title: Immunosuppressive properties of Pluchea lanceolata leaves.
abstract: OBJECTIVE
  To investigate the immunosuppressive potential of Pluchea lanceolata 50% ethanolic extract (PL) and its bioactive chloroform fraction (PLC).
  
  
  METHODS
  Preliminary screening of the Pluchea lanceolata 50% ethanolic extract (PL) was carried out with basic models of immunomodulation, such as, the humoral antibody response (hemagglutination antibody titers), cell-mediated immune response (delayed-type hypersensitivity), skin allograft rejection test, in vitro (C. albicans method), and in vivo phagocytosis (carbon clearance test). The extract was then fractionated with chloroform, n-butanol, and water to receive the respective fractions by partitioning. These fractions were employed for flow cytometry to study the T-cell specific immunosuppressive potential of these fractions.
  
  
  RESULTS
  Oral administration of PL at doses of 50 to 800 mg/kg in mice, with sheep red blood cells (SRBC) as an antigen, inhibited both humoral and cell-mediated immune responses, as evidenced by the production of the circulating antibody titer and delayed-type hypersensitiviy reaction results, respectively, and the immune suppression was statistically significant (P < 0.01) in Balb/C mice. PL also decreased the process of phagocytosis both in vitro (31.23%) and ex vivo (32.81%) and delayed the graft rejection time (30.76%). To study the T-cell-specific activities, chloroform, n-butanol, and water fractions from P. lanceolata were tested for T-cell specific immunosuppressive evaluation, wherein only the chloroform fraction (PLC) showed significant (P < 0.01) suppression of CD8+ / CD4+ T-cell surface markers and intracellular Th1 (IL-2 and IFN-(Y)) cytokines at 25 - 200 mg/kg p.o. doses. PLC, however, did not show significant suppression of the Th2 (IL-4) cytokine.
  
  
  CONCLUSIONS
  The findings from the present investigation reveal that P. lanceolata causes immunosuppression by inhibiting Th1 cytokines.
authors.affiliation: Pharmacology Research Laboratory, ASBASJSM College of Pharmacy, Bela (Ropar), Punjab, India.
authors.forename: D P
authors.initials: DP
authors.lastname: Bhagwat
authors.forename: M D
authors.initials: MD
authors.lastname: Kharya
authors.forename: Sarang
authors.initials: S
authors.lastname: Bani
authors.forename: Anpurna
authors.initials: A
authors.lastname: Kaul
authors.forename: Kiranjeet
authors.initials: K
authors.lastname: Kour
authors.forename: Prashant Singh
authors.initials: PS
authors.lastname: Chauhan
authors.forename: K A
authors.initials: KA
authors.lastname: Suri
authors.forename: N K
authors.initials: NK
authors.lastname: Satti