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Anwar A, Khan NA, Alharbi AM, Alhazmi A, Siddiqui R. Applications of photodynamic therapy in keratitis. Int Ophthalmol 2024; 44:140. [PMID: 38491335 DOI: 10.1007/s10792-024-03062-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 02/16/2024] [Indexed: 03/18/2024]
Abstract
Keratitis is corneal inflammatory disease which may be caused by several reason such as an injury, allergy, as well as a microbial infection. Besides these, overexposure to ultraviolet light and unhygienic practice of contact lenses are also associated with keratitis. Based on the cause of keratitis, different lines of treatments are recommended. Photodynamic therapy is a promising approach that utilizes light activated compounds to instigate either killing or healing mechanism to treat various diseases including both communicable and non-communicable diseases. This review focuses on clinically-important patent applications and the recent literature for the use of photodynamic therapy against keratitis.
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Affiliation(s)
- Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Petaling Jaya, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
| | - Ahmad M Alharbi
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, 21944, Taif, Saudi Arabia
| | - Ayman Alhazmi
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, 21944, Taif, Saudi Arabia
| | - Ruqaiyyah Siddiqui
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh, EH14 4AS, UK
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Ning X, He G, Zeng W, Xia Y. The photosensitizer-based therapies enhance the repairing of skin wounds. Front Med (Lausanne) 2022; 9:915548. [PMID: 36035433 PMCID: PMC9403269 DOI: 10.3389/fmed.2022.915548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/26/2022] [Indexed: 11/29/2022] Open
Abstract
Wound repair remains a clinical challenge and bacterial infection is a common complication that may significantly delay healing. Therefore, proper and effective wound management is essential. The photosensitizer-based therapies mainly stimulate the photosensitizer to generate reactive oxygen species through appropriate excitation source irradiation, thereby killing pathogenic microorganisms. Moreover, they initiate local immune responses by inducing the recruitment of immune cells as well as the production of proinflammatory cytokines. In addition, these therapies can stimulate the proliferation, migration and differentiation of skin resident cells, and improve the deposition of extracellular matrix; subsequently, they promote the re-epithelialization, angiogenesis, and tissue remodeling. Studies in multiple animal models and human skin wounds have proved that the superior sterilization property and biological effects of photosensitizer-based therapies during different stages of wound repair. In this review, we summarize the recent advances in photosensitizer-based therapies for enhancing tissue regeneration, and suggest more effective therapeutics for patients with skin wounds.
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Affiliation(s)
- Xiaoying Ning
- Department of Dermatology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Gang He
- State Key Laboratory for Strength and Vibration of Mechanical Structures, Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an, China
- Xi’an Key Laboratory of Sustainable Energy Materials Chemistry, Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Weihui Zeng
- Department of Dermatology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Yumin Xia
- Department of Dermatology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- *Correspondence: Yumin Xia,
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Wehelie YI, Khan NA, Fatima I, Anwar A, Kanwal K, Khan KM, Siddiqui R, Tong YK, Anwar A. Novel Tetrazoles against Acanthamoeba castellanii Belonging to the T4 Genotype. Chemotherapy 2021; 67:183-192. [PMID: 34724675 DOI: 10.1159/000520585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 10/31/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Acanthamoeba castellanii is a pathogenic free-living amoeba responsible for blinding keratitis and fatal granulomatous amoebic encephalitis. However, treatments are not standardized but can involve the use of amidines, biguanides, and azoles. OBJECTIVES The aim of this study was to synthesize a variety of synthetic tetrazole derivatives and test their activities against A. castellanii. METHODS A series of novel tetrazole compounds were synthesized by one-pot method and characterized by NMR and mass spectroscopy. These compounds were subjected to amoebicidal, and cytotoxicity assays against A. castellanii belonging to the T4 genotype and human keratinocyte skin cells respectively. Additionally, reactive oxygen species determination and electron microscopy studies were carried out. Furthermore, two of the seven compounds were conjugated with silver nanoparticles to study their antiamoebic potential. RESULTS A series of seven tetrazole derivatives were synthesized successfully. The selected tetrazoles showed anti-amoebic activities at 10µM concentration against A. castellanii in vitro. The compounds tested caused increased reactive oxygen species generation in A castellanii, and significant morphological damage to amoebal membranes. Moreover, conjugation of silver nanoparticles enhanced antiamoebic effects of two tetrazoles. CONCLUSIONS The results showed that azole compounds hold promise in the development of new formulations of anti-Acanthamoebic agents.
