of gene transcription. Functional dissection of human peroxisome proliferator activated receptor alpha promoter B revealed the role of predicted CCAAT/enhancer-binding protein binding site (-164/+34) in mediating the interleukin-6 inhibitory effects on peroxisome proliferator activated receptor alpha mRNA expression and electrophoretic mobility shift assay showed the binding of CCAAT/enhancer-binding protein isoforms to this cis-acting elements was increased in interleukin-6-treated HepG2 cells. Co-transfection experiments, then, demonstrated that CCAAT/enhancer-binding protein beta either in homodimer or heterodimer with CCAAT/enhancer-binding protein alpha and CCAAT/enhancer-binding protein delta plays a predominant role in inhibiting the transcriptional activity of peroxisome proliferator activated receptor alpha promoter B, thus, reducing the peroxisome proliferator activated receptor alpha mRNA expression. These studies, therefore, suggest a novel mechanism for interleukin-6-mediated inhibition of peroxisome proliferator activated receptor alpha gene expression that involves the activation of CCAAT/enhancer-binding protein isoforms with CCAAT/enhancer-binding protein beta may play a major role.
  4. Fulltext Cytotoxic data of 14-deoxy-11, 12-didehydroandrographolide (14-DDA), double transfection and DDIT3 silencing data in T-47D breast carcinoma cells
    Tan HK, Tengku Muhammad TS, Tan ML
    Data Brief, 2016 Jun;7:1506-10.
    PMID: 27182548 DOI: 10.1016/j.dib.2016.04.046
    The data presented in this article are related to the research article entitled "14-deoxy-11,12-didehydroandrographolide induces DDIT3-dependent endoplasmic reticulum stress-mediated autophagy in T-47D breast carcinoma cells", which the mechanistic toxicology properties of 14-deoxy-11,12-didehydroandrographolide (14-DDA) were investigated (Tan et al., 2016 [1]). This article describes the derivation of cytotoxic parameters of 14-DDA, cell viability data after double transfection and DDIT3 silencing in T-47D cells.
  5. Molecular characterisation of six alternatively spliced variants and a novel promoter in human peroxisome proliferator-activated receptor alpha
    Chew CH, Samian MR, Najimudin N, Tengku-Muhammad TS
    Biochem Biophys Res Commun, 2003 May 30;305(2):235-43.
    PMID: 12745064
    Peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcriptional factor that governs many biological processes, including lipid metabolism, inflammation, and atherosclerosis. We demonstrate here the existence of six variants and multiple transcriptional start sites of the 5(') untranslated region (UTR) of hPPARalpha gene, originating from the use of alternative splicing mechanisms and four different promoters. Three new novel exons at the 5(')-untranslated region of human PPARalpha gene were also identified and designated as Exon A, Exon B, and Exon 2b. In addition, 1.2kb promoter fragment which drives the transcription of 2 variants with Exon B (hPPARalpha4 and 6) was successfully cloned and characterised. Sequencing results revealed promoter B did not contain a conservative TATA box within the first 100 nucleotides from transcriptional start site but has several GC-rich regions and putative Sp1 sites. Using luciferase reporter constructs transfected into HepG2 and Hep3B cell lines, promoter B was shown to be functionally active. Basal transcriptional activity was significantly high in the promoter fragment -341/+34, but lower in the region -341/-1147 as compared to the fragment -341/+34, indicating the presence of an element conferring transcriptional activation between positions -341 and +34 or alternatively, the presence of transcriptional repression between positions -341 and -1147 in the promoter B of hPPARalpha.
  6. Molecular cloning and characterisation of peroxisome proliferator activated receptor gamma1 (PPARgamma1) cDNA gene from guinea pig (Cavia porcellus): tissue distribution
    Khoo BY, Samian MR, Najimudin N, Tengku Muhammad TS
    Comp Biochem Physiol B Biochem Mol Biol, 2003 Jan;134(1):37-44.
