Amoebicidal, anti-adhesive, and low-cytotoxic effects of Mangifera indica L. leaf extract against ocular Acanthamoeba spp.: First evidence supporting plant-based therapeutic potential

Vet World Vol.18 November-2025 Article - 3

Research Article

Veterinary World, 18(11): 3322-3334

https://doi.org/10.14202/vetworld.2025.3322-3334

Diana Mendonça^1,2, Hazel A. Tabo³, Siriphorn Chimplee⁴, Sónia M. R. Oliveira^1,5, Pattamaporn Kwankaew⁶, Ana Paula Girol^7,8,9, Julieta Z. Dungca¹⁰, Mazdida Sulaiman¹¹, Subha Bhassu¹², Muhammad Nawaz¹³, Polrat Wilairatana¹⁴, Christophe Wiart¹⁵, Karma G. Dolma¹⁶, Sunil Kayesth¹⁷, Veeranoot Nissapatorn¹⁸, and Maria De Lourdes Pereira^1,19

1. CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.

2. Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.

3. Department of Biological Sciences, College of Science, De La Salle University-Dasmariñas, Cavite 4114, Philippines.

4. Department of General Education, School of Languages and General Education, Walailak University, Thai Buri, Nakhon Si Thammarat, 80160, Thailand.

5. Faculty of Dental Medicine, Catholic University, 3504-505 Viseu, Portugal.

6. Department of Medical Technology, School of Allied Health Sciences, Walailak University, Thai Buri, Nakhon Si Thammarat, 80160, Thailand.

7. Post Graduate Program in Structural and Functional Biology, Escola Paulista de Medicina (UNIFESP-EPM), Federal University of São Paulo, 04023-062, SP, Brazil.

8. Department of Biology, Institute of Biosciences, Humanities and Exact Sciences (Ibilce), São Paulo State University (UNESP), São José do Rio Preto, 15.054-999, SP, Brazil.

9. Experimental and Clinical Research Center (CEPEC), Padre Albino University Center (UNIFIPA), Catanduva, 15809-144, SP, Brazil.

10. School of Science and Technology, Centro Escolar University, Manila, 1005, Philippines.

11. Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, 50603, Malaysia.

12. Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, 50603, Malaysia.

13. Department of Nano-Medicine Research, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, 31451, Saudi Arabia.

14. Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.

15. Department of Microbiology, Institute for Tropical Biology and Conservation, University Malaysia Sabah, Kota Kinabalu 88400, Malaysia.

16. Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Sikkim, India.

17. Department of Zoology, Medicinal Plant and Health Research Lab, Deshbandhu College, University of Delhi, Delhi 110019, India.

18. Futuristic Science Research Center-School of Science, World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat, 80160, Thailand.

19. Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal.

Background and Aim: Acanthamoeba spp. is free-living protozoa capable of causing severe infections, notably Acanthamoeba keratitis, which is difficult to manage due to cyst resistance and the cytotoxicity of current treatments. Plant-derived compounds represent a promising alternative strategy. This study investigated the amoebicidal, anti-adhesive, and cytotoxic properties of Mangifera indica L. (mango) leaf extract against ocularly relevant Acanthamoeba spp.

Materials and Methods: Crude ethanolic leaf extract of M. indica was prepared and evaluated against Acanthamoeba polyphaga American Type Culture Collection (ATCC) 30461 and Acanthamoeba castellanii ATCC 50739. Minimum inhibitory concentration (MIC) and minimum parasiticidal concentration were determined for trophozoites and cysts. Morphological changes were analyzed by scanning electron microscopy (SEM). Anti-adhesion assays were conducted using polystyrene surfaces, with a commercial multipurpose contact lens (CL) solution as a control. Cytotoxicity was tested in Vero cells using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay to establish the minimum cytotoxic concentration.

Results: The extract inhibited trophozoite growth at 2 mg/mL and demonstrated cysticidal activity at 4 mg/mL for A. polyphaga and 32 mg/mL for A. castellanii. SEM revealed disruption of trophozoite morphology, loss of acanthopodia, and surface perforations in cysts. At MIC levels, adhesion was reduced by >70%, and even at 1/8 MIC, inhibition remained above 50%, comparable to a commercial multipurpose solution. Cytotoxicity assessment showed >80% Vero cell viability at 0.125 mg/mL, indicating a favorable therapeutic window.

Conclusion: This is the first report demonstrating amoebicidal and anti-adhesive effects of M. indica L. leaf extract against ocular Acanthamoeba species. The dual trophozoiticidal and anti-adhesive actions, combined with low cytotoxicity, highlight its potential for development as a plant-based therapeutic agent, particularly in ocular formulations or CL disinfectants. Future work should focus on phytochemical isolation, mechanistic studies, and novel delivery systems to enhance efficacy and safety.

Keywords: Acanthamoeba, amoebicidal activity, anti-adhesion, cytotoxicity, Mangifera indica L., ocular infection.

How to cite this article: Mendonça D, Tabo HA, Chimplee S, Oliveira SMR, Kwankaew P, Girol AP, Dungca JZ, Sulaiman M, Bhassu S, Nawaz M, Wilairatana P, Wiart C, Dolma KG, Kayesth S, Nissapatorn V, and Pereira MDL (2025) Amoebicidal, anti-adhesive, and low-cytotoxic effects of Mangifera indica L. leaf extract against ocular Acanthamoeba spp.: First evidence supporting plant-based therapeutic potential, Veterinary World, 18(11): 3322-3334.

Received: 23-05-2025 Accepted: 15-10-2025 Published online: 06-11-2025

Corresponding author: Veeranoot Nissapatorn and Maria de Lourdes Pereira E-mail: nissapat@gmail.com and mlourdespereira@ua.pt

DOI: 10.14202/vetworld.2025.3322-3334

Copyright: Mendonça, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.