Displaying publications 21 - 40 of 161 in total

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  1. Jeyamogan S, Khan NA, Siddiqui R
    Arch Med Res, 2021 02;52(2):131-142.
    PMID: 33423803 DOI: 10.1016/j.arcmed.2020.10.016
    The number of cancer cases worldwide in terms of morbidity and mortality is a serious concern, despite the presence of therapeutic interventions and supportive care. Limitations in the current available diagnosis methods and treatments methods may contribute to the increase in cancer mortality. Theranostics, is a novel approach that has opened avenues for the simultaneous precise diagnosis and treatment for cancer patients. Although still in the early development stage, theranostic agents such as quantum dots, radioisotopes, liposomes and plasmonic nanobubbles can be bound to anticancer drugs, cancer cell markers and imaging agents, with the support of available imaging techniques, provide the potential to facilitate diagnosis, treatment and management of cancer patients. Herein, we discuss the potential benefits of several theranostic tools for the management of cancer. Specifically, quantum dots, radio-labelled isotopes, liposomes and plasmonic nanobubbles coupled with targeting agents and/or anticancer molecules and imaging agents as theranostic agents are deliberated upon in this review. Overall, the use of theranostic agents shows promise in cancer management. Nevertheless, intensive research is required to realize these expectations.
  2. Soopramanien M, Khan NA, Ghimire A, Sagathevan K, Siddiqui R
    Biology (Basel), 2020 Jul 02;9(7).
    PMID: 32630812 DOI: 10.3390/biology9070150
    Despite intensive research, cancer incidence and mortality continue to rise. Consequently, the necessity to develop effective anti-cancer therapy is apparent. We have recently shown that the gut bacteria of animals living in polluted environments, such as crocodiles, are a potential source of novel anti-tumor molecules. To extend this work to other resilient species, we investigated the anti-tumor effects of gut bacteria of Heterometrus spinifer (a scorpion). Bacteria from the feces and gut were isolated, identified and evaluated for their anti-tumor effects. Bacterial-conditioned media was prepared in Roswell Park Memorial Institute (RPMI) 1640 media, and cytotoxicity and growth inhibitory properties were examined against cervical (HeLa) cancer cells. Liquid chromatography-mass spectrometry (LC-MS) was conducted to establish the identity of the molecules. Eighteen bacteria species from the gut (HSG01-18) and ten bacteria species from feces (HSF01-10) were tested for anti-tumor effects. Bacterial-conditioned media from scorpion gut and feces exhibited significant growth inhibitory effects against HeLa cells of 66.9% and 83.8%, respectively. Microscopic analysis of cancer cells treated with conditioned media HSG12 and HSG16 revealed apoptosis-like effects. HSG12 was identified as Pseudomonas aeruginosa and HSG16 was identified as Bacillus subtilis. Both conditioned media exhibited 100% growth inhibitory effects versus a selection of cancer cells, comprising cervical, breast and prostate cancer cells. LC-MS indicated the presence of 72 and 38 compounds, detected from HSG12 and HSG16, respectively. Out of these compounds, 47 were successfully identified while the remainder were unidentified and are possibly novel. This study suggests that the fecal and gut microbiota of scorpions might possess molecules with anti-cancer properties, however, further intensive research is needed to assess these expectations.
  3. Masri A, Khan NA, Zoqratt MZHM, Ayub Q, Anwar A, Rao K, et al.
    BMC Microbiol, 2021 Feb 17;21(1):51.
    PMID: 33596837 DOI: 10.1186/s12866-021-02097-2
    BACKGROUNDS: Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study.