    PMID: 12524031
    The coding region of guinea pig peroxisome proliferator activated receptor gamma1 (gpPPARgamma1) cDNA was successfully cloned from adipose tissue by reverse transcription polymerase chain reaction (RT-PCR) using the designated primers based on the conserved regions of the other mammalian PPARgamma1 sequence. From RT-PCR, a combination of three cDNA fragments that comprised of the full length coding region PPARgamma1 cDNA gene were amplified, with the size of 498, 550 and 557 bp, respectively. All three fragments were then successfully assembled by utilising the internal restriction sites present at the overlapping regions to give rise to the full-length coding region of gpPPARgamma1 with the size of 1428 bp and consisting of 475 amino acids. Guinea pig PPARgamma1 is highly conserved with those of other species at protein and nucleotide levels. Gene expression studies showed that gpPPARgamma mRNA was predominantly expressed in adipose tissue followed by lung and spleen. However, at the protein level, PPARgamma was also found to be expressed in skeletal muscle.
  7. Fulltext Vitex rotundifolia fractions induce apoptosis in human breast cancer cell line, MCF-7, via extrinsic and intrinsic pathways
    Chaudhry GE, Jan R, Mohamad H, Tengku Muhammad TS
    Res Pharm Sci, 2019 Jun;14(3):273-285.
    PMID: 31160905 DOI: 10.4103/1735-5362.258496
    Breast cancer is amongst frequently diagnosed cancer type throughout the world. Due to reduced efficacy of current chemotherapeutics, several natural products have been screened for better alternatives. The cytotoxic activity of fractions prepared from leaves extract of Vitex rotundifolia (V. rotundifolia) on human breast cancer cell line, MCF-7 was studied. The fractions F1, F2, F3, and F5 of V. rotundifolia produced concentration-dependent cytotoxic effects on MCF-7 cell line. The relative potential of cytotoxicity of the fractions on MCF-7 cell line was found to be F3 > F2 > F5 > F1. The active fractions induce apoptosis in MCF-7 cell line determined by annexin V base assay. The phosphatidylserine externalization and the presence of DNA fragmentation in treated cells confirms the early and late apoptosis in treated cells. The V. rotundifolia fractions induced apoptosis by both pathways; extrinsic pathways via activation of caspase-8 and intrinsic pathways through enhanced bax/bcl-2 ratio and activation of caspase-3/7 and caspase-9 proapoptotic proteins. Furthermore, chemical profiling indicates various phenolic, flavonoids, and terpenoids compounds in the active fractions. Thus, V. rotundifolia might be a suitable candidate to investigate further and develop molecular targeted cancer therapeutics by understanding the fundamental mechanisms involved in the regulation of cell death in cancer cells.
  8. Fulltext Phaleria macrocarpa Boerl. (Thymelaeaceae) leaves increase SR-BI expression and reduce cholesterol levels in rats fed a high cholesterol diet
    Andriani Y, Tengku-Muhammad TS, Mohamad H, Saidin J, Syamsumir DF, Chew GS, et al.
    Molecules, 2015 Mar 09;20(3):4410-29.
    PMID: 25759957 DOI: 10.3390/molecules20034410
    In vitro and in vivo studies of the activity of Phaleria macrocarpa Boerl (Thymelaeaceae) leaves against the therapeutic target for hypercholesterolemia were done using the HDL receptor (SR-BI) and hypercholesterolemia-induced Sprague Dawley rats. The in vitro study showed that the active fraction (CF6) obtained from the ethyl acetate extract (EMD) and its component 2',6',4-trihydroxy-4'-methoxybenzophenone increased the SR-BI expression by 95% and 60%, respectively. The in vivo study has proven the effect of EMD at 0.5 g/kgbw dosage in reducing the total cholesterol level by 224.9% and increasing the HDL cholesterol level by 157% compared to the cholesterol group. In the toxicity study, serum glutamate oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) activity were observed to be at normal levels. The liver histology also proved no toxicity and abnormalities in any of the treatment groups, so it can be categorized as non-toxic to the rat liver. The findings taken together show that P. macrocarpa leaves are safe and suitable as an alternative control and prevention treatment for hypercholesterolemia in Sprague Dawley rats.
