title: Radical scavenging, prolyl endopeptidase inhibitory, and antimicrobial potential of a cultured Himalayan lichen Cetrelia olivetorum.
abstract: BACKGROUND
  Lichens are source of natural bioactive compounds which are traditionally used to cure a variety of ailments.
  
  
  OBJECTIVE
  The objective of this study is to assess free radical scavenging, prolyl endopeptidase inhibitory (PEPI), and antimicrobial potential of a high altitude lichen species Cetrelia olivetorum (Nyl.) W. L. Culb. & C. F. Culb (Parmeliaceae).
  
  
  METHODS
  Lichen C. olivetorum has been cultured in vitro, and optimized culture conditions were implemented in bioreactor to obtain high quantity of biomass for the study of radical scavenging, PEPI, and antimicrobial activities. Radical scavenging activity of methanol extract of Cetrelia olivetorum (MECO) was tested at 100 µg/mL, PEPI activity at 25 and 50 µg/mL, and antimicrobial activity at 5, 25, 50, and 100 µg/mL conc. All the biological activities of natural thallus extract and its derived culture extract were evaluated spectrophotometrically.
  
  
  RESULTS
  Murashige and Skoog medium supplemented with 3% glucose and 100 ppb indole-3-butyric acid (IBA) supported biomass growth at flask level and yielded 5.095 g biomass in bioreactor. MECO of both the cultured and the natural lichen exhibited half inhibiting concentration (IC50) for radical scavenging activities in the range of 50-60 µg/mL, whereas the IC50 value of standard antioxidants was found to be in the range of 12-29 µg/mL. The IC50 value of lichen extract for PEPI activity was 144-288 µg/mL, whereas the IC50 value of standard prolyl endopeptidase inhibitor, Z-pro-prolinal, was 57.73 µg/mL. As far as the antimicrobial activity of MECO is concerned, minimum inhibitory concentration (MIC) value of lichen extracts against tested microorganisms was obtained in the range of 50-104 µg/mL and found to be more effective than commercially available standard erythromycin.
  
  
  CONCLUSIONS
  Murashige and Skoog medium containing IBA was found to be suitable for maximum biomass production of C. olivetorum under bioreactor conditions. The cultured lichen biomass extract also showed antioxidant, PEPI, and antimicrobial potential.
  
  
  CONCLUSIONS
  The present study indicates therapeutic potential of Himalayan lichen C. olivetorum against neurodegenerative diseases owing to its radical scavenging, PEPI, and antimicrobial activities. Further, the result encourages its commercial exploitation through mass culture for production of its bioactive components and their use in pharmaceutical and nutraceutical industries.
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Swapnil Anil
authors.initials: SA
authors.lastname: Savale
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Chaitrali Satish
authors.initials: CS
authors.lastname: Pol
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Roshni
authors.initials: R
authors.lastname: Khare
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Verma
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Subhash
authors.initials: S
authors.lastname: Gaikwad
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Bapi
authors.initials: B
authors.lastname: Mandal
authors.affiliation: a Agharkar Research Institute , Pune , Maharashtra , India.
authors.forename: Bhaskar C
authors.initials: BC
authors.lastname: Behera
mesh_terms: D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001688:Biological Products / Q000302:isolation & purification / Q000494:pharmacology*; D002478:Cells, Cultured; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology*; D008011:Lichens; D008826:Microbial Sensitivity Tests / Q000379:methods; D000085822:Prolyl Oligopeptidases; D011480:Protease Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D001688:Biological Products; D016166:Free Radical Scavengers; D011480:Protease Inhibitors; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases
keywords: Antioxidants; lichenized fungi; minimum inhibitory concentration; neurodegenerative diseases