    RESULTS: 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P

  4. Rajendran K, Anwar A, Khan NA, Shah MR, Siddiqui R
    ACS Chem Neurosci, 2019 06 19;10(6):2692-2696.
    PMID: 30970208 DOI: 10.1021/acschemneuro.9b00111
    Primary amoebic meningoencephalitis (PAM), a deadly brain infection, is caused by brain-eating amoeba Naegleria fowleri. The current first line of treatment against PAM is a mixture of amphotericin B, rifampin, and miltefosine. Since, no single effective drug has been developed so far, the mortality rate is above 95%. Moreover, severe adverse side effects are associated with these drugs. Nanotechnology has provided several advances in biomedical applications especially in drug delivery and diagnosis. Herein, for the first time we report antiamoebic properties of cinnamic acid (CA) and gold nanoparticles conjugated with CA (CA-AuNPs) against N. fowleri. CA-AuNPs were successfully synthesized by sodium borohydride reduction of tetrachloroauric acid. Size and morphology were determined by atomic force microscopy (AFM) while the surface plasmon resonance band was analyzed by ultraviolet-visible (UV-vis) spectrophotometry for the characterization of the nanoparticles. Amoebicidal and cytopathogenicity (host cell cytotoxicity) assays revealed that both CA and CA-AuNPs displayed significant anti- N. fowleri properties ( P < 0.05), whereas nanoparticles conjugation further enhanced the anti- N. fowleri effects of CA. This study established a potential drug lead, while CA-AuNPs appear to be promising candidate for drug discovery against PAM.
  5. Mungroo MR, Khan NA, Anwar A, Siddiqui R
    Int Microbiol, 2021 Aug 09.
    PMID: 34368912 DOI: 10.1007/s10123-021-00201-0
    Pathogenic free-living amoebae are known to cause fatal central nervous system infections with extremely high mortality rates. High selectivity of the blood-brain barrier hampers delivery of drugs and untargeted delivery of drugs can cause severe side effects. Nanovehicles can be used for targeted drug delivery across the blood-brain barrier. Inorganic nanoparticles have been explored as carriers for various biomedical applications and can be modified with various ligands for efficient targeting and cell selectivity while lipid-based nanoparticles have been extensively used in the development of both precision and colloidal nanovehicles. Nanomicelles and polymeric nanoparticles can also serve as nanocarriers and may be modified so that responsiveness of the nanoparticles and release of the loads are linked to specific stimuli. These nanoparticles are discussed here in the context of the treatment of central nervous system infections due to pathogenic amoebae. It is anticipated that these novel strategies can be utilized in tandem with novel drug leads currently in the pipeline and yield in the development of much needed treatments against these devastating parasites.
  6. Soopramanien M, Khan NA, Sagathevan K, Siddiqui R
    Int Microbiol, 2021 Jan;24(1):47-56.
    PMID: 32737845 DOI: 10.1007/s10123-020-00139-9
    Pollution, unhygienic conditions and organic waste are detrimental to human health. On the contrary, animals living in polluted environments, feeding on organic waste and exposed to noxious agents such as heavy metals must possess remarkable properties against contracting diseases. Species such as cockroaches and water monitor lizards thrive in unhygienic conditions and feed on decaying matter. Here, we investigated the antitumour properties of metabolites produced by gut bacteria isolated from Varanus salvator (Asian water monitor lizard). An adult water monitor lizard and a juvenile water monitor lizard were acquired, and dissected. Their aerobic gut bacteria were isolated and identificated through 16S rDNA sequencing. Next, bacterial conditioned media (CM) were prepared and utilised for subsequent assays. Growth inhibition, MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay, cytotoxicity and cell survival assays were accomplished against a panel of cancer cells as well as a normal cell line. Furthermore, liquid chromatography-mass spectrometry (LC-MS) was employed to identify potential antitumour molecules. A plethora of bacteria were isolated from the gut of juvenile and adult V. salvator respectively. Moreover, CM prepared from selected bacteria exhibited antitumour activity. Of note, LC-MS results indicated the presence of several molecules with reported antitumour activity, namely, 3-butylidene-7-hydroxyphthalide, C75, enigmol, estrone 16-oxime, proglumide and S-allyl-L-cysteine. Furthermore, 356 potentially novel molecules from juvenile V. salvator and 184 from adult V. salvator were depicted. Thus, the gut microbiota of V. salvator might be considered as a great niche of antitumour molecules; however, further in vitro and in vivo studies are needed to assess the antitumour properties of these molecules.
  7. Jeyamogan S, Khan NA, Sagathevan K, Siddiqui R
    Anticancer Agents Med Chem, 2020;20(13):1558-1570.
    PMID: 32364082 DOI: 10.2174/1871520620666200504103056
    BACKGROUND: Cancer contributes to significant morbidity and mortality despite advances in treatment and supportive care. There is a need for the identification of effective anticancer agents. Reptiles such as tortoise, python, and water monitor lizards are exposed to heavy metals, tolerate high levels of radiation, feed on rotten/germ-infested feed, thrive in unsanitary habitat and yet have prolonged lifespans. Such species are rarely reported to develop cancer, suggesting the presence of anticancer molecules/mechanisms.