  9. Fulltext Cytochrome P450 induction properties of food and herbal-derived compounds using a novel multiplex RT-qPCR in vitro assay, a drug-food interaction prediction tool
    Koe XF, Tengku Muhammad TS, Chong AS, Wahab HA, Tan ML
    Food Sci Nutr, 2014 Sep;2(5):500-20.
    PMID: 25473508 DOI: 10.1002/fsn3.122
    A multiplex RT-qPCR was developed to examine CYP1A2, CYP2D6, and CYP3A4 induction properties of compounds from food and herbal sources. The induction of drug metabolizing enzymes is an important pharmacokinetic interaction with unique features in comparison with inhibition of metabolizing enzymes. Cytochrome induction can lead to serious drug-drug or drug-food interactions, especially if the coadministered drug plasma level is critical as it can reduce therapeutic effects and cause complications. Using this optimized multiplex RT-qPCR, cytochrome induction properties of andrographolide, curcumin, lycopene, bergamottin, and resveratrol were determined. Andrographolide, curcumin, and lycopene produced no significant induction effects on CYP1A2, CYP2D6, and CYP3A4. However, bergamottin appeared to be a significant in vitro CYP1A2 inducer starting from 5 to 50 μmol/L with induction ranging from 60 to 100-fold changes. On the other hand, resveratrol is a weak in vitro CYP1A2 inducer. Examining the cytochrome induction properties of food and herbal compounds help complement CYP inhibition studies and provide labeling and safety caution for such products.
  10. Identification of Wap65, a human homologue of hemopexin as a copper-inducible gene in swordtail fish, Xiphophorus helleri
    Aliza D, Ismail IS, Kuah MK, Shu-Chien AC, Tengku Muhammad TS
    Fish Physiol Biochem, 2008 Jun;34(2):129-38.
    PMID: 18649030 DOI: 10.1007/s10695-007-9153-6
    Copper is one of the major heavy metal pollutants found in the aquatic environment. Therefore, it is important for determining the genes that play a key role in copper metabolism in aquatic organisms. This study, thus, aimed to identify a new copper-inducible gene in swordtail fish, Xiphophorus helleri. Using ACP-based RT-PCR coupled with RLM-RACE, we cloned Wap65, a mammalian homologue of hemopexin gene. The gene exhibits high identity at amino acid levels with the Wap65 gene of other fish species (42-68%) and mammalian hemopexin gene (35-37%). In addition, ten cysteine and two histidine residues are conserved in the swordtail fish Wap65 gene. These cysteine residues are vital for structural integrity, and histidine residues provide high binding affinity towards heme. As revealed by RT-PCR, the gene was upregulated in swordtail fish that were exposed to copper in a dose- and time-dependent manner. Therefore, the identification of Wap65, a mammalian homologue of hemopexin, as a new copper-inducible gene will provide greater insight into the role of this gene in copper metabolism.
  11. Blood-Brain Barrier Permeability of Asiaticoside, Madecassoside and Asiatic Acid in Porcine Brain Endothelial Cell Model
    Hanapi NA, Mohamad Arshad AS, Abdullah JM, Tengku Muhammad TS, Yusof SR
    J Pharm Sci, 2021 02;110(2):698-706.
    PMID: 32949562 DOI: 10.1016/j.xphs.2020.09.015
    Neurotherapeutic potentials of Centella asiatica and its reputation to boost memory, prevent cognitive deficits and improve brain functions are widely acknowledged. The plant's bioactive compounds, i.e. asiaticoside, madecassoside and asiatic acid were reported to have central nervous system (CNS) actions, particularly in protecting the brain against neurodegenerative disorders. Hence, it is important for these compounds to cross the blood-brain barrier (BBB) to be clinically effective therapeutics. This study aimed to explore the capability of asiaticoside, madecassoside and asiatic acid to cross the BBB using in vitro BBB model from primary porcine brain endothelial cells (PBECs). Our findings showed that asiaticoside, madecassoside and asiatic acid are highly BBB permeable with apparent permeability (Papp) of 70.61 ± 6.60, 53.31 ± 12.55 and 50.94 ± 10.91 × 10-6 cm/s respectively. No evidence of cytotoxicity and tight junction disruption of the PBECs were observed in the presence of these compounds. Asiatic acid showed cytoprotective effect towards the PBECs against oxidative stress. This study reported for the first time that Centella asiatica compounds demonstrated high capability to cross the BBB, comparable to central nervous system drugs, and therefore warrant further development as therapeutics for the treatment of neurodegenerative diseases.
