title: Antihistaminic and mast cell stabilizing activity of Striga orobanchioides.
abstract: The ethanolic and aqueous extracts of the whole plant of S. orobanchioides were evaluated for antihistaminic and mast cell stabilizing activities. Both extracts inhibited histamine-induced contractions of the guinea-pig ileum at the concentration range of 2.5-25 microg/ml in a dose-related manner. At 25 microg/ml, both extracts inhibited the response of histamine (0.5 microg/ml) almost completely. The effect of these two extracts on the degranulation rate of sensitized peritoneal cells of albino rats when challenged with antigen (horse serum) was studied. Triple vaccine was used as adjuvant. Ketotifen and prednisolone were used for comparison. The ethanolic extract at 100 and 200 mg/kg body weight was found to significantly inhibit degranulation of mast cells to an extent of 52.14+/-3.24 and 67.96+/-3.70%, respectively. At the same doses, the aqueous extract showed 42.09+/-2.91 and 60.67+/-3.50% reduction in degranulation of mast cells, respectively. Hence, both extracts markedly protected the rats against antigen-induced challenge of mast cells.
authors.affiliation: Government College of Pharmacy, -560 027, Bangalore, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Harish
authors.forename: M
authors.initials: M
authors.lastname: Nagur
authors.forename: S
authors.initials: S
authors.lastname: Badami
mesh_terms: D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000302:isolation & purification / Q000627:therapeutic use* / Q000633:toxicity; D007082:Ileum / Q000187:drug effects; D008297:Male; D008407:Mast Cells / Q000187:drug effects*; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use* / Q000633:toxicity; D051381:Rats
chemical_list: D006634:Histamine H1 Antagonists; D010936:Plant Extracts