    METHODS: Here, we tested effects from sera of Asian water monitor lizard (Varanus salvator), python (Malayopython reticulatus) and tortoise (Cuora kamaroma amboinensis) against cancer cells. Sera were collected and cytotoxicity assays were performed using prostate cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7), as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid chromatography mass spectrometry was performed for molecular identification.

    RESULTS: The findings revealed that reptilian sera, but not bovine serum, abolished viability of Hela, PC3 and MCF7 cells. Samples were subjected to liquid chromatography mass spectrometry, which detected 57 molecules from V. salvator, 81 molecules from Malayopython reticulatus and 33 molecules from C. kamaroma amboinensis and putatively identified 9 molecules from V. salvator, 20 molecules from Malayopython reticulatus and 9 molecules from C. kamaroma amboinensis when matched against METLIN database. Based on peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 123 potential Anticancer Peptides (ACPs) were identified from 883 peptides from V. salvator, 306 potential ACPs from 1074 peptides from Malayopython reticulatus and 235 potential ACPs from 885 peptides from C. kamaroma amboinensis.

    CONCLUSION: To our knowledge, for the first time, we reported comprehensive analyses of selected reptiles' sera using liquid chromatography mass spectrometry, leading to the identification of potentially novel anticancer agents. We hope that the discovery of molecules from these animals will pave the way for the rational development of new anticancer agents.

  8. Soopramanien M, Khan NA, Abdalla SAO, Sagathevan K, Siddiqui R
    Asian Pac J Cancer Prev, 2020 Oct 01;21(10):3011-3018.
    PMID: 33112561 DOI: 10.31557/APJCP.2020.21.10.3011
    OBJECTIVES: It is noteworthy that several animal species are known to withstand high levels of radiation, and are exposed to heavy metals but rarely been reported to develop cancer. For example, the scorpion has been used as folk medicine in ancient civilizations of Iran and China, while amphibian skin is known to possess medicinal properties. Here, we elucidated the anti-tumour activity of the scorpion (Uropygi) and frog (Lithobates catesbeianus).

    MATERIALS AND METHODS: Animals were procured and their organ lysates and sera were prepared and tested against Michigan Cancer Foundation-7 breast cancer (MCF-7), prostate cancer (PC3), Henrietta Lacks cervical cancer (HeLa), and normal human keratinocyte cells. Exoskeleton, appendages and hepatopancreas were dissected from the scorpion, whereas liver, lungs, heart, oviduct, gastrointestinal tract, gall bladder, kidneys, eggs and sera were collected from frog and organ lysates/sera were prepared. Growth inhibition assays and cytotoxicity assays were performed.

    RESULTS: Appendages, exoskeleton lysates, and hepatopancreas from scorpion exhibited potent growth inhibition, and cytotoxic effects. Furthermore, lungs, liver, gastrointestinal tract, heart, oviduct, kidneys, eggs, and sera from frog displayed growth inhibition and cytotoxic effects.

    CONCLUSION: Organ lysates, sera of scorpion, and amphibians possess anti-tumour activities. This is a worthy area of research as the molecular identity of the active molecule(s) together with their mechanism of action will lead to the rational development of novel anticancer agent(s).

