Bioprospecting of Endophytic Actinobacteria from Selected Ethno-Medicinal Plants for Antibacterial and Anticancer Activities : Therapeutic Potential of Endophytic Actinobacteria

Iqra Safdar; Afifa Israr; Naila Noureen; Imran Sajid

doi:10.54393/fbt.v5i4.208

Authors

Iqra Safdar Department of Microbiology, University of Central Punjab, Lahore, Pakistan
Afifa Israr Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan https://orcid.org/0000-0002-9290-0107
Naila Noureen Department of Microbiology, University of Central Punjab, Lahore, Pakistan
Imran Sajid Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan

DOI:

https://doi.org/10.54393/fbt.v5i4.208

Keywords:

Endophytic Actinobacteria, Medicinal Plants, Antibacterial Activity, Anticancer Activity, Bioprospecting, Streptomyces

Abstract

Endophytic actinobacteria are promising sources of secondary metabolites to combat antimicrobial resistance and cancer. Objectives: To isolate endophytic actinobacteria from ethnomedicinal plants and to evaluate their antibacterial, antibiofilm, and in-vitro anticancer potential. Methods: The endophytic actinobacteria were isolated from Aloe barbadensis and Azadirachta indica using the spread-plate technique on selective media. Purified isolates were screened for antibacterial activity by well diffusion assay and for general cytotoxicity by brine shrimp lethality assay. The crude methanolic extracts of bioactive strains were further tested against A549 lung carcinoma cells (MTT assay) and Escherichia coli biofilms and chemically profiled by TLC and GC-MS. Results: Several endophytic actinobacteria isolates were recovered, many of which inhibited at least one test bacterium. The extracts of strains IEA2, IEA4, IEA5, IEA14, and IEA18 reduced A549 cell viability by approximately 32-87% at 0.1-1 mg/ml, indicating strong in-vitro anticancer potential. The extracts of isolates IEA2, IEA4, and IEA5 dispersed the E. coli biofilms by 85%, 87%, and 79% at 3µg/mL, demonstrating marked antibiofilm activity. GC-MS analysis of active extracts revealed multiple low-molecular-weight metabolites (≈100-500 Da), consistent with the production of diverse secondary metabolites by actinobacteria. Conclusions: Five strains reduced A549 viability by 32-87% and dispersed E. coli biofilms by 79-87%, indicating that aloe- and neem-derived endophytes are promising sources of compounds against drug-resistant bacteria and lung cancer; however, these findings are based on crude extracts and need confirmation by purification and mechanistic studies.

References

Liu C, Zhuang X, Yu Z, Wang Z, Wang Y, Guo X et al. Community Structures and Antifungal Activity of Root-Associated Endophytic Actinobacteria of Healthy and Diseased Soybean. Microorganisms. 2019 Aug; 7(8): doi: 10.3390/microorganisms7080243.

Purushotham N, Jones E, Monk J, Ridgway H. Community Structure, Diversity and Potential of Endophytic Bacteria in the Primitive New Zealand Medicinal Plant Pseudowintera Colorata. Plants. 2020 Jan; 9(2): 156. doi: 10.3390/plants9020156.

Silva CF, Vitorino LC, Mendonça MA, Araújo WL, Dourado MN, Albuquerque LC et al. Screening of Plant Growth-Promoting Endophytic Bacteria from the Roots of the Medicinal Plant Aloe Vera. South African Journal of Botany. 2020 Nov; 134: 3-16. doi: 10.1016/j.sajb.2019.09.019.

Sharma A, Malhotra B, Kharkwal H, Kulkarni GT, Kaushik N. Therapeutic Agents from Endophytes Harbored in Asian Medicinal Plants. Phytochemistry Reviews. 2020 Jun; 19(3): 691-720. doi: 10.1007/s11101-020-09683-8.

Boukhatem ZF, Merabet C, Tsaki H. Plant Growth Promoting Actinobacteria, the Most Promising Candidates as Bioinoculants?. Frontiers in Agronomy. 2022 Mar; 4: 849911. doi: 10.3389/fagro.2022.849911.

Sivalingam P, Easwaran M, Ganapathy D, Basha SF, Poté J. Endophytic Streptomyces: An Underexplored Source with Potential for Novel Natural Drug Discovery and Development. Archives of Microbiology. 2024 Nov; 206(11): 442. doi: 10.1007/s00203-024-04169-z.

Cao P, Li C, Wang H, Yu Z, Xu X, Wang X et al. Community Structures and Antifungal Activity of Root-Associated Endophytic Actinobacteria in Healthy and Diseased Cucumber Plants and Streptomyces Sp. HAAG3-15 As A Promising Biocontrol Agent. Microorganisms. 2020 Feb; 8(2): 236. doi: 10.3390/microorganisms8020236.

Krishnan K. Targeting Multidrug-Resistant Bacterial Pathogens by Actinomycetes Derived Chemical Compounds and New Chemical Entities: A Review.

Hazarika SN, Saikia K, Thakur D. Characterization and Selection of Endophytic Actinobacteria for Growth and Disease Management of Tea (Camellia Sinensis L.). Frontiers in Plant Science. 2022 Nov; 13: 989794. doi: 10.3389/fpls.2022.989794.

Adeela F, Riaz S, Sajid I. Anti-MRSA Potential and Metabolic Fingerprinting of Actinobacteria from Cholistan Desert, Pakistan. Trop. J. Pharm Res [Internet]. 2019 Mar; 17(10): 2037-46. Doi: 10.4314/tjpr.v17i10.21.