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Affiliation(s)
- Yassmin Isse Wehelie
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Itrat Fatima
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Areeba Anwar
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Kanwal Kanwal
- Institute of Marine Biotechnology, University Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Khalid M Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Yuh Koon Tong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Selangor, Malaysia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Selangor, Malaysia
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Ahmed U, Anwar A, Ong SK, Anwar A, Khan NA. Applications of medicinal chemistry for drug discovery against Acanthamoeba infections. Med Res Rev 2021; 42:462-512. [PMID: 34472107 DOI: 10.1002/med.21851] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 07/13/2021] [Accepted: 08/17/2021] [Indexed: 01/16/2023]
Abstract
Acanthamoeba is a genus of free-living amoebae, pervasively found in the environment. Most of its pathogenic species are the causative agent of sight-threatening Acanthamoeba keratitis and fatal granulomatous amoebic encephalitis. Despite the advancements in the field of chemotherapy, treating Acanthamoeba infections is still challenging due to incomplete knowledge of the complicated pathophysiology. In case of infection, the treatment regimen for the patients is often ineffective due to delayed diagnosis, poor specificity, and side-effects. Besides the resistance of Acanthamoeba cysts to most of the drugs, the recurrence of infection further complicates the recovery. Thus, it is necessary to develop an effective treatment which can eradicate these rare, but serious infections. Based on various computational and in vitro studies, it has been established that the synthetic scaffolds such as heterocyclic compounds may act as potential drug leads for the development of antiamoebic drugs. In this review, we report different classes of synthetic compounds especially heterocyclic compounds which have shown promising results against Acanthamoeba. Moreover, the antiamoebic activities of synthetic compounds with their possible mode of actions against Acanthamoeba, have been summarized and discussed in this review.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Seng-Kai Ong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Areeba Anwar
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lampur, Malaysia
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE
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Siddiqui R, Makhlouf Z, Khan NA. The Increasing Importance of Vermamoeba vermiformis. J Eukaryot Microbiol 2021; 68:e12857. [PMID: 33987951 DOI: 10.1111/jeu.12857] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Vermamoeba vermiformis are one of the most prevalent free-living amoebae. These amoebae are ubiquitous and also thermotolerant. Of concern, V. vermiformis have been found in hospital water networks. Furthermore, associations between V. vermiformis and pathogenic bacteria have been reported, such as Legionella pneumophila. Moreover, V. vermiformis are well known to host viruses, bacteria, and other microorganisms and cases of keratitis due to V. vermiformis in conjunction with other amoebae have been reported. Despite the preceding, the medical importance of V. vermiformis is still an ongoing discussion and its genome has been only recently sequenced. Herein, we present a review of the current understanding of the biology and pathogenesis pertaining to V. vermiformis, as well as its' role as an etiological agent and trojan horse. An approach known as theranostics which combines both diagnosis and therapy could be utilized to eradicate and diagnose keratitis cases caused by such amoebae. Given the rise in global warming, it is imperative to investigate these rarely studied amoebae and to understand their importance in human health.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, Sharjah, UAE