  9. Khan NA, Soopramanien M, Maciver SK, Anuar TS, Sagathevan K, Siddiqui R
    Molecules, 2021 Aug 18;26(16).
    PMID: 34443585 DOI: 10.3390/molecules26164999
    Crocodiles are remarkable animals that have the ability to endure extremely harsh conditions and can survive up to a 100 years while being exposed to noxious agents that are detrimental to Homo sapiens. Besides their immunity, we postulate that the microbial gut flora of crocodiles may produce substances with protective effects. In this study, we isolated and characterized selected bacteria colonizing the gastrointestinal tract of Crocodylusporosus and demonstrated their inhibitory effects against three different cancerous cell lineages. Using liquid chromatography-mass spectrometry, several molecules were identified. For the first time, we report partial analyses of crocodile's gut bacterial molecules.
  10. Soopramanien M, Khan NA, Siddiqui R
    J Appl Microbiol, 2021 Sep;131(3):1039-1055.
    PMID: 33368930 DOI: 10.1111/jam.14981
    Cancer is a prominent cause of morbidity and mortality worldwide, in spite of advances in therapeutic interventions and supportive care. In 2018 alone, there were 18·1 million new cancer cases and 9·6 million deaths indicating the need for novel anticancer agents. Plant-based products have often been linked with protective effects against communicable and non-communicable diseases. Recently, we have shown that animals such as crocodiles thrive in polluted environments and are often exposed to carcinogenic agents, but still benefit from prolonged lifespan. The protective mechanisms shielding them from cancer could be attributed to the immune system, and/or it is possible that their gut microbiota produce anticancer molecules. In support, several lines of evidence suggest that gut microbiota plays a critical role in the physiology of its host. Here, we reviewed the available literature to assess whether the gut microbiota of animals thriving in polluted environment possess anticancer molecules.
  11. Khan NA, Anwar A, Siddiqui R
    Curr Med Chem, 2018 May 10.
    PMID: 29745319 DOI: 10.2174/0929867325666180510125633
    BACKGROUND: First discovered in the early 1970s, Acanthamoeba keratitis has remained a major eye infection and presents a significant threat to the public health, especially in developing countries. The aim is to present a timely review of our current understanding of the advances made in this field in a comprehensible manner and includes novel concepts and provides clear directions for immediate research priorities.

    METHOD: We undertook a search of bibliographic databases for peer-reviewed research literature and also summarized our published results in this field.

    RESULTS: The present review focuses on novel diagnostic and therapeutic strategies in details which can provide access to management and treatment of Acanthamoeba keratitis. This coupled with the recently available genome sequence information together with high throughput genomics technology and innovative approaches should stimulate interest in the rational design of preventative and therapeutic measures. Current treatment of Acanthamoeba keratitis is problematic and often leads to infection recurrence. Better understanding of diagnosis, pathogenesis, pathophysiology and therapeutic regimens, would lead to novel strategies in treatment and prophylaxis.

  12. Jeyamogan S, Khan NA, Anwar A, Shah MR, Siddiqui R
    SAGE Open Med, 2018;6:2050312118781962.
    PMID: 30034805 DOI: 10.1177/2050312118781962
    Objectives: To synthesize novel compounds belonging to Benzodioxane, Naphthalene diimide, Aminophenol derivatives and Porphyrin classes and test their potential anticancer properties.

    Methods: Several compounds were synthesized and their molecular identity was confirmed using nuclear magnetic resonance. Potential anticancer properties were determined using cytopathogenicity assays and growth inhibition assays using cervical cancer cells (HeLa). Cells were incubated with different concentrations of compounds belonging to Benzodioxane, Naphthalene diimide, Aminophenol derivatives and Porphyrins and effects were determined. HeLa cells cytopathogenicity was determined by measuring lactate dehydrogenase release using cytotoxicity detection assay. Growth inhibition assays were performed by incubating 50% semi-confluent HeLa cells with Benzodioxane, Naphthalene diimide, Aminophenol derivatives and Porphyrin compounds and HeLa cell proliferation was observed. Growth inhibition and host cell death were compared in the presence and absence of drugs.