Kaur T, Khanna K, Sharma S, Manhas RK. Mechanistic Insights into The Role of Actinobacteria as Potential Biocontrol Candidates Against Fungal Phytopathogens. Journal Of Basic Microbiology. 2023 Nov; 63(11): 1196-218. doi: 10.1002/jobm.202300027.

Alam K, Mazumder A, Sikdar S, Zhao YM, Hao J, Song C et al. Streptomyces: The Biofactory of Secondary Metabolites. Frontiers in Microbiology. 2022 Sep; 13: 968053. doi: 10.3389/fmicb.2022.968053.

Singh SB, Young K, Silver LL. What is an “Ideal” Antibiotic? Discovery Challenges and Path Forward. Biochemical Pharmacology. 2017 Jun; 133:63-73. doi: 10.1016/j.bcp.2017.01.003

Vo QT, Ballard RA, Barnett SJ, Franco CM. Isolation and Characterisation of Endophytic Actinobacteria and Their Effect on the Growth and Nodulation of Chickpea (Cicer Arietinum). Plant and Soil. 2021 Sep; 466(1): 357-71. doi: 10.1007/s11104-021-05008-6.

Machavariani NG, Kustova NA, Galatenko OA. Isolation of Actinomycetes – Producers of Antibiotics – From Soil by Selective Methods Based on Activation of Spore Germination. Chemical and Petroleum Engineering. 2011 Mar; 46(11–12): 667–9.

Agarwal S, Sharma G, Mathur V. Plant Endophytes: A Treasure House of Antimicrobial Compounds. Inmedicinal Plants and Antimicrobial Therapies. Singapore: Springer Nature Singapore. 2024 Jan; 107-123.

Miller KI, Qing C, Sze DM, Roufogalis BD, Neilan BA. Culturable Endophytes of Medicinal Plants and the Genetic Basis for their Bioactivity. Microbial Ecology. 2012 Aug; 64(2): 431-49.

Cansizoglu MF, Toprak E. Fighting Against Evolution of Antibiotic Resistance by Utilizing Evolvable Antimicrobial Drugs. Current Genetics. 2017 Dec; 63(6): 973-6. doi: 10.1007/s00294-017-0703-x.

Gürgen A, Tabbouche SA, Yıldız S, Kılıç AO. Antimicrobial and Anti-Quorum Sensing Activity of Some Wild Mushrooms Collected from Turkey. Mus Alparslan University Journal of Science. 2017; 5(2): 453-7. doi: 10.18586/msufbd.347692.

Xie J, Xu Y, Huang X, Chen Y, Fu J, Xi M et al. Berberine-Induced Apoptosis in Human Breast Cancer Cells is Mediated by Reactive Oxygen Species Generation and Mitochondrial-Related Apoptotic Pathway. Tumor Biology. 2015 Feb; 36(2): 1279-88. doi: 10.1007/s13277-014-2754-7.

Waturangi DE, Rahayu BS, Kezia Yolanda Lalu M, Mulyono N. Characterization of Bioactive Compound from Actinomycetes for Antibiofilm Activity Against Gram-Negative and Gram-Positive Bacteria. Malaysian Journal of Microbiology. 2016: 291-9. doi: 10.21161/mjm.80915.

Veena VK, Popavath RN, Kennedy K, Sakthivel N. In Vitro Antiproliferative, Pro-Apoptotic, Antimetastatic and Anti-Inflammatory Potential of 2, 4-Diacteylphloroglucinol (DAPG) by Pseudomonas Aeruginosa Strain FP10. Apoptosis. 2015 Oct; 20(10): 1281-95. doi: 10.1007/s10495-015-1162-9.

Borah A and Thakur D. Phylogenetic and Functional Characterization of Culturable Endophytic Actinobacteria Associated with Camellia Spp. for Growth Promotion in Commercial Tea Cultivars. Frontiers in Microbiology. 2020 Feb; 11: 318. doi: 10.3389/fmicb.2020.00318.

Assad BM, Savi DC, Biscaia SM, Mayrhofer BF, Iantas J, Mews M et al. Endophytic Actinobacteria of Hymenachne Amplexicaulis from the Brazilian Pantanal Wetland Produce Compounds with Antibacterial and Antitumor Activities. Microbiological Research. 2021 Jul; 248: 126768. doi: 10.1016/j.micres.2021.126768.

Benhadj M, Gacemi-Kirane D, Menasria T, Guebla K, Ahmane Z. Screening of Rare Actinomycetes Isolated from Natural Wetland Ecosystem (Fetzara Lake, Northeastern Algeria) For Hydrolytic Enzymes and Antimicrobial Activities. Journal of King Saud University-Science. 2019 Oct; 31(4): 706-12. doi: 10.1016/j.jksus.2018.03.008.

Saikia J, Mazumdar R, Thakur D. Phylogenetic Affiliation of Endophytic Actinobacteria Associated with Selected Orchid Species and their Role in Growth Promotion and Suppression of Phytopathogens. Frontiers in Plant Science. 2022 Dec; 13: 1058867. doi: 10.3389/fpls.2022.1058867.

Hassan A, Ponomareva LV, Thorson JS, Shaaban KA, Sajid I. Bioactivity and Metabolomics Profiling of Endophytic Actinobacteria Isolated from Roots of the Medicinal Plants Dominant in South Asian Region. Advancements in Life Sciences. 2023 Jun; 10(2): 200. doi: 10.62940/als.v10i2.1602.