Title:The Bioactive Potential of Culturable Fungal Endophytes Isolated From the Leaf of Catharanthus roseus (L.) G. Don
Volume: 21
Issue: 10
Author(s): Sucheta Singh*, Surjeet Verma, Dharmendra K. Yadav, Anant Kumar, Rekha Tyagi, Priyanka Gupta, Dnyaneshwar U. Bawankule, Mahendra P. Darokar, Santosh K. Srivastava and Alok Kalra
Affiliation:
- Microbial Technology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow- 226015,India
Keywords:
α, β-Dehydrocurvularin, Endophyte, Molecular docking, Minimum inhibitory concentration, Anti-inflammatory
agents, Antimicrobial.
Abstract: Introduction: Endophyte is considered a source of natural bioactive secondary metabolites
that provides an array of bioactive lead compounds. The present study was aimed to determine
the antimicrobial and anti-inflammatory potential of fungal endophytes isolated from Catharanthus
roseus.
Methods: A total of seven fungal endophytes crude extract were screened against bacterial pathogens.
Of these, Curvularia geniculata CATDLF7 crude extract exhibited the most potent inhibitory
activity against bacterial pathogens. Hence, CATDLF7 crude extract was subjected to chromatographic
separation. This purification leads to the isolation of six pure compounds (1PS - 6PS). Of
these, 3PS was found to be a major constituent and most effective against clinical isolates of methicillin-
resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) values
ranging from 100 to 200 μg/ml. Based on the spectroscopic data, 3PS was characterized as α,β-
dehydrocurvularin. This compound also showed synergistic interaction with norfloxacin and reduced
its MIC up to 32-folds with a fractional inhibitory concentration index (FICI) of 0.09.
Results: To understand the possible antibacterial mechanism of action, α,β-dehydrocurvularin
alone (100 μg/ml) exhibited efflux pump inhibitory potential by 0.84 fold decreasing in ethidium
bromide (EtBr) fluorescence. In addition, α,β-dehydrocurvularin inhibited inflammatory cytokines
TNF-α and IL-6 production, which is further validated by molecular docking scores -4.921 and
-5.641, respectively, for understanding orientation and binding affinity.
Conclusion: Overall, the results highlighted identifying bioactive compound α,β-dehydrocurvularin,
which could be used as an antimicrobial and anti-inflammatory agent.
