title: A novel sesquiterpene acid and an alkaloid from leaves of the Eastern Nigeria mistletoe, Loranthus micranthus with potent immunostimulatory activity on C57BL6 mice splenocytes and CD69 molecule.
abstract: BACKGROUND
  The Eastern Nigeria mistletoe, Loranthus micranthus Linn. (Loranthaceae), is used in the treatment of several diseases including immune-modifying diseases and thus there is a need to identify the immunoactive constituents.
  
  
  OBJECTIVE
  This research isolated and characterized the immunoactive constituents in the Eastern Nigeria mistletoe.
  
  
  METHODS
  Bioassay-guided fractionation was employed in the isolation and purification of the constituents. The characterized compounds were screened for immunostimulatory activities on isolated C57BL/6 mice splenocytes and early activation marker, CD69 at concentrations of 10, 25, and 100 μg/mL using flow cytometry techniques and compared to lipopolysaccharide (LPS; 10 μg/mL) and concanavalin A (ConA; 2 μg/mL) as standards.
  
  
  RESULTS
  Two compounds, a novel sesquiterpene, 2, 3-dimethoxy-benzo [a, b] cyclopentenyl-3′,3′,5′-trimethyl pyran-4-carboxylic acid, and a known alkaloid, lupinine were isolated and characterized. The compounds (25 μg/mL) showed statistically significantly (p < 0.05) stimulatory activity on the splenocytes with values of 56.34 ± 0.26% and 69.84 ± 0.19%, respectively, compared to 7.58 ± 0.42% recorded for the unstimulated control. Similarly, the CD69 expression assay showed immunostimulation with statistically significant values (p < 0.05) of 2.31 ± 0.07% and 2.71 ± 0.03%, respectively, compared to 1.69 ± 0.05% recorded for the nonstimulated control.
  
  
  CONCLUSIONS
  These data suggest that the isolated compounds possess immunomodifying abilities. In addition, the activation of the CD69 molecule is possibly one of its mechanisms of action.
  
  
  CONCLUSIONS
  These compounds may be responsible in part, for the immunostimulatory activities already established for the Eastern Nigeria mistletoes.
authors: Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria. winnomeje@yahoo.com
authors: Edwin Ogechukwu
authors: EO
authors: Omeje
authors: Patience Ogoamaka
authors: PO
authors: Osadebe
authors: Chukwuemeka Sylvester
authors: CS
authors: Nworu
authors: Justina Ngozi
authors: JN
authors: Nwodo
authors: Wilfred Ofem
authors: WO
authors: Obonga
authors: Akira
authors: A
authors: Kawamura
authors: Charles Okechukwu
authors: CO
authors: Esimone
authors: Peter
authors: P
authors: Proksch
mesh_terms: D000276:Adjuvants, Immunologic; D000470:Alkaloids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis*; D049109:Cell Proliferation / Q000187:drug effects; D002725:Chloroform; D037181:Lectins, C-Type / Q000096:biosynthesis*; D028183:Loranthaceae / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D009549:Nigeria; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D012997:Solvents; D013154:Spleen / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D000099192:CD69 Antigens
chemical_list: D000276:Adjuvants, Immunologic; D000470:Alkaloids; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D002725:Chloroform; D037181:Lectins, C-Type; D010936:Plant Extracts; D012717:Sesquiterpenes; D012997:Solvents; D000099192:CD69 Antigens