| | - Zinb Makhlouf
- College of Arts and Sciences, American University of Sharjah, Sharjah, UAE
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE.,Research Institute for Medical and Health Sciences, University of Sharjah, Sharjah, UAE
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Masri A, Abdelnasir S, Anwar A, Iqbal J, Numan A, Jagadish P, Shahabuddin S, Khalid M. Antimicrobial properties of multifunctional polypyrrole-cobalt oxide-silver nanocomposite against pathogenic bacteria and parasite. Appl Microbiol Biotechnol 2021; 105:3315-3325. [PMID: 33797573 DOI: 10.1007/s00253-021-11221-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 02/15/2021] [Accepted: 03/03/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Conducting polymer based nanocomposites are known to be effective against pathogens. Herein, we report the antimicrobial properties of multifunctional polypyrrole-cobalt oxide-silver nanocomposite (PPy-Co3O4-AgNPs) for the first time. Antibacterial activities were tested against multi-drug-resistant Gram-negative Escherichia coli (E. coli) and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) bacteria, while antiamoebic effects were assessed against opportunistic protist Acanthamoeba castellanii (A. castellanii). RESULTS The ternary nanocomposite containing conducting polymer polypyrrole, cobalt oxide, and silver nanoparticles showed potent antimicrobial effects against these pathogens. The antibacterial assay showed that PPy-Co3O4-AgNPs exhibited significant bactericidal activity against neuropathogenic E. coli K1 at only 8 μg/mL as compared to individual components of the nanocomposite, whereas a 70 % inhibition of A. castellanii viability was observed at 50 μg/mL. Moreover, PPy-Co3O4-AgNPs were found to have minimal cytotoxicity against human keratinocytes HaCaT cells in vitro even at higher concentration (50 μg/mL), and also reduced the microbes-mediated cytopathogenicity against host cells. CONCLUSION These results demonstrate that PPy-Co3O4-AgNPs hold promise in the development of novel antimicrobial nanomaterials for biomedical applications. KEY POINTS •Synthesis of polypyrrole-cobalt oxide-silver (PPy-Co3O4-AgNPs) nanocomposite. •Antimicrobial activity of nanocomposite. •PPy-Co3O4-AgNPs hold promise for biomedical applications.
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Affiliation(s)
- Abdulkader Masri
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Sumayah Abdelnasir
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
| | - Javed Iqbal
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
- Center of Nanotechnology, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Arshid Numan
- Graphene and Advanced 2D Materials Research Group, School of Engineering and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Priyanka Jagadish
- Graphene and Advanced 2D Materials Research Group, School of Engineering and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Syed Shahabuddin
- Department of Science, School of Technology, Pandit Deendayal Petroleum University, Knowledge Corridor, Gandhi Nagar, Gujarat, 382007, India
| | - Mohammad Khalid
- Graphene and Advanced 2D Materials Research Group, School of Engineering and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
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Isoniazid Conjugated Magnetic Nanoparticles Loaded with Amphotericin B as a Potent Antiamoebic Agent against Acanthamoeba castellanii. Antibiotics (Basel) 2020; 9:antibiotics9050276. [PMID: 32466210 PMCID: PMC7277095 DOI: 10.3390/antibiotics9050276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 01/02/2023] Open
Abstract
The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC50 of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells.
