First report of endophytic Bipolaris axonopicola from untapped Bastar forests, India, producing human lipase and histone deacetylase inhibitors

The present study explores the potential of 12 endophytic fungi isolated from rhizomes of Curcuma caesia for their antibacterial, anti-obesity and cytotoxic properties. Amongst them, the ethyl acetate (EA) residues of only two endophytic fungi CcR3 and CcR8 exhibited antibacterial activities with a zone of inhibition (ZOI) ranging between 11.5 to 27.74 mm in agar well diffusion assay and a minimal inhibitory concentration (MIC) ranging between 3.9 to 125 µg/ml respectively against the spectrum of tested microorganisms. Similarly, the spent broth of three endophytic fungi (CcR3, CcR8 and CcR10), when evaluated for their pancreatic lipase (PL) inhibitory activities, displayed 59.36 – 94.39% inhibition of PL in rhodamine and phenol red plate assays. The EA residue of CcR8 exhibited 97.58% inhibition of PL with an IC50 value of 3.09 μg/ml, that was quite comparable to inhibition shown by only antiobesity drug in market Orlistat (IC50 = 2.81 μg/ml). Furthermore, the EA residue of three endophytic fungi (CcR3, CcR5 and CcR8) showed strong cytotoxic properties (55.09 – 77.57%) against breast cancer cell lines MCF-7 under tested in vitro conditions. Based on taxonomic studies, the most bioactive endophytic fungus CcR8, possessing antimicrobial, anti cancer and anti obesity property was identified as Bipolaris axonopicola. This is the first report of Bipolaris axonopicola exhibiting such properties. cytotoxic. The GCMS– analysis of the EA fraction revealed the presence of majorly three compounds n-Hexadecanoic acid, 1,14-Tetradecanediol and an unknown compound. Molecular docking studies revealed that n-Hexadecanoic acid (-5.2 kcal/mol) binds with high affinity to human lipase than Orlistat (-4.9 kcal/mol), thereby inhibiting the enzyme to a greater extent. Similarly, the binding capacity of n-Hexadecanoic acid (-7.5 kcal/mol) to histone deacetylase is greater than Varinostat (-6.9 kcal/mol), a well-known anticancer drug.