  12. Pro-atherogenic proteoglycanase ADAMTS-1 is down-regulated by lauric acid through PI3K and JNK signaling pathways in THP-1 derived macrophages
    Ong MH, Wong HK, Tengku-Muhammad TS, Choo QC, Chew CH
    Mol Biol Rep, 2019 Jun;46(3):2631-2641.
    PMID: 30989556 DOI: 10.1007/s11033-019-04661-6
    The prevalence of atherosclerosis has increased significantly in the recent years due to sedentary lifestyle and high-fat diet. However, the association between saturated fat intake and the increased risk for atherosclerotic cardiovascular diseases remains heavily debated. Lauric acid belongs to the saturated fatty acid group and its unique medium chain fatty acid properties are proven to be beneficial to humans in many ways. Thus, the aim of this project is to investigate the effect of lauric acid on the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) genes-ADAMTS-1, ADAMTS-4, and ADAMTS-5-in macrophages. These genes encode for proteases that participate in the extracellular matrix remodeling and they play important roles in the vulnerability of atherosclerotic plaque. Here, we show that the treatment of 20 µM of lauric acid successfully reduced both transcriptional and translational expressions of these genes in THP-1 differentiated macrophages after 24-h incubation. Further cell signaling experiments using a panel of kinase inhibitors and phosphorylated antibodies proved that lauric acid down-regulated ADAMTS-1 by reducing the activation of PI3K and JNK at Tyr458 and Tyr185, respectively. Finally, JNK1 siRNA knockdown assay confirmed that ADAMTS-1 was regulated through JNK pathway, and lauric acid interfered with this pathway to down-regulate ADAMTS-1 expression. Although preliminary, this present study indicates that lauric acid has the potential to stabilize atherosclerotic plaque and may prevent thrombosis by interfering with the ADAMTS-1 expression through PI3K/JNK pathways.
  13. Fulltext Inhibitory effects of tangeretin and trans-ethyl caffeate on the HMG-CoA reductase activity: Potential agents for reducing cholesterol levels
    Pangestika I, Oksal E, Tengku Muhammad TS, Amir H, Syamsumir DF, Wahid MEA, et al.
    Saudi J Biol Sci, 2020 Aug;27(8):1947-1960.
    PMID: 32714018 DOI: 10.1016/j.sjbs.2020.06.010
    One of the pathways to reduce cholesterol production in the liver is through the inhibition of HMG-Coa reductase (HMGCR) by current drugs, statins. However, these have side effects if consumed in prolonged periods. Tangeretin and trans-ethyl caffeate as alternative drugs in reducing hypercholesterolemia and preventing atherosclerosis have never been reported. Their effects on inhibiting HMGCR activity were investigated through enzymatic method (in vitro and in vivo). The toxicity property was analyzed on the Serum Glutamate Oxalate Transaminase (SGOT)/Serum Glutamate Piruvate Transaminase (SGPT) levels and rat liver histology. The results showed that both compounds inhibited HMGCR activity significantly compare to the control simvastatin (p 
  14. Fulltext Acaudina molpadioides mediates lipid uptake by suppressing PCSK9 transcription and increasing LDL receptor in human liver cells
    Jack A, Mohd MA, Kamaruddin NN, Mohd Din LH, Hajri NA, Tengku Muhammad TS
    Saudi J Biol Sci, 2021 Dec;28(12):7105-7116.