    Results: Cytopathogenicity assays showed that the selected compounds were cytotoxic against HeLa cells, killing up to 90% of cells. Growth inhibition assays exhibited 100% growth inhibition. These effects are likely via oxidative stress, production of reactive oxygen species, changes in cytosolic and intracellular calcium/adenine nucleotide homeostasis, inhibition of ribonucleotide reductase/cyclooxygenase and/or glutathione depletion.

    Conclusions: Benzodioxane, Naphthalene diimide, Aminophenol derivatives and Porphyrins exhibited potent anticancer properties. These findings are promising and should pave the way in the rationale development of anticancer drugs. Using different cancer cell lines, future studies will determine their potential as anti-tumour agents as well as their precise molecular mode of action.

  13. Jeyamogan S, Khan NA, Sagathevan K, Siddiqui R
    Anticancer Agents Med Chem, 2019;19(18):2251-2268.
    PMID: 31660845 DOI: 10.2174/1871520619666191011161314
    BACKGROUND: Species of crocodiles and cockroaches can withstand high radiation, reside in unsanitary conditions, thrive on germ-infested feed, and are exposed to heavy metals, yet they are not reported to develop cancer. It has been postulated that such species have mechanisms to defend themselves against developing cancer. Here, selected species have been tested for potential cytotoxicity against selected cancer cell lines.

    METHODS: In this study, various species of vertebrates and invertebrates were procured including Columba livia, Gallus gallus domesticus, Varanus salvator, Cuora kamamora amboinensis, Reticulatus malayanus, Oreochromis mossambicus, Rattus rattus, American bullfrog, Donax sp., Polymesoda coaxans, Tenebrio molitor, Lumbricus terrestris, Blatta lateralis, Grammostola rosea, and Penaeus monodon. Species were dissected and their organ lysates/sera/haemolymph were prepared. Cytotoxicity assays were performed using Prostate Cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7) as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid Chromatography-Mass Spectrometry (LC-MS/MS) was performed for molecular identification.

    RESULTS: The results revealed that body lysates of Polymesoda coaxans demonstrated more than 99% growth inhibition of all cancer cell lines tested but not on normal Hacat cells. More importantly, the serum of M. reticulatus abolished growth and produced cytotoxicity. Hence these samples were subjected to Liquid Chromatography- Mass Spectrometry (LC-MS/MS), which detected 81 small molecules and putatively identified 20 molecules when matched against the METLIN database. Out of 1094 peptides, 21 peptides were identified, while 1074 peptides were categorized as novel peptides. Based on properties such as peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 306 potential peptides were identified.

    CONCLUSION: To our knowledge, here for the first time, we report a comprehensive analysis of sera exhibiting cytotoxicity against cancer cell lines tested and identified several molecules using LC-MS/MS.