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Anwar A, Soomaroo A, Anwar A, Siddiqui R, Khan NA. Metformin-coated silver nanoparticles exhibit anti-acanthamoebic activities against both trophozoite and cyst stages. Exp Parasitol 2020; 215:107915. [PMID: 32461112 DOI: 10.1016/j.exppara.2020.107915] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022]
Abstract
Acanthamoeba castellanii is an opportunistic protozoan responsible for serious human infections including Acanthamoeba keratitis and granulomatous amoebic encephalitis. Despite advances in antimicrobial therapy and supportive care, infections due to Acanthamoeba are a major public concern. Current methods of treatment are not fully effective against both the trophozoite and cyst forms of A. castellanii and are often associated with severe adverse effects, host cell cytotoxicity and recurrence of infection. Therefore, there is an urgent need to develop new therapeutic approaches for the treatment and management of Acanthamoebic infections. Repurposing of clinically approved drugs is a viable avenue for exploration and is particularly useful for neglected and rare diseases where there is limited interest by pharmaceutical companies. Nanotechnology-based drug delivery systems offer promising approaches in the biomedical field, particularly in diagnosis and drug delivery. Herein, we conjugated an antihyperglycemic drug, metformin with silver nanoparticles and assessed its anti-acanthamoebic properties. Characterization by ultraviolet-visible spectrophotometry and atomic force microscopy showed successful formation of metformin-coated silver nanoparticles. Amoebicidal and amoebistatic assays revealed that metformin-coated silver nanoparticles reduced the viability and inhibited the growth of A. castellanii significantly more than metformin and silver nanoparticles alone at both 5 and 10 μM after 24 h incubation. Metformin-coated silver nanoparticles also blocked encystation and inhibited the excystation in Acanthamoeba after 72 h incubation. Overall, the conjugation of metformin with silver nanoparticles was found to enhance its antiamoebic effects against A. castellanii. Furthermore, the pretreatment of A. castellanii with metformin and metformin-coated silver nanoparticles for 2 h also reduced the amoebae-mediated host cell cytotoxicity after 24 h incubation from 73% to 10% at 10 μM, indicating that the drug-conjugated silver nanoparticles confer protection to human cells. These findings suggest that metformin-coated silver nanoparticles hold promise in the improved treatment and management of Acanthamoeba infections.
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Affiliation(s)
- Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, 47500, Selangor, Malaysia.
| | - Akshinee Soomaroo
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, 47500, Selangor, Malaysia
| | - Areeba Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, 47500, Selangor, Malaysia
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah, 26666, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah, 26666, United Arab Emirates
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Drug Discovery against Acanthamoeba Infections: Present Knowledge and Unmet Needs. Pathogens 2020; 9:pathogens9050405. [PMID: 32456110 PMCID: PMC7281112 DOI: 10.3390/pathogens9050405] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022] Open
Abstract
Although major strides have been made in developing and testing various anti-acanthamoebic drugs, recurrent infections, inadequate treatment outcomes, health complications, and side effects associated with the use of currently available drugs necessitate the development of more effective and safe therapeutic regimens. For any new anti-acanthamoebic drugs to be more effective, they must have either superior potency and safety or at least comparable potency and an improved safety profile compared to the existing drugs. The development of the so-called 'next-generation' anti-acanthamoebic agents to address this challenge is an active area of research. Here, we review the current status of anti-acanthamoebic drugs and discuss recent progress in identifying novel pharmacological targets and new approaches, such as drug repurposing, development of small interfering RNA (siRNA)-based therapies and testing natural products and their derivatives. Some of the discussed approaches have the potential to change the therapeutic landscape of Acanthamoeba infections.
