title: Immunosuppressive potential of Botryosphaeria dothidea, an endophyte isolated from Kigelia africana.
abstract: BACKGROUND
  For years, natural products from microbes have been used as drugs. Endophytes are the most important fungi that produce many novel metabolites for potential use in pharmacology and agriculture.
  
  
  OBJECTIVE
  The objective of the present study was to explore new endophytes for novel natural products.
  
  
  METHODS
  An endophyte BAK-I was isolated from the bark of Kigelia africana (Lam.) Beneth (Bignoniaceae). BAK-I was characterized morphologically and on the basis of ITS-5.8S rDNA sequences. BAK-I was fermented to yield an extract, which was evaluated for its anticancer, antimicrobial, and immunomodulatory activities, using MTT, agar well-diffusion, tube dilution method, lymphocyte proliferation, and pro-inflammatory cytokines (TNF-α) (by macrophages) evaluation assays. For lymphocyte proliferation and pro-inflammatory cytokines studies, four concentrations were evaluated 10, 30, 100, and 1000 µg/mL and the experiments were conducted for 72 and 48 h, respectively.
  
  
  CONCLUSIONS
  The BAK-I showed pink cottony growth. SEM studies showed smooth fusoid-oblong conidia with a truncated base. Furthermore, ITS-5.8S rDNA sequence showed 99% homology with the Botryosphaeria dothidea strain suggesting that the endophyte is a strain of the genus Botryosphaeria. Less than 50% growth inhibition of SF295, Lung A-549, and THP-1 cancer cell lines after treatment with BAK-I extract suggested that it did not have significant cytotoxic potential, whereas it is bactericidal for Gram-positive pathogens MRSA and VRE with MIC value 200 and 250 µg/mL, respectively. To elucidate its immunomodulation potential, splenocyte proliferation studies showed that BAK-1 suppressed the T cell proliferation by 50%. TNF-α evaluation studies also showed that the extract inhibited TNF-α production in a concentration-dependent manner suggesting that it had immunosuppressive potential. Inhibition at 10 µg/mL was found to be 55% as against 48% using β-methasone.
  
  
  CONCLUSIONS
  The results suggested that BAK-I extract can be used as a potential immunosuppressive agent.
authors.affiliation: Biotechnology Division .
authors.forename: Meenu
authors.initials: M
authors.lastname: Katoch
authors.forename: Anamika
authors.initials: A
authors.lastname: Khajuria
authors.forename: P R
authors.initials: PR
authors.lastname: Sharma
authors.forename: Ajit Kumar
authors.initials: AK
authors.lastname: Saxena
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry / Q000254:growth & development; D029402:Bignoniaceae / Q000737:chemistry* / Q000382:microbiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D060026:Endophytes / Q000737:chemistry / Q000254:growth & development; D007166:Immunosuppressive Agents / Q000302:isolation & purification / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology; D008297:Male; D008807:Mice, Inbred BALB C; D024301:Plant Bark / Q000737:chemistry / Q000382:microbiology; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha
keywords: Lymphocyte; MTT assay; SEM; TNF-alpha; macrophage; splenocyte