  14. Mungroo MR, Shahbaz MS, Anwar A, Saad SM, Khan KM, Khan NA, et al.
    ACS Chem Neurosci, 2020 08 19;11(16):2438-2449.
    PMID: 31961126 DOI: 10.1021/acschemneuro.9b00596
    Naegleria fowleri and Balamuthia mandrillaris are protist pathogens that infect the central nervous system, causing primary amoebic meningoencephalitis and granulomatous amoebic encephalitis with mortality rates of over 95%. Quinazolinones and their derivatives possess a wide spectrum of biological properties, but their antiamoebic effects against brain-eating amoebae have never been tested before. In this study, we synthesized a variety of 34 novel arylquinazolinones derivatives (Q1-Q34) by altering both quinazolinone core and aryl substituents. To study the antiamoebic activity of these synthetic arylquinazolinones, amoebicidal and amoebistatic assays were performed against N. fowleri and B. mandrillaris. Moreover, amoebae-mediated host cells cytotopathogenicity and cytotoxicity assays were performed against human keratinocytes cells in vitro. The results revealed that selected arylquinazolinones derivatives decreased the viability of B. mandrillaris and N. fowleri significantly (P < 0.05) and reduced cytopathogenicity of both parasites. Furthermore, these compounds were also found to be least cytotoxic against HaCat cells. Considering that nanoparticle-based materials possess potent in vitro activity against brain-eating amoebae, we conjugated quinazolinones derivatives with silver nanoparticles and showed that activities of the drugs were enhanced successfully after conjugation. The current study suggests that quinazolinones alone as well as conjugated with silver nanoparticles may serve as potent therapeutics against brain-eating amoebae.
  15. Anwar A, Khan NA, Siddiqui R
    ACS Chem Neurosci, 2020 08 19;11(16):2378-2384.
    PMID: 32073257 DOI: 10.1021/acschemneuro.9b00613
    Brain-eating amoebae including Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris cause rare infections of the central nervous system that almost always result in death. The high mortality rate, lack of interest for drug development from pharmaceutical industries, and no available effective drugs present an alarming challenge. The current drugs employed in the management and therapy of these devastating diseases are amphotericin B, miltefosine, chlorhexidine, pentamidine, and voriconazole which are generally used in combination. However, clinical evidence shows that these drugs have limited efficacy and high host cell cytotoxicity. Repurposing of drugs is a practical approach to utilize commercially available, U.S. Food and Drug Administration approved drugs for one disease against rare diseases caused by brain-eating amoebae. In this Perspective, we highlight some of the success stories of drugs repositioned against neglected parasitic diseases and identify future potential for effective and sustainable drug development against brain-eating amoebae infections.
  16. Anwar A, Masri A, Rao K, Rajendran K, Khan NA, Shah MR, et al.
    Sci Rep, 2019 02 28;9(1):3122.
    PMID: 30816269 DOI: 10.1038/s41598-019-39528-0
    Herein, we report green synthesized nanoparticles based on stabilization by plant gums, loaded with citrus fruits flavonoids Hesperidin (HDN) and Naringin (NRG) as novel antimicrobial agents against brain-eating amoebae and multi-drug resistant bacteria. Nanoparticles were thoroughly characterized by using zetasizer, zeta potential, atomic force microscopy, ultravoilet-visible and Fourier transform-infrared spectroscopic techniques. The size of these spherical nanoparticles was found to be in the range of 100-225 nm. The antiamoebic effects of these green synthesized Silver and Gold nanoparticles loaded with HDN and NRG were tested against Acanthamoeba castellanii and Naegleria fowleri, while antibacterial effects were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and neuropathogenic Escherichia coli K1. Amoebicidal assays revealed that HDN loaded Silver nanoparticles stabilized by gum acacia (GA-AgNPs-HDN) quantitatively abolished amoeba viability by 100%, while NRG loaded Gold nanoparticles stabilized by gum tragacanth (GT-AuNPs-NRG) significantly reduced the viability of A. castellanii and N. fowleri at 50 µg per mL. Furthermore, these nanoparticles inhibited the encystation and excystation by more than 85%, as well as GA-AgNPs-HDN only completely obliterated amoeba-mediated host cells cytopathogenicity. Whereas, GA-AgNPs-HDN exhibited significant bactericidal effects against MRSA and E. coli K1 and reduced bacterial-mediated host cells cytotoxicity. Notably, when tested against human cells, these nanoparticles showed minimal (23%) cytotoxicity at even higher concentration of 100 µg per mL as compared to 50 µg per mL used for antimicrobial assays. Hence, these novel nanoparticles formulations hold potential as therapeutic agents against infections caused by brain-eating amoebae, as well as multi-drug resistant bacteria, and recommend a step forward in drug development.
  17. Gabriel S, Khan NA, Siddiqui R
    J Water Health, 2019 Feb;17(1):160-171.
    PMID: 30758312 DOI: 10.2166/wh.2018.164