    PMID: 34867013 DOI: 10.1016/j.sjbs.2021.08.003
    Acaudina molpadioides has been long used as traditional medicinal resources and reported to demonstrate various important bioactivities such as anticoagulation, antithrombosis, anti-hyperglycemia and anticancer. However, its lipid lowering activity is yet to be fully explored. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is an enzyme that enhances the lysosomal degradation of hepatic low density lipoprotein receptor (LDLR) resulting in excessive accumulation of the plasma levels of LDL-cholesterols (LDL-C) which subsequently accelerate atherosclerosis. In the present study, A. molpadioides fractions were subjected to promoter-reporter luciferase assay to determine its role as PCSK9 inhibitors. It was found both fractions (EFA and EFB) reduced the transcriptional activity of PCSK9 promoter. Among the seven 5'end deletion constructs of PCSK9 promoter, fragments D1 (-1,711/-94), D3 (-709/-94) and D4 (-440/-94), were suppressed in the presence of both fractions whereas D2 (-1,214/-94), and, D6 (-351/-94) as well as D7 (-335/-94) were inhibited only by EFA and EFB, respectively. Further transcription factor binding sites prediction using MatInspector software discovered various potential cis-regulatory elements namely, PPAR, KLFs, RBPJ-kappa and SREBP that may potentially be involved in ameliorating the transcriptional activity of PCSK9. Immunofluorescence staining was used to evaluate the effects of both fractions on LDL-C and LDLR. Results showed that levels of LDL-C uptake in EFA-treated cells were 69.1% followed by EFB at 32.6%, as compared to untreated control after 24 h treatment. The LDLR protein distribution was induced by 62.41% and 32.2%, which corresponded to an increase in LDL-C uptake in both EFA and EFB treatment, respectively. Hence, the inhibition of PCSK9 by bioactive compounds in EFA and EFB could be another promising therapeutic agent in reducing the cholesterol levels and atherosclerosis by targeting PCSK9.
  15. Advancing Research on Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors: A Scientometric Analysis
    Matin A, Chaudhry GE, Azra MN, Gazali M, Yeong YS, Tengku Muhammad TS
    Malays J Med Sci, 2024 Aug;31(4):14-34.
    PMID: 39247108 DOI: 10.21315/mjms2024.31.4.2
    Atherosclerosis is characterised by the accumulation of fatty deposits and plaque as a result of a continuously high level of low-density lipoprotein cholesterol (LDL-C) in the blood. The primary objective of this research is to assess the current status of knowledge, research endeavours and developmental trajectories about proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in correlation with atherosclerosis treatment. Additionally, this study aims to compile bibliometric and scientometric investigations within this domain through rigorous scientometric analysis. Analysing the bibliometric landscape and global research trends associated with PCSK9 inhibitors can contribute valuable insights into comprehending atherosclerosis. This is exemplified by examining publications within the Web of Science Core Collection (WOSCC) database from 2008 to 2022. Citespace was used for frequency, co-occurrence, co-citation, grouping and burst analysis, and Microsoft Excel was used to manage descriptive datasets. Eight hundred eighty-five publications available from WOSCC database between the years 2008 and 2022 were extracted and examined. Over the period, 3,138 collaborating institutions from 87 countries, a staggering 7,750 writers involved and 325 distinct journals published about PCSK9 inhibitors studies. Among authors, Sabatine et al. and the journal The New England Journal of Medicine has had the most significant impact. Lipid-lowering therapy and bempedoic acid are the most prominent topical clusters associated with PCSK9 inhibitors, and the most often used keywords are efficacy, safety and PCSK9 inhibitors. We believe this is the first comprehensive analysis of PCSK9 inhibitors research and publications conducted using Scientometric. These results demonstrate the nascence of PCSK9 inhibitors research. They may encourage a wide range of stakeholders, particularly early career researchers from various disciplines, to work together in the future.
  16. Discovery of new nanomolar peroxisome proliferator-activated receptor γ activators via elaborate ligand-based modeling
    Al-Najjar BO, Wahab HA, Tengku Muhammad TS, Shu-Chien AC, Ahmad Noruddin NA, Taha MO
    Eur J Med Chem, 2011 Jun;46(6):2513-29.