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Anwar A, Yi YP, Fatima I, Khan KM, Siddiqui R, Khan NA, Anwar A. Antiamoebic activity of synthetic tetrazoles against Acanthamoeba castellanii belonging to T4 genotype and effects of conjugation with silver nanoparticles. Parasitol Res 2020; 119:1943-1954. [PMID: 32385711 DOI: 10.1007/s00436-020-06694-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/15/2020] [Indexed: 01/16/2023]
Abstract
Acanthamoeba causes diseases such as Acanthamoeba keratitis (AK) which leads to permanent blindness and granulomatous Acanthamoeba encephalitis (GAE) where there is formation of granulomas in the brain. Current treatments such as chlorhexidine, diamidines, and azoles either exhibit undesirable side effects or require immediate and prolonged treatment for the drug to be effective or prevent relapse. Previously, antifungal drugs amphotericin B, nystatin, and fluconazole-conjugated silver with nanoparticles have shown significantly increased activity against Acanthamoeba castellanii. In this study, two functionally diverse tetrazoles were synthesized, namely 5-(3-4-dimethoxyphenyl)-1H-tetrazole and 1-(3-methoxyphenyl)-5-phenoxy-1H-tetrazole, denoted by T1 and T2 respectively. These compounds were evaluated for anti-Acanthamoeba effects at different concentrations ranging from 5 to 50 μM. Furthermore, these compounds were conjugated with silver nanoparticles (AgNPs) to enhance their efficacy. Particle size analysis showed that T1-AgNPs and T2-AgNPs had an average size of 52 and 70 nm respectively. After the successful synthesis and characterization of tetrazoles and tetrazole-conjugated AgNPs, they were subjected to anti-Acanthamoeba studies. Amoebicidal assay showed that at concentration 10 μM and above, T2 showed promising antiamoebic activities between the two compounds while encystation and excystation assays reveal that both T1 and T2 have inhibited differentiation activity against Acanthamoeba castellanii. Conjugation of T1 and T2 to AgNP also increased efficacy of tetrazoles as anti-Acanthamoeba agents. This may be due to the increased bioavailability as AgNP allows better delivery of treatment compounds to A. castellanii. Human cell cytotoxicity assay revealed that tetrazoles and AgNPs are significantly less toxic towards human cells compared with chlorhexidine which is known to cause undesirable side effects. Cytopathogenicity assay also revealed that T2 conjugated with AgNPs significantly reduced cytopathogenicity of A. castellanii compared with T2 alone, suggesting that T2-conjugated AgNP is an effective and safe anti-Acanthamoeba agent. The use of a synthetic azole compound conjugated with AgNPs can be an alternative strategy for drug development against A. castellanii. However, mechanistic and in vivo studies are needed to explore further translational values.
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Affiliation(s)
- Areeba Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Yim Pei Yi
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Itrat Fatima
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan.,Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, 31441, Saudi Arabia
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah, 26666, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah, 26666, United Arab Emirates
| | - Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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Pertiwi YD, Chikama T, Sueoka K, Ko JA, Kiuchi Y, Onodera M, Sakaguchi T. Antimicrobial Photodynamic Therapy with the photosensitizer TONS504 eradicates Acanthamoeba. Photodiagnosis Photodyn Ther 2019; 28:166-171. [DOI: 10.1016/j.pdpdt.2019.08.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 11/24/2022]
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Khan NA, Anwar A, Siddiqui R. Acanthamoeba Keratitis: Current Status and Urgent Research Priorities. Curr Med Chem 2019; 26:5711-5726. [DOI: 10.2174/0929867325666180510125633] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/10/2018] [Accepted: 05/01/2018] [Indexed: 12/13/2022]
Abstract
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.Methods: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.
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Affiliation(s)
- Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Ayaz Anwar
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
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Anwar A, Siddiqui R, Khan NA. Importance of Theranostics in Rare Brain-Eating Amoebae Infections. ACS Chem Neurosci 2019; 10:6-12. [PMID: 30149693 DOI: 10.1021/acschemneuro.8b00321] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pathogenic free-living amoebae including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri cause infections of the central nervous system (CNS), which almost always prove fatal. The mortality rate is high with the CNS infections caused by these microbes despite modern developments in healthcare and antimicrobial chemotherapy. The low awareness, delayed diagnosis, and lack of effective drugs are major hurdles to overcome these challenges. Nanomaterials have emerged as vital tools for concurrent diagnosis and therapy, which are commonly referred to as theranostics. Nanomaterials offer highly sensitive diagnostic systems and viable therapeutic effects as a single modality. There has been good progress to develop nanomaterials based efficient theranostic systems against numerous kinds of tumors, but this field is yet immature in the context of infectious diseases, particularly parasitic infections. Herein, we describe the potential value of theranostic applications of nanomaterials against brain infections due to pathogenic amoebae.
