Mechanism of spasmolytic activity of a fraction of Sarcostemma brevistigma Wight.
The effect of chloroform soluble fraction (F-A) of twigs of Sarcostemma brevistigma on contractions induced by KCl, histamine, and acetylcholine in the isolated guinea pig ileum and taenia coli smooth muscles has been evaluated. F-A (19.5 microg/ml) significantly inhibited the contraction induced by 40 mM KCl to the extent of 87.6% in the isolated guinea pig ileum. In the isolated guinea pig ileum, F-A (64.3 and 59.2 microg/ml) significantly inhibited the contractions induced by acetylcholine and histamine to the extent of 85 and 83% respectively. In the isolated guinea pig taenia coli, F-A (65.2 microg/ml) significantly inhibited the contraction induced by 40 mM KCl to the extent of 96.0%. The inhibitory effect of F-A (40 microg/ml) on the isolated guinea pig taenia coli was reduced by Bay K 8644 (10(-6) M) to the extent of 61.6 from 73.6%. These results suggest that the F-A may exhibit smooth muscle relaxant activity by blocking the Ca2+ channels.
Kumar
P Suresh
PS
Department of Pharmacology, The Bombay College of Pharmacy, Sunder Nagar, Kalina, Santacruz (E), Mumbai 400 098, India.
Soni
K
K
Jadhav
S R
SR
Doshi
N S
NS
Saraf
M N
MN
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D029062:Apocynaceae / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D010276:Parasympatholytics; D010936:Plant Extracts; D011189:Potassium Chloride; D006632:Histamine; D014700:Verapamil; D000109:Acetylcholine