    PMID: 21482446 DOI: 10.1016/j.ejmech.2011.03.040
    Peroxisome Proliferator-Activated Receptor γ (PPARγ) activators have drawn great recent attention in the clinical management of type 2 diabetes mellitus, prompting several attempts to discover and optimize new PPARγ activators. With this in mind, we explored the pharmacophoric space of PPARγ using seven diverse sets of activators. Subsequently, genetic algorithm and multiple linear regression analysis were employed to select an optimal combination of pharmacophoric models and 2D physicochemical descriptors capable of accessing self-consistent and predictive quantitative structure-activity relationship (QSAR) (r2(71)=0.80, F=270.3, r2LOO=0.73, r2PRESS against 17 external test inhibitors=0.67). Three orthogonal pharmacophores emerged in the QSAR equation and were validated by receiver operating characteristic (ROC) curves analysis. The models were then used to screen the national cancer institute (NCI) list of compounds. The highest-ranking hits were tested in vitro. The most potent hits illustrated EC50 values of 15 and 224 nM.
  17. Tumour necrosis factor alpha down-regulates the expression of peroxisome proliferator activated receptor alpha (PPARα) in human hepatocarcinoma HepG2 cells by activation of NF-κB pathway
    Lim WS, Ng DL, Kor SB, Wong HK, Tengku-Muhammad TS, Choo QC, et al.
    Cytokine, 2013 Jan;61(1):266-74.
    PMID: 23141142 DOI: 10.1016/j.cyto.2012.10.007
    Peroxisome proliferator activated receptor-alpha (PPARα) plays a major role in the regulation of lipid and glucose homeostasis, and inflammatory responses. The objectives of the study were to systematically investigate the effects of TNF-α and its regulatory pathway on PPARα expression in HepG2 cells using Real-Time RT-PCR and western blot analysis. Here, TNF-α suppressed PPARα mRNA expression in a dose- and time-dependent manner at the level of gene transcription. Pre-treatment of cells with 10μM of Wedelolactone for 2h was sufficient to restore PPARα expression to basal levels and also affected the expression of PPARα-regulated genes. This study also demonstrated that TNF-α represses PPARα expression by augmenting the activity of canonical NF-κB signalling pathway. This was shown by the abrogation of TNF-α-mediated PPARα down-regulation, after both p65 and p50 were knocked down via siRNA. The IKK contributes to IκBα degradation and mediates inducible phosphorylation of p105 at Ser933. Surprisingly, phosphorylation of p65 at Ser468 and Ser536 were severely abrogated with Wedelolactone inhibition, suggesting that Ser468 and Ser536, but not Ser276, may mediate the TNF-α inhibitory action on PPARα gene expression. These results suggest that TNF-α might, at least in part, suppress PPARα expression through activation of IKK/p50/p105/p65 pathway. Furthermore, phosphorylation of p65 at Ser468 and Ser536 may play a crucial role in the mechanism that limits PPARα production in the human HepG2 cells.
  18. Fulltext Induction of cytotoxicity by Bruguiera gymnorrhiza in human breast carcinoma (MCF-7) cell line via activation of the intrinsic pathway
    Chaudhry GE, Rahman NH, Sevakumaran V, Ahmad A, Mohamad H, Zafar MN, et al.
    J Adv Pharm Technol Res, 2020 10 10;11(4):233-237.
    PMID: 33425710 DOI: 10.4103/japtr.JAPTR_81_20
    Breast cancer is among the frequently occurring cancer worldwide. The foremost underline aim of this study was to determine the growth inhibitory effect along with mechanistic study of a Bruguiera gymnorrhiza extract on MCF-7. The cytotoxicity activity was determined by using the MTS assay. Butanol extract exhibited the maximum cytotoxicity activity against the MCF-7 cells with IC50 of 3.39 μg/mL, followed by diethyl ether and methanol extract (IC50 at 16.22 μg/mL and 37.15 μg/mL, respectively) at 72 h. The DeadEndTM Colorimetric Apoptosis Detection System confirmed the induction of apoptosis (via DNA fragmentation) in MCF-7 cells. Both butanol and diethyl ether extracts of B. gymnorrhiza significantly increase the caspase-3 level. However, the diethyl ether extract induced higher caspase-9 levels compared to caspase-8, suggesting that the intrinsic pathway was the major route in the process of apoptosis. Thin-layer chromatography profiling demonstrated the presence of phenolic, terpene, and alkaloid compounds in crude methanol, diethyl ether, and butanol extracts. The phytochemicals present in the extracts of B. gymnorrhiza might have the potential to be a future therapeutic agent against breast cancer.