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Affiliation(s)
- Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor 47500, Malaysia
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor 47500, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor 47500, Malaysia
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Wang J, Liu L, Yin L, Chen L. Acid-triggered synergistic chemo-photodynamic therapy systems based on metal-coordinated supramolecular interaction. J Biomed Mater Res A 2018; 106:2955-2962. [DOI: 10.1002/jbm.a.36484] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/16/2018] [Accepted: 06/06/2018] [Indexed: 01/26/2023]
Affiliation(s)
- Jinze Wang
- Department of Chemistry; Northeast Normal University; Changchun, 130022 People's Republic of China
| | - Lin Liu
- Department of Chemistry; Northeast Normal University; Changchun, 130022 People's Republic of China
| | - Liping Yin
- Department of Chemistry; Northeast Normal University; Changchun, 130022 People's Republic of China
| | - Li Chen
- Department of Chemistry; Northeast Normal University; Changchun, 130022 People's Republic of China
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Anwar A, Khan NA, Siddiqui R. Combating Acanthamoeba spp. cysts: what are the options? Parasit Vectors 2018; 11:26. [PMID: 29316961 PMCID: PMC5759203 DOI: 10.1186/s13071-017-2572-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/05/2017] [Indexed: 11/29/2022] Open
Abstract
Acanthamoeba spp. are protist pathogens and causative agents of serious infections including keratitis and granulomatous amoebic encephalitis. Its ability to convert into dormant and highly resistant cysts form limits effectiveness of available therapeutic agents and presents a pivotal challenge for drug development. During the cyst stage, Acanthamoeba is protected by the presence of hardy cyst walls, comprised primarily of carbohydrates and cyst-specific proteins, hence synthesis inhibition and/or degradation of cyst walls is of major interest. This review focuses on targeting of Acanthamoeba cysts by identifying viable therapeutic targets.
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Affiliation(s)
- Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, Malaysia.
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, Malaysia
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Siddiqui R, Yee Ong TY, Jung SY, Khan NA. Acanthamoeba castellanii interactions with Streptococcus pneumoniae and Streptococcus pyogenes. Exp Parasitol 2017; 183:128-132. [PMID: 28823705 DOI: 10.1016/j.exppara.2017.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/10/2017] [Accepted: 08/10/2017] [Indexed: 11/25/2022]
Abstract
Among the genus Streptococcus, S. pyogenes and S. pneumoniae are the major causes of pharyngitis, impetigo, pneumonia and meningitis in humans. Streptococcus spp. are facultative anaerobes that are nutritionally fastidious, yet survive in the environment and target the predisposed population. Antibacterial disinfectants have been partially effective only, indicating the need for novel preventative measures and to understand mechanisms of bacterial resistance. Acanthamoeba is a free-living protist that is known to harbour microbial pathogens, provide shelter, and assist in their transmission to susceptible population. The overall aim of this study was to determine whether S. pyogenes and S. pneumoniae can interact with A. castellanii by associating, invading, and surviving inside trophozoites and cysts. It was observed that both S. pyogenes and S. pneumoniae were able to associate as well as invade and/or taken up by the phagocytic A. castellanii trophozoite. Notably, S. pyogenes and S. pneumoniae survived the encystation process, avoided phagocytosis, multiplied, and exhibited higher recovery from the mature cysts, compared with the trophozoite stage (approximately 2 bacteria per amoebae ratio for cyst stage versus 0.02 bacteria per amoeba ration for trophozoite stage). As Acanthamoeba cysts are resilient and can disperse through the air, A. castellanii can act as a vector in providing shelter, facilitating growth and possibly genetic exchanges. In addition, these interactions may contribute to S. pyogenes and S. pneumoniae survival in harsh environments, and transmission to susceptible population and possibly affecting their virulence. Future studies will determine the molecular mechanisms associated with Acanthamoeba interactions with Streptococcus and the evolution of pathogenic bacteria and in turn expedite the discovery of novel therapeutic and/or preventative measures.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Malaysia.