    The aim of this study was to determine the occurrence of free-living amoebae (FLA) in Peninsular Malaysia and to compare different methodologies to detect them from water samples. Water samples were collected from tap water, recreational places, water dispensers, filtered water, etc. and tested for FLA using both cultivation and polymerase chain reaction (PCR) via plating assays and centrifugation methods. Amoebae DNA was extracted using Instagene matrix and PCR was performed using genus-specific primers. Of 250 samples, 142 (56.8%) samples were positive for presence of amoebae, while 108 (43.2%) were negative. Recreational water showed higher prevalence of amoebae than tap water. PCR for the plating assays revealed the presence of Acanthamoeba in 91 (64%) samples and Naegleria in 99 (70%) of samples analysed. All samples tested were negative for B. mandrillaris. In contrast, the centrifugation method was less effective in detecting amoebae as only one sample revealed the presence of Acanthamoeba and 52 (29%) samples were positive for Naegleria. PCR assays were specific and sensitive, detecting as few as 10 cells. These findings show the vast distribution and presence of FLA in all 11 states of Peninsular Malaysia. Further studies could determine the possible presence of pathogenic species and strains of free-living amoebae in public water supplies in Malaysia.
  18. Mungroo MR, Anwar A, Khan NA, Siddiqui R
    Mini Rev Med Chem, 2019;19(12):980-987.
    PMID: 30868950 DOI: 10.2174/1389557519666190313161854
    Pathogenic free-living amoeba are known to cause a devastating infection of the central nervous system and are often referred to as "brain-eating amoebae". The mortality rate of more than 90% and free-living nature of these amoebae is a cause for concern. It is distressing that the mortality rate has remained the same over the past few decades, highlighting the lack of interest by the pharmaceutical industry. With the threat of global warming and increased outdoor activities of public, there is a need for renewed interest in identifying potential anti-amoebic compounds for successful prognosis. Here, we discuss the available chemotherapeutic options and opportunities for potential strategies in the treatment and diagnosis of these life-threatening infections.
  19. Mungroo MR, Anwar A, Khan NA, Siddiqui R
    ACS Omega, 2020 Jun 02;5(21):12467-12475.
    PMID: 32548431 DOI: 10.1021/acsomega.0c01305
    Balamuthia mandrillaris and Naegleria fowleri are free-living amoebae that cause infection of the central nervous system, granulomatous amoebic encephalitis (GAE) and primary amoebic meningoencephalitis (PAM), respectively. The fact that mortality rates for cases of GAE and PAM are more than 95% indicates the need for new therapeutic agents against those amoebae. Considering that curcumin exhibits a wide range of biological properties and has shown efficacy against Acanthamoeba castellanii, we evaluated the amoebicidal properties of curcumin against N. fowleri and B. mandrillaris. Curcumin showed significant amoebicidal activities with an AC50 of 172 and 74 μM against B. mandrillaris and N. fowleri, respectively. Moreover, these compounds were also conjugated with gold nanoparticles to further increase their amoebicidal activities. After conjugation with gold nanoparticles, amoebicidal activities of the drugs were increased by up to 56 and 37% against B. mandrillaris and N. fowleri, respectively. These findings are remarkable and suggest that clinically available curcumin and our gold-conjugated curcumin nanoparticles hold promise in the improved treatment of fatal infections caused by brain-eating amoebae and should serve as a model in the rationale development of therapeutic interventions against other infections.
  20. Jeyamogan S, Khan NA, Siddiqui R
    Asian Pac J Cancer Prev, 2021 Feb 12;22(S1):97-106.
    PMID: 33576218 DOI: 10.31557/APJCP.2021.22.S1.97
    OBJECTIVES: Here we determined antitumour effects of purified compounds such as Valdecoxib, Rofecoxib, L-Methionine and Artocarpin against cancer cell lines.

    METHODS: Using purified compounds, assays were performed to determine their effects against cancer cell lines using growth inhibition assays, cytotoxicity assays, and cell survival assays against HeLa, PC3 and MCF7 cells.

    RESULTS: The results showed that the selected small molecules L-Methionine, Rofecoxib, and Artocarpin suppressed the growth of more than 90% PC3 cells at 40µM. Similarly, Valdecoxib alone and in combination with other molecules exhibited potent growth inhibition and cytotoxicity against cancer cells tested. Peptide from the serum of M. reticulatus, demonstrated selective cytotoxicity against cancer cells without inhibiting the growth of normal cells.

    CONCLUSION: These findings are significant and provide a basis for the rational development of therapeutic anticancer agents, however intensive research is needed to determine in vivo effects of the identified molecules together with their mode of action to realize these expectations. 
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