  19. Fulltext Induction of Apoptosis by Acanthaster planci sp., and Diadema setosum sp., Fractions in Human Cervical Cancer Cell Line, HeLa
    Chaudhry GE, Islamiah M, Zafar MN, Bakar K, Aziz N, Saidin J, et al.
    Asian Pac J Cancer Prev, 2021 May 01;22(5):1365-1373.
    PMID: 34048163 DOI: 10.31557/APJCP.2021.22.5.1365
    Cancer is an uncontrolled multiplication of cells. The desire efficacy and severe toxicity of current anticancer drugs urge exploring and investigating a better alternative to existing chemotherapeutics. Natural products of marine origin are excellent sources of potential new drugs of enhanced biological activities.

    OBJECTIVES: Thus, the cytotoxic effects along with investigating the mode of cell death exerted by fractions, AP-9, AP-THR, DS-8 and DS-9 fraction of Acanthaster planci, Diadema setosum sp., on the human cervical cancer cell line, HeLa.

    METHODS: The cytotoxicity of fractions has determined by using an MTS assay. The early and late apoptosis was studied by using the High content Screening (HCS) instrument.

    RESULTS: The four fractions produced effective cytotoxicity effects with IC50 values at 72hr of less than 20 μg/ml in the order of AP-9 > DS-9 > APTHR-9 > DS-8. The fraction s exhibited cytotoxicity via mediating apoptotic mode of cell death. The early apoptosis by exposure of phosphatidylserine to the outer leaflet of the plasma membrane and late apoptosis due to the presence of green stain (DNA fragmentation) in treated cells.

    CONCLUSION: The potent bioactive compounds might be responsible for inducing apoptosis in cancer cells and, thus, the potential to be a successful candidate for exploring upcoming chemotherapeutic drugs.

  20. Fulltext Hippocampal amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid GluA1 (AMPA GluA1) receptor subunit involves in learning and memory improvement following treatment with Centella asiatica extract in adolescent rats
    Binti Mohd Yusuf Yeo NA, Muthuraju S, Wong JH, Mohammed FR, Senik MH, Zhang J, et al.
    Brain Behav, 2018 09;8(9):e01093.
    PMID: 30105867 DOI: 10.1002/brb3.1093
    INTRODUCTION: Centella asiatica is an herbal plant that contains phytochemicals that are widely believed to have positive effects on cognitive function. The adolescent stage is a critical development period for the maturation of brain processes that encompass changes in physical and psychological systems. However, the effect of C. asiatica has not been extensively studied in adolescents. The aim of this study was therefore to investigate the effects of a C. asiatica extract on the enhancement of learning and memory in adolescent rats.

    METHODS: The locomotor activity, learning, and memory were assessed by using open field test and water T-maze test. This study also examined changes in neuronal cell morphology using cresyl violet and apoptosis staining. We also performed immunohistochemical study to analyse the expression of the glutamate AMPA receptor (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) GluA1 subunit and the GABA receptor (γ-Aminobutyric Acid) subtype GABAA α1 subunit in the hippocampus of the same animals.

    RESULTS: We found no significant changes in locomotor activity (p > 0.05). The water T-maze data showed that 30 mg/kg dose significantly (p  0.05). Histological data revealed no neuronal morphological changes. Immunohistochemical analysis revealed increased expression of the AMPA GluA1 receptor subunit but there was no effect on GABAA receptor α1 subunit expression in the CA1 and CA2 subregions of the hippocampus.

    CONCLUSIONS: The C. asiatica extract therefore improved hippocampus-dependent spatial learning and memory in a dose-dependent manner in rats through the GluA1-containing AMPA receptor in the CA1 and CA2 sub regions of the hippocampus.

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