| | - Timothy Yu Yee Ong
- Department of Biological Sciences, School of Science and Technology, Sunway University, Malaysia
| | - Suk Yul Jung
- Department of Biomedical Laboratory Science, Namseoul University, South Korea
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Malaysia
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Lakhundi S, Siddiqui R, Khan NA. Pathogenesis of microbial keratitis. Microb Pathog 2017; 104:97-109. [DOI: 10.1016/j.micpath.2016.12.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 11/30/2016] [Accepted: 12/05/2016] [Indexed: 01/03/2023]
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Abstract
For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis, respectively. The discovery of a plethora of antiacanthamoebic compounds has not yielded effective marketed chemotherapeutics. The rate of development of novel antiacanthamoebic chemotherapies of translational value and the lack of interest of the pharmaceutical industry in developing such chemotherapies have been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multi-billion-dollar industry and has been successful and profitable. A better understanding of drugs, their targets, and mechanisms of action will facilitate the development of more-effective chemotherapies. Here, we review the progress toward phenotypic drug discovery, emphasizing the shortcomings of useable therapies.
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Gold Nanoparticle Conjugation Enhances the Antiacanthamoebic Effects of Chlorhexidine. Antimicrob Agents Chemother 2015; 60:1283-8. [PMID: 26666949 DOI: 10.1128/aac.01123-15] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 11/24/2015] [Indexed: 01/14/2023] Open
Abstract
Acanthamoeba keratitis is a serious infection with blinding consequences and often associated with contact lens wear. Early diagnosis, followed by aggressive topical application of drugs, is a prerequisite in successful treatment, but even then prognosis remains poor. Several drugs have shown promise, including chlorhexidine gluconate; however, host cell toxicity at physiologically relevant concentrations remains a challenge. Nanoparticles, subcolloidal structures ranging in size from 10 to 100 nm, are effective drug carriers for enhancing drug potency. The overall aim of the present study was to determine whether conjugation with gold nanoparticles enhances the antiacanthamoebic potential of chlorhexidine. Gold-conjugated chlorhexidine nanoparticles were synthesized. Briefly, gold solution was mixed with chlorhexidine and reduced by adding sodium borohydride, resulting in an intense deep red color, indicative of colloidal gold-conjugated chlorhexidine nanoparticles. The synthesis was confirmed using UV-visible spectrophotometry that shows a plasmon resonance peak of 500 to 550 nm, indicative of gold nanoparticles. Further characterization using matrix-assisted laser desorption ionization-mass spectrometry showed a gold-conjugated chlorhexidine complex at m/z 699 ranging in size from 20 to 100 nm, as determined using atomic force microscopy. To determine the amoebicidal and amoebistatic effects, amoebae were incubated with gold-conjugated chlorhexidine nanoparticles. For controls, amoebae also were incubated with gold and silver nanoparticles alone, chlorhexidine alone, neomycin-conjugated nanoparticles, and neomycin alone. The findings showed that gold-conjugated chlorhexidine nanoparticles exhibited significant amoebicidal and amoebistatic effects at 5 μM. Amoebicidal effects were observed by parasite viability testing using a Trypan blue exclusion assay and flow-cytometric analysis using propidium iodide, while amoebistatic effects were observed using growth assays. In contrast, chlorhexidine alone, at a similar concentration, showed limited effects. Notably, neomycin alone or conjugated with nanoparticles did not show amoebicidal or amoebistatic effects. Pretreatment of A. castellanii with gold-conjugated chlorhexidine nanoparticles reduced amoeba-mediated host cell cytotoxicity from 90% to 40% at 5 μM. In contrast, chlorhexidine alone, at similar concentrations, had no protective effects for the host cells. Similarly, amoebae treated with neomycin alone or neomycin-conjugated nanoparticles showed no protective effects. Overall, these findings suggest that gold-conjugated chlorhexidine nanoparticles hold promise in the improved treatment of A. castellanii keratitis.
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