title: Protection of immunocompromised mice from fungal infection with a thymus growth-stimulatory component from Selaginella involvens, a fern.
abstract: BACKGROUND
  Recent studies have shown that the water extract of Selaginella involvens (Sw.) Spring, a wild fern, exhibits thymus growth-stimulatory activity in adult mice (reversal of involution of thymus) and remarkable anti-lipid peroxidation activity. Follow-up studies were carried out in the present study.
  
  
  METHODS
  Activity-guided isolation of the active component (AC) was carried out. The effect of AC on immune function was studied using fungal (Aspergillus fumigatus) challenge in cortisone-treated mice. The in vitro antifungal activity of AC was assayed using disc diffusion assay. In vitro and in vivo effect of AC on DNA synthesis in thymus was studied using (3)H-thymidine incorporation. In in vitro anti-lipid peroxidation, hydroxyl radical scavenging and inhibition of superoxide production were assayed.
  
  
  RESULTS
  The active principle/component (AC) was isolated in a chromatographically pure form from the water extract of S. involvens. AC showed positive reaction to glycosides. AC possessed both thymus growth-stimulatory and antioxidant properties. It protected cortisone-treated mice from A. fumigatus challenge. It did not exhibit in vitro antifungal activity. Increased (3)H-thymidine incorporation was observed in the reticuloepithelium of thymus obtained from AC-treated mice. However, in vitro AC treatment to thymus for 5 h did not result in an increase in (3)H-thymidine incorporation.
  
  
  CONCLUSIONS
  AC (named as Selagin), from S. involvens, could reverse involution of thymus to a large extent, exhibit remarkable antioxidant activity, and protect immunocompromised mice from fungal infection. Therefore, it is very promising for the development of a drug to ameliorate old age-related health problems and prolong lifespan.
authors.affiliation: Tropical Botanic Garden and Research Institute, Pacha-Palode, Thiruvananthapuram 695 562, Kerala State, India.
authors.forename: V
authors.initials: V
authors.lastname: Gayathri
authors.forename: V V
authors.initials: VV
authors.lastname: Asha
authors.forename: J Anil
authors.initials: JA
authors.lastname: John
authors.forename: A
authors.initials: A
authors.lastname: Subramoniam
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000276:immunology / Q000494:pharmacology / Q000627:therapeutic use*; D029624:Ferns / Q000276:immunology; D016867:Immunocompromised Host / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D009181:Mycoses / Q000276:immunology / Q000517:prevention & control*; D010936:Plant Extracts / Q000276:immunology / Q000494:pharmacology / Q000627:therapeutic use*; D032503:Selaginellaceae / Q000276:immunology; D013950:Thymus Gland / Q000187:drug effects* / Q000254:growth & development / Q000276:immunology
chemical_list: D000935:Antifungal Agents; D010936